[Statistical study of the impulse activity of posterior hypothalamic neurons in the presence of local changes in its temperature].

Distribution of the intervals between spikes of 50 neurons in the posterior hypothalamus were studied in 17 unanesthetized rabbits. Three main types of the interspike-interval distribution were found in the thermoneutral zone: 1) unimodal, mode 2-4 ms; 2) unimodal, mode 16-512 ms; 3) bimodal, modes 2-10 ms and 64-512 ms (the posterior hypothalamus temperature was 39.1 +/- 0.02 degrees C). When the posterior hypothalamus temperature was increased or decreased (by 0.5-1.5 degrees C), changes in the initial interspike-interval distributions were observed in 11 neurons. The changes disappeared when the thermal stimuli were removed; 6 neurons (of 11) altered the mean firing rates too when the posterior hypothalamus temperature was changed.