[Temperature dependence of neuronal activity in hypothalamic and hippocampal slices of the guinea-pig]

Unit activity in slices of the hippocampus and medial preoptic area of the hypothalamus of guinea-pigs was extracellularly recorded under conditions of temperature changes. Seven out of nineteen hypothalamic neurons showed changes in the firing rate at threshold temperatures of 36-38 degrees C. In the suprathreshold range the activity of these neurons depended on the temperature level. It is suggested that such neurons may form a sensory part of the system controlling brain temperature within a narrow (1-2 degrees C) range. The pyramidal layer cells of the control structure (hippocampus) were insensitive to the temperature level within 32-40 degrees C.