Neurociencia

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Neuroscience
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Drawing of the cells in the
chicken cerebellum by S. Ramón y CajalNeuroscience is a scientific discipline that studies the structure, function, development, genetics, biochemistry, physiology, pharmacology, and pathology of the nervous system. Traditionally it is seen as a branch of biological sciences. However, recently there has been of convergence of interest from many allied disciplines, including psychology, computer science, statistics, physics, and medicine. The scope of neuroscience has now broadened to include any systematic scientific experimental and theoretical investigation of the central and peripheral nervous system of biological organisms. The methodologies employed by neuroscientists have been enormously expanded, from biochemical and genetic analysis of dynamics of individual nerve cells and their molecular constituents to imaging representations of perceptual and motor tasks in the brain.
Neuroscience is at the frontier of investigation of the brain and mind. The study of the brain is becoming the cornerstone in understanding how we perceive and interact with the external world and, in particular, how human experience and human biology influence each other.
Overview
The scientific study of the nervous systems has exploded in the second half of the twentieth century, principally due to revolutions in molecular biology, neural networks and computational neuroscience. It has become possible to understand, in exquisite detail, the complex processes occuring inside a single neuron and in a network that eventually produces the intellectual behavior, cognition and physiological responses.
The task of neural science is to explain behavior in terms of the activities of the brain. How does the brain marshal its millions of individual nerve cells to produce behavior, and how are these cells influenced by the environment...? The last frontier of the biological sciences--their ultimate challenge--is to understand the biological basis of consciousness and the mental processes by which we perceive, act, learn, and remember. - Eric Kandel, Principles of Neural science, fourth edition The task of neural science is to explain behavior in terms of the activities of the brain. How does the brain marshal its millions of individual nerve cells to produce behavior, and how are these cells influenced by the environment...? The last frontier of the biological sciences--their ultimate challenge--is to understand the biological basis of consciousness and the mental processes by which we perceive, act, learn, and remember. - Eric Kandel, Principles of Neural science, fourth edition
The nervous system is composed of a network of neurons and other supportive cells (such as glial cells), each with a complete copy of the organism's genome. Neurons form functional circuits, each responsible for specific tasks to the behaviors at the organism level. Thus, neuroscience can be studied at many different levels, ranging from molecular level to cellular level to systems level to cognitive level.
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 are born and die, 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 ways in which neurons and their connections are modified by experience are addressed at the physiological and cognitive levels.)
At the cellular level, the fundamental questions addressed in
cellular neuroscience are the mechanisms of how neurons process signals physiologically and electrochemically. They address how signals are processed by the dendrites, somas and axons, and how neurotransmitters and electrical signals are used to process signals in a neuron.
At the systems level, the questions addressed in
systems neuroscience include how the circuits are formed and used anatomically and physiologically to produce the physiological functions, such as reflexes, sensory integration, motor coordination, emotional responses, learning and memory, etc. 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? The related field of neuroethology, in particular, addresses the complex question of how neural substrates underlies specific animal behavior.
At the cognitive level,
cognitive neuroscience addresses the questions of how pyschological/cognitive functions are produced by the neural circuitry. The emergence of powerful experimental techniques such as fMRI, electrophysiology and human genetic analysis allows neuroscientists to address abstract questions such as how human cognition and emotion are mapped to specific neural circuitries. Many mental processes previously thought to be beyond scientific understanding have been shown to have robust neural correlates.
Neuroscience is also beginning to become allied with
social sciences, and burgeoning interdiciplinary fields of neuroeconomics, decision theory, social neuroscience are starting to address some of the most complex questions involving interactions of brain with environment.
Neuroscience generally includes all scientific studies involving the nervous system. Psychology, as the scientific study of mental processes, may be considered a sub-field of neuroscience, although some mind/body theorists argue that the definition goes the other way - that psychology is a study of mental processeses that can be modeled by many other abstract principles and theories that are independent of the underlying neural circuitries. The term neurobiology is sometimes used interchangeably with neuroscience, though the former refers to the biology of nervous system, whereas the latter refers to science of mental functions that are built upon by the constituent neural circuitries.
Neurology and Psychiatry are medical specialties and are generally considered, in academic research, subfields of neuroscience that specifically address the diseases of the nervous system. These terms also refer to clinical diciplines involving diagnosis and treatment of theses diseases. Neurology deals with diseases of the central and peripheral nervous systems such as ALS and stroke, while psychiatry focuses on mental illnesses. The boundaries between the two have been blurring recently and physicians who specialize in either generally receive training in both. Both neurology and psychiatry are heavily involved in and influenced by basic research in neuroscience.
History of Neuroscience
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Main article: History of the brain
Even though it is believed that ancient hominods performed
trepanation with the aim to cure, perhaps headaches or mental disorders, manuscripts dating 5000 years indicated that egyptians had some knowledge about symptoms of brain damage.
Early views on the function of the
brain, regarded it to be a form of “cranial stuffing” of sorts. In 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. 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.’
The view that the heart was the source of conciousness was not challenged until the time of
Hippocrates. He believed that the brain, not only was involved with sensation since most specialized organs (eyes, ears and tongue) are located in the head, but also was the seat of intelligence. However, Aristotle strung to the believe that the heart was the center of intelligence and thus, this the brain was a "cooling device". This view was accepted until the Roman Galen embraced Hippocrates belief. Galen was a physician of gladiators and had the opportunity to observe the consecuences of brain and spinal injury. He also performed numerous animal dissections and he described the cerebrum, cerebellum and ventricles. When he observed the fluid inside the ventricles his observations agreed with the general idea that the body functioned according to the balance of the four vital fluids or humors.
Sophisticated studies of the brain were not possible until after the invention of the
microscope and the development of a staining procedure by Camillo Golgi during the late 1890s that uses a silver chromate salt to reveal the intricate structures of single 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. 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. The hypotheses of the neuron doctrine were supported by experiments following Galvani's pioneering work in the electrical excitability of muscles and neurons. In the late 19th cnetury, DuBois-Reymond, Müller, and von Helmholtz showed neurons were electrically excitable, and their activity predictably affected the electrical state of adjacent neurons.
Further work with brain-damaged patients by
Broca suggested that certain regions of the brain were responsible for certain functions. This hypothesis was supported by observations of epileptic patients conducted by John Hughlings Jackson, who correctly deduced the organization of motor cortex by watching the progression of seizures through the body. Wernicke developed the theory of the specialization of specific brain structures in language comprehension and production.
ref: Principles of Neural Science, 4th ed. Eric R. Kandel, James H. Schwartz, Thomas M. Jessel, eds. McGraw-Hill:New York, NY. 2000.
Andrea Vesalius (1514-1564) Rene Descartes (1596-1650)
Major Branches of Neuroscience
Current neuroscience 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 approaches. Individual neuroscientists, however, often work on questions that span several distinct subfields.
Branch Major Topics and Concepts Experimental and Theoretical Methods Branch Major Topics and Concepts Experimental and Theoretical Methods
MolecularMolecular and Cellular Neuroscience behavioral genetics, neurocytology, Glia, Protein trafficking, Ion channel, Synapse, Action potential, Neurotransmitters, behavioral genetics, neurocytology, Glia, Protein trafficking, Ion channel, Synapse, Action potential, Neurotransmitters, Neuroimmunology PCR, Immunohistochemistry, Patch clamp, voltage clamp, molecular cloning, gene knockout, biochemical assays, linkage analysis, fluorescent in situ hybridization, Southern blots, DNA microarray, GFP, calcium imaging, PCR, Immunohistochemistry, Patch clamp, voltage clamp, molecular cloning, gene knockout, biochemical assays, linkage analysis, fluorescent in situ hybridization, Southern blots, DNA microarray, GFP, calcium imaging, two-photon microscopy Molecular and Cellular Neuroscience behavioral genetics, neurocytology, Glia, Protein trafficking, Ion channel, Synapse, Action potential, Neurotransmitters, Neuroimmunology PCR, Immunohistochemistry, Patch clamp, voltage clamp, molecular cloning, gene knockout, biochemical assays, linkage analysis, fluorescent in situ hybridization, Southern blots, DNA microarray, GFP, calcium imaging, two-photon microscopy
Systems Neuroscience The Primary Visual Cortex, Perception, Audition, Sensory Integration, Population Coding, Pain,Spontaneous and Evoked Activity, Color vision, olfaction,taste,motor system,spinal cord, sleep, homeostasis, arousal, attention, The Primary Visual Cortex, Perception, Audition, Sensory Integration, Population Coding, Pain,Spontaneous and Evoked Activity, Color vision, olfaction,taste,motor system,spinal cord, sleep, homeostasis, arousal, attention, play single unit recording, intrinsic signal imaging, microstimulation, voltage sensitive dyes, fMRI, patch clamp, genomics, training awake behaving animals, local field potentials, ROC, cortical cooling, calcium imaging, single unit recording, intrinsic signal imaging, microstimulation, voltage sensitive dyes, fMRI, patch clamp, genomics, training awake behaving animals, local field potentials, ROC, cortical cooling, calcium imaging, two-photon microscopy Systems Neuroscience The Primary Visual Cortex, Perception, Audition, Sensory Integration, Population Coding, Pain,Spontaneous and Evoked Activity, Color vision, olfaction,taste,motor system,spinal cord, sleep, homeostasis, arousal, attention, play single unit recording, intrinsic signal imaging, microstimulation, voltage sensitive dyes, fMRI, patch clamp, genomics, training awake behaving animals, local field potentials, ROC, cortical cooling, calcium imaging, two-photon microscopy
Developmental Neuroscience axon guidance,neural crest,growth factors,growth cone,neuromuscular junction,cell proliferation,neuronal differentiation, cell survival and apoptosisaxon guidance,neural crest,growth factors,growth cone,neuromuscular junction,cell proliferation,neuronal differentiation, cell survival and apoptosis, synaptic formation, motor differentiation, injury and regeneration Xenopusoocyte, protein chemistry, genomics,Drosophila,Xenopus oocyte, protein chemistry, genomics,Drosophila,Hox gene Developmental Neuroscience axon guidance,neural crest,growth factors,growth cone,neuromuscular junction,cell proliferation,neuronal differentiation, cell survival and apoptosis, synaptic formation, motor differentiation, injury and regeneration Xenopus oocyte, protein chemistry, genomics,Drosophila,Hox gene
Cognitive Neuroscience language,emotion, motor learning,sexual behavior,decision making,behavioral genetics,motivation,language,emotion, motor learning,sexual behavior,decision making,behavioral genetics,motivation,social neuroscience psychometrics,EEG,MEG,fMRI,PET,SPECT,single unit recording,psychometrics,EEG,MEG,fMRI,PET,SPECT,single unit recording,human genetics Cognitive Neuroscience language,emotion, motor learning,sexual behavior,decision making,behavioral genetics,motivation,social neuroscience psychometrics,EEG,MEG,fMRI,PET,SPECT,single unit recording,human genetics
ComputationalComputational and Theoretical Neuroscience cable theory,hodgkin-huxley model,neuronal networks,voltage-gated currents,cable theory,hodgkin-huxley model,neuronal networks,voltage-gated currents,Hebbian learning markov chain monte carlo,simulated annealing,high performance computing,partial differential equations,self-organizing nets,markov chain monte carlo,simulated annealing,high performance computing,partial differential equations,self-organizing nets,pattern recognition Computational and Theoretical Neuroscience cable theory,hodgkin-huxley model,neuronal networks,voltage-gated currents,Hebbian learning markov chain monte carlo,simulated annealing,high performance computing,partial differential equations,self-organizing nets,pattern recognition
Neuroscience of Diseases and Aging dementia,peripherial neuropathy,spinal cord injury,autonomic systems,depression,anxiety,Parkinson's,Addiction,dementia,peripherial neuropathy,spinal cord injury,autonomic systems,depression,anxiety,Parkinson's,Addiction,memory loss clinical trials,neuropharmacology,deep brain stimulation,clinical trials,neuropharmacology,deep brain stimulation,neurosurgery Neuroscience of Diseases and Aging dementia,peripherial neuropathy,spinal cord injury,autonomic systems,depression,anxiety,Parkinson's,Addiction,memory loss clinical trials,neuropharmacology,deep brain stimulation,neurosurgery
Neural engineering Neuroprosthetic,Neuroprosthetic,brain-computer interface Neural engineering Neuroprosthetic,brain-computer interface
Major Themes of Research
Neuroscience research from different areas can also be seen as focusing on a set of specific themes and questions. (Some of these are taken from )
· Behavior/Cognition/Language
·
Biological Rhythms
· Brain Imaging or
neuroimaging
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Cell Biology
· Cell Imaging &
Electrophysiology
· Computational
· Development
·
Hearing Sciences
· Learning/Memory
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Mechanisms of Drug Action
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molecular neuroscience
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Motor Control
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Neurobiology of Disease
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Neuroendocrinology
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Neuroimmunology
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Signal transduction
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Systems Neuroscience
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Vision Sciences
· Neurobiology of the neuron
· Sensation and perception
· Sleep
· Autonomic systems and homeostasis
· Arousal, attention and emotion
· Genetics of the nervous system
· Injury of the nervous systems
Allied and Overlapping Fields
Neuroscience, by its very interdiciplinary nature, overlaps with and emcompasses many different subjects. Bellow is a list of related subjects and fields.
· Aphasiology · Behavioral Neuroscience · Machine Learning · Neural Networks · Evolutionary neuroscience · Neural engineering · Neuroanatomy · Neurobiology · Neurochemistry · Neuroeconomics · Neuroergonomics · Neuroendocrinology · Neuroesthetics · Neuroethics · Neuroethology · Neurogenetics · Neurogenomics · Neuroheuristic · Neuroimaging · Neurolinguistics · Neuromarketing · Neuropharmacology · Neurophenomenology · Neurophilosophy · Neurophysiology · Neuroproteomics · Neuroprosthetics · Neuropsychiatry · Neuropsychology · Neuropsychopharmacology · Neurotheology (also Biotheology) · Psychiatry · Psychopharmacology · Psychobiology (also Biopsychology, also Biological psychology) · Vision
Future directions
Main article: Unsolved problems in neuroscienceSee also
· Applied Neuroscience, Austria
·
List of neuroscience topics
·
Important publications in neuroscience
·
List of neuroscientists
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Wikibook on consciousnessReferences
Textbooks
· Bear, M.F., B.W. Connors, and M.A. Paradiso (2001). Neuroscience: Exploring the Brain. Baltimore: Lippincott. ISBN 0-7817-3944-6.
·
Kandel, ER, Schwartz JH, Jessell TM (2000). Principles of Neural Science, 4th ed., 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 0-262-68108-0Online textbooks
· 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.
·
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.
Popular works
· Andreasen, Nancy C. (March 4 2004). Brave New Brain: Conquering Mental Illness in the Era of the Genome. Oxford University Press. 392 pages, 56 halftones & line illus.; 8 color plates, 234x154 mm. ISBN 978-0-19-516728-3.
· 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)
· 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
· 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
· Ramachandran, V.S. (1998).
Phantoms in the Brain. New York, New York Harper Collins. ISBN 0-688-15247-3 (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.
Notes From Online Courses
· Intro to Neuroscience - Smith College Spring 2005
External links
· Books with Neuroscience Protocols
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Neuroanatomy is an annual journal of clinical neuroanatomy.
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High-Resolution Cytoarchitectural Primate Brain Atlases
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Society for Neuroscience
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American Society for Neurochemistry
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Neuroscience News Neuroscience news, forum, job listings, labs...
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Neurotransmitter.netNeuroscience resources and news
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Neuroanatomy & Neuropathology on the InternetHigh quality links
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Neuroscience. 2nd ed. by Purves et al (online textbook)
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Nature Reviews Neuroscience (journal home)
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Neuroscience for Kids
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NeuroWiki, a wiki website for Neuroscience related topics. All content (unless explicitly proclaimed otherwise) is published to the public domain thus can be relocated to the Wikipedia.
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Dana.org for information about brain research, immunology and arts education
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Neuroscience Methods and Techniques
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Behavioral Neuroscience Links
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Neuroscience Notes

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