PONTINE NEURONS WHICH RELAY PROJECTIONS FROM THE SUPERIOR COLLICULUS TO THE POSTERIOR VERMIS OF THE CEREBELLUM IN THE CAT - DISTRIBUTION AND VISUAL PROPERTIES

Extracellular unit recording revealed that the dorsolateral pontine nu cleus (DLPN) and nucleus reticularis tegmenti pontis (NRTP) of the cat constituted pontine relays for transmission of visual information fro m the superior colliculus (SC) to the posterior vermis (lobules VI and VII) of the cerebellum. The relay neurons in DLPN/NRTP responded to m oving visual stimuli with large receptive fields (23-75 degrees) which occupied mainly the contralateral hemifield including the fovea. Thes e neurons were usually more responsive to large-sized stimuli than to discrete-spot stimuli, had direction selectivity, and showed preferenc e to visual motion at a relatively high speed. No clear differences in visual properties were observed between DLPN and NRTP. After a local injection of lidocaine into SC, the visual responses in DLPN/NRTP tran siently disappeared, indicating that DLPN/NRTP received the visual inp uts through SC. (C) 1997 Elsevier Science Ireland Ltd.