TEMPERATURE REGULATION "CENTERS" 
extent the work of one man. J. Hughlings Jackson was led by clinical 
observations of neurological disease to subdivide the brain in a 
series of horizontal components, each of which maintained excitatory 
or inhibitory dominance over the segments below. Analysis of these 
segments was carried out by transections of the brain at various 
levels. I. P. Pavlov, on the basis of his conditional reflex studies, 
divided the brain into a series of vertical segments, or what he 
called motor and sensory analyzers. These consisted of chains of 
neurons extending from the sensory receptor through the spinal 
cord and basal ganglia to the cortex, or in the opposite direction 
from the cortex down to the effector without significant transverse 
interaction being postulated at intervening way stations. 
Another series of subdivisions was developed by C. Judson 
Herrick and others on the basis of caom pa rat ive behavioral studies 
and the comparative anatomy of the vertebrates. He based his sub- 
division largely on the phylogenetic differentiation of the parts of 
the brain, which ultimately led to recognition of the importance of 
various parts of the limbic lobe in behavior. Each of these views 
was carefully developed over a period of many years and was based 
on a systematic observation of total behavior, that is, the behavior 
of animals in the intact state. The doctrine of the centers had no 
direct relationship to any of these systems, nor, for that matter, 
to any other. Rather, it developed from observations of isolated 
"evoked" responses in non-behavioral contexts. It was not the work 
of any one man or any one school and has yet to be given a formal 
and logical description. Yet it has been as widely accepted and used 
as any of the other three. 
Historically, the term 'center' first came into general usage 
after 1870. Prior to that time it was rarely used in text books, but 
thereafter it occurred in almost all major text books of physiology 
and clinical neurology. Specifically, it seems to have followed the 
discoveries by Fritsch and Hitzig in 1870 (see Brazier, 1959) of the 
excitable motor cortex and by Claude Bernard of the hyperglycemia 
produced by stimulation of the medulla. Several kinds of influence 
seem to have facilitated its immediate acceptance as a method of 
analyzing or describing brain function. First among these was un- 
doubtedly the development of new techniques for histological stain- 
ing, which showed that the brain could be subdivided, or was 
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