Effects of vestibular stimulations on guinea pig posterior hypothalamic neuron activity

Abstract

The effects of rotation stimulation and caloric stimulation on the neuronal activity in the posterior hypothalamus (PH) were studied in anesthetized guinea pigs. The spontaneous discharge of PH neurons demonstrated a change in 63%, and the main change was inhibition. It started gradually after the rotation began and then lasted for several minutes even after the rotational cycle. Caloric stimulation produced a neuronal activity change in almost 60% of the tested PH neurons. The PH neurons which were excited by hot stimulation were excited by cold stimulation, and the PH neurons which were inhibited by hot stimulation were inhibited by cold stimulation. the above response pattern therefore closely correlated with the regulatory mechanism of the vestibulo-autonomic reflex.