Amine-containing peptidergic synapses in a parasympathetic ganglion?

Following fixation with the modified chromaffin reaction of Tranzer and Richards (1976) unusual nerve profiles were found forming synapses on neurons in a parasympathetic ganglion intrinsic to the rabbit rectococcygeus muscle. Synaptic profiles were remarkable in having very high proportions of large filled vesicles. In addition to numerous large filled vesicles, many of these profiles contained a few chromaffin-reactive small granular vesicles. It is suggested that these profiles contain and may release both peptides and amines or amine-like substances which could mediate or modulate synpatic transmission in the ganglion.