Catecholamine cell groups of the cat medulla oblongata.

The distribution of catecholamine-containing cells within the cat medulla oblongata has been studied using formaldehyde-glutaraldehyde fluorescence histochemistry. The diffuse ventrolateral cells (A1) were scattered around but not within the lateral reticular nucleus and no cells were found dorsal to the inferior olivary nucleus. The dorsomedial (A2) cells were scattered within the nucleus tractus solitarius with an occasional cell within the dorsal motor nucleus of the vagus. No A2 cells were found within or ventral to the hypoglossal nucleus. This description contrasts in several respects with a recently published atlas of the catecholamine-containing neurons in the cat medulla.