Genetic manipulations of GABAA receptor in mice make inhibition exciting.

The inhibitory neurotransmitter gamma-aminobutyric acid (GABA) plays an important role in brain development and behavior. GABA(A) receptor subunits knock-out and knock-in mice have proven that GABA(A) receptors are involved in control of motor coordination, learning, and memory and play a role in anxiety, panic, and epileptogenesis. In addition, these receptors are involved in the molecular mechanisms of action of many drugs and participate actively in cortical plasticity. The use of genetically engineered mice has perhaps never been as successful as in understanding the importance of the heterogeneity of GABA(A) receptors. We review these findings and speculate on the new directions that the use of mice with altered expression of GABA(A) receptor subunits may provide.