Primatologia. Handbook of Primatology

While the literature and textbooks contain descriptions of cord form and function , none fully accounts for primates. This, then, is a general review of the neuro-anatomy and neurophysiology of the spinal cord in primates, with especial reference to squirrel, spider, and rhesus monkeys, chimpanzee, and man. It is timely because (1) studies of axonal pathways using silver impregnation and electrophysi-ological methods first worked out in the cat have now been extended to primates, (2) Rexed's laminar method of describing the gray matter of the cord of the cat has now also been extended to several primates, and (3) the descriptions in the literature of the "generalized higher mammalian cord" are inadequate as bases for further anatomical or physiological study of the central nervous system of primates. The authors first give an account of some of the differences in gross morphology of the cord in different species. Peripheral nerves are then described with regard to fiber classification, dermatome patterns, and the course and pattern of termination of the dorsal root fibers within the cord. There are 10 large photographs of Nissl sections taken from different levels of the cord of the rhesus monkey, showing the gray matter divided into laminae according to Rexed's system of description, and correlating the laminae with the older nomenclature of gray matter nuclei. Some of the projections of cells in the gray matter are then described, especially those that make up the pathways that ascend to the encephalon. Descending pathways are discussed, with particular regard for their precise origin and termination which one end on motoneurons, which on interneurons, and in what laminae. There are short summaries of placement within the cord of the motoneurons with respect to the muscles they innervate, of some of the interneuronal circuits within the cord, and of presumed patterns of control of these mechanisms by the brain. The anatomy comes through much better than the physiology: there is the gate-control pain theory of Melzack and Wall, without the recent evidence and objections of Perl; there is little effort to describe or make much functional sense out of the interneuronal circuits as has recently been attempted by Lundberg and colleagues (though admittedly mostly in the cat); there is no attempt to explain control by gamma loop or Golgi tendon organ systems. But the anatomical diagrams are clear, the references to the anatomical literature rich, and the writing for the most …