By controlling spike timing and sculpting neuronal rhythms, inhibitory interneurons play a key role in brain function. GABAergic interneurons are highly diverse. The respective GABAA receptor subtypes, therefore, provide new opportunities not only for understanding GABA-dependent pathophysiologies but also for targeting of selective neuronal circuits by drugs. The pharmacological relevance of GABAA receptor subtypes is increasingly being recognized. A new central nervous system pharmacology is on the horizon. The development of anxiolytic drugs devoid of sedation and of agents that enhance hippocampus-dependent learning and memory has become a novel and highly selective therapeutic opportunity.