ELECTRON-MICROSCOPIC STUDY OF MAOB-CONTAINING STRUCTURES IN THE NUCLEUS-ACCUMBENS SHELL - USING MAOA-DEFICIENT TRANSGENIC MICE

MAOB-containing structures in the nucleus accumbens were ultrastructur ally studied for the first time, using MAOA-deficient transgenic mice and MAO enzyme histochemistry. Among the striatal structures, the nucl eus accumbens, and in particular its dorsal shell, showed the stronges t MAOB activity. MAOB-active cell bodies were embedded in a dense MAOB -active fiber plexus. MAOB-positive terminals formed axo-dendritic syn apses which were exclusively of the asymmetric type. It is suggested t hat dopamine in the nucleus accumbens shell is transported into MAOB-p ositive fibers where it is degraded by MAOB. (C) 1997 Elsevier Science B.V.