Slow bursting thermal sensitive neurons in the preoptic area of the rabbit.

Recent data have shown the presence of some hypothalamic neurons with a slow bursting activity. This study reports the interactions of slow bursting neurons with thermoregulatory control in the preoptic/anterior hypothalamus (POAH). Ninety-seven single units studied with direct thermal stimulation and with central injections of norepinephrine (NE) or serotonin (5-HT) were assessed for slow bursting activity. Twenty-one percent of the neurons had slow bursting activity patterns with frequencies ranging from 0.02-0.10 Hz. Intraventricular or direct POAH injected monoamines frequently inhibited bursting activity during normothermia and/or POAH thermal stimulation. Slow bursting neurons may elicit rhythmic thermoregulatory motor outputs, neurosecretion, and infraslow DC potentials in the central nervous system.