SYNAPTIC RELATIONSHIPS BETWEEN CORTICOCUNEATE TERMINALS AND GLYCINE-IMMUNOREACTIVE NEURONS IN THE RAT CUNEATE NUCLEUS

The present study describes the ultrastructural synaptic relationships between corticocuneate terminals (CCTs) and glycine-immunoreactive (g lycine-IR) neurons in the cuneate nucleus of rats using anterograde tr act-tracing of wheatgerm agglutinin conjugated with horseradish peroxi dase (WGA-HRP) and anti-glycine immunoperoxidase labeling methods. The HRP-labeled CCTs made axodendritic synapses preferentially in the ven tral part of the cuneate nucleus near the obex. In a total of 182 CCTs surveyed, 14 of them made direct synaptic contacts with immunoperoxid ase-labeled glycine-IR dendrites. The present results suggest that cor tical modulation on the sensory transmission of cuneate nucleus may be mediated through glycine-IR neurons. (C) 1997 Elsevier Science B.V.