Excitatory effect of the superior colliculus on the motor neurons of extra-ocular muscles of cats]

The synaptic actions which might underline the caccadic eye movements induced by stimulation of the superior colliculus have been studied in the unanesthetized cat "encéphale isolé". Intracellular recordings of extraocular muscle medial rectus motoneurons have revealed a minimally disynaptic excitatory projection from the superior colliculus to the ipsilateral medial rectus motoneurons (latency 1.3 to 2.6 msec).