C-FOS EXPRESSION IN THE ACCESSORY OCULOMOTOR NUCLEI FOLLOWING NEOCEREBELLAR STIMULATION

THE present study was carried out to determine whether, in the rat, th e electric activation of the projection from the cerebellar lateral nu cleus (LN) to the accessory oculomotor nuclei (AON; nucleus of posteri or commissure, nucleus of Darkschewitsch, interstitial nucleus of Caja l) is capable of inducing c-fos expression. In particular, we compared the effects of a continuous LN stimulation at low-frequency (tonic st imulation) with those induced by high frequency pulse trains (phasic s timulation). The observed results show that the stimulation of LN indu ces c-fos expression in a significant proportion of neurones in the co ntralateral AON. Phasic stimulation was slightly more effective than t onic stimulation in producing c-fos expression.