Effects of co-administration of the GABAB receptor agonist baclofen and a positive allosteric modulator of the GABAB receptor,CGP7930,on the development and expression of amphetamineinduced locomotor sensitization in rats

Background: several of the behavioral effects of amphetamine (amph) are mediated by an increase in dopamine neurotransmission in the nucleus accumbens. however,evidence shows that g-aminobutyric acid b (gabab) receptors are involved in the behavioral effects of psychostimulants,including amph. here,we examined the effects of co-administration of the gabab receptor agonist baclofen and a positive allosteric modulator of thegabab receptor,cgp7930,on amph-induced locomotor sensitization. methods: in a series of experiments,we examined whether baclofen (2.0,3.0 and 4.0 mg/kg),cgp7930 (5.0,10.0 and 20.0 mg/kg),or co-administration of cgp7930 (5.0,10.0 and 20.0 mg/kg) with a lower dose of baclofen (2.0 mg/kg) could prevent the development and expression of locomotor sensitization produced by amph (1.0 mg/kg). results: the results showed that baclofen treatment prevented both the development and expression of amph-induced locomotor sensitization in a dose-dependent manner. furthermore,the positive allosteric modulator of the gabab receptor,cgp7930,increased the effects of a lower dose of baclofen on amph-induced locomotor sensitization under both conditions. conclusion: these data provide further evidence thatgabab receptor ligands may modulate psychostimulant-induced behaviors.copyright © 2013 by institute of pharmacology polish academy of sciences.