Both fast and slow relay cells in lateral geniculate nucleus of rabbits receive recurrent inhibition

Lack of visual suppression in the rabbit lateral geniculate nucleus during blink reflex

Stimulation of the supraorbital branch of the trigeminal nerve (SO) elicited eye blinks in the rabbit, but did not decrease the amplitude of visual cortical evoked potential from stimulation of the optic chiasm (OX). In addition, the SO stimulation neither induced an inhibitory postsynaptic potential (IPSP) in LGN cells, nor activated inhibitory interneurons in the thalamic reticular nucleus (TRN), which proved to mediate both recurrent inhibition and saccadic suppression in the dorsal lateral geniculate nucleus (LGN). All these indicate that there is no visual suppression in the rabbit LGN during blink reflex.

Lack of binocular inhibition in monocular segment of lateral geniculate nucleus of rabbits

In the monocular segment of the rabbit lateral geniculate nucleus, relay cells responded exclusively to the contralateral optic input with an EPSP-IPSP sequence. The ipsilateral optic input could neither evoke PSPs nor facilitate the PSPs from the contralateral eye, indicating the absence of binocular inhibition in the segment.