Activation of the cannabinoid receptor by Delta super(9)-tetrahydrocannabinol reduces gamma -aminobutyric acid uptake in the globus pallidus

The interaction between GABA ( gamma -aminobutyric acid) and cannabinoids in the globus pallidus was investigated by evaluating the effects of Delta super(9)-tetrahydrocannabinol on [ super(3)H]GABA uptake into slices of rat globus pallidus. Delta super(9)-Tetrahydrocannabinol caused a concentration-dependent decrease in GABA uptake (51% decrease at 100 mu M Delta super(9)-tetrahydrocannabinol, IC sub(50) = 18.95 mu M). This effect was reversed in a concentration-dependent manner (IC sub(50) = 11.9 mu M) by the cannabinoid receptor antagonist SR 141716A (N-(piperidin-1-yl-)5-(4-chlorophenyl) 1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole 3-arboxiamidehydrochloride. SR 141716A alone did not affect GABA uptake. These results show that cannabinoid receptor activation reduces GABA uptake in the globus pallidus.