Differential effects of endocannabinoids on[3H]-GABA uptake in the rat globus pallidus

In the globus pallidus, cannabinoid CB1 receptors are localized pre-synaptically on GABAergic neurons, We assessed the influence of the endocannabinoids, anandamide, 2-arachidonoyl-glycerol (2-AG) and noladin ether. on the uptake of [H-3]-GABA in pallidal slices from rat. Both 2-AG and noladin ether increased [H-3]-GABA uptake (by 40.8 +/- 8.0% and 38 +/- 12.5%). The effect ct of 2-AG was blocked by the cannabinoid CB1 receptor antagonist AM 251. In contrast, neither anandamide nor the agonist WIN 55.212-2 had in eflect on [H-3]-GABA uptake. Different roles might be played by different endocannabinoids, both physiologically and in basal ganglia disorders. such as Parkinson's disease. (c) 2005 Elsevier Inc. All rights reserved.