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Neurons and interneuronal connections of the central visual system
BOOK REVIEWS
559
data and dosage. There is a generous selection of references and a good index. Particular attention in various parts of the review is devoted to the potentiators of levodopa, including amantadine, anticholinergics and peripheral dopa decarboxylase inhibitors. The utility of this review is enhanced by the authors' habit of providing a concise summary of the contents of the papers supporting the authors' discussion together with their evaluation of the quality of the studies. This enables the reader of the review to gain insight into the adequacy of the experimental and clinical data which form the basis of current concepts o f the rationale for therapy of Parkinson's disease with levodopa. There are no important omissions among the subjects the authors considered to be related to the broad subject of levodopa. However, since neurologists are among those who will be most interested in this review, more papers could well have been included documenting changes in the EEG. Also, in view of the frequency of the problem, a longer discussion of the proposed mechanisms of anorexia, nausea and vomiting may have been in order. On the other hand, some other aspects are the subject of controversy, and this review summarizes the various viewpoints very well. This is particularly true of the summation of ideas concerning the mechanisms of hypotension attendant on levodopa administration. This review is complete enough to be useful to the investigator busy with some aspect of the pharmacology of levodopa. At the same time, considerable effort is taken throughout the paper to define medical and pharmacologic terms in footnotes or parentheses. This renders the review very useful for interested readers in paramedical fields without interfering with the continuity of the text or making it unduly long and therefore tedious for readers already familiar with the terminology. All points considered, this is an excellent review which will remain a useful reference work for a number of years. T. A. NEWKIRK
Letterman General Hospital, San Francisco, Calif. (U.S.A.) Structure and function of synapses. - - G. D. Pappns and D. P. Purpura (Editors). (Raven Press, New York, 1972, 308 p., $18.00). This volume deals with the microscopic anatomy, neurophysiology, and biochemistry of synapses. The editors, contributors and the publisher have worked together to make this book one of the most useful and handsome volumes that this reviewer has seen in many years. Each of the chapters constitutes a major, in-depth review of some special topic in synaptology. The editors have obviously instructed the contributors to this volume to attempt to evaluate critically current knowledge of the morphophysiology and biochemistry of synaptic function. In this respect, the volume is a total success. One can progress through these chapters and end with a most comprehensive knowledge of the entire field of synaptic study. The expositions should appeal to professionals, students and those in other fields who desire an intimate understanding of the basis for synaptic function.
In another sense the book is so constructed that almost anyone interested in science should find something of interest in it. In this sense, the editors have presented the reader with one of the grand natural designs. The molecular and morphological transmissional architecture of nervous systems from invertebrates to primates emerges clearly. In this respect the book should be useful to both clinicians and researchers in neurology and electroencephalography. One of the reasons for the excellence of this book is the superb quality of the illustrations. These illustrations, particularly the electron-micrographs of Pappas and Waxman and the freeze-etch EMs of Akert, Pfenninger, Sandri and Moor are among the clearest and sharpest to be reproduced by the printing press to date. In addition to the excellent illustrations, there are extensive bibliographies which cover most of the major work done in the field. As far as this reviewer can determine, these are not padded just to increase coverage. The only minor complaint is that the editors have neglected to include an author index, which might have made access to these bibliographies somewhat easier on the reader. In summary, I enthusiastically recommend this book to all serious research workers in neuroanatomy, neurophysiology and neurochemistry. In addition, I believe the book will provide fascinating reading for neurologists, electroencephalographers and other workers in the neurosciences. WILLIAMJ. ADELMANJR.
National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Md. 20014 (U.S.A.)
Neurons and interneuronal connections of the central visual system. - - E. G. Shkornik-Yarros (B. Haigh, Translator; R. W. Duty, Editor). (Plenum, New York, 1971, 295 p., $22.50). The anatomical analysis of the cerebral cortex, so neglected in Western Europe and America, has long been the preoccupation of the Brain Institute at Moscow. Yet its publications are practically unknown to anatomists of the Western world, because of the language barrier. Mention of Sukhanov, Poliakov and Filimonov is apt to be met with an attentive silence. Catherine Shkol'nik-Yarros has been publishing, in Russian, on brain anatomy since 1950 and this book was published first in 1965, unbeknownst to almost all of us. Its excellent translation by Basil Haigh, and its scientific mis-en-scbne by Robert W. Doty, have combined to make an easy-reading text in current scientific vernacular. It is adequately illustrated, but it seems unfortunate that the excellent line drawings have been screened by the hand of the author. (Its list price of $22.50 is not reflected in the format of this small, plain book.) The object of the book is to use neuronal visualization of the neuronal structure of the lateral geniculate body and occipital cortex by light microscopy to carry the interpretations of the central visual mechanisms as far as these methods will permit. The Golgi method is utilized, practically to the exclusion of the visualization of degenerated neurons. The Golgi method has already been ably applied to the visual
560 cortex by Cajal, by Lorente de N6, by O+Leary and by Polyak, so it is only natural that we find little that is novel in this book. No one before, though, has carried the method up through the mammalian class with comparisons along the way. Indeed one comes out of a perusal of this section, which accounts for about half of the book, with a deeper understanding of the visual mechanisms. The second half of the book is mostly synthesis and an attempt at interpretation. with full regard for the existing literature. Several neuron types are recognized in the lateral geniculate, notably the "mi~lget cells". Yet the neuronal profile of the lateral geniculate is disappointingly similar to that of the other thalamic nuclei, in spite of all the specificity that must be immanent in transmission of a fully detailed picture in color. In area 17, layers IVa, b and c are exquisitely analyzed differentially and illustrated with pen drawings. The star cells are reaffirmed and their axons traced out from the cortex. These increase in the monkey, and enormously in man, so are considered significant. The evolution of the giant pyramids of Meynert is neatly traced to a crescendo in man. Their axons run to the superior colliculus. Then there are the large pyramids of the lower part of layer III, whose axons also leave the cerebral cortex. Thus, we have three extracortical axons and three places for them to go: superior colliculus, lateral geniculate and areas 18 and 19. The efferents are well taken care of, but what anatomical substrate is there for the discreteness and organization of the visual image'? It must be right there, in area 17, for we kno~. from experimental degenerations that there is no intercom system in or under area 17 sufficient to synthesize the visual
BOOK REVIEWS image m any one place within itself, or to transfer it to anywhere else. A glance at the cabbage-bud pattern in an occipital section of man or monkey, and the thin subcortical layer of fibers+ especially when we subtract the bulky contribution of visual radiation+ internal sagittal stratum of corticifugal axons, and the tapetum to the callosum, shows that there simply is not enough wiring behind the microcircuitry of the cortex to allow the visible image to be anywhere other than in the primary visual cortex itself. Yet Golgi preparations give no token of how this operation bootstrap is effected+ The fact is that, as Shkol'nik-Yarros testifies, there is but scant callosal connection between the two halves of this visual image, and yet there is never a seam in the midline of our visual image. The image must be all in area 17, and the rest of the cortex must get its information by looking at it along with us. But that is only the beginning. Where is the Golgi manifestation of the three-color system+ where is the neuronal expression of the binocular illusion of depth, and where the geometrics required for the line slope, movement, and quadrangular synthesis so elegantly shown in the single cell work of Hubel and Wiesel? Possibly the Golgi approach has nearly run its course, as has already the hope of electron microscope analysis, so that we are left to wait for some great third wave. And that may be the single-cell evoked potential, with positive identification, over the entire cortex. WENDEI.I, J. S. KRIE(; Northwestern University, Medical School, ('hica~lo, Ill. 60611 ( (/.S.A, i
559
data and dosage. There is a generous selection of references and a good index. Particular attention in various parts of the review is devoted to the potentiators of levodopa, including amantadine, anticholinergics and peripheral dopa decarboxylase inhibitors. The utility of this review is enhanced by the authors' habit of providing a concise summary of the contents of the papers supporting the authors' discussion together with their evaluation of the quality of the studies. This enables the reader of the review to gain insight into the adequacy of the experimental and clinical data which form the basis of current concepts o f the rationale for therapy of Parkinson's disease with levodopa. There are no important omissions among the subjects the authors considered to be related to the broad subject of levodopa. However, since neurologists are among those who will be most interested in this review, more papers could well have been included documenting changes in the EEG. Also, in view of the frequency of the problem, a longer discussion of the proposed mechanisms of anorexia, nausea and vomiting may have been in order. On the other hand, some other aspects are the subject of controversy, and this review summarizes the various viewpoints very well. This is particularly true of the summation of ideas concerning the mechanisms of hypotension attendant on levodopa administration. This review is complete enough to be useful to the investigator busy with some aspect of the pharmacology of levodopa. At the same time, considerable effort is taken throughout the paper to define medical and pharmacologic terms in footnotes or parentheses. This renders the review very useful for interested readers in paramedical fields without interfering with the continuity of the text or making it unduly long and therefore tedious for readers already familiar with the terminology. All points considered, this is an excellent review which will remain a useful reference work for a number of years. T. A. NEWKIRK
Letterman General Hospital, San Francisco, Calif. (U.S.A.) Structure and function of synapses. - - G. D. Pappns and D. P. Purpura (Editors). (Raven Press, New York, 1972, 308 p., $18.00). This volume deals with the microscopic anatomy, neurophysiology, and biochemistry of synapses. The editors, contributors and the publisher have worked together to make this book one of the most useful and handsome volumes that this reviewer has seen in many years. Each of the chapters constitutes a major, in-depth review of some special topic in synaptology. The editors have obviously instructed the contributors to this volume to attempt to evaluate critically current knowledge of the morphophysiology and biochemistry of synaptic function. In this respect, the volume is a total success. One can progress through these chapters and end with a most comprehensive knowledge of the entire field of synaptic study. The expositions should appeal to professionals, students and those in other fields who desire an intimate understanding of the basis for synaptic function.
In another sense the book is so constructed that almost anyone interested in science should find something of interest in it. In this sense, the editors have presented the reader with one of the grand natural designs. The molecular and morphological transmissional architecture of nervous systems from invertebrates to primates emerges clearly. In this respect the book should be useful to both clinicians and researchers in neurology and electroencephalography. One of the reasons for the excellence of this book is the superb quality of the illustrations. These illustrations, particularly the electron-micrographs of Pappas and Waxman and the freeze-etch EMs of Akert, Pfenninger, Sandri and Moor are among the clearest and sharpest to be reproduced by the printing press to date. In addition to the excellent illustrations, there are extensive bibliographies which cover most of the major work done in the field. As far as this reviewer can determine, these are not padded just to increase coverage. The only minor complaint is that the editors have neglected to include an author index, which might have made access to these bibliographies somewhat easier on the reader. In summary, I enthusiastically recommend this book to all serious research workers in neuroanatomy, neurophysiology and neurochemistry. In addition, I believe the book will provide fascinating reading for neurologists, electroencephalographers and other workers in the neurosciences. WILLIAMJ. ADELMANJR.
National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Md. 20014 (U.S.A.)
Neurons and interneuronal connections of the central visual system. - - E. G. Shkornik-Yarros (B. Haigh, Translator; R. W. Duty, Editor). (Plenum, New York, 1971, 295 p., $22.50). The anatomical analysis of the cerebral cortex, so neglected in Western Europe and America, has long been the preoccupation of the Brain Institute at Moscow. Yet its publications are practically unknown to anatomists of the Western world, because of the language barrier. Mention of Sukhanov, Poliakov and Filimonov is apt to be met with an attentive silence. Catherine Shkol'nik-Yarros has been publishing, in Russian, on brain anatomy since 1950 and this book was published first in 1965, unbeknownst to almost all of us. Its excellent translation by Basil Haigh, and its scientific mis-en-scbne by Robert W. Doty, have combined to make an easy-reading text in current scientific vernacular. It is adequately illustrated, but it seems unfortunate that the excellent line drawings have been screened by the hand of the author. (Its list price of $22.50 is not reflected in the format of this small, plain book.) The object of the book is to use neuronal visualization of the neuronal structure of the lateral geniculate body and occipital cortex by light microscopy to carry the interpretations of the central visual mechanisms as far as these methods will permit. The Golgi method is utilized, practically to the exclusion of the visualization of degenerated neurons. The Golgi method has already been ably applied to the visual
560 cortex by Cajal, by Lorente de N6, by O+Leary and by Polyak, so it is only natural that we find little that is novel in this book. No one before, though, has carried the method up through the mammalian class with comparisons along the way. Indeed one comes out of a perusal of this section, which accounts for about half of the book, with a deeper understanding of the visual mechanisms. The second half of the book is mostly synthesis and an attempt at interpretation. with full regard for the existing literature. Several neuron types are recognized in the lateral geniculate, notably the "mi~lget cells". Yet the neuronal profile of the lateral geniculate is disappointingly similar to that of the other thalamic nuclei, in spite of all the specificity that must be immanent in transmission of a fully detailed picture in color. In area 17, layers IVa, b and c are exquisitely analyzed differentially and illustrated with pen drawings. The star cells are reaffirmed and their axons traced out from the cortex. These increase in the monkey, and enormously in man, so are considered significant. The evolution of the giant pyramids of Meynert is neatly traced to a crescendo in man. Their axons run to the superior colliculus. Then there are the large pyramids of the lower part of layer III, whose axons also leave the cerebral cortex. Thus, we have three extracortical axons and three places for them to go: superior colliculus, lateral geniculate and areas 18 and 19. The efferents are well taken care of, but what anatomical substrate is there for the discreteness and organization of the visual image'? It must be right there, in area 17, for we kno~. from experimental degenerations that there is no intercom system in or under area 17 sufficient to synthesize the visual
BOOK REVIEWS image m any one place within itself, or to transfer it to anywhere else. A glance at the cabbage-bud pattern in an occipital section of man or monkey, and the thin subcortical layer of fibers+ especially when we subtract the bulky contribution of visual radiation+ internal sagittal stratum of corticifugal axons, and the tapetum to the callosum, shows that there simply is not enough wiring behind the microcircuitry of the cortex to allow the visible image to be anywhere other than in the primary visual cortex itself. Yet Golgi preparations give no token of how this operation bootstrap is effected+ The fact is that, as Shkol'nik-Yarros testifies, there is but scant callosal connection between the two halves of this visual image, and yet there is never a seam in the midline of our visual image. The image must be all in area 17, and the rest of the cortex must get its information by looking at it along with us. But that is only the beginning. Where is the Golgi manifestation of the three-color system+ where is the neuronal expression of the binocular illusion of depth, and where the geometrics required for the line slope, movement, and quadrangular synthesis so elegantly shown in the single cell work of Hubel and Wiesel? Possibly the Golgi approach has nearly run its course, as has already the hope of electron microscope analysis, so that we are left to wait for some great third wave. And that may be the single-cell evoked potential, with positive identification, over the entire cortex. WENDEI.I, J. S. KRIE(; Northwestern University, Medical School, ('hica~lo, Ill. 60611 ( (/.S.A, i