Effects of serotonergic agents on apomorphine-induced locomotor activity.

Autor: Young, Keith, Zavodny, Randall, Hicks, Paul
Zdroj: Psychopharmacology; 1993, Vol. 110 Issue 1/2, p97-102, 6p
Abstrakt: The interactions of serotonin 5-HT, 5-HT and 5-HT receptor subtypes with apomorphine-induced locomotor activity (AILA) were investigated in Sprague-Dawley rats. The 5-HT antagonists ondansetron and ICS 205-930 had no significant effects on AILA. The 5-HT agonist 8-hydroxy-2-(di-N-propylamino) tetralin (8-OH-DPAT) produced an increase in locomotor activity that was independent of DA neurotransmission. The locomotor activity induced by co-administration of apomorphine (APO; 0.25 mg/kg) and 8-OH-DPAT (0.25-1.0 mg/kg) was not significantly higher than those induced by APO alone during the peak period of APO stimulation of locomotor activity, nor were they higher than activity induced by 8-OH-DPAT alone during the same time intervals. The 5-HT antagonist (1)-propranolol had a depressant effect on AILA, but only at high doses. Co-administration of (1)-propranolol (5 mg/kg) and 8-OH-DPAT (1.0 mg/kg) elevated spontaneous locomotor activity for the first 10 min of the session when compared to 8-OH-DPAT (1.0 mg/kg) alone. The 5-HT antagonist ketanserin along with moderate and high doses of mesulergine depressed AILA, effects which may be mediated by the 5-HT antagonist properties of these drugs, by nonspecific sedation or by direct effects of these compounds on DA D receptors. In contrast to the high-dose mesulergine depression of AILA, a low dose (0.1 mg/kg) of mesulergine elevated AILA, an effect which was blocked by the 5-HT agonist 1-(2,-5-dimethoxy-4-iodophenyl) -2-aminopropane (DOI: 1 mg/kg). Neither of these compounds at the doses tested had significant effects on spontaneous locomotor activity. In addition, stereotypy was increased in rats co-administered DOI and APO. These findings suggest that the 5-HT and possibly the 5-HT receptor subtypes are prime targets for drug interventions intended to modulate DA neurotransmission. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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