EXPRESSION OF SEROTONIN TRANSPORTER MESSENGER-RNA IN RAT-BRAIN - PRESENCE IN NEURONAL AND NONNEURONAL CELLS AND EFFECT OF PAROXETINE

The expression of serotonin transporter mRNA in rat brain was examined by in situ hybridisation. Hybridisation was observed in cells of the known serotonergic nuclei and no other neuronal populations. It was al so associated with ependymal cells of the aqueduct which may indicate a specialisation of this part of the ventricular system in anatomical and neurophysiological terms. The effect of the selective serotonin re uptake inhibitor paroxetine on neuronal expression of the serotonin tr anporter mRNA was examined. Quantitation at the cellular level in the dorsal and median raphe nuclei was carried out by analysis of the mean number of silver grains per cell in autoradiographed sections. No sig nificant change (P > 0.1) in serotonin transporter mRNA expression was observed following 21 day administration of paroxetine (5 mg/kg per d ay). (C) 1997 Elsevier Science B.V.