Effects of caloric vestibular stimulation on serotoninergic system in the media vestibular nuclei of guinea pigs.

Background: Anatomic and electrophysiological studies have revealed that the neurons located in the media vestibular nuclei (MVN) receive most of the sensory vestibular input coming from the ipsilateral labyrinth and the responses of MVN neurons to caloric stimulation directly reflect changes in primary vestibular afferent activity. The aim of this study was to clarify the intrinsic characteristics of serotonin (5-hydroxytryptamine, 5-HT) release in the MVN during the period of vertigo induced by caloric stimulation.

Methods: We used an in vivo microdialysis technique to examine the effects of caloric stimulation on the serotoninergic system in MVN.