In animals, the brain is the control center of the central nervous system, responsible for behavior. The human brain controls the Central nervous system (CNS by way of the Cranial nerves and Spinal cord, the Peripheral nervous system (PNS In Vertebrates the central nervous system ( CNS) is the part of the Nervous system which is enclosed in the Meninges. Behavior or behaviour (see spelling differences) refers to the actions or Reactions of an object or Organism, usually In mammals, the brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing, equilibrioception (balance), sense of taste, and olfaction (smell). In Psychology, visual perception is the ability to interpret information from Visible light reaching the Eyes The resulting Perception is also Equilibrioception or sense of balance is one of the physiological Senses It helps prevent Humans and Animals from falling over when Taste (or more formally gustation) is a form of direct Chemoreception and is one of the traditional five Senses Olfaction (also known as olfactics or smell) refers to the Sense of smell.

While all vertebrates have a brain, most invertebrates have either a centralized brain or collections of individual ganglia. Vertebrates are members of the Subphylum Vertebrata, Chordates with backbones or spinal columns The grouping sometimes includes An invertebrate is an Animal lacking a Vertebral column. The group includes 98% of all animal Species — all animals except those in the Chordate In Anatomy, a ganglion (pl ganglia) is a tissue mass. Neurology In neurological contexts ganglia are composed mainly of Some animals such as cnidarians and echinoderms do not have a centralized brain, and instead have a decentralized nervous system, while animals such as sponges lack both a brain and nervous system entirely. Cnidaria (naɪˈdɛəriə is a phylum containing some 9000 Species of Animals found exclusively in aquatic mostly marine, environments Echinoderms (Phylum Echinodermata) are a phylum of marine Animals (including Sea stars) The sponges or poriferans (from Latin porus "pore" and ferre "to bear" are Animals

Brains can be extremely complex. For example, the human brain contains roughly 100 billion neurons, each linked to as many as 10,000 other neurons. The human brain controls the Central nervous system (CNS by way of the Cranial nerves and Spinal cord, the Peripheral nervous system (PNS Neurons (ˈnjuːɹɒn also known as neurones and nerve cells) are responsive cells in the Nervous system that process and transmit information

Contents 1 History 2 Mind and brain 3 Comparative anatomy 3.1 Insects 3.2 Cephalopods 3.3 Mammals and other vertebrates 3.3.1 Vertebrate brain regions 3.3.2 Humans 4 Neurobiology 4.1 Structure 4.2 Function 4.2.1 Neurotransmitter systems 4.3 Origin 4.4 Pathology 5 Study of the brain 5.1 Fields of study 5.2 Methods of observation 5.2.1 Electrophysiology 5.2.2 EEG 5.2.3 MEG 5.2.4 fMRI and PET 5.2.5 Behavioral 5.2.6 Anatomical 5.3 Other studies 6 As food 7 Brain energy consumption 8 See also 9 Further reading 10 References 11 External links

History

Main article: History of the brain

Early views on the function of the brain regarded it as little more than cranial stuffing. The history of the brain details the development of thoughts speculations and ideas as to the function of the Central nervous system, over the last five thousand years In Ancient Egypt, from the late Middle Kingdom onwards, in preparation for mummification, the brain was regularly removed, for it was the heart that was assumed to be the seat of intelligence. Ancient Egypt was an Ancient Civilization in eastern North Africa, concentrated along the lower reaches of the Nile River in what is now The heart is a muscular organ in all Vertebrates responsible for pumping Blood through the Blood vessels by repeated rhythmic According to Herodotus, during the first step of mummification, "The most perfect practice is to extract as much of the brain as possible with an iron hook, and what the hook cannot reach is mixed with drugs. Herodotus of Halicarnassus ( Greek: Hēródotos Halikarnāsseús) was a Greek Historian who lived in the 5th century BC ( 484 BC&ndash " Over the next five-thousand years, this view came to be reversed; the brain is now known to be seat of intelligence, although idiomatic variations of the former remain, as in memorizing something "by heart". An idiom is a Phrase whose meaning cannot be deduced from the literal Definition, but refers instead to a figurative meaning that is known only ^[1]

The first thoughts on the field of psychology came from ancient philosophers, such as Aristotle. Psychology (from Greek grc ψῡχή psȳkhē, "breath life soul" and grc -λογία -logia) is an Academic and This page lists some links to ancient philosophy. In Western philosophy, the spread of Christianity through the Roman Empire marked the end of Hellenistic Aristotle (Greek Aristotélēs) (384 BC – 322 BC was a Greek philosopher a student of Plato and teacher of Alexander the Great. As thinkers became more in tune with biomedical research over time, as was the case with medieval psychologists such as Alhazen and Avicenna for example, the concepts of experimental psychology and clinical psychology began emerging. Biomedical research (or experimental medicine) in general simply known as medical research, is the Basic research or Applied research conducted TemplateInfobox Muslim scholars --> ( Arabic: ابو علی، حسن بن حسن بن هيثم Latinized TemplateInfobox Muslim scholars --> ( Persian /ابو علی الحسین ابن عبدالله ابن سینا (born Experimental psychology approaches Psychology as one of the natural sciences investigates it using the experimental method. Clinical psychology includes the scientific study and application of Psychology for the purpose of understanding preventing From that point, different branches of psychology emerged with different individuals creating new ideas, with modern psychologists such as Freud and Jung contributing to the field. Mental health professional A psychologist is a practitioner of Psychology, the systematic investigation of the mind including Behavior, Cognition, Sigmund Freud (ˈziːkmʊnt ˈfʁɔʏt born Sigismund Shlomo Freud (May 6 1856 &ndash September 23 1939 was an Austrian Psychiatrist who founded

Mind and brain

The distinction between the mind and the brain is fundamental in philosophy of mind. MIND ( Moving In New Directions) (est 1975 is an alternative education high school in Montreal, Quebec, Canada. Philosophy of mind is the branch of Philosophy that studies the nature of the Mind, Mental events Mental functions mental properties The mind-body problem is one of the central problems in the history of philosophy. Philosophy of mind is the branch of Philosophy that studies the nature of the Mind, Mental events Mental functions mental properties Philosophy is the study of general problems concerning matters such as existence knowledge truth beauty justice validity mind and language The brain is the physical and biological matter contained within the skull, responsible for electrochemical neuronal processes. Matter is commonly defined as being anything that has mass and that takes up space. The mind, in contrast, consists in mental attributes, such as beliefs, desires, perceptions, and so on. Belief is the psychological state in which an individual holds a Proposition or Premise to be true In Psychology and the Cognitive sciences perception is the process of attaining awareness or understanding of sensory Information. There are scientifically demonstrable correlations between mental events and neuronal events; the philosophical question is whether these phenomena are identical, at least partially distinct, or related in some other way.

Philosophical positions on the mind-body problem fall into two main categories. The first category is dualism, according to which the mind exists independently of the brain. In Philosophy of mind, dualism is a set of views about the relationship between mind and matter which begins with the claim that mental phenomena are in some Dualist theories are further divided into substance dualism and property dualism. In Philosophy of mind, dualism is a set of views about the relationship between mind and matter which begins with the claim that mental phenomena are in some Property dualism describes a category of positions in the Philosophy of mind which hold that while the world is constituted of just one kind of Substance - the physical René Descartes is perhaps the most prominent substance dualist, while property dualism is more popular among contemporary dualists like David Chalmers. David John Chalmers (born April 20, 1966) is a Philosopher in the area of Philosophy of mind. The second category is materialism, according to which mental phenomena are identical to neuronal phenomena. The Philosophy of materialism holds that the only thing that can be truly proven to exist is Matter, and is considered a form of Physicalism. A third category of view, idealism, claims that only mental substances and phenomena exist. In Western civilization, Idealism is the philosophy which maintains that the Ultimate nature of reality is ideal or based upon ideas values essences The so-called This view, most prominently held by 18th century Irish philosopher Bishop George Berkeley, has few contemporary adherents. George Berkeley (ˈbɑrkli (12 March 1685 14 January 1753 also known as Bishop Berkeley, was a Philosopher.

Both dualism and materialism face serious philosophical challenges. Dualism requires admitting non-physical substances or properties into ontology, which is in apparent conflict with the scientific world view. In Philosophy, ontology (from the Greek, genitive: of being (part The term scientism can be used as a neutral term to describe the view that Natural science has authority over all other interpretations of life such as philosophical Materialism, on the other hand, must provide an explanation of how two seemingly different kinds of phenomena – the mental and the physical – could be identical. This is particularly challenging in that mental phenomena have certain characteristics – particularly intentionality and phenomenal character – that cannot (at least currently) be explained satisfactorily by a purely physical analysis of the brain. The term intentionality is often simplistically summarised as "aboutness" In Epistemology and the Philosophy of perception, phenomenalism is the view that physical objects do not exist as things in themselves but only as perceptual

Comparative anatomy

Three groups of animals have notably complex brains: the arthropods (insects, crustaceans, arachnids, and others), the cephalopods (octopuses, squids, and similar mollusks), and the craniates (vertebrates and hagfish). Arthropods are Animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, " Joint " Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described Structure of crustaceans As Arthropods crustaceans have a stiff Exoskeleton, which must be shed to allow the animal to grow ( Ecdysis or molting Arachnids are a class ( Arachnida) of joint-legged Invertebrate Animals in the subphylum Chelicerata. The cephalopods ( Greek plural (kephalópoda "head-feet" are the Mollusc class Cephalopoda characterized by The Squid are marine Cephalopods of the order Teuthida, which comprises around 300 species Molluscs are animals belonging to the phylum Mollusca. There are around 250000 extant Species within the phylum with an estimated 70000 For the class of Brachiopods see Craniforma. Craniata (sometimes Craniota) is a proposed Clade of Vertebrates are members of the Subphylum Vertebrata, Chordates with backbones or spinal columns The grouping sometimes includes Hagfish are marine Craniates of the class Myxini, also known as Hyperotreti. ^[2] The brain of arthropods and cephalopods arises from twin parallel nerve cords that extend through the body of the animal. Arthropods have a central brain with three divisions and large optical lobes behind each eye for visual processing. Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain ^[2]

The brain of craniates develops from the anterior section of a single dorsal nerve cord, which later becomes the spinal cord. In fields of Anatomy, anatomical terms of location are descriptive terms to help identify relative positions or directions within a species In the developing vertebrate the neural tube is the Embryo 's precursor to the Central nervous system, which comprises the Brain and Spinal cord The spinal cord is a long thin tubular bundle of Nerves that is an extension of the Central nervous system from the brain and is enclosed in and protected ^[3] In craniates, the brain is protected by the bones of the skull. Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce

Mammals have a six-layered neocortex (or homotypic cortex, neopallium), in addition to having some parts of the brain that are allocortex. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands The neocortex ( Latin for "new Bark " or "new Rind " is a part of the Brain of Mammals It is the outer layer of ^[3] In mammals, increasing convolutions of the brain are characteristic of animals with more advanced brains. These convolutions provide a larger surface area for a greater number of neurons while keeping the volume of the brain compact enough to fit inside the skull. The folding allows more grey matter to fit into a smaller volume. The folds are called sulci, while the spaces between the folds are called gyri. In Neuroanatomy, a sulcus ( Latin: "furrow" pl sulci) is a depression or fissure in the surface of the brain A gyrus (pl gyri) is a ridge on the cerebral cortex. It is generally surrounded by one or more sulci.

In birds, the part of the brain that functionally corresponds to the neocortex is called nidopallium and derives from a different part of the brain. Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. The nidopallium, meaning nested pallium is the region of the avian Brain that is used mostly for some types of executive functions but also other higher cognitive tasks Some birds (like corvids and parrots), are thought by some to have high intelligence, but even in these, the brain region that forms the mammalian neocortex is in fact almost entirely absent. Corvidae is a cosmopolitan family of Oscine Passerine Birds that contains the Crows Ravens rooks Parrots are birds of the roughly 350 Species in 85 genera comprising the order Psittaciformes, found in most warm and tropical regions

Although the general histology of the brain is similar from person to person, the structural anatomy can differ. Histology (from the Greek = 'tissue' is the study of the microscopic anatomy of cells and tissues of Plants and Apart from the gross embryological divisions of the brain, the location of specific gyri and sulci, primary sensory regions, and other structures differs between species. Embryology (from Greek grc ἔμβρυον embryon, "unborn embryo" and grc -λογία -logia) is the study of the development

Insects

In insects, the brain has four parts, the optical lobes, the protocerebrum, the deutocerebrum, and the tritocerebrum. The optical lobes are behind each eye and process visual stimuli. ^[2] The protocerebrum contains the mushroom bodies, which respond to smell, and the central body complex. The mushroom bodies or corpora pedunculata are a pair of structures in the Brain of Insects and other Arthropods They are usually Olfaction (also known as olfactics or smell) refers to the Sense of smell. In some species such as bees, the mushroom body receives input from the visual pathway as well. In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. Bees are flying Insects closely related to Wasps and Ants Bees are a Monophyletic lineage within the superfamily Apoidea The deutocerebrum includes the antennal lobes, which are similar to the mammalian olfactory bulb, and the mechanosensory neuropils which receive information from touch receptors on the head and antennae. Antennal lobe is the deutocerebral Neuropil of the insect which receives the input from the Olfactory sensory neurons on the antenna. The olfactory bulb is a structure of the Vertebrate Forebrain involved in Olfaction, the perception of Odors. Neuropil consists of unmyelinated neuronal processes (axonal and dendritic within the gray matter of the central nervous system Antennae (singular antenna) are paired Appendages connected to the front-most segments of Arthropods In Crustaceans they are The antennal lobes of flies and moths are quite complex. True flies are Insects of the Order Diptera ( Greek: di = two and pteron = wing possessing a single pair of A moth is an Insect closely related to the Butterfly, both being of the order Lepidoptera.

Cephalopods

In cephalopods, the brain has two regions: the supraesophageal mass and the subesophageal mass,^[2] separated by the esophagus. The esophagus or oesophagus (see American and British English spelling differences) sometimes known as the gullet, is an organ in The supra- and subesophageal masses are connected to each other on either side of the esophagus by the basal lobes and the dorsal magnocellular lobes. ^[2] The large optic lobes are sometimes not considered to be part of the brain, as they are anatomically separate and are joined to the brain by the optic stalks. However, the optic lobes perform much visual processing, and so functionally are part of the brain.

Mammals and other vertebrates

The telencephalon (cerebrum) is the largest region of the mammalian brain. The telencephalon (tɛlɛnˈsɛfəlɒn cerebrum, or forebrain is the most Anterior or especially in humans most Dorsal region of the This is the structure that is most easily visible in brain specimens, and is what most people associate with the "brain". In humans and several other animals, the fissures (sulci) and convolutions (gyri) give the brain a wrinkled appearance. In non-mammalian vertebrates with no cerebrum, the metencephalon is the highest center in the brain. The metencephalon is a developmental categorization of portions of the Central nervous system. Because humans walk upright, there is a flexure, or bend, in the brain between the brain stem and the cerebrum. The brain stem (or brainstem) is the lower part of the Brain, adjoining and structurally continuous with the Spinal cord. Other vertebrates do not have this flexure. Generally, comparing the locations of certain brain structures between humans and other vertebrates often reveals a number of differences.

Behind (or in humans, below) the cerebrum is the cerebellum. The cerebellum is known to be involved in the control of movement,^[3] and is connected by thick white matter fibers (cerebellar peduncles) to the pons. The pons (sometimes pons Varolii after Costanzo Varolio) is a structure located on the Brain stem. ^[4] The cerebrum has two cerebral hemispheres. A cerebral hemisphere ( hemispherium cerebrale) is defined as one of the two regions of the Brain that are delineated by the body's median plane. The cerebellum also has hemispheres. The cerebellum ( Latin: "little brain" is a region of the Brain that plays an important role in the integration of sensory perception The telencephalic hemispheres are connected by the corpus callosum, another large white matter tract. The corpus callosum is a structure of the Mammalian Brain in the longitudinal fissure that connects the left and right Cerebral hemispheres It also facilitates An outgrowth of the telencephalon called the olfactory bulb is a major structure in many animals, but in humans and other primates it is relatively small. The olfactory bulb is a structure of the Vertebrate Forebrain involved in Olfaction, the perception of Odors.

Vertebrate nervous systems are distinguished by bilaterally symmetrical encephalization. "Bilateral symmetry" redirects here For bilateral symmetry in mathematics see Reflection symmetry. Encephalization is defined as the amount of Brain mass exceeding that related to an animal's total body mass. Encephalization refers to the tendency for more complex organisms to gain larger brains through evolutionary time. Larger vertebrates develop a complex, layered and interconnected neuronal circuitry. In modern species most closely related to the first vertebrates, brains are covered with gray matter that has a three-layer structure (allocortex). Their brains also contain deep brain nuclei and fiber tracts forming the white matter. Most regions of the human cerebral cortex have six layers of neurons (neocortex). ^[4]

Vertebrate brain regions

(See related article at List of regions in the human brain)

According to the hierarchy based on embryonic and evolutionary development, chordate brains are composed of the three regions that later develop into five total divisions:

• Rhombencephalon (hindbrain)
  • Myelencephalon
  • Metencephalon
• Mesencephalon (midbrain)
• Prosencephalon (forebrain)
  • Diencephalon
  • Telencephalon

The brain can also be classified according to function, including divisions such as:

• Limbic system
• Sensory systems
  • Visual system
  • Olfactory system
  • Gustatory system
  • Auditory system
  • Somatosensory system
• Motor system
• Associative areas

In recent years it was realized that certain birds have developed high intelligence entirely convergently from mammals such as humans. Chordates ( Phylum Chordata) are a group of Animals that includes the Vertebrates together with several closely related Invertebrates The rhombencephalon (or hindbrain) is a developmental categorization of portions of the Central nervous system in Vertebrates. The myelencephalon is a developmental categorization of a portion of the Central nervous system. The metencephalon is a developmental categorization of portions of the Central nervous system. In biological anatomy the mesencephalon (or midbrain) comprises the Tectum (or corpora quadrigemini Tegmentum, the ventricular mesocoelia (or "iter" In the Anatomy of the Brain of Vertebrates, the prosencephalon (or forebrain) is the Rostral -most (forward-most portion of the The diencephalon (or interbrain is the region of the Brain that includes the Thalamus, Hypothalamus, Epithalamus, Prethalamus or The telencephalon (tɛlɛnˈsɛfəlɒn cerebrum, or forebrain is the most Anterior or especially in humans most Dorsal region of the The limbic system, or Paleomammalian brain is a term for a set of brain structures including the Hippocampus and Amygdala and anterior thalamic nuclei and a limbic See also Sense A sensory system is a part of the Nervous system responsible for processing sensory information The visual system is the part of the Nervous system which allows organisms to see. The Olfactory helps and relates sense of smell. The olfactory system is the Sensory system used for Olfaction. The gustatory system is the Sensory system for the sense of Taste. The auditory system is the Sensory system for the sense of hearing. Muscle (from Latin musculus, diminutive of mus "mouse" is contractile tissue of the body and is derived from the The cerebral cortex is a structure within the Brain that plays a key role in Memory, Attention, perceptual Awareness, Thought, Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. Convergent evolution describes the acquisition of the same biological trait in unrelated lineages Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands Hence, the functional areas of the avian brain have been redefined by the Avian Brain Nomenclature Consortium. The Avian Brain Nomenclature Consortium is a group of Neuroscientists working on standardizing and updating the scientific language used to describe parts of Bird See also Bird intelligence. Bird intelligence deals with the definition of Intelligence and its measurement as it applies to Birds Traditionally birds have been considered inferior in intelligence

Humans

Main article: Human brain

The structure of the human brain differs from that of other animals in several important ways. The human brain controls the Central nervous system (CNS by way of the Cranial nerves and Spinal cord, the Peripheral nervous system (PNS These differences allow for many abilities over and above those of other animals, such as advanced cognitive skills. Human encephalization is especially pronounced in the neocortex, the most complex part of the cerebral cortex. The neocortex ( Latin for "new Bark " or "new Rind " is a part of the Brain of Mammals It is the outer layer of The cerebral cortex is a structure within the Brain that plays a key role in Memory, Attention, perceptual Awareness, Thought, The proportion of the human brain that is devoted to the neocortex—especially to the prefrontal cortex—is larger than in all other mammals (indeed larger than in all animals, although only in mammals has the neocortex evolved to fulfill this kind of function). Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands

Humans have unique neural capacities, but much of their brain structure is similar to that of other mammals. Basic systems that alert the nervous system to stimulus, that sense events in the environment, and monitor the condition of the body are similar to those of even non-mammalian vertebrates. The neural circuitry underlying human consciousness includes both the advanced neocortex and prototypical structures of the brainstem. The brain stem (or brainstem) is the lower part of the Brain, adjoining and structurally continuous with the Spinal cord. The human brain also has a massive number of synaptic connections allowing for a great deal of parallel processing. Parallel processing is also another term for Parallel computing.

The human brain is also the largest organ in the Nervous System.

Neurobiology

The brain is composed of two broad classes of cells, neurons and glia, both of which contain several different cell types which perform different functions. Neurons (ˈnjuːɹɒn also known as neurones and nerve cells) are responsive cells in the Nervous system that process and transmit information Glial cells, commonly called neuroglia or simply glia (Greek for "glue" are non- Neuronal cells that provide support and nutrition Interconnected neurons form neural networks (or neural ensembles). Traditionally the term neural network had been used to refer to a network or circuit of biological neurons. A neural ensemble is a population of Nervous system cells (or cultured Neurons) involved in a particular neural computation These networks are similar to man-made electrical circuits in that they contain circuit elements (neurons) connected by biological wires (nerve fibers). An electrical network is an interconnection of Electrical elements such as Resistors Inductors Capacitors Transmission lines Voltage These do not form simple one-to-one electrical circuits like many man-made circuits, however. Typically neurons connect to at least a thousand other neurons. ^[5] These highly specialized circuits make up systems which are the basis of perception, different types of action, and higher cognitive function. In Psychology and the Cognitive sciences perception is the process of attaining awareness or understanding of sensory Information.

Structure

Structure of a typical neuron

Neuron
Dendrite Soma Axon Nucleus Node of Ranvier Axon Terminal Schwann cell Myelin sheath

Neurons are the cells that convey information to other cells; these constitute the essential class of brain cells. Neurons (ˈnjuːɹɒn also known as neurones and nerve cells) are responsive cells in the Nervous system that process and transmit information Dendrites (from Greek δένδρον déndron, “tree” are the branched projections of a Neuron that act to conduct the electrochemical The soma, or cyton or perikaryon, is the bulbous end of a Neuron, containing the Cell nucleus. An axon or nerve fiber is a long slender projectionof a nerve cell or Neuron, that conducts electrical impulses away from the neuron's Cell In Cell biology, the nucleus (pl nuclei; from Latin la ''nucleus'' or la ''nuculeus'' "little nut" or kernel is a membrane-enclosed Nodes of Ranvier are known as the gaps (about 1 micrometer in diameter formed between myelin sheath cells along axons or nerve fibers Chemical synapses are specialized junctions through which Neurons signal to each other and to non-neuronal cells such as those in Muscles or Glands Named after the German physiologist Theodor Schwann, Schwann cells (also referred to as neurolemmocytes) are a variety of Glial cell that mainly Myelin is an electrically-insulating Dielectric Phospholipid layer that surrounds only the Axons of many Neurons It is an outgrowth

In addition to neurons, the brain contains glial cells in a roughly 10:1 proportion to neurons. Glial cells, commonly called neuroglia or simply glia (Greek for "glue" are non- Neuronal cells that provide support and nutrition Glial cells ("glia" is Greek for “glue”) form a support system for neurons. They create the insulating myelin, provide structure to the neuronal network, manage waste, and clean up neurotransmitters. Most types of glia in the brain are present in the entire nervous system. The nervous system is a Network of specialized cells that communicate information about an animal's surroundings and itself Exceptions include the oligodendrocytes which myelinate neural axons (a role performed by Schwann cells in the peripheral nervous system). Origin Oligodendroglia arise during development from an Oligodendrocyte precursor cell, which can be identified by its expression of a number of Antigens, including An axon or nerve fiber is a long slender projectionof a nerve cell or Neuron, that conducts electrical impulses away from the neuron's Cell Named after the German physiologist Theodor Schwann, Schwann cells (also referred to as neurolemmocytes) are a variety of Glial cell that mainly The myelin in the oligodendrocytes insulates the axons of some neurons. White matter in the brain is myelinated neurons, while grey matter contains mostly cell soma, dendrites, and unmyelinated portions of axons and glia. White matter is one of the three main solid components of the Central nervous system. The soma, or cyton or perikaryon, is the bulbous end of a Neuron, containing the Cell nucleus. Dendrites (from Greek δένδρον déndron, “tree” are the branched projections of a Neuron that act to conduct the electrochemical The space between neurons is filled with dendrites as well as unmyelinated segments of axons; this area is referred to as the neuropil. Neuropil consists of unmyelinated neuronal processes (axonal and dendritic within the gray matter of the central nervous system

In mammals, the brain is surrounded by connective tissues called the meninges, a system of membranes that separate the skull from the brain. Connective tissue is one of the four types of tissue in traditional classifications (the others being epithelial, Muscle, and Nervous tissue) The meninges (singular meninx) is the system of membranes which envelops the Central nervous system. This three-layered covering is composed of (from the outside in) the dura mater, arachnoid mater, and pia mater. The dura mater (from the Latin "hard mother" or pachymeninx, is the tough and inflexible outermost of the three layers of the Meninges surrounding the The arachnoid mater is one of the three Meninges, the membranes that cover the Brain and Spinal cord. The pia mater (Latin "tender mother" itself a translation from Arabic) is the delicate innermost layer of the Meninges - the membranes surrounding the The arachnoid and pia are physically connected and thus often considered as a single layer, the pia-arachnoid. Below the arachnoid is the subarachnoid space which contains cerebrospinal fluid, a substance that protects the nervous system. Cerebrospinal fluid ( CSF) Liquor cerebrospinalis, is a clear Bodily fluid that occupies the Subarachnoid space and the Ventricular system Blood vessels enter the central nervous system through the perivascular space above the pia mater. The blood vessels are part of the Circulatory system and function to transport Blood throughout the body The cells in the blood vessel walls are joined tightly, forming the blood-brain barrier which protects the brain from toxins that might enter through the blood. The blood-brain barrier (BBB is a metabolic or cellular structure in the Central nervous system (CNS that restricts the passage of various chemical substances and microscopic A toxin ( Greek:, toxikon, lit (poison for use on arrows is a Poisonous substance produced by living cells or organisms that is active at very low

The brain is bathed in cerebrospinal fluid (CSF), which circulates between layers of the meninges and through cavities in the brain called ventricles. Cerebrospinal fluid ( CSF) Liquor cerebrospinalis, is a clear Bodily fluid that occupies the Subarachnoid space and the Ventricular system The ventricular system is a set of structures in the Brain continuous with the Central canal of the Spinal cord. It is important both chemically for metabolism and mechanically for shock-prevention. Metabolism is the set of Chemical reactions that occur in living Organisms in order to maintain Life. For example, the human brain weighs about 1-1. 5 kg or about 2-3 lb. The pound or pound-mass (abbreviation lb, lbm, or sometimes in the United States #) is a unit of Mass The mass and density of the brain are such that it will begin to collapse under its own weight if unsupported by the CSF. Mass is a fundamental concept in Physics, roughly corresponding to the Intuitive idea of how much Matter there is in an object The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different The CSF allows the brain to float, easing the physical stress caused by the brain’s mass. Stress is a measure of the average amount of Force exerted per unit Area.

Function

Vertebrate brains receive signals through nerves arriving from the sensors of the organism. These signals are then processed throughout the central nervous system; reactions are formulated based upon reflex and learned experiences. A similarly extensive nerve network delivers signals from a brain to control important muscles throughout the body. Anatomically, the majority of afferent and efferent nerves (with the exception of the cranial nerves) are connected to the spinal cord, which then transfers the signals to and from the brain. Cranial nerves are Nerves that emerge directly from the Brain stem in contrast to Spinal nerves which emerge from segments of the Spinal cord.

Sensory input is processed by the brain to recognize danger, find food, identify potential mates, and perform more sophisticated functions. Visual, touch, and auditory sensory pathways of vertebrates are routed to specific nuclei of the thalamus and then to regions of the cerebral cortex that are specific to each sensory system, the visual system, the auditory system, and the somatosensory system. In Psychology, visual perception is the ability to interpret information from Visible light reaching the Eyes The resulting Perception is also The thalamus (from Greek θάλαμος = room chamber, IPA= /ˈθæləməs/ is a pair and symmetric part of the brain See also Sense A sensory system is a part of the Nervous system responsible for processing sensory information The visual system is the part of the Nervous system which allows organisms to see. The auditory system is the Sensory system for the sense of hearing. Olfactory pathways are routed to the olfactory bulb, then to various parts of the olfactory system. The Olfactory helps and relates sense of smell. The olfactory system is the Sensory system used for Olfaction. Taste is routed through the brainstem and then to other portions of the gustatory system. Taste (or more formally gustation) is a form of direct Chemoreception and is one of the traditional five Senses The gustatory system is the Sensory system for the sense of Taste.

To control movement the brain has several parallel systems of muscle control. The motor system controls voluntary muscle movement, aided by the motor cortex, cerebellum, and the basal ganglia. Motor cortex is a term that describes regions of the Cerebral cortex involved in the planning control and execution of voluntary motor functions The cerebellum ( Latin: "little brain" is a region of the Brain that plays an important role in the integration of sensory perception The basal ganglia (or basal nuclei) are a group of nuclei in the Brain interconnected with the Cerebral cortex, Thalamus and The system eventually projects to the spinal cord and then out to the muscle effectors. Nuclei in the brain stem control many involuntary muscle functions such as heart rate and breathing. In addition, many automatic acts (simple reflexes, locomotion) can be controlled by the spinal cord alone.

Brains also produce a portion of the body's hormones that can influence organs and glands elsewhere in a body—conversely, brains also react to hormones produced elsewhere in the body. Hormones (from Greek ὁρμή - "impetus" are chemicals released by cells that affect cells in other parts of the body In mammals, the hormones that regulate hormone production throughout the body are produced in the brain by the structure called the pituitary gland. The pituitary gland, or hypophysis, is an Endocrine gland about the size of a Pea.

Evidence strongly suggests that developed brains derive consciousness from the complex interactions between the numerous systems within the brain. Cognitive processing in mammals occurs in the cerebral cortex but relies on midbrain and limbic functions as well. The limbic system, or Paleomammalian brain is a term for a set of brain structures including the Hippocampus and Amygdala and anterior thalamic nuclei and a limbic Among "younger" (in an evolutionary sense) vertebrates, advanced processing involves progressively rostral (forward) regions of the brain.

Hormones, incoming sensory information, and cognitive processing performed by the brain determine the brain state. Stimulus from any source can trigger a general arousal process that focuses cortical operations to processing of the new information. This focusing of cognition is known as attention. Attention is the Cognitive process of selectively concentrating on one aspect of the environment while ignoring other things Cognitive priorities are constantly shifted by a variety of factors such as hunger, fatigue, belief, unfamiliar information, or threat. The simplest dichotomy related to the processing of threats is the fight-or-flight response mediated by the amygdala and other limbic structures. The fight-or-flight response', also called the fright, fight or flight response, hyperarousal or the acute stress response, was first The la amygdalae ( Latin, also la corpus amygdaloideum, singular la amygdala, from Greek el αμυγδαλή grc-Latn amygdalē, 'almond'

Neurotransmitter systems

Main article: Neurotransmitter systems

Neurons expressing certain types of neurotransmitters sometimes form distinct systems, where activation of the system causes effects in large volumes of the brain, called volume transmission. In neuroscience neuromodulation is the process in which several classes of Neurotransmitters in the nervous system regulate diverse populations of Neurons (one

The major neurotransmitter systems are the noradrenaline (norepinephrine) system, the dopamine system, the serotonin system and the cholinergic system. Norepinephrine ( INN) (abbreviated norepi or NE) or noradrenaline ( BAN) (abbreviated NA or NAd) is a Dopamine is a Hormone and Neurotransmitter occurring in a wide variety of animals including both vertebrates and invertebrates Serotonin (ˌsɛrəˈtoʊnən ( 5-hydroxytryptamine, or 5-HT) is a Monoamine Neurotransmitter synthesized in serotonergic Neurons A receptor is cholinergic if it uses Acetylcholine as its Neurotransmitter.

Drugs targeting the neurotransmitter of such systems affects the whole system, which explains the mode of action of many drugs;

• Cocaine, for example, blocks the reuptake of dopamine, leaving these neurotransmitters in the synaptic gap longer. Cocaine ( benzoylmethyl ecgonine) is a Crystalline Tropane Alkaloid that is obtained from the leaves of the Coca plant Dopamine is a Hormone and Neurotransmitter occurring in a wide variety of animals including both vertebrates and invertebrates Chemical synapses are specialized junctions through which Neurons signal to each other and to non-neuronal cells such as those in Muscles or Glands
• Prozac is a selective serotonin reuptake inhibitor (SSRI), hence potentiating the effect of naturally released serotonin. Selective serotonin reuptake inhibitors ( SSRIs) are a class of Antidepressants used in the treatment of depression, Anxiety disorders
• AMPT prevents the conversion of tyrosine to L-DOPA, the precursor to dopamine; reserpine prevents dopamine storage within vesicles; and deprenyl inhibits monoamine oxidase (MAO)-B and thus increases dopamine levels. Alpha-methyl-p-tyrosine (AMPT is a drug that temporarily reduces Brain Catecholamine activity by competitively inhibiting Tyrosine hydroxylase Reserpine is an Indole Alkaloid Antipsychotic and Antihypertensive drug that has been used for the control of high blood pressure Selegiline (l-deprenyl Eldepryl Zelapar or Anipryl Veterinary) is a drug used for the treatment of early-stage Parkinson's disease, Depression

Diseases may affect specific neurotransmitter systems. For example, Parkinson's disease is at least in part related to failure of dopaminergic cells in deep-brain nuclei, for example the substantia nigra. Parkinson's disease (also known as Parkinson disease or PD) is a degenerative disorder of the Central nervous system that often impairs the sufferer's The substantia nigra ( Latin for "black substance" Sömmering) or locus niger is a heterogeneous portion of the midbrain, separating Treatments potentiating the effect of dopamine precursors have been proposed and effected, with moderate success.

A brief comparison of the major neurotransmitter systems follows:

Neurotransmitter systems

System	Origin	[6] Effects[6]
Noradrenaline system	locus coeruleus	arousal reward
	Lateral tegmental field
Dopamine system	dopamine pathways: mesocortical pathway mesolimbic pathway nigrostriatal pathway tuberoinfundibular pathway	motor system, reward, cognition, endocrine, nausea
Serotonin system	caudal dorsal raphe nucleus	Increase introversion, mood, satiety, body temperature and sleep, while decreasing nociception. The Locus ceruleus also spelled locus caeruleus or locus coeruleus (Latin for 'the blue spot' is a nucleus in the Brain stem involved with physiological The tegmentum (from Latin for "covering" is a general area within the Brainstem. Dopamine is a Hormone and Neurotransmitter occurring in a wide variety of animals including both vertebrates and invertebrates A neural pathway is a Neural tract connecting one part of the Nervous system with another usually consisting of bundles of elongated Myelin -insulated The mesocortical pathway is a Neural pathway that connects the Ventral tegmentum to the Cerebral cortex, particularly the Frontal lobes It is The mesolimbic pathway is one of the Neural pathways in the Brain that links the Ventral tegmentum in the Midbrain to the Nucleus accumbens The nigrostriatal pathway is a Neural pathway that connects the Substantia nigra with the Striatum. The tuberoinfundibular pathway refers to a population of dopamine neurons in the Arcuate nucleus of the mediobasal Hypothalamus (the 'tuberal region' that project The motor system is the part of the peripheral nervous system that is involved to movement Cognition is a concept used in different ways by different disciplines but is generally accepted to mean the process of awareness or thought The endocrine system is an integrated system of small organs that involve the release of extracellular signaling molecules known as Hormones The endocrine system is instrumental Nausea ( Latin: Nausea, Greek:, " Sea-sickness " also called wamble) is the sensation of unease and discomfort The dorsal raphe nucleus is a part of the Raphe nucleus and consists of rostral and caudal subdivisions The trait of Extraversion-Introversion is a central dimension of human personality. A mood is a relatively long lasting affective or emotional state Cholecystokinin ( CCK; from Greek chole, "bile" cysto, "sac" kinin, "move" hence move the bile-sac Core temperature, also called core body temperature, is the operating Temperature of an Organism, specifically in deep structures of the body such as the Sleep is a Natural state of bodily rest observed throughout the animal kingdom Nociception (synonym nociperception is defined as "the neural processes of encoding and processing Noxious stimuli.
	rostral dorsal raphe nucleus
Cholinergic system	pontomesencephalotegmental complex	learning short-term memory arousal reward
	basal optic nucleus of Meynert
	medial septal nucleus

Origin

Since even unicellular organisms can have, at least, photosensitive eyespots and react to tactile stimuli, it is hypothesized that sensory organs developed before the brain did. The dorsal raphe nucleus is a part of the Raphe nucleus and consists of rostral and caudal subdivisions In the fields of Neuropsychology, Personal development and Education, Learning is one of the most important Mental function of humans In Psychology, memory is an organism's ability to store retain and subsequently retrieve information The basal nucleus of Meynert (NBM is a group of nerve cells in the Substantia innominata of the Basal forebrain, in the lateral part of the Tuber cinereum The septal nuclei are structures in the middle anteroventral cerebrum that are composed of medium-size neurons grouped into medial lateral and posterior groups The eyespot apparatus (or Stigma) is a photoreceptive Organelle found in the flagellate (motile cells of Green algae and other unicellular ^[7] The brain is an information-processing organ and its evolution is dependent on the presence of information accessed into sensory organs, sensory input, and the need to process this information and transmit it.

Pathology

Clinically, death is defined as an absence of brain activity as measured by EEG. Death is the termination of the biological functions that define living Organisms It refers both to a specific Injuries to the brain tend to affect large areas of the organ, sometimes causing major deficits in intelligence, memory, and movement. Head trauma caused, for example, by vehicle or industrial accidents, is a leading cause of death in youth and middle age. In many cases, more damage is caused by resultant edema than by the impact itself. Oedema (or Edema in American English formerly known as dropsy or hydropsy, is the increase of Interstitial fluid in any organ &mdash swelling Stroke, caused by the blockage or rupturing of blood vessels in the brain, is another major cause of death from brain damage. A stroke is the rapidly developing loss of brain functions due to a disturbance in the blood vessels supplying blood to the brain

Other problems in the brain can be more accurately classified as diseases rather than injuries. Neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, motor neurone disease, and Huntington's disease are caused by the gradual death of individual neurons, leading to decrements in movement control, memory, and cognition. Neurodegenerative Disease ( Greek νέυρο- néuro-, "nerval" and Latin dēgenerāre, "to decline" or "to Alzheimer's disease ( AD) also called Alzheimer disease or simply Alzheimer's, is the most common form of Dementia. Parkinson's disease (also known as Parkinson disease or PD) is a degenerative disorder of the Central nervous system that often impairs the sufferer's The motor neurone diseases (or motor neuron diseases) (MND are a group of progressive neurological disorders that destroy Motor neurones the cells that control voluntary Huntington's disease, also called Huntington's chorea, chorea major, or HD, is a genetic neurological disorder characterized after Currently only the symptoms of these diseases can be treated. Mental illnesses, such as clinical depression, schizophrenia, bipolar disorder, and post-traumatic stress disorder are brain disorders that impact personality and, typically, other aspects of mental and somatic function. Mental disorder or mental illness is a psychological or behavioral pattern that occurs in an individual and is thought to cause distress or disability that is not expected as Major depressive disorder, also known as major depression, unipolar depression, unipolar disorder, clinical depression, or simply depression Schizophrenia ( from the Greek roots schizein (σχίζειν "to split" and phrēn Post traumatic stress disorder It is a severe and ongoing emotional reaction to These disorders may be treated by psychiatric therapy, pharmaceutical intervention, or through a combination of treatments; therapeutic effectiveness varies significantly among individuals. Psychiatry is a medical specialty which exists to study, prevent, and treat Mental disorders in Humans Psychiatric Medication, also referred to as medicine, can be loosely defined as any substance intended for use in the diagnosis cure mitigation treatment or prevention of disease

Some infectious diseases affecting the brain are caused by viruses and bacteria. A virus (from the Latin virus meaning Toxin or Poison) is a sub-microscopic infectious agent that is unable The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have Infection of the meninges, the membrane that covers the brain, can lead to meningitis. The meninges (singular meninx) is the system of membranes which envelops the Central nervous system. Meningitis is Inflammation of the protective membranes covering the Brain and Spinal cord, known collectively as the Meninges. Bovine spongiform encephalopathy (also known as mad cow disease), is deadly in cattle and humans and is linked to prions. Bovine Spongiform Encephalopathy ( BSE) commonly known as Mad-Cow Disease ( MCD) is a fatal Neurodegenerative disease in Cattle Cattle, colloquially referred to as cows, are domesticated Ungulates a member of the Subfamily Bovinae of the family A prion (ˈpriːɒn is thought to be an infectious agent that according to current scientific consensus is comprised entirely of a propagated, mis-folded Kuru is a similar prion-borne degenerative brain disease affecting humans. Kuru is a disease which affects the Brain. It was endemic among the Fore tribe of Papua New Guinea and was universally fatal Both are linked to the ingestion of neural tissue, and may explain the tendency in some species to avoid cannibalism. Cannibalism (from Spanish es ''caníbal'' in connection with cannibalism among the Antillean Caribs, also called anthropophagy (from Greek ἄνθρωπος Viral or bacterial causes have been reported in multiple sclerosis and Parkinson's disease, and are established causes of encephalopathy, and encephalomyelitis. Multiple sclerosis (abbreviated MS also known as disseminated sclerosis or encephalomyelitis disseminata) is an autoimmune condition in which the Parkinson's disease (also known as Parkinson disease or PD) is a degenerative disorder of the Central nervous system that often impairs the sufferer's Encephalopathy /ɛnˌsɛfəˈlɒpəθi/ literally means Disease of the Brain. Encephalomyelitis is a general term for Inflammation of the Brain and Spinal cord, describing a number of disorders Acute disseminated

Many brain disorders are congenital. A congenital disorder is a disease or disorder that is present at birth Tay-Sachs disease, Fragile X syndrome, and Down syndrome are all linked to genetic and chromosomal errors. Tay-Sachs disease (abbreviated TSD, also known as GM2 Gangliosidosis, Hexosaminidase A deficiency or Sphingolipidosis) is a Genetic Fragile X syndrome, or Martin-Bell syndrome, is a genetic Syndrome which results in a spectrum (from none to severe of characteristic physical intellectual emotional Down syndrome, Down's syndrome, or trisomy 21 is a Chromosomal disorder caused by the presence of all or part of an extra 21st chromosome. History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance A chromosome is an organized structure of DNA and Protein that is found in cells. Many other syndromes, such as the intrinsic circadian rhythm disorders, are suspected to be congenital as well. Malfunctions in the embryonic development of the brain can be caused by genetic factors, drug use, nutritional deficiencies, and infectious diseases during pregnancy. The study of neural development draws on both Neuroscience and Developmental biology to describe the cellular and molecular mechanisms by which complex Nervous Drugs can be used in many different ways as detailed below Medication See also Medication People can use drugs to relieve pain or discomfort or to cure Many Diseases in humans are directly or indirectly caused by improper eating habits and Malnutrition. An infectious disease is a clinically evident Disease resulting from the presence of Pathogenic microbial agents including Pathogenic viruses Pathogenic Pregnancy ( Latin graviditas) is the carrying of one or more offspring known as a Fetus or Embryo, inside the Uterus of a Female

Certain brain disorders are treated by brain neurosurgeons while others are treated by neurologists and psychiatrists. Neurosurgery is the surgical discipline focused on treating those central, Peripheral nervous system and spinal column diseases amenable to surgical

Study of the brain

Fields of study

Neuroscience seeks to understand the nervous system, including the brain, from a biological and computational perspective. Neuroscience is a field devoted to the scientific study of the nervous system Computational neuroscience is an interdisciplinary science that links the diverse fields of Neuroscience, Cognitive science, Electrical engineering, Psychology seeks to understand behavior and the brain. Psychology (from Greek grc ψῡχή psȳkhē, "breath life soul" and grc -λογία -logia) is an Academic and Neurology refers to the medical applications of neuroscience. Medicine is the art and science of healing It encompasses a range of Health care practices evolved to maintain and restore Human Health by the The brain is also one of the most important organs studied in psychiatry, the branch of medicine which exists to study, prevent, and treat mental disorders. Psychiatry is a medical specialty which exists to study, prevent, and treat Mental disorders in Humans Psychiatric Mental disorder or mental illness is a psychological or behavioral pattern that occurs in an individual and is thought to cause distress or disability that is not expected as ^[8][9][10] Cognitive science seeks to unify neuroscience and psychology with other fields that concern themselves with the brain, such as computer science (artificial intelligence and similar fields) and philosophy. Cognitive science may be broadly defined as the multidisciplinary study of mind and behavior Computer science (or computing science) is the study and the Science of the theoretical foundations of Information and Computation and their Philosophy is the study of general problems concerning matters such as existence knowledge truth beauty justice validity mind and language

Methods of observation

Main article: neuroimaging

Each method for observing activity in the brain has its advantages and drawbacks. Neuroimaging includes the use of various techniques to either directly or indirectly image the structure, function/ Pharmacology of the Brain

Electrophysiology

Electrophysiology allows scientists to record the electrical activity of individual neurons or groups of neurons.

EEG

By placing electrodes on the scalp one can record the summed electrical activity of the cortex in a technique known as electroencephalography (EEG). EEG measures the mass changes in electrical current from the cerebral cortex, but can only detect changes over large areas of the brain with very little sub-cortical activity.

MEG

Apart from measuring the electric field around the skull it is possible to measure the magnetic field directly in a technique known as magnetoencephalography (MEG). Magnetoencephalography ( MEG) is an imaging technique used to measure the Magnetic fields produced by electrical activity in the This technique has the same temporal resolution as EEG but much better spatial resolution, although admittedly not as good as fMRI. The main advantage over fMRI is a direct relationship between neural activation and measurement.

fMRI and PET

Functional magnetic resonance imaging (fMRI) measures changes in blood flow in the brain, but the activity of neurons is not directly measured, nor can it be distinguished whether this activity is inhibitory or excitatory. Blood flow is the flow of Blood in the Cardiovascular system. fMRI is a noninvasive, indirect method for measuring neural activity that is based on BOLD; Blood Oxygen Level Dependent changes. The changes in blood flow that occur in capillary beds in specific regions of the brain are thought to represent various neuronal activities (metabolism of synaptic reuptake). Metabolism is the set of Chemical reactions that occur in living Organisms in order to maintain Life. Similarly, a positron emission tomography (PET), is able to monitor glucose and oxygen metabolism as well as neurotransmitter activity in different areas within the brain which can be correlated to the level of activity in that region. Positron emission tomography ( PET) is a Nuclear medicine imaging technique which produces a three-dimensional image or map of functional processes in the Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the

Behavioral

Behavioral tests can measure symptoms of disease and mental performance, but can only provide indirect measurements of brain function and may not be practical in all animals. In humans however, a neurological exam can be done to determine the location of any trauma, lesion, or tumor within the brain, brain stem, or spinal cord. A lesion is any abnormal tissue found on or in an organism usually damaged by disease or trauma See also Cancer A tumor or tumour is the name for a swelling or lesion formed by an abnormal growth of cells (termed neoplastic

Anatomical

Autopsy analysis of the brain allows for the study of anatomy and protein expression patterns, but is only possible after the human or animal is dead. An autopsy, also known as a post-mortem examination, necropsy, or obduction, is a Medical procedure that consists of a thorough Examination Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Magnetic resonance imaging (MRI) can be used to study the anatomy of a living creature and is widely used in both research and medicine.

Other studies

Computer scientists have produced simulated "artificial neural networks" loosely based on the structure of neuron connections in the brain. Computer science (or computing science) is the study and the Science of the theoretical foundations of Information and Computation and their An artificial neural network (ANN, often just called a "neural network" (NN is a Mathematical model or Computational model based on Biological neural Some artificial intelligence research seeks to replicate brain function—although not necessarily brain mechanisms—but as yet has been met with limited success.

Creating algorithms to mimic a biological brain is very difficult because the brain is not a static arrangement of circuits, but a network of vastly interconnected neurons that are constantly changing their connectivity and sensitivity. In Mathematics, Computing, Linguistics and related subjects an algorithm is a sequence of finite instructions often used for Calculation More recent work in both neuroscience and artificial intelligence models the brain using the mathematical tools of chaos theory and dynamical systems. Mathematics is the body of Knowledge and Academic discipline that studies such concepts as Quantity, Structure, Space and In Mathematics, chaos theory describes the behavior of certain dynamical systems – that is systems whose state evolves with time – that may exhibit dynamics that The dynamical system concept is a mathematical Formalization for any fixed "rule" which describes the Time dependence of a point's position Current research has also focused on recreating the neural structure of the brain with the aim of producing human-like cognition and artificial intelligence.

As food

Like most other internal organs, the brain can serve as nourishment. For example, in the Southern United States canned pork brain in gravy can be purchased for consumption as food. The Southern United States &mdashcommonly referred to as the American South, Dixie, or simply the South &mdashconstitutes a large distinctive Pork' is the Culinary name for Meat from the domestic Pig ( Sus scrofa) often specifically the fresh meat but can be used as an all-inclusive Gravy is an English Sauce made often from the juices that run naturally from meat or vegetables during cooking This form of brain is often fried with scrambled eggs to produce the famous "Eggs n' Brains". Scrambled eggs is a dish made from beaten whites and yolks of eggs (usually Chicken) Eggs n' Brains is a breakfast meal consisting of pork brains (or from another mammal and Scrambled eggs. ^[11] The brain of animals also features in French cuisine such as in the dish tête de veau, or head of calf. French cuisine is a style of cooking derived from the nation of France. Although it sometimes consists only of the outer meat of the skull and jaw, the full meal includes the brain, tongue, and glands. The jaw is either of the two opposable structures forming or near the entrance to the Mouth. The tongue is the large bundle of Skeletal muscles on the floor of the Mouth that manipulates Food for chewing and swallowing (deglutition A gland is an organ in an animal's body that synthesizes a substance for release such as Hormones or Breast milk, often into the Bloodstream Similar delicacies from around the world include Mexican tacos de sesos made with cattle brain as well as squirrel brain in the US South. The United Mexican States ( or commonly Mexico (ˈmɛksɪkoʊ () is a federal constitutional Republic in North America. A taco ( is a traditional Mexican dish composed of a Maize or wheat Tortilla folded or rolled around a filling A squirrel is one of the many small or medium-sized Rodents in the family Sciuridae. ^[12] The Anyang tribe of Cameroon practiced a tradition in which a new tribal chief would consume the brain of a hunted gorilla while another senior member of the tribe would eat the heart. The Republic of Cameroon is a unitary republic of central and western Africa. A traditional tribal chief is the leader of a Tribe, or the head of a tribal form of self-government Gorillas, the largest of the living Primates are ground-dwelling Herbivores that inhabit the Forests of Africa. A tribe, viewed historically or developmentally consists of a Social group existing before the development of or outside of States Many anthropologists use ^[13] Indonesian cuisine specialty in Minangkabau cuisine also served beef brain in a gravy coconut milk named gulai otak (beef brain curry). The Republic of Indonesia ( (Republik Indonesia is a Country in Southeast Asia. The Minangkabau ethnic group (also known as Minang or Padang) is indigenous to the highlands of West Sumatra, in Indonesia. Roasted or fried goat brain is eaten in south India and some parts of north India. Norwegian cuisine includes smalahove where a singed lamb's head, including the brain, tongue and eye, serves two people. Smalahove (also called Smalehovud or Skjelte) is a Norwegian traditional dish usually eaten around and before Christmas

Consuming the brain and other nerve tissue of animals is not without risks. The first problem is that the makeup of the brain is 60% fat due to large quantities of myelin (which itself is 70% fat) insulating the axons of neurons. Myelin is an electrically-insulating Dielectric Phospholipid layer that surrounds only the Axons of many Neurons It is an outgrowth ^[14] As an example, a 140 g can of "pork brains in milk gravy", a single serving, contains 3500 milligrams of cholesterol, 1170% of our recommended daily intake. Cholesterol is a Lipid found in the Cell membranes and transported in the Blood plasma of all Animals It is an essential component of mammalian ^[15]

Brain consumption can result in contracting fatal transmissible spongiform encephalopathies such as Variant Creutzfeldt-Jakob disease and other prion diseases in humans and mad cow disease in cattle. Transmissible spongiform encephalopathies' ( TSEs, also known as prion diseases) are a group of progressive conditions that affect the Brain and Creutzfeldt-Jakob disease ( CJD) is a very rare and incurable degenerative neurological disorder ( Brain Disease) that is ultimately A prion (ˈpriːɒn is thought to be an infectious agent that according to current scientific consensus is comprised entirely of a propagated, mis-folded Bovine Spongiform Encephalopathy ( BSE) commonly known as Mad-Cow Disease ( MCD) is a fatal Neurodegenerative disease in Cattle ^[16] Another prion disease called kuru has been traced to a funerary ritual among the Fore people of Papua New Guinea in which those close to the dead would eat the brain of the deceased to create a sense of immortality. Kuru is a disease which affects the Brain. It was endemic among the Fore tribe of Papua New Guinea and was universally fatal The Fore live in the Okapa District of the Eastern Highlands Province, Papua New Guinea. Papua New Guinea (or ˈpæpjuːə in Tok Pisin: Papua Niugini) officially the Independent State of Papua New Guinea, is a country in Oceania Immortality (or eternal life) is the concept of living in physical or spiritual form for an Infinite length of Time. ^[17] Some archaeological evidence suggests that the mourning rituals of European Neanderthals also involved the consumption of the brain. Archaeology, archeology, or archæology (from Greek grc ἀρχαιολογία archaiologia – grc ἀρχαῖος archaīos The Neanderthal (neɪˈændərtɑːl also with /niː-/ and /-θɔːl/ or Neandertal, is an extinct member of the Homo genus that is known from ^[18] Because of the risk of being infected by prions one should always wear gloves when handling brains.

It is also well-known in the hunting community that the brain of wild animals should not be consumed, due to the risk of chronic wasting disease. Chronic wasting disease (CWD is a Transmissible spongiform encephalopathy (TSE of Deer, Elk (wapiti and Moose. The brain is still useful to hunters, in that most animals have enough brain matter for use in the tanning of their own hides. Tanning is the process of converting Putrescible skin into non-putrescible Leather, usually with Tannin, an Acidic Chemical compound

Brain energy consumption

Although the brain represents only 2% of the body weight, it receives 15% of the cardiac output, 20% of total body oxygen consumption, and 25% of total body glucose utilization. Positron emission tomography ( PET) is a Nuclear medicine imaging technique which produces a three-dimensional image or map of functional processes in the The energy consumption for the brain to simply survive is 0. 1 calories per minute, while this value can be as high as 1. 5 calories per minute during crossword puzzle-solving. ^[19] The demands of the brain limit its size in many species. Molossid bats and the Vespertilionid Nyctalus spp. Molossidae, or Free-tailed bats, are a family of bats within the Chiroptera order Evening bats or perhaps more correctly Vesper bats (family Vespertilionidae) are the largest and best-known family of Bats They belong to the suborder The bat genus Nyctalus (Noctule bats are members of the family Vespertilionidae ( Vesper bats or sometimes Evening bats. have brains that have been reduced from the ancestral form to invest in wing-size for the sake of maneuverability. This contrasts with fruit bats, which require more advanced neural structures and do not pursue their prey. For other uses of the term "Flying fox" see Flying fox (disambiguation Megabats is the term used informally to refer to bats ^[20]

See also

• Traumatic brain injury

Further reading

• Junqueira, L. Traumatic brain injury (TBI also called intracranial injury, occurs when Physical trauma injures the Brain. C. , and J. Carneiro (2003). Basic Histology: Text and Atlas, Tenth Edition. Lange Medical Books McGraw-Hill. ISBN 0-07-121565-4.  
• Kinseher Richard, Geborgen in Liebe und Licht – Gemeinsame Ursache von Intuition, Déjà-vu-, Schutzengel-, und Nahtod-Erlebnissen, BoD, 2006, ISBN 3-8334-51963, German language: (A new theory: A LIVE-scan of the episodic memory, can be observed during near-death-experiences. The stored experiences are then judged by the topical intellect. )
• Sala, Sergio Della, editor. (1999). Mind myths: Exploring popular assumptions about the mind and brain. J. Wiley & Sons, New York. ISBN 0-471-98303-9.  
• Vander, A. , J. Sherman, D. Luciano (2001). Human Physiology: The Mechanisms of Body Function. McGraw Hill Higher Education. ISBN 0-07-118088-5.  
• Scaruffi, Piero. Piero Scaruffi (born in Trivero, Italy, in 1955 but based in California since 1983 is an Italian-American cultural historian The Nature of Consciousness. Omniware. ISBN 0-9765531-1-2.  

References

• Doidge, Norman (2007-03-15). The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science. Viking Adult.  

External links

• How Your Brain Works at HowStuffWorks
• The HOPES Brain Tutorial at hopes.stanford.edu
• Comparative Mammalian Brain Collection
• Brain Research News from ScienceDaily
• BrainInfo for Neuroanatomy
• Neuroscience for kids
• Everything you wanted to know about the brain – Provided by New Scientist. New Scientist is a weekly International science magazine and website covering recent developments in science and technology for a general English -speaking
• Fact sheets on brain injury - causes, effects and coping strategies
• Neuroscience wiki.
• BrainMaps.org, interactive high-resolution digital brain atlas based on scanned images of serial sections of both primate and non-primate brains
• Scientific American Magazine (September 2003 Issue) Ultimate Self-Improvement
• Brain Research and Information Network B.R.A.I.N.

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