GABA receptor alterations after chronic lithium administration. Comparison with carbamazepine and sodium valproate

Motohashi Nobutaka: GABA Receptor Alterations After Chronic Lithium Administration. Comparison With Carbamazepine And Sodium Valproate. Prog. Neuro-Psychopharmacol. & Biol. Psychiat. 1992, 16 (4): 571–579. 1. 1. Effects of lithium, carbamazepine, sodium valproate and baclofen on GABA receptors were examined in several regions of the rat brain. 2. 2. [ 3H]Muscimol (MUS) and [ 3h] (−) baclofen (BAC) were used to label GABA A and GABA B receptors, respectively, in synaptic membranes from rat brain. 3. 3. Single treatment with lithium chloride, carbamazepine or sodium valproate did not change [ 3H]MUS or [ 3H]BAC binding in the frontal cortex, hippocampus and thalamus. 4. 4. Following chronic treatment with lithium, carbamazepine or sodium valproate, [ 3H]BAC binding was significantly increased in the hippocampus but not in the frontal cortex, thalamus or striatum. 5. 5. [ 3H]Muscimol binding did not change in any region examined after chronic treatment with lithium, carbamazepine or sodium valproate. 6. 6. Single and chronic administration of baclofen did not change [ 3H]MUS or [ 3h]BAC binding. 7. 7. One common mechanism of action of mood stabilizers may be mediated by GABA B receptors in the hippocampus.