Download Citation on ResearchGate | Principios de neurociencia / editado por Eric R. Kandel, James H. Schwartz, Thomas M. Jessell | Traducción de. Get this from a library! Principios de neurociencia. [Eric R Kandel; James H Schwartz; Thomas M Jessell; Agud Aparicio.; Angel Hernando Saudan; et al]. Get this from a library! Principios de neurociencia. [Eric R Kandel; James H Schwartz; Thomas M Jessell;].
|Published (Last):||21 June 2007|
|PDF File Size:||16.52 Mb|
|ePub File Size:||9.6 Mb|
|Price:||Free* [*Free Regsitration Required]|
Mechanisms for the generation of synapse speci- ficity long-term memory: Heurociencia this chapter we consider to what degree mental functions are located in specific regions of the brain and to what degree such local mental processes can be understood in terms of the properties of specific nerve cells and their interconnections.
Figure B The four lobes of the cerebral cortex. Studies of aphasia afford unusual insight into how the brain is organized for language. Certain disorders of affective language that are localized to the right hemisphere, called aprosodias, are classified as neugociencia, motor, or conduction aprosodias, following the classification used for aphasias.
Advances in molecular neural science have been matched by advances in our understanding of the biology of higher brain functions. Transmitters can be small molecules, such as L-glutamate and acetylcholine, or they can be peptides like enkephalin Chapter AndreasenPeter H. The neural basis of language is discussed more fully in Chapter Thus, when words are heard Wernicke’s area becomes active, but when words are seen but not heard or spoken Wernicke’s area is not activated.
Darleane Hoffman e Harold S. Aphasia patients not only manifest cognitive defects in language, but also have trouble with the affective aspects of language, such as intonation or prosody. Glial cells in the vertebrate nervous system are divided into two major classes: Whereas destructive lesions bring about loss of function, often through the disconnection of specialized areas, the electrical storm of epilepsy can increase activity in the regions affected, leading to excessive expression of emotion or over-elaboration of ideas.
Beginning in the late s, Edgar Adrian in England and Wade Marshall and Philip Bard in the United States discovered that applying a tactile stimulus to different parts of a cat’s body elicits electrical activity in distinctly different subregions of the cortex, allowing for the establishment of a precise map of the body surface in specific areas of the cerebral cortex described by Brodmann. With this fourth and millennial edition, we hope to encourage the next generation of undergraduate, graduate, and medical students to approach the study of behavior in a way that unites its social and its biological dimensions.
Our common sense tell us that we store each piece of our knowledge of the world as a single representation that can be recalled by memory-jogging stimuli or even by the imagination alone. In the late s Wilder Penfield, and more recently George Ojemann used small electrodes to stimulate the cortex of awake patients during brain surgery for epilepsy carried out under local anesthesiain search of areas that produce language.
An essay concerning humane understanding.
Excitatory connections with the leg’s extensor muscles cause these muscles to contract, while connections with certain inhibitory interneurons prevent the antagonist flexor muscles from being called to action.
The tendon of the quadriceps femoris, an extensor muscle that moves the lower leg, is attached to the tibia through the tendon of the kneecap, the patellar tendon. When the muscle stretches in response to the pull of the tendon, information regarding this change in the muscle is conveyed by afferent sensory neurons to the central nervous system. There, if the receptor potential is sufficiently large, it triggers an action potential, which then propagates actively and without change along the axon to the terminal region.
We shall learn more about the mechanisms underlying the resting potential and action potential in Chapters 6,7,8,9. Painfully aware of their own errors, they are unable to put them right. J Exp Zool According to this view, it was brain mass, not its neuronal components, that was crucial to its function. Indeed, the voltage signals of action potentials carried into the nervous system by a sensory axon often are indistinguishable from those carried out of the nervous system to the muscles by a motor axon.
At the same time, progress in neural science is providing clearer guidance to clinicians, particularly in the treatment of behavioral disorders.
The Modifiability of Specific Connections Contributes to the Adaptability of Behavior That neurons make specific connections with one another simple reflexes can undergo modification that lasts minutes, and much learning results in behavioral change that can endure for years.
The Integrative Action of the Nervous System, 2nd ed. This recommendation is of particular importance in connection with new or infrequently used drugs. Here the receptive and motor speech zones themselves are spared but the neuronal fiber pathways that connect them are destroyed.
Here we shall examine in general terms how a behavior is produced by considering a simple stretch reflex, the knee jerk. The amplitude and duration of the receptor potential depends on the intensity of the muscle stretch. Commentary on the Effect of Electricity on Muscular Motion. Cortical damage, regardless of site, caused patients to regress from a rich, abstract language to the impoverished utterances of aphasia. In the knee jerk the receptor potential in the sensory neuron propagates to the first node of Ranvier in the axon, where, if it is large enough, it generates an action potential, which then propagates without failure by a regenerative mechanism discussed in Chapter 9 to the axon terminals in the spinal cord.
Finally, the 80, genes of the human genome are nearly sequenced. Thus the main reason it has taken so long to appreciate which mental activities are localized within which regions of the brain is that we are dealing here with biology’s deepest riddle: In our example of the knee jerk, the action potential in the sensory neuron releases a chemical signal a neurotransmitter across the synaptic cleft. Except as permitted under the United States Copyright Act ofno part of this publication may be reproduced or distributed in any form or by any means, or stored in a data base or retrieval system, without the prior written permission of the publisher.
The point at which two neurons communicate is known as a synapse. The transmitter binds to receptor proteins on the motor neuron, and the resulting reaction transduces the potential chemical energy of the transmitter into electrical energy.
In retrospect, it is hard to appreciate how difficult it was to persuade scientists of this elementary idea. Characterizations of the genes encoding growth factors and their receptors, transcriptional regulatory factors, and cell and substrate adhesion molecules have changed the study of neural development from a descriptive discipline into a mechanistic one. We will encounter many examples of feed-forward and feedback inhibition when we examine more complex behaviors in later chapters.
The features ofreceptor and synaptic potentials are summarized in Table CalabreseThoma s M. Adapted from Geschwind Questa IV edizione italiana basata sulla V inglese viene pubblicata a dodici anni di distanza dalla precedente. Wernicke postulated that language involves separate motor and sensory programs, each governed by separate cortical regions.