Sites in the rabbit flocculus specifically related to eye blinking and neck muscle contraction

In alert rabbits, the cerebellar flocculus was mapped for effects of local stimuli delivered through glass microelectrodes. Triple-barreled glass microelectrodes were used, each barrel of which was filled with solution containing one of three different dyes (Fast Green FCF, Pontamine Sky Blue and Nigrosine) for differentially labeling the sites exhibiting different stimulus effects. In addition to eye movements reported earlier, eye blinking and contraction of dorsal neck muscles were elicited from limited areas of the flocculus. Eye blinking sites were concentrated rostroventrally and neck muscle contraction sites caudoventrally within the flocculus. The present results suggest that the rabbit flocculus contains specific sites devoted to the control of eye blinking and neck posture.