Order Vestibular Neurons Research Articles

Reticular Control of the Vestibular Nuclei : Physiology and Pharmacology

The lack of detailed anatomical information concerning the reticular projections to the vestibular nuclei, experimental evidence indicates that the brain stem reticular neurons influence the activity of the second order vestibular neurons. In unrestrained and unanesthetized preparations, the spontaneous activity of these vestibular neurons changes during the sleep-waking cycle to the level of activity of the reticular activating system. During desynchronized sleep, there is a typical change in the spontaneous discharge of the neurons localized in the medial vestibular nuclei, characterized by bursts of rapid firing sometimes followed by periods of relative silence. These bursts of unit discharge lead to the appearance of rapid eye movements (REMs), which are typical of this phase of sleep. Intravenous injection of eserine sulphate performed in precollicular decerebrate animals leads to rhythmic changes in unit discharge of the vestibular neurons, which are responsible for the occurrence of regular bursts of conjugate rapid eye movements. These rhythmic changes in firing discharge of the vestibular neurons, which resemble those occurring during the REM bursts of desynchronized sleep, are attributed to tonic activation of cholinergic reticular neurons, whose discharge probably acts on the vestibular neurons through both excitatory and inhibitory pathways.