Figure 8.

Ultrastructure of reticuloreticular axon terminals. Axon terminals that were labeled with BDA (At*) following the injection of the cMRF shown in Figure 7 were electron dense. Most of these terminals contacted (arrowheads) small dendrites (Den). These labeled terminals were heterogeneous: some were packed with clear spherical vesicles (A–C) and displayed asymmetric synaptic densities (C). Others contained pleomorphic vesicles and made symmetric contacts (D–F). Postembedding immunohistochemistry for gamma-aminobutyric acid (GABA) labeled a portion of the BDA labeled axon terminals (At^*+), as well as some terminals not labeled with BDA (At⁺). The BDA labeled terminals that were overlain with numerous gold particles indicating they were GABAergic contained pleomorphic vesicles and made symmetric synaptic contacts (D–F).