Ultrastructural study of small granule containing (SGC) cells in the lower mesenteric ganglion in drug treated guinea-pigs.

Small granule containing cells (SGC or SIF cells) in the lower mesenteric ganglion of the guinea-pig were studied in control and experimental animals. After reserpine administration a decrease of dense population of granular vesicles was found. After injection of nialamide and dopamine to the animals in SGC cells significantly increased the number and density of granular vesicles. No real efferent synapses were found on SGC cell processes, although sites with accumulated synaptic-like vesicles, mostly with a dense core, were often observed.