An acute exposure of electroacupuncture (EA) treatment (10 Hz, 1 volt) to adult male albino rats significantly increases GABA level at 12 and 30 min after periods of 15-min EA treatment in hypothalamus (Hy) and thalamus (Th). No significant change in GABA level is observed during EA analgesia (EAA) in these two brain regions. Other regions (cerebral cortex (CC), pons-medulla (PM) and spinal cord (SC)) of CNS remain unaffected during and after periods of EAA. Glutamate (Glu) level is increased significantly at the onset (2 min) of EAA in PM, at optimum period of analgesia (10 min) in CC and at the end of 15 min of EA in Th. Glu level in PM, on the other hand, is significantly reduced at the optimum period of EAA. No significant change in Glu level is observed in the remaining phases of EAA and the post period of EA in different regions of CNS. The activity of glutamic acid decarboxylase (GAD) is significantly increased 30 min after EA in Hy but in PM it is decreased at the onset and at the 30 min after EAA. GABA-transaminase (GABA-T) activity in PM and Th significantly increases at the onset, optimum and at the end of the optimum period of EAA. GABA-T activity in SC increases only at onset of EAA and in Th at 30 min after EAA. These results suggest that the central GABergic system, depending on the region of the CNS, is involved in a characteristic manner duirng and after periods of EAA.