Neuronal organization of the thermosensory region of the anterior hypothalamus.

Changes in extracellular unit activity of 236 neurons of the medial preoptic and septal regions to local temperature stimulation were studied in acute experiments on rabbits anesthetized with urethane and chloralose. Of this total number of neurons 27% were highly sensitive to changes in brain temperature (15% to heat, 12% to cold). Altogether 6% of neurons gave an on-response and 5% a prolonged after-effect to temperature stimulation. The possible role of these neurons in the regulation of temperature homeostasis is discussed.