Synaptic contacts between CGRP-immunoreactive terminals and enkephalin-immunoreactive neurons in the central amygdaloid nucleus of the rat.

An immunoelectron microscopic method combined with immunofluorescence double staining was carried out to examine the relationship between calcitonin gene-related peptide (CGRP)-like immunoreactive (LI) axon terminals and enkephalin (ENK)-LI neurons in the central amygdaloid nucleus (Ce) of the rat. The latter method showed that many ENK-LI cell bodies are densely surrounded by CGRP-LI axons in the lateral subdivision of the Ce (CeL). After taking fluorescence micrographs, the immunoperoxidase technique was used to examine the CGRP-LI axonal profiles under an electron microscope. CGRP-LI terminals were frequently found to form axo-somatic synaptic contacts with ENK-LI neurons in the CeL.