LOCALIZATION, BY THE BRAIN SLICING METHOD, OF THE LEVEL OR LEVELS OF THE CEPHALIC BRAINSTEM UPON WHICH EFFECTIVE HEAT DISSIPATION IS DEPENDENT

The neural integration of heat dissipation is wholly dependent upon the anatomical integrity of the subthalamic and cephalic midbrain level of the brainstem. Except for a possible permissive function, heat dissipation is quite independent of the hypothalamus. Presumptively, it is concluded that tissues within or near the anterior hypothalamus play a permissive role concerned with determining the core temperature level (39°C.) at which the heat-dissipation outflow is activated. Afferent impingements originating from non-thermal peripheral receptors exert a modulating influence on the central integration of responses to both heat and cold. The neural integration of resistance-to-hypothermia is wholly dependent upon the anatomical integrity of the hypothalamic grey and is completely independent of tissues lying cephalad to the hypothalamus. The resistance-to-hypothermia outflow is more susceptible to impairment than is the heat-dissipation outflow following trauma to the cephalic portion of the diencephalon.