Voltammetric study of 8-OH-DPAT effect on the raphe-trigeminal 5-HT system

Abstract

The effect of i.p. administration of the selective 5-HT1A agonist 8-hydroxy-2-(di-N-propylamino) tetralin (8-OH-DPAT) (100 micrograms kg-1) has been investigated by in vivo 5-hydroxyindole electrochemical (peak 3) detection in the nucleus raphe magnus (NRM) and medullary dorsal horn (MDH) of acute anaesthetized and unanaesthetized freely moving rats. 8-OH-DPAT induced a small but significant decrease in peak 3 in the NRM and MDH of anaesthetized rats. In freely moving animals, a similar small effect was observed at both NRM and MDH levels. With reference to similar in vivo studies demonstrating differential responsiveness of ascending serotonergic systems to 8-OH-DPAT, it is concluded that the serotonergic NRM-dorsal horn system is slightly affected by this 5-HT1A agonist.