GABAergic neurones in the rat periaqueductal grey matter express α4, β1 and δ GABAA receptor subunits: Plasticity of expression during the estrous cycle

We propose that GABAA receptors with the α4β1δ configuration are expressed by GABAergic neurones in the periaqueductal gray matter and that the numbers of cells expressing these subunits are increased in late diestrus in line with falling plasma progesterone levels. Changes in GABAA receptor expression may lead to changes in the excitability of the neural circuitry in the periaqueductal gray matter.