Altered anxiety and depression-related behaviour in mice lacking GABAB(2) receptor subunits

Metabotropic GABA(B) receptors predominantly function as heterodimers of GABA(B(1)) and GABA(B(2)) subunits, but GABA(B(1)) can also form functional receptors in the absence of GABA(B(2)). Mice lacking the GABA(B(1)) subunit have altered behavioural responses in tests for anxiety and depression. In these studies, we investigated anxiety and depression in GABA(B(2))-deficient mice. We compared the effects directly with that of genetic deletion of the GABA(B(1)) receptor subunit. Both GABA(B(1)) and GABA(B(2))-deficient mice were found to be more anxious than wild type in the light-dark box paradigm. In contrast, these mice exhibited an antidepressant-like behaviour in the forced swim test. Taken together, these data suggest that heterodimeric GABA(B(1,2)) receptors are required for the normal regulation of emotional behaviour. (c) 2005 Lippincott Williams & Wilkins.