Human Cognome Project
Encyclopedia
The Human Cognome Project is an effort to reverse engineer
the human brain
by studying both its structure and function, in order to fully understand mental processes, also known as cognition
. The project has many parallels to the Human Genome Project
. The human cognome project spans various scientific fields, including neuroscience
, cognitive science
, artificial intelligence
, and psychology
. A better understanding of the cognome can illuminate how the brain perceives and responds to the environment, thereby augmenting artificial intelligence technology. It also has many important implications for the study of disease progression by observing changes in cognition to localized damage. A map of the cognome will also increase mechanistic understandings of the brain. The Human Cognome Project has been endorsed by the National Science Foundation
.
.
is the study of structure of the brain and its distinctive structural features. These features are determined during development, when the cells are differentiating into their respective types that become the brain's well-known structure. Neurogenesis
usually populates the growing brain, however the process can continue into adulthood in the hippocampus
and subventricular zone
. Declining neurogenesis correlates with a decrease in cognitive performance. The understanding of morphology provides a connection to cognition, which aids in the study of the cognome.
migrate to specific regions of the brain using glia, specifically astroglia
. The structure of the brain centers on the neural and glial networks of which it is composed. The structure and interactions of these cells form the morphology of the brain. Early neuronal migrations are guided by radial glia (astrocytes
) that serve as scaffolds to deliver neurons to their proper layered location
. All neurons do not necessarily use the glial scaffold, only the cells that are layered. This includes cells in the cortex
, hippocampus
, cerebellum
, and spinal cord
. Radial glia are the first cells that can be distinguished from neuroepithelium and are the first cells to appear during neurogenesis
. In the adult brain, neural precursor cells in the ventricular zone and subventricular zone
migrate to their final destinations to maintain brain morphology.
and growth factors
. Inductive signals promoting both neuronal and glial development include retinoic acid
, fibroblast growth factor
, bone morphogenetic proteins
, and sonic hedgehog
. These factors regulate the Hox genes that promote development of the major brain regions, thus contributing to brain morphology. Hox genes have also been implicated in directing neural cell fate
Other transcription factors affect the basic structure of the neuron, giving it its characteristic polarized morphology. The polarized morphology refers to the differentiation between dendrites
present on the cell body and the axon
which propagates the action potential
away from the cell body. This polarization is essential to generating neuronal circuits in the developing brain. Factors that affect the development of the axon include molecular scaffolds, Rho-GTPases
and their regulators, protein kinases, kinesin
motors, and microtubule-associated proteins (MAPs). Extracellular signals promoting axon development include neurotrophin BDNF and the growth factor TGF-β that act through the protein kinases SAD-A/B and the Par complex. Other signals promote the development of dendritic spines. Semaphorin 3A
promotes the recruitment of dendritic spines to nascent neurons. Foxo
transcription factors have also been implicated as major regulators of the development of neuronal polarity. The human cognome project will help uncover the complex relationships between transcription factors and their implicated mechanisms in neuron development, location, and morphology.
, or oxygenation levels within brain regions. This oxygenation indicates activation of that region, which corresponds to different brain functions. This ability to observe brain function can lead to new understanding of brain organization. Despite its relative infancy, fMRI
has already been used to identify abnormal functional brain activity, study the modulatory effects of genetic risk factors for neurological disease on brain activation, predict the course of a disease, and reveal processes related to neuroplasticity
. As more advances in this technology are discovered, new applications for fMRI may be utilized which could provide insights into the function of fine-scale neural circuitry of the human brain in health and disease.
function contribute to the pathophysiological process of Alzheimer’s disease (AD) and related disorders. FMRI
may be useful in detecting these alterations in brain function long before clinical symptoms and specific neuropathology
develop. FMRI detects alterations in the pattern and degree of regional brain activation during task performance, which is particularly advantageous in the early discovery and differential diagnosis of disorders causing cognitive impairment. For instance, fMRI may be helpful in distinguishing a neurodegenerative
process from depression
in elderly individuals with cognitive symptoms. Studies using fMRI in this setting showed that hippocampal
activation during memory tasks was decreased in AD patients compared with controls and depressed patients. On the other hand, orbitofrontal and cingulated activation were greater in depressed patients than in AD subjects and controls. This ability to distinguish one cognitive process from another provides further insight into brain function that is particularly useful for the Human Cognome Project.
and fMRI
have helped uncover disease mechanisms and connectivity problems implicated in autism. Recent studies have delved into elucidating the structural connectivity issues implicated in autism
. Using MRI
and fMRI
researchers have found decelerated white matter
in the frontal
, temporal
, parietal
, and occipital
lobes. The impaired growth of white matter in these regions provides a link between the characteristic social impairments associated with autism. Connectivity in cortical networks was also explored using fMRI. White matter was observed to be depleted using fMRI in brain regions involved with social behaviors and language. The sources of demyelination
in these areas remains an ongoing research topic. The use of fMRI in the Human Cognome Project will help elucidate brain disease mechanisms and deficiencies in neurological disorders.
region of the brain. In a recent study, real time fMRI (rtfMRI
I) was used to track the blood oxygen level in this region by patients who were trained to exert control over their insular region. The insula has been linked to emotion recognition, an ability lacking in many schizophrenic patients. Previous studies have shown that the insula is depleted in schizophrenic patients. rtfMRI
can be used to enhance neural networks and support behavioral modifications in schizophrenic populations. Mapping neurological disorders using fMRI can help the Human Cognome project uncover the mechanisms underlying schizophrenia and other diseases.
by their nature. Dementia
, delirium
, Down syndrome
, and amnesia
are all cognitive disorders. Other diseases, such as schizophrenia
and progressive multifocal leukoencephalopathy
can have cognitive implications as they progress. The Human Cognome Project will provide an approach to studying and understanding these diseases, by first understanding the basic principles behind human cognition.
The brain is composed of numerous neural subtypes. These are determined by a neuron's position along the axis of the central nervous system
, age, genes, and surrounding neurons. Pluripotent
stem cells
have given researchers the opportunity to create multifarious populations of neurons in vitro. These neurons are genetically manipulated, which provides data to examine neurodevelopment in mammals. Genetic alterations cause changes in neuronal function, and therefore illuminate that gene's role in the cell. Stem cells
that are induced into neurons found in the prosencephalon
become either cortical projection neurons
or ventral forebrain neurons. Cerebellar
neurons are found in the hindbrain
. Pluripotent stem cells are also induced to become neurons in the mesencephalon and spinal cord
. The neuron is the basic structure of the brain, and the discovery of specific neuronal functions in each of these main sections of the brain is a key to understanding the cognome..
: verbal comprehension (VCI), perceptual organization (POI), working memory (WMI), and processing speed (PSI). Significant relationships were found in researches between brain deficits and lesion regions. Lesions in left inferior frontal cortex impair performance in verbal comprehension (VCI), left frontal and parietal cortex in working memory (WMI), and right parietal cortex in perceptual organization (POI). Deficit in processing speed (PSI) was not correlated with lesions within a single location, but across both hemispheres. The correlation between dysfunctional brain areas and brain deficits make brain mapping a potentially very powerful diagnostic tool.
Reverse engineering
Reverse engineering is the process of discovering the technological principles of a device, object, or system through analysis of its structure, function, and operation...
the human brain
Human brain
The human brain has the same general structure as the brains of other mammals, but is over three times larger than the brain of a typical mammal with an equivalent body size. Estimates for the number of neurons in the human brain range from 80 to 120 billion...
by studying both its structure and function, in order to fully understand mental processes, also known as cognition
Cognition
In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...
. The project has many parallels to the Human Genome Project
Human Genome Project
The Human Genome Project is an international scientific research project with a primary goal of determining the sequence of chemical base pairs which make up DNA, and of identifying and mapping the approximately 20,000–25,000 genes of the human genome from both a physical and functional...
. The human cognome project spans various scientific fields, including neuroscience
Neuroscience
Neuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...
, cognitive science
Cognitive science
Cognitive science is the interdisciplinary scientific study of mind and its processes. It examines what cognition is, what it does and how it works. It includes research on how information is processed , represented, and transformed in behaviour, nervous system or machine...
, artificial intelligence
Artificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
, and psychology
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
. A better understanding of the cognome can illuminate how the brain perceives and responds to the environment, thereby augmenting artificial intelligence technology. It also has many important implications for the study of disease progression by observing changes in cognition to localized damage. A map of the cognome will also increase mechanistic understandings of the brain. The Human Cognome Project has been endorsed by the National Science Foundation
National Science Foundation
The National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...
.
.
Background Information
Brain morphologyMorphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
is the study of structure of the brain and its distinctive structural features. These features are determined during development, when the cells are differentiating into their respective types that become the brain's well-known structure. Neurogenesis
Neurogenesis
Neurogenesis is the process by which neurons are generated from neural stem and progenitor cells. Most active during pre-natal development, neurogenesis is responsible for populating the growing brain with neurons. Recently neurogenesis was shown to continue in several small parts of the brain of...
usually populates the growing brain, however the process can continue into adulthood in the hippocampus
Hippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...
and subventricular zone
Subventricular zone
The subventricular zone is a paired brain structure situated throughout the lateral walls of the lateral ventricles. It has been associated with having four distinct layers of variable thickness and cell density, as well as cellular composition....
. Declining neurogenesis correlates with a decrease in cognitive performance. The understanding of morphology provides a connection to cognition, which aids in the study of the cognome.
Glial monorail
NeuronsNeuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
migrate to specific regions of the brain using glia, specifically astroglia
Astrocyte
Astrocytes , also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord...
. The structure of the brain centers on the neural and glial networks of which it is composed. The structure and interactions of these cells form the morphology of the brain. Early neuronal migrations are guided by radial glia (astrocytes
Astrocyte
Astrocytes , also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord...
) that serve as scaffolds to deliver neurons to their proper layered location
. All neurons do not necessarily use the glial scaffold, only the cells that are layered. This includes cells in the cortex
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
, hippocampus
Hippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...
, cerebellum
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
, and spinal cord
Spinal cord
The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...
. Radial glia are the first cells that can be distinguished from neuroepithelium and are the first cells to appear during neurogenesis
Neurogenesis
Neurogenesis is the process by which neurons are generated from neural stem and progenitor cells. Most active during pre-natal development, neurogenesis is responsible for populating the growing brain with neurons. Recently neurogenesis was shown to continue in several small parts of the brain of...
. In the adult brain, neural precursor cells in the ventricular zone and subventricular zone
Subventricular zone
The subventricular zone is a paired brain structure situated throughout the lateral walls of the lateral ventricles. It has been associated with having four distinct layers of variable thickness and cell density, as well as cellular composition....
migrate to their final destinations to maintain brain morphology.
Inductive factors
The early morphology of the brain is dictated by transcriptionTranscription factor
In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow of genetic information from DNA to mRNA...
and growth factors
Growth factor
A growth factor is a naturally occurring substance capable of stimulating cellular growth, proliferation and cellular differentiation. Usually it is a protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes....
. Inductive signals promoting both neuronal and glial development include retinoic acid
Retinoic acid
Retinoic acid is a metabolite of vitamin A that mediates the functions of vitamin A required for growth and development. Retinoic acid is required in chordate animals which includes all higher animals from fishes to humans...
, fibroblast growth factor
Fibroblast growth factor
Fibroblast growth factors, or FGFs, are a family of growth factors involved in angiogenesis, wound healing, and embryonic development. The FGFs are heparin-binding proteins and interactions with cell-surface associated heparan sulfate proteoglycans have been shown to be essential for FGF signal...
, bone morphogenetic proteins
Bone morphogenetic protein
Bone morphogenetic proteins are a group of growth factors also known as cytokines and as metabologens . Originally discovered by their ability to induce the formation of bone and cartilage, BMPs are now considered to constitute a group of pivotal morphogenetic signals, orchestrating tissue...
, and sonic hedgehog
Sonic hedgehog
Sonic hedgehog homolog is one of three proteins in the mammalian signaling pathway family called hedgehog, the others being desert hedgehog and Indian hedgehog . SHH is the best studied ligand of the hedgehog signaling pathway. It plays a key role in regulating vertebrate organogenesis, such as...
. These factors regulate the Hox genes that promote development of the major brain regions, thus contributing to brain morphology. Hox genes have also been implicated in directing neural cell fate
Other transcription factors affect the basic structure of the neuron, giving it its characteristic polarized morphology. The polarized morphology refers to the differentiation between dendrites
Dendrite
Dendrites are the branched projections of a neuron that act to conduct the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project...
present on the cell body and the axon
Axon
An axon is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma....
which propagates the action potential
Action potential
In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and...
away from the cell body. This polarization is essential to generating neuronal circuits in the developing brain. Factors that affect the development of the axon include molecular scaffolds, Rho-GTPases
Rho family of GTPases
The Rho family of GTPases is a family of small signaling G protein , and is a subfamily of the Ras superfamily. The members of the Rho GTPase family have been shown to regulate many aspects of intracellular actin dynamics, and are found in all eukaryotic organisms including yeasts and some plants...
and their regulators, protein kinases, kinesin
Kinesin
A kinesin is a protein belonging to a class of motor proteins found in eukaryotic cells. Kinesins move along microtubule filaments, and are powered by the hydrolysis of ATP . The active movement of kinesins supports several cellular functions including mitosis, meiosis and transport of cellular...
motors, and microtubule-associated proteins (MAPs). Extracellular signals promoting axon development include neurotrophin BDNF and the growth factor TGF-β that act through the protein kinases SAD-A/B and the Par complex. Other signals promote the development of dendritic spines. Semaphorin 3A
SEMA3A
Semaphorin-3A is a protein that in humans is encoded by the SEMA3A gene.This gene is a member of the semaphorin family and encodes a protein with an Ig-like C2-type domain, a PSI domain and a Sema domain...
promotes the recruitment of dendritic spines to nascent neurons. Foxo
FOX proteins
FOX proteins are a family of transcription factors that play important roles in regulating the expression of genes involved in cell growth, proliferation, differentiation, and longevity...
transcription factors have also been implicated as major regulators of the development of neuronal polarity. The human cognome project will help uncover the complex relationships between transcription factors and their implicated mechanisms in neuron development, location, and morphology.
Brain mapping
Functional MRI (fMRI) has been utilized in the mapping of different functional regions of the human cortex by recording changes in brain hemodynamicsHemodynamics
Hemodynamics, meaning literally "blood movement" is the study of blood flow or the circulation.All animal cells require oxygen for the conversion of carbohydrates, fats and proteins into carbon dioxide , water and energy in a process known as aerobic respiration...
, or oxygenation levels within brain regions. This oxygenation indicates activation of that region, which corresponds to different brain functions. This ability to observe brain function can lead to new understanding of brain organization. Despite its relative infancy, fMRI
Functional magnetic resonance imaging
Functional magnetic resonance imaging or functional MRI is a type of specialized MRI scan used to measure the hemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuroimaging...
has already been used to identify abnormal functional brain activity, study the modulatory effects of genetic risk factors for neurological disease on brain activation, predict the course of a disease, and reveal processes related to neuroplasticity
Neuroplasticity
Neuroplasticity is a non-specific neuroscience term referring to the ability of the brain and nervous system in all species to change structurally and functionally as a result of input from the environment. Plasticity occurs on a variety of levels, ranging from cellular changes involved in...
. As more advances in this technology are discovered, new applications for fMRI may be utilized which could provide insights into the function of fine-scale neural circuitry of the human brain in health and disease.
fMRI and early differential diagnosis
There is a growing body of evidence that suggests alterations in synapticSynapse
In the nervous system, a synapse is a structure that permits a neuron to pass an electrical or chemical signal to another cell...
function contribute to the pathophysiological process of Alzheimer’s disease (AD) and related disorders. FMRI
Functional magnetic resonance imaging
Functional magnetic resonance imaging or functional MRI is a type of specialized MRI scan used to measure the hemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuroimaging...
may be useful in detecting these alterations in brain function long before clinical symptoms and specific neuropathology
Neuropathology
Neuropathology is the study of disease of nervous system tissue, usually in the form of either small surgical biopsies or whole autopsy brains. Neuropathology is a subspecialty of anatomic pathology, neurology, and neurosurgery...
develop. FMRI detects alterations in the pattern and degree of regional brain activation during task performance, which is particularly advantageous in the early discovery and differential diagnosis of disorders causing cognitive impairment. For instance, fMRI may be helpful in distinguishing a neurodegenerative
Neurodegeneration
Neurodegeneration is the umbrella term for the progressive loss of structure or function of neurons, including death of neurons. Many neurodegenerative diseases including Parkinson’s, Alzheimer’s, and Huntington’s occur as a result of neurodegenerative processes. As research progresses, many...
process from depression
Depression (differential diagnoses)
Depression, one of the most commonly diagnosed psychiatric disorders, is being diagnosed in increasing numbers in various segments of the population worldwide. Depression in the United States alone affects 17.6 million Americans each year or 1 in 6 people. Depressed patients are at increased risk...
in elderly individuals with cognitive symptoms. Studies using fMRI in this setting showed that hippocampal
Hippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...
activation during memory tasks was decreased in AD patients compared with controls and depressed patients. On the other hand, orbitofrontal and cingulated activation were greater in depressed patients than in AD subjects and controls. This ability to distinguish one cognitive process from another provides further insight into brain function that is particularly useful for the Human Cognome Project.
MRI and autism
The use of brain mapping and MRI have helped shed light on previously elusive neurological disorders. Analyzing the autistic brain using MRIMagnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
and fMRI
Functional magnetic resonance imaging
Functional magnetic resonance imaging or functional MRI is a type of specialized MRI scan used to measure the hemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuroimaging...
have helped uncover disease mechanisms and connectivity problems implicated in autism. Recent studies have delved into elucidating the structural connectivity issues implicated in autism
Autism
Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...
. Using MRI
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
and fMRI
Functional magnetic resonance imaging
Functional magnetic resonance imaging or functional MRI is a type of specialized MRI scan used to measure the hemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuroimaging...
researchers have found decelerated white matter
White matter
White matter is one of the two components of the central nervous system and consists mostly of myelinated axons. White matter tissue of the freshly cut brain appears pinkish white to the naked eye because myelin is composed largely of lipid tissue veined with capillaries. Its white color is due to...
in the frontal
Frontal lobe
The frontal lobe is an area in the brain of humans and other mammals, located at the front of each cerebral hemisphere and positioned anterior to the parietal lobe and superior and anterior to the temporal lobes...
, temporal
Temporal lobe
The temporal lobe is a region of the cerebral cortex that is located beneath the Sylvian fissure on both cerebral hemispheres of the mammalian brain....
, parietal
Parietal lobe
The parietal lobe is a part of the Brain positioned above the occipital lobe and behind the frontal lobe.The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the...
, and occipital
Occipital lobe
The occipital lobe is the visual processing center of the mammalian brain containing most of the anatomical region of the visual cortex. The primary visual cortex is Brodmann area 17, commonly called V1...
lobes. The impaired growth of white matter in these regions provides a link between the characteristic social impairments associated with autism. Connectivity in cortical networks was also explored using fMRI. White matter was observed to be depleted using fMRI in brain regions involved with social behaviors and language. The sources of demyelination
Myelin
Myelin is a dielectric material that forms a layer, the myelin sheath, usually around only the axon of a neuron. It is essential for the proper functioning of the nervous system. Myelin is an outgrowth of a type of glial cell. The production of the myelin sheath is called myelination...
in these areas remains an ongoing research topic. The use of fMRI in the Human Cognome Project will help elucidate brain disease mechanisms and deficiencies in neurological disorders.
MRI and schizophrenia
Schizophrenia is linked to dysfunction in the insular cortexInsular cortex
In each hemisphere of the mammalian brain the insular cortex is a portion of the cerebral cortex folded deep within the lateral sulcus between the temporal lobe and the frontal lobe. The cortical area overlying it towards the lateral surface of the brain is the operculum...
region of the brain. In a recent study, real time fMRI (rtfMRI
Functional magnetic resonance imaging
Functional magnetic resonance imaging or functional MRI is a type of specialized MRI scan used to measure the hemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuroimaging...
I) was used to track the blood oxygen level in this region by patients who were trained to exert control over their insular region. The insula has been linked to emotion recognition, an ability lacking in many schizophrenic patients. Previous studies have shown that the insula is depleted in schizophrenic patients. rtfMRI
Functional magnetic resonance imaging
Functional magnetic resonance imaging or functional MRI is a type of specialized MRI scan used to measure the hemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuroimaging...
can be used to enhance neural networks and support behavioral modifications in schizophrenic populations. Mapping neurological disorders using fMRI can help the Human Cognome project uncover the mechanisms underlying schizophrenia and other diseases.
Cognitive disorders
Cognitive disorders are those that disrupt normal human thought processesCognition
In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...
by their nature. Dementia
Dementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...
, delirium
Delirium
Delirium or acute confusional state is a common and severe neuropsychiatric syndrome with core features of acute onset and fluctuating course, attentional deficits and generalized severe disorganization of behavior...
, Down syndrome
Down syndrome
Down syndrome, or Down's syndrome, trisomy 21, is a chromosomal condition caused by the presence of all or part of an extra 21st chromosome. It is named after John Langdon Down, the British physician who described the syndrome in 1866. The condition was clinically described earlier in the 19th...
, and amnesia
Amnesia
Amnesia is a condition in which one's memory is lost. The causes of amnesia have traditionally been divided into categories. Memory appears to be stored in several parts of the limbic system of the brain, and any condition that interferes with the function of this system can cause amnesia...
are all cognitive disorders. Other diseases, such as schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
and progressive multifocal leukoencephalopathy
Progressive multifocal leukoencephalopathy
Progressive multifocal leukoencephalopathy , also known as progressive multifocal leukoencephalitis, is a rare and usually fatal viral disease that is characterized by progressive damage or inflammation of the white matter of the brain at multiple locations .It occurs almost exclusively in...
can have cognitive implications as they progress. The Human Cognome Project will provide an approach to studying and understanding these diseases, by first understanding the basic principles behind human cognition.
Pluripotent stem cells
Neuraxis
Neuraxis is a Canadian technical/melodic death metal band. It was formed in Montreal in 1994 by Steven Henry, Yan Thiel and Felipe Angel Quinzanos...
, age, genes, and surrounding neurons. Pluripotent
Cell potency
The potency of a cell specifies its differentiation potential, or potential to differentiate into different cell types.-Totipotency:Totipotency is the ability of a single cell to divide and produce all the differentiated cells in an organism, including extraembryonic tissues.Totipotent cells...
stem cells
Stem cell
This article is about the cell type. For the medical therapy, see Stem Cell TreatmentsStem cells are biological cells found in all multicellular organisms, that can divide and differentiate into diverse specialized cell types and can self-renew to produce more stem cells...
have given researchers the opportunity to create multifarious populations of neurons in vitro. These neurons are genetically manipulated, which provides data to examine neurodevelopment in mammals. Genetic alterations cause changes in neuronal function, and therefore illuminate that gene's role in the cell. Stem cells
Stem cell
This article is about the cell type. For the medical therapy, see Stem Cell TreatmentsStem cells are biological cells found in all multicellular organisms, that can divide and differentiate into diverse specialized cell types and can self-renew to produce more stem cells...
that are induced into neurons found in the prosencephalon
Prosencephalon
In the anatomy of the brain of vertebrates, the prosencephalon is the rostral-most portion of the brain. The prosencephalon, the mesencephalon , and rhombencephalon are the three primary portions of the brain during early development of the central nervous system...
become either cortical projection neurons
Pyramidal cell
Pyramidal neurons are a type of neuron found in areas of the brain including cerebral cortex, the hippocampus, and in the amygdala. Pyramidal neurons are the primary excitation units of the mammalian prefrontal cortex and the corticospinal tract. Pyramidal neurons were first discovered and...
or ventral forebrain neurons. Cerebellar
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
neurons are found in the hindbrain
Rhombencephalon
The rhombencephalon is a developmental categorization of portions of the central nervous system in vertebrates.The rhombencephalon can be subdivided in a variable number of transversal swellings called rhombomeres...
. Pluripotent stem cells are also induced to become neurons in the mesencephalon and spinal cord
Spinal cord
The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...
. The neuron is the basic structure of the brain, and the discovery of specific neuronal functions in each of these main sections of the brain is a key to understanding the cognome..
Diagnostics
There are four indices in the Wechsler Adult Intelligence Scale (WAIS)Wechsler Adult Intelligence Scale
The Wechsler Adult Intelligence Scale intelligence quotient tests are the primary clinical instruments used to measure adult and adolescent intelligence. The original WAIS was published in February 1955 by David Wechsler, as a revision of the Wechsler-Bellevue Intelligence Scale...
: verbal comprehension (VCI), perceptual organization (POI), working memory (WMI), and processing speed (PSI). Significant relationships were found in researches between brain deficits and lesion regions. Lesions in left inferior frontal cortex impair performance in verbal comprehension (VCI), left frontal and parietal cortex in working memory (WMI), and right parietal cortex in perceptual organization (POI). Deficit in processing speed (PSI) was not correlated with lesions within a single location, but across both hemispheres. The correlation between dysfunctional brain areas and brain deficits make brain mapping a potentially very powerful diagnostic tool.
External links
- The Redwood Center for Theoretical Neuroscience (founded by Jeff Hawkins)
- This Is Your Brain Online "Paul Allen’s $100 million for mapping the brain will produce the largest trove of biological data ever." Allen Brain Atlas
- BrainMaps.org High-Resolution Brain Maps and Interactive Brain Atlases
- The Brain Mind Institute in Switzerland, affiliated with the University of Geneva, the University of Lausanne, and others.