Discovering the Brain (1992) / Chapter Skim
Currently Skimming:
1 The Promise of Neuroscience
1 The Promise of Neuroscience
Pages 1-12
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The brain is active throughout every day, even as we sleep, but we rarely, if ever, stop to consider that our thoughts, actions, and perceptions are the outcome of several trillion sicnals exchanged among nerve cells. The brain is such an efficient processor of information that most of the time we do not realize the magnitude of its task.
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Domenici, and others. At the beginning of the 199Os, neuroscience combines mature theory, lively new possibilities for investigation, and technology that can yield information unheard of even a few years ago: the genetic markers for an inherited predisposition toward some mental disorder, or the intimate structure, down to the individual molecules, of a receptor in the brain for a particular chemical compound, or medical images that convey the flow of energy in different areas while the brain manages such tasks as reading and thinking.
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From page 3... ...
Neuroscience is, rather, a way to approach specific questions about the structure and function of the human brain, whether in healthy development or when afflicted with injury or disease. Neuroscientific investigation may require the hands-on familiarity of neuroanatomy and physiology, the biochemical framework of neuroimmunology, or the specialized calculations of genetics; it may call for the bright scans of neural images that must be "read" with an eye for subtle changes, or the observation of full-scale behavior, as studied in neuropsychology; it can involve the advanced mathematics of the computational sciences and the intricate cellular workings of molecular biology.
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From page 4... ...
The two-way channel of information continues to expand: findings from the laboratory lead toward sharper criteria for diagnosing mental disorders and more effective methods for treating them, and in turn the clinician's increasingly acute skills of diagnosis and observation supply the research scientist with more precise data for study in the lab. The data under examination in such laboratories often come in forms that would have been unimaginable a decade or two ago.
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From page 5... ...
The basal ganglia are important for the control of movement, for which they receive signals from the cerebral cortex; electrical recordings show both these areas to be active a fraction of a second before a movement takes place. To map the pathways of these nerve signals has called for a solid foundation of anatomy, highly refined techniques for the selective staining of particular cells, and close studies of signal-carrying agents such as
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(This cautious phrasing means that the principles have held up in rigorous testing so far, in a great variety of settings; but scientists stop short of guaranteeing them against future refinements or corrections, since a willingness to test rather than to keep faith is a hallmark of science.) One such principle is the current understanding that nerve cells can be excited by both electrical and chemical signals and that both types of signals act by altering the flow of ions (positively or negatively charged particles)
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Other imaging modes offer unique advantages as well: computed tomography, which can clearly distinguish gray ancT white matter; magnetic resonance spectroscopy, which can measure differing rates of energy metabolism in the course of a disease; magnetic source imaging, which
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What is novel in the 1990s is the intriguing set of questions that are open to exploration including some that could not even be framed, much less addressed, as recently as 15 years ago. For example, the role of genetics in several mental disorders was long suspected and is now gaining confirmation, as painstaking studies of heredity covering several generations of afflictecl families reveal patterns of inheritance; at the same time, molecular biological studies are closing in on a physical explanation of how particular defects in the genes could ultimately lead to recognizable clinical symptoms.
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From page 9... ...
characteristically human abilities. With their large cell bodies and their long axons for transmitting signals, pyramidal neurons are excellently suited to their task of bringing together information from one region of the enormously extensive cortex to another; Dominick Purpura only half-jokingly calls them "the acme of biological cellular evolution on earth." These specialized cells not only transmit signals; they also incorporate into their structure a very effective pattern of sites for receiving signals.
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From page 10... ...
This substance appears to act as part of a chain of chemical signals that affect mood; as a vitamin, though, it is also crucial in embryonic development, and its blockage during a pregnancy can lead to birth defects. Thus, an older observation that lithium can be harmful during pregnancy—may be explained by the compound's interference with inositol.
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From page 11... ...
Under the sponsorship of the Institute of Medicine and the National Institute of Mental Health, many of the worId's eminent neuroscientists gathered in July 1990 to discuss some of the exciting results from recent investigations and to plan research strategies for the future strategies to make the most of the new prospects created by technology and by alliances between the public and private sectors (see Chapter 9~. Maxwell Cowan, chief scientific officer of the Howard Hughes Medical Institute and chairman of the symposium's steering committee, listed three objectives for the event.
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From page 12... ...
ACKNOWLEDGMENTS Chapter 1 is based on presentations by Maxwell Cowan, Enoch Gordis, and Dominick Purpura.
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