Neuroscience

The Human Nervous System

Neuroscience is an interdisciplinary field in science that is organized around the study of the nervous system. As such, the field encompasses the scientific study of the structure, function, and development of nervous systems, normal and abnormal variants, ranging from the simple systems of such invertebrates as platyhelminthes and nematodes to the complex systems of vertebrates like human beings, as well as including treatment of disorders and diseases of the nervous system. Among the components that are studied are the brain, dorsal and ventral nerve cords, spinal cord, nerves, muscles, neurons (nerve cells), central nervous system, peripheral nervous system, neurotransmitters, sense organs and senses (such as taste and touch), and so forth. As an interdisciplinary field, interconnections are made with such disciplines as biology, chemistry, physics, computer science, mathematics, engineering, linguistics, medicine, and psychology.

There are many sub-disciplines within the field of neuroscience, including such major branches as neurology, affective neuroscience, molecular and cellular neuroscience, evolutionary neuroscience, cognitive and behavioral neuroscience, computational neuroscience, neuropsychology, and so forth. The term neurology was once used more generally for the study of the nervous system but now refers to the medical specialty dealing with disorders and diseases of the nervous system, including Alzheimer's disease, seizures, paralysis, coma, Parkinson's disease, hearing loss, meningitis, encephalitis, migraine, stroke, Lou Gehrig's disease, multiple sclerosis, and the nature of pain.

Overview

Drawing by Santiago Ramón y Cajal (1899) of neurons in the pigeon cerebellum

The nervous system is the network of specialized cells, tissues, and organs in a multicellular animal that coordinates the body's interaction with the environment, including sensing internal and external stimuli, monitoring the organs, coordinating the activity of muscles, initiating actions, and regulating behavior. All parts of the nervous system are made of nervous tissue, which conducts electrical impulses. Nervous tissue is prominent in almost every major animal phylum, including platyhelminthes and nematodes. However, it is mot complex in vertebrate animals.

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, medicine and allied disciplines, philosophy, physics, and psychology. It also exerts influence on other fields, such as neuroeducation and neurolaw. The term neurobiology is usually used interchangeably with the term neuroscience, although the former refers specifically to the biology of the nervous system, whereas the latter refers to the entire science of the nervous system.

Components that are part of this study include the brain, spine, nerve cord, nerves, muscles, central nervous system and the peripheral nervous system or vertebrates, and so forth. a medical specialty dealing with disorders of the nervous system. Neurologists are individuals in the profession, who strive to understand the nervouse system, such as how vision and hearing work, nerve disorders, embryological develoment, how the brain processes information, etc.

Neurology includes "understanding the biochemcial and genetic basis for various neurological disorders" such as Alzheimer's disease, seizurs, parkinsonism, paralysis, coma, and the nature of pain, the sense organs, and viral diseases of hte nerous system such as meingitis, encephalitis, herpes simple virus 2. amnesia, Parkinson's disease; paraplegia, hearing loss,

the sense organs, and viral diseases of hte nerous system such as meingitis, encephalitis, herpes simple virus 2. amnesia, Parkinson's disease; paraplegia, hearing loss,

spinal

It also involves the medical speciality dealing with disorders of the nervous system, including such neurological disorders as

Neurology is

The term comes from the (from Greek νεῦρον, neuron, "nerve" + the suffix -λογία, '-logia', "study of").

The scope of neuroscience has broadened to include different approaches used to study the molecular, cellular, developmental, structural, functional, evolutionary, computational, and medical aspects of the nervous system. The techniques used by neuroscientists have also expanded enormously, from molecular and cellular studies of individual nerve cells to imaging of sensory and motor tasks in the brain. Recent theoretical advances in neuroscience have also been aided by the study of neural networks.

Neurology is

Neuroscientists are those individuals specialized in this field, including physicians trained to diagnose and treat neurological disorders. Neurosurgery is a corresponding surgical specialty.

The scope of neuroscience has broadened to include different approaches used to study the molecular, cellular, developmental, structural, functional, evolutionary, computational, and medical aspects of the nervous system. The techniques used by neuroscientists have also expanded enormously, from molecular and cellular studies of individual nerve cells to imaging of sensory and motor tasks in the brain. Recent theoretical advances in neuroscience have also been aided by the study of neural networks.

Because of the increasing number of scientists who study the nervous system, several prominent neuroscience organizations have been formed to provide a forum to all neuroscientists and educators. For example, the International Brain Research Organization was founded in 1960, the International Society for Neurochemistry in 1963, the European Brain and Behaviour Society in 1968, and the Society for Neuroscience in 1969.

History

Illustration from Gray's Anatomy (1918) of a lateral view of the human brain, featuring the hippocampus among other neuroanatomical features

The study of the nervous system dates back to ancient Egypt. Evidence of trepanation, the surgical practice of either drilling or scraping a hole into the skull with the purpose of curing headaches or mental disorders or relieving cranial pressure, being performed on patients dates back to Neolithic times and has been found in various cultures throughout the world. Manuscripts dating back to 1700 BC indicated that the Egyptians had some knowledge about symptoms of brain damage.

Early views on the function of the brain regarded it to be a "cranial stuffing" of sorts. In Egypt, from the late Middle Kingdom onwards, the brain was regularly removed in preparation for mummification. It was believed at the time that the heart was the seat of intelligence. According to Herodotus, the first step of mummification was to "take a crooked piece of iron, and with it draw out the brain through the nostrils, thus getting rid of a portion, while the skull is cleared of the rest by rinsing with drugs."

The view that the heart was the source of consciousness was not challenged until the time of the Greek physician Hippocrates. He believed that the brain was not only involved with sensation—since most specialized organs (e.g., eyes, ears, tongue) are located in the head near the brain—but was also the seat of intelligence. Plato also speculated that the brain was the seat of the rational part of the soul. Aristotle, however, believed the heart was the center of intelligence and that the brain regulated the amount of heat from the heart. This view was generally accepted until the Roman physician Galen, a follower of Hippocrates and physician to Roman gladiators, observed that his patients lost their mental faculties when they had sustained damage to their brains.

Abulcasis, Averroes, Avenzoar, and Maimonides, active in the Medieval Muslim world, described a number of medical problems related to the brain. In Renaissance Europe, Vesalius (1514–1564) and René Descartes (1596–1650) also made several contributions to neuroscience.

The Golgi stain first allowed for the visualization of individual neurons.

Studies of the brain became more sophisticated after the invention of the microscope and the development of a staining procedure by Camillo Golgi during the late 1890s. The procedure used a silver chromate salt to reveal the intricate structures of individual neurons. His technique was used by Santiago Ramón y Cajal and led to the formation of the neuron doctrine, the hypothesis that the functional unit of the brain is the neuron.^{[citation needed]} Golgi and Ramón y Cajal shared the Nobel Prize in Physiology or Medicine in 1906 for their extensive observations, descriptions, and categorizations of neurons throughout the brain. While Luigi Galvani's pioneering work in the late 1700s had set the stage for studying the electrical excitability of muscles and neurons, it was in the late 19th century that Emil du Bois-Reymond, Johannes Peter Müller, and Hermann von Helmholtz demonstrated that the electrical excitation of neurons predictably affected the electrical states of adjacent neurons.^{[citation needed]}

In parallel with this research, work with brain-damaged patients by Paul Broca suggested that certain regions of the brain were responsible for certain functions. At the time, Broca's findings were seen as a confirmation of Franz Joseph Gall's theory that language was localized and that certain psychological functions were localized in specific areas of the cerebral cortex. The localization of function hypothesis was supported by observations of epileptic patients conducted by John Hughlings Jackson, who correctly inferred the organization of the motor cortex by watching the progression of seizures through the body. Carl Wernicke further developed the theory of the specialization of specific brain structures in language comprehension and production. Modern research still uses the Brodmann cerebral cytoarchitectonic map (referring to study of cell structure) anatomical definitions from this era in continuing to show that distinct areas of the cortex are activated in the execution of specific tasks.

In 1952, Alan Lloyd Hodgkin and Andrew Huxley presented a mathematical model for transmission of electrical signals in neurons of the giant axon of a squid, action potentials, and how they are initiated and propagated, known as the Hodgkin-Huxley model. In 1961-2, Richard FitzHugh and J. Nagumo simplified Hodgkin-Huxley, in what is called the FitzHugh–Nagumo model. In 1962, Bernard Katz modeled neurotransmission across the space between neurons known as synapses. In 1981 Catherine Morris and Harold Lecar combined these models in the Morris-Lecar model. In 1984, J. L. Hindmarsh and R.M. Rose further modeled neurotransmission.

Beginning in 1966, Eric Kandel and collaborators examined biochemical changes in neurons associated with learning and memory storage.

Modern neuroscience

Human nervous system

The scientific study of the nervous system has increased significantly during the second half of the twentieth century, principally due to advances in molecular biology, electrophysiology, and computational neuroscience. This has allowed neuroscientists to study the nervous system in all its aspects: how it is structured, how it works, how it develops, how it malfunctions, and how it can be changed. For example, it has become possible to understand, in much detail, the complex processes occurring within a single neuron. Neurons are cells specialized for communication. They are able to communicate with neurons and other cell types through specialized junctions called synapses, at which electrical or electrochemical signals can be transmitted from one cell to another. Many neurons extrude long thin filaments of protoplasm called axons, which may extend to distant parts of the body and are capable of rapidly carrying electrical signals, influencing the activity of other neurons, muscles, or glands at their termination points. A nervous system emerges from the assemblage of neurons that are connected to each other.

In vertebrates, the nervous system can be split into two parts, the central nervous system (brain and spinal cord), and the peripheral nervous system. In many species — including all vertebrates — the nervous system is the most complex organ system in the body, with most of the complexity residing in the brain. The human brain alone contains around one hundred billion neurons and one hundred trillion synapses; it consists of thousands of distinguishable substructures, connected to each other in synaptic networks whose intricacies have only begun to be unraveled. The majority of the approximately 20–25,000 genes belonging to the human genome are expressed specifically in the brain. Due to the plasticity of the human brain, the structure of its synapses and their resulting functions change throughout life. Thus the challenge of making sense of all this complexity is formidable.

Molecular and cellular neuroscience

Photograph of a stained neuron in a chicken embryo

The study of the nervous system can be done at multiple levels, ranging from the molecular and cellular levels to the systems and cognitive levels. At the molecular level, the basic questions addressed in molecular neuroscience include the mechanisms by which neurons express and respond to molecular signals and how axons form complex connectivity patterns. At this level, tools from molecular biology and genetics are used to understand how neurons develop and how genetic changes affect biological functions. The morphology, molecular identity, and physiological characteristics of neurons and how they relate to different types of behavior are also of considerable interest.

The fundamental questions addressed in cellular neuroscience include the mechanisms of how neurons process signals physiologically and electrochemically. These questions include how signals are processed by neurites – thin extensions from a neuronal cell body, consisting of dendrites (specialized to receive synaptic inputs from other neurons) and axons (specialized to conduct nerve impulses called action potentials) – and somas (the cell bodies of the neurons containing the nucleus), and how neurotransmitters and electrical signals are used to process information in a neuron. Another major area of neuroscience is directed at investigations of the development of the nervous system. These questions include the patterning and regionalization of the nervous system, neural stem cells, differentiation of neurons and glia, neuronal migration, axonal and dendritic development, trophic interactions, and synapse formation.

Neural circuits and systems

At the systems level, the questions addressed in systems neuroscience include how neural circuits are formed and used anatomically and physiologically to produce functions such as reflexes, sensory integration, motor coordination, circadian rhythms, emotional responses, learning, and memory. In other words, they address how these neural circuits function and the mechanisms through which behaviors are generated. For example, systems level analysis addresses questions concerning specific sensory and motor modalities: how does vision work? How do songbirds learn new songs and bats localize with ultrasound? How does the somatosensory system process tactile information? The related fields of neuroethology and neuropsychology address the question of how neural substrates underlie specific animal and human behaviors. Neuroendocrinology and psychoneuroimmunology examine interactions between the nervous system and the endocrine and immune systems, respectively. Despite many advancements, the way networks of neurons produce complex cognitions and behaviors is still poorly understood.

Cognitive and behavioral neuroscience

At the cognitive level, cognitive neuroscience addresses the questions of how psychological functions are produced by neural circuitry. The emergence of powerful new measurement techniques such as neuroimaging (e.g., fMRI, PET, SPECT), electrophysiology, and human genetic analysis combined with sophisticated experimental techniques from cognitive psychology allows neuroscientists and psychologists to address abstract questions such as how human cognition and emotion are mapped to specific neural substrates.

Neuroscience is also allied with the social and behavioral sciences as well as nascent interdisciplinary fields such as neuroeconomics, decision theory, and social neuroscience to address complex questions about interactions of the brain with its environment.

Ultimately neuroscientists would like to understand every aspect of the nervous system, including how it works, how it develops, how it malfunctions, and how it can be altered or repaired. The specific topics that form the main foci of research change over time, driven by an ever-expanding base of knowledge and the availability of increasingly sophisticated technical methods. Over the long term, improvements in technology have been the primary drivers of progress. Developments in electron microscopy, computers, electronics, functional brain imaging, and most recently genetics and genomics, have all been major drivers of progress.

Translational research and medicine

Further information: Translational research

File:Parasagittal MRI of human head in patient with benign familial macrocephaly prior to brain injury (ANIMATED).gif

Parasagittal MRI of the head of a patient with benign familial macrocephaly

Neurology, psychiatry, neurosurgery, psychosurgery, anesthesiology, neuropathology, neuroradiology, clinical neurophysiology and addiction medicine are medical specialties that specifically address the diseases of the nervous system. These terms also refer to clinical disciplines involving diagnosis and treatment of these diseases. Neurology works with diseases of the central and peripheral nervous systems, such as amyotrophic lateral sclerosis (ALS) and stroke, and their medical treatment. Psychiatry focuses on affective, behavioral, cognitive, and perceptual disorders. Anesthesiology focuses on perception of pain, and pharmacologic alteration of consciousness. Neuropathology focuses upon the classification and underlying pathogenic mechanisms of central and peripheral nervous system and muscle diseases, with an emphasis on morphologic, microscopic, and chemically observable alterations. Neurosurgery and psychosurgery work primarily with surgical treatment of diseases of the central and peripheral nervous systems. The boundaries between these specialties have been blurring recently as they are all influenced by basic research in neuroscience. Brain imaging also enables objective, biological insights into mental illness, which can lead to faster diagnosis, more accurate prognosis, and help assess patient progress over time.

Integrative neuroscience makes connections across these specialized areas of focus.

Major branches

Modern neuroscience education and research activities can be very roughly categorized into the following major branches, based on the subject and scale of the system in examination as well as distinct experimental or curricular approaches. Individual neuroscientists, however, often work on questions that span several distinct subfields.

Branch	Description
Affective neuroscience	Affective neuroscience is the study of the neural mechanisms involved in emotion, typically through experimentation on animal models.
Behavioral neuroscience	Behavioral neuroscience (also known as biological psychology, biopsychology, or psychobiology) is the application of the principles of biology (viz., neurobiology) to the study of genetic, physiological, and developmental mechanisms of behavior in humans and non-human animals.
Cellular neuroscience	Cellular neuroscience is the study of neurons at a cellular level including morphology and physiological properties.
Clinical neuroscience	This consists of medical specialties such as neurology and psychiatry, as well as many allied health professions such as speech-language pathology. Neurology is the medical specialty that works with disorders of the nervous system. Psychiatry is the medical specialty that works with the disorders of the mind—which include various affective, behavioral, cognitive, and perceptual disorders. (Also see note below.)
Cognitive neuroscience	Cognitive neuroscience is the study of biological and neuropsychological substrates underlying cognition with a specific focus on the neural substrates of mental processes.
Computational neuroscience	Computational neuroscience is the study of brain function in terms of the information processing properties of the structures that make up the nervous system. Computational neuroscience can also refer to the use of computer simulations and theoretical models to study the function of the nervous system.
Cultural neuroscience	Cultural neuroscience is the study of how cultural values, practices and beliefs shape and are shaped by the mind, brain and genes across multiple timescales.
Developmental neuroscience	Developmental neuroscience studies the processes that generate, shape, and reshape the nervous system and seeks to describe the cellular basis of neural development to address underlying mechanisms.
Evolutionary neuroscience	Evolutionary neuroscience is an interdisciplinary scientific research field that studies the evolution of nervous systems.
Molecular neuroscience	Molecular neuroscience is a branch of neuroscience that examines the biology of the nervous system with molecular biology, molecular genetics, protein chemistry, and related methodologies.
Neuroengineering	Neuroengineering is a discipline within biomedical engineering that uses engineering techniques to understand, repair, replace, or enhance neural systems.
Neuroethology	Neuroethology is an interdisciplinary branch that studies the neural basis of natural animal behavior.
Neuroheuristics	Neuroheuristics (or Neuristics) is a transdisciplinary paradigm that studies the information processing effected by the brain as an outcome of nurture versus nature, at the crossing of top-down and bottom-up strategies.
Neuroimaging	Neuroimaging includes the use of various techniques to either directly or indirectly image the structure and function of the brain.
Neuroinformatics	Neuroinformatics is a discipline within bioinformatics that conducts the organization of neuroscience data and application of computational models and analytical tools.
Neurolinguistics	Neurolinguistics is the study of the neural mechanisms in the human brain that control the comprehension, production, and acquisition of language.
Neurophysiology	Neurophysiology is the study of the functioning of the nervous system, generally using physiological techniques that include measurement and stimulation with electrodes or optically with ion- or voltage-sensitive dyes or light-sensitive channels.
Neuropsychology	Neuropsychology is a discipline that resides under the umbrellas of both psychology and neuroscience, and is involved in activities in the arenas of both basic science and applied science. In psychology, it is most closely associated with biopsychology, clinical psychology, cognitive psychology, and developmental psychology. In neuroscience, it is most closely associated with the cognitive, behavioral, social, and affective neuroscience areas. In the applied and medical domain, it is related to neurology and psychiatry.
Paleoneurology	Paleoneurology is a field which combines techniques used in paleontology and archeology to study brain evolution, especially that of the human brain.
Social neuroscience	Social neuroscience is an interdisciplinary field devoted to understanding how biological systems implement social processes and behavior, and to using biological concepts and methods to inform and refine theories of social processes and behavior.
Systems neuroscience	Systems neuroscience is the study of the function of neural circuits and systems.

Neuroscience organizations

The largest professional neuroscience organization is the Society for Neuroscience (SFN), which is based in the United States but includes many members from other countries. Since its founding in 1969 the SFN has grown steadily: as of 2010 it recorded 40,290 members from 83 different countries. Annual meetings, held each year in a different American city, draw attendance from researchers, postdoctoral fellows, graduate students, and undergraduates, as well as educational institutions, funding agencies, publishers, and hundreds of businesses that supply products used in research.

Other major organizations devoted to neuroscience include the International Brain Research Organization (IBRO), which holds its meetings in a country from a different part of the world each year, and the Federation of European Neuroscience Societies (FENS), which holds a meeting in a different European city every two years. FENS comprises a set of 32 national-level organizations, including the British Neuroscience Association, the German Neuroscience Society (Neurowissenschaftliche Gesellschaft), and the French Société des Neurosciences. The Molecular and Cellular Cognition Society is an international neuroscience society with courses and meetings in North America, Europe and Asia, and with more than 5000 members world-wide.

In 2013, the BRAIN Initiative was announced in the US.

Public education and outreach

In addition to conducting traditional research in laboratory settings, neuroscientists have also been involved in the promotion of awareness and knowledge about the nervous system among the general public and government officials. Such promotions have been done by both individual neuroscientists and large organizations. For example, individual neuroscientists have promoted neuroscience education among young students by organizing the International Brain Bee (IBB), which is an academic competition for high school or secondary school students worldwide. In the United States, large organizations such as the Society for Neuroscience have promoted neuroscience education by developing a primer called Brain Facts, collaborating with public school teachers to develop Neuroscience Core Concepts for K-12 teachers and students, and cosponsoring a campaign with the Dana Foundation called Brain Awareness Week to increase public awareness about the progress and benefits of brain research.

Finally, neuroscientists have also collaborated with other education experts to study and refine educational techniques to optimize learning among students, an emerging field called educational neuroscience. Federal agencies in the United States, such as the National Institute of Health (NIH) and National Science Foundation (NSF), have also funded research that pertains to best practices in teaching and learning of neuroscience concepts.

See also

Neuroscience Portal

At Wikiversity, you can learn about:

Topic: Neuroscience

• List of neuroscience databases
• List of neuroscience topics
• List of neuroscientists
• List of topics related to brain mapping

Further reading

• Bear, M. F. and B. W. Connors, and M. A. Paradiso (2006). Neuroscience: Exploring the Brain, 3rd, Philadelphia: Lippincott. ISBN 0-7817-6003-8. 
• (2009) Encyclopedia of Neuroscience. Springer. ISBN 978-3-540-23735-8. 
• Kandel, ER and Schwartz JH, Jessell TM (2000). Principles of Neural Science, 4th, New York: McGraw-Hill. ISBN 0-8385-7701-6. 
• Squire, L. et al. (2003). Fundamental Neuroscience, 2nd edition. Academic Press; ISBN 0-12-660303-0
• Byrne and Roberts (2004). From Molecules to Networks. Academic Press; ISBN 0-12-148660-5
• Sanes, Reh, Harris (2005). Development of the Nervous System, 2nd edition. Academic Press; ISBN 0-12-618621-9
• Siegel et al. (2005). Basic Neurochemistry, 7th edition. Academic Press; ISBN 0-12-088397-X
• Rieke, F. et al. (1999). Spikes: Exploring the Neural Code. The MIT Press; Reprint edition ISBN 0-262-68108-0
• section.47 Neuroscience 2nd ed. Dale Purves, George J. Augustine, David Fitzpatrick, Lawrence C. Katz, Anthony-Samuel LaMantia, James O. McNamara, S. Mark Williams. Published by Sinauer Associates, Inc., 2001.
• section.18 Basic Neurochemistry: Molecular, Cellular, and Medical Aspects 6th ed. by George J. Siegel, Bernard W. Agranoff, R. Wayne Albers, Stephen K. Fisher, Michael D. Uhler, editors. Published by Lippincott, Williams & Wilkins, 1999.
• Andreasen, Nancy C. (March 4 2004). Brave New Brain: Conquering Mental Illness in the Era of the Genome. Oxford University Press. ISBN 978-0-19-514509-0. 
• Damasio, A. R. (1994). Descartes' Error: Emotion, Reason, and the Human Brain. New York, Avon Books. ISBN 0-399-13894-3 (Hardcover) ISBN 0-380-72647-5 (Paperback)
• Gardner, H. (1976). The Shattered Mind: The Person After Brain Damage. New York, Vintage Books, 1976 ISBN 0-394-71946-8
• Goldstein, K. (2000). The Organism. New York, Zone Books. ISBN 0-942299-96-5 (Hardcover) ISBN 0-942299-97-3 (Paperback)
• Lauwereyns, Jan (February 2010). The Anatomy of Bias: How Neural Circuits Weigh the Options. Cambridge, MA: The MIT Press. ISBN 0-262-12310-X. 
• Llinas R. (2001). I of the Vortex: From Neurons to Self MIT Press. ISBN 0-262-12233-2 (Hardcover) ISBN 0-262-62163-0 (Paperback)
• Luria, A. R. (1997). The Man with a Shattered World: The History of a Brain Wound. Cambridge, Massachusetts, Harvard University Press. ISBN 0-224-00792-0 (Hardcover) ISBN 0-674-54625-3 (Paperback)
• Luria, A. R. (1998). The Mind of a Mnemonist: A Little Book About A Vast Memory. New York, Basic Books, Inc. ISBN 0-674-57622-5
• Medina, J. (2008). Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School. Seattle, Pear Press. ISBN 0-9797777-0-4 (Hardcover with DVD)
• Pinker, S. (1999). How the Mind Works. W. W. Norton & Company. ISBN 0-393-31848-6
• Pinker, S. (2002). The Blank Slate: The Modern Denial of Human Nature. Viking Adult. ISBN 0-670-03151-8
• Robinson, D. L. (2009). Brain, Mind and Behaviour: A New Perspective on Human Nature, 2nd, Dundalk, Ireland: Pontoon Publications. ISBN 978-0-9561812-0-6. 
• Ramachandran, V. S. (1998). Phantoms in the Brain. New York, New York Harper Collins. ISBN 0-688-15247-3 (Paperback)
• Rose, S. (2006). 21st Century Brain: Explaining, Mending & Manipulating the Mind ISBN 0-09-942977-2 (Paperback)
• Sacks, O. The Man Who Mistook His Wife for a Hat. Summit Books ISBN 0-671-55471-9 (Hardcover) ISBN 0-06-097079-0 (Paperback)
• Sacks, O. (1990). Awakenings. New York, Vintage Books. (See also Oliver Sacks) ISBN 0-671-64834-9 (Hardcover) ISBN 0-06-097368-4 (Paperback)
• Sternberg, E. (2007) Are You a Machine? The Brain, the Mind and What it Means to be Human. Amherst, NY: Prometheus Books.
• Churchland, P. S. (2011) Braintrust: What Neuroscience Tells Us about Morality. Princeton University Press. ISBN 0-691-13703-X

is a medical specialty dealing with disorders of the nervous system. Neurologists can opine on the subject matter of a psychiatrist. To be specific, neurology deals with the diagnosis and treatment of all categories of disease involving the central and peripheral nervous system; or equivalently, the autonomic nervous systems and the somatic nervous systems, including their coverings, blood vessels, and all effector tissue, such as muscle.

A neurologist is a physician specializing in neurology and trained to investigate, or diagnose and treat neurological disorders. Neurologists may also be involved in clinical research, and clinical trials, as well as basic research and translational research. While neurology is a non-surgical specialty, its corresponding surgical specialty is neurosurgery. Neurology, being a branch of medicine, differs from neuroscience, which is the scientific study of the nervous system in all of its aspects.

Field of work

A large number of neurological disorders have been described. These can affect the central nervous system (brain and spinal cord), the peripheral nervous system, or the autonomic nervous system.

Qualifications

Jean-Martin Charcot is considered one of the fathers of neurology.

In the United States and Canada, neurologists are physicians who have completed postgraduate training in neurology after graduation from medical school. Neurologists complete, on average, at least 10–13 years of college education and clinical training. This training includes obtaining a four-year undergraduate degree, a medical degree (D.O. or M.D.), which comprises an additional four years of study, and then completing a three or four-year residency in neurology. The four-year residency consists of one year of internal medicine training followed by three years of training in neurology. Some neurologists complete a one or two-year fellowship after completing a neurology residency. Sub-specialties include: brain injury medicine, clinical neurophysiology, epilepsy, hospice and palliative medicine, neurodevelopmental disabilities, neuromuscular medicine, pain medicine and sleep medicine, and vascular medicine.

Many neurologists also have additional subspecialty training (fellowships) after completing their residency in one area of neurology such as stroke or vascular neurology, interventional neurology, neurosonology, epilepsy, neuromuscular, neurorehabilitation, behavioral neurology, sleep medicine, pain management, neuro immunology, clinical neurophysiology, or movement disorders.

In Germany, a compulsory year of psychiatry must be done to complete a residency of neurology.

In the United Kingdom and Ireland, neurology is a subspecialty of general (internal) medicine. After five to nine years of medical school and a year as a pre-registration house officer (or two years on the Foundation Programme), a neurologist must pass the examination for Membership of the Royal College of Physicians (or the Irish equivalent) before completing two years of core medical training and then entering specialist training in neurology. A generation ago, some neurologists would have also spent a couple of years working in psychiatric units and obtain a Diploma in Psychological Medicine. However, this requirement has become uncommon, and, now that a basic psychiatric qualification takes three years to obtain, the requirement is no longer practical. A period of research is essential, and obtaining a higher degree aids career progression: Many found it was eased after an attachment to the Institute of Neurology at Queen Square in London. Some neurologists enter the field of rehabilitation medicine (known as physiatry in the US) to specialise in neurological rehabilitation, which may include stroke medicine as well as brain injuries.

Physical examination

During a neurological examination, the neurologist reviews the patient's health history with special attention to the current condition. The patient then takes a neurological exam. Typically, the exam tests mental status, function of the cranial nerves (including vision), strength, coordination, reflexes, and sensation. This information helps the neurologist determine whether the problem exists in the nervous system and the clinical localization. Localization of the pathology is the key process by which neurologists develop their differential diagnosis. Further tests may be needed to confirm a diagnosis and ultimately guide therapy and appropriate management.

Clinical tasks

General caseload

Neurologists are responsible for the diagnosis, treatment, and management of all the conditions mentioned above. When surgical intervention is required, the neurologist may refer the patient to a neurosurgeon. In some countries, additional legal responsibilities of a neurologist may include making a finding of brain death when it is suspected that a patient is deceased. Neurologists frequently care for people with hereditary (genetic) diseases when the major manifestations are neurological, as is frequently the case. Lumbar punctures are frequently performed by neurologists. Some neurologists may develop an interest in particular subfields, such as stroke, dementia, movement disorders, headaches, epilepsy, sleep disorders, chronic pain management, multiple sclerosis, or neuromuscular diseases.

Overlapping areas

There is some overlap with other specialties, varying from country to country and even within a local geographic area. Acute head trauma is most often treated by neurosurgeons, whereas sequelae of head trauma may be treated by neurologists or specialists in rehabilitation medicine. Although stroke cases have been traditionally managed by internal medicine or hospitalists, the emergence of vascular neurology and interventional neurologists has created a demand for stroke specialists. The establishment of JCAHO certified stroke centers has increased the role of neurologists in stroke care in many primary as well as tertiary hospitals. Some cases of nervous system infectious diseases are treated by infectious disease specialists. Most cases of headache are diagnosed and treated primarily by general practitioners, at least the less severe cases. Likewise, most cases of sciatica and other mechanical radiculopathies are treated by general practitioners, though they may be referred to neurologists or a surgeon (neurosurgeons or orthopedic surgeons). Sleep disorders are also treated by pulmonologists and psychiatrists. Cerebral palsy is initially treated by pediatricians, but care may be transferred to an adult neurologist after the patient reaches a certain age. In the United Kingdom and other countries, many of the conditions encountered by older patients such as movement disorders including Parkinson's Disease, stroke, dementia or gait disorders are managed predominantly by specialists in geriatric medicine.

Clinical neuropsychologists are often called upon to evaluate brain-behavior relationships for the purpose of assisting with differential diagnosis, planning rehabilitation strategies, documenting cognitive strengths and weaknesses, and measuring change over time (e.g., for identifying abnormal aging or tracking the progression of a dementia).

Relationship to clinical neurophysiology

In some countries, e.g. USA and Germany, neurologists may specialize in clinical neurophysiology, the field responsible for EEG, nerve conduction studies, EMG and evoked potentials. In other countries, this is an autonomous specialty (e.g., United Kingdom, Sweden).

Overlap with psychiatry

Further information: Psychoneuroimmunology

Although mental illnesses are believed by some to be neurological disorders affecting the central nervous system, traditionally they are classified separately, and treated by psychiatrists. In a 2002 review article in the American Journal of Psychiatry, Professor Joseph B. Martin, Dean of Harvard Medical School and a neurologist by training, wrote that "the separation of the two categories is arbitrary, often influenced by beliefs rather than proven scientific observations. And the fact that the brain and mind are one makes the separation artificial anyway".

Neurological diseases often have psychiatric manifestations, such as post-stroke depression, depression and dementia associated with Parkinson's disease, mood and cognitive dysfunctions in Alzheimer's disease and Huntington disease, to name a few. Hence, there is not always a sharp distinction between neurology and psychiatry on a biological basis. The dominance of psychoanalytic theory in the first three quarters of the 20th century has since then been largely replaced by a focus on pharmacology. Despite the shift to a medical model, brain science has not advanced to the point where scientists or clinicians can point to readily discernible pathologic lesions or genetic abnormalities that in and of themselves serve as reliable or predictive biomarkers of a given mental disorder.

Neurological enhancement

The emerging field of neurological enhancement highlights the potential of therapies to improve such things as workplace efficacy, attention in school, and overall happiness in personal lives. However, this field has also given rise to questions about neuroethics and the psychopharmacology of lifestyle drugs.

A neurologist is a physician who specializes in neurology, and is trained to investigate, or diagnose and treat neurological disorders.

Neurology is the medical specialty related to the human nervous system. The nervous system encompasses the brain, spinal cord, and peripheral nerves. A specialist physician who treats patients suffering from neurological disease is called a neurologist. Related yet distinct fields of medicine include: psychiatry, neurosurgery and their subspecialties.

Overview

{{#invoke:Message box|ambox}} Neurologists examine patients who have been referred to them by other physicians in both the inpatient and outpatient settings. A neurologist will begin their interaction with a patient by taking a comprehensive medical history, and then perform a physical examination focusing on evaluating the nervous system. Components of the neurological examination include assessment of the patient's cognitive function, cranial nerves, motor strength, sensation, reflexes, coordination, and gait.

In some instances, neurologists may order additional diagnostic tests as part of the evaluation. Commonly employed tests in neurology include imaging studies such as computed axial tomography (CAT) scans, magnetic resonance imaging (MRI), and ultrasound of major blood vessels of the head and neck. Neurophysiologic studies, including electroencephalography (EEG), electromyography (EMG), and evoked potentials are also commonly ordered. Neurologists frequently perform lumbar punctures in order to assess characteristics of a patient's cerebrospinal fluid.

Some of the commonly encountered conditions treated by neurologists include headaches, radiculopathy, neuropathy, stroke, dementia, seizures and epilepsy, Parkinson's Disease, multiple sclerosis, head trauma, sleep disorders, neuromuscular diseases, and various infections and tumors of the nervous system. Neurologists are also asked to evaluate unresponsive patients on life support in order to confirm brain death.

Treatment options vary depending on the neurological problem. They can include everything from referring the patient to a physiotherapist, to prescribing medications, to recommending a surgical procedure.

Some neurologists specialize in certain parts of the nervous system or in specific procedures. For example, clinical neurophysiologists specialize in the use of electrodiagnostic techniques (EEG and EMG) in order to diagnose certain neurological disorders. Neurosurgery is a distinct specialty which involves a different training path, and emphasizes the surgical treatment of neurological disorders.

There are also many non-medical doctors, those with PhD degrees in subjects such as biology and chemistry, who study and research the nervous system. Working in labs in universities, hospitals, and private companies, these neuroscientists perform clinical and laboratory experiments and tests in order to learn more about the nervous system and find cures or new treatments for diseases and disorders.

There is a great deal of overlap between neuroscience and neurology. A large number of neurologists work in academic training hospitals, where they conduct research as neuroscientists in addition to treating patients and teaching neurology to medical students.

Working Conditions

{{#invoke:Message box|ambox}} Neurologists often spend part of their day in their office, interviewing and examining patients, and then spend another part of the day visiting other patients in the hospital and reviewing their progress. They also spend time meeting with doctors who have referred patients to them, discussing the patients' progress.

Most neurologists and neuroscientists are employed full-time, working a 5-day, 40 to 50-hour week. However, this number can vary considerably, depending on experience and the type of position held. Many doctors may be expected to work more hours each week, especially at the beginning of their careers. It is not uncommon for a doctor to put in more than 60 hours a week.

Neurologists who work in hospitals usually have to work evening and weekend shifts to meet the needs of their patients. Doctors are also often "on-call" at times when they are not at work. This means that they can be called in at any time, day or night, to attend to emergencies. On-call activities can add several hours to a neurologist's workweek.

While neurology is not physically demanding work, there can be a great deal of stress involved. This is especially true if neurologists are working with patients who are extremely sick, or even terminally ill.

Education and Training

Persons who are interested in becoming a neurologist must first attend medical school. Good grades in high school and university are generally required, as well as taking the Medical College Admission Test (MCAT) if one is to pursue a Doctor of Medicine degree or a Doctor of Osteopathic Medicine degree. Undergraduate and Medical school students are required to take classes such as anatomy, biochemistry, physiology, pharmacology, psychology, microbiology, pathology, medical ethics, and laws governing medicine. Matriculants generally hold at minimum a bachelor's degree. Medical school provides a general medical education and grants students a Doctor of Medicine (MD), Doctor of Osteopathic Medicine (DO), or Bachelor of Medicine/Bachelor of Surgery (MBBS, MBChB) upon successful completion. Graduating medical students then elect a post-graduate or residency program in neurology or pediatrics or one year of internal medicine. Residents in either pediatrics or internal medicine must then enroll into neurology fellowships such as pediatric neurology, or general neurology. Neurologists may choose from a variety of subspecialties.

Neurology residency consists of practical, on-the-job training, in hospitals or other medical settings. The training program provides residents with specific training as a neurologist, and usually takes about four years to complete. In the United States, the first of these four years consists of either a transitional or internal medicine internship, which includes broad exposure to general adult medicine. The second through fourth postgraduate years are spent in a devoted neurology residency, after which time the successful graduate can apply for licensure. After residency, graduates may choose to pursue board certification through the American Board of Psychiatry and Neurology. Some neurologists will complete voluntary, additional training in a fellowship program in order to gain experience in a subspecialty area.^{[citation needed]}

Persons wishing to become a non-medical neuroscientist must first complete a bachelor's degree in neuroscience or a related discipline. The next step is to obtain a master's degree in neuroscience (two years to complete) and then a Ph.D. (at least four years). While there may be research positions available to those with a master's degree, a Ph.D. is generally required to become a university professor or a senior research scientist.^{[citation needed]}

See also

• American Board of Psychiatry and Neurology
• American Osteopathic Board of Neurology and Psychiatry
• List of neurologists
• Neurohospitalist, a physician interested in inpatient neurological care

External links

• American Academy of Neurology
• American Neurological Association
• European Federation of Neurological Societies
• European Journal of Neurology
• National Institute of Neurological Disorders and Stroke (NINDS)
• Neurology, official journal of the AAN
• World Congress of Neurology
• United Council for Neurologic Subspecialties

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