Fig. 14.

Zero or low levels of VGAT in subpopulations of nerve terminals that are enriched with GABA or glycine. Adjacent ultrathin sections of LSO were incubated with antibodies to GABA (A), glycine (B), and VGAT (C). Two putatively “pure” glycinergic terminals (T_aand T_b), synapsing on a neuronal soma (S), show differential VGAT labeling. AlthoughT_b is enriched with VGAT,T_a is not. In A, contrast the lack of GABA immunoreactivity in vesicle-containing areas ofT_a and T_b with the intense labeling of a nearby small terminal (at the top border). A myelinated axon (A) is immunoreactive for glycine. Insets, A GABA-labeled terminal (T_c), forming a symmetric synapse on a dendrite (D), is not labeled for glycine or for VGAT. Another terminal (T_d) apposed to the same dendrite is unlabeled with all three antibodies. The postsynaptic neuronal soma (S) has a moderate glycine signal and a slight VGAT signal. Scale bars, 0.5 μm.