Some data on GABA-ergic innervation of nucleus rotundus in chicks.

The EM preparates displayed in the nucleus rotundus also symmetrical type of synapses with flattened vesicles, known this type as inhibitory synapsis. To prove this supposition and to find the sources of inhibitory terminals GABA-immunostaining was applied in the diencephalon of chicks. The preparates were examined by light- and electronmicroscope. In nucl. rotundus the large terminal profiles on the cell membrane of principal neurons, on the dendrites and branching areas of terminal branchings of dendrites proved to be GABA positive. The sources of GABA-ergic fibers seemed to be the subpretectal and ventral posterior thalamic nuclei.