Monoamine distribution on the ventral surface of the rat medulla oblongata.

The distribution of monoamine transmitters in the area near the ventral surface of the rat medulla oblongata was studied using the Falck-Hillarp histofluorescence method. Histological examination and scanning electron microscopy of these regions were also performed. It was found that there is a wide area dense with catecholamine terminals in the external layer of the ventral medulla oblongata. 5-Hydroxytryptamine-containing terminals and nerve cell bodies on and near the surface were also found. Due to their superficial localization these monoamines may influence the content of cerebrospinal fluid and in this way have effects on cardiovascular and other physiological functions.