Fluorescence histochemistry of monoamine‐containing cell bodies in the brain stem of the squirrel monkey (Saimiri sciureus). II. Catecholamine‐containing groups

Abstract In this second paper of the series on the monoamine‐containing cell bodies found in the brain stem of the squirrel monkey ( Saimiri sciureus ) by the fluorescence histochemical technique, a description is presented of the catecholaminergic neurons. The first paper was a report on the locus caeruleus (a norepinephrine containing group), which, in consideration of its physiological importance, was the object of a particularly detailed study. The other groups of catecholaminergic cell bodies were found to have a topographic distribution and general morphological characteristics quite similar to those described for the rat. In particular, in the squirrel monkey brain stem homologous groups of neurons were observed for each group described in the rat, with the exception of the weakly fluorescing group A3. In comparing the findings on the squirrel monkey with the description of the catecholaminergic cell groups in the cat some significant differences were noticed.