The benzodiazepine Midazolam mitigates the breathing defects of Mecp2-deficient mice.

Rett syndrome is a severe neurodevelopmental disease caused by mutations of the transcriptional repressor methyl-CpG-binding protein 2 (MeCP2) that induce complex, disabling symptoms, including breathing symptoms. Males of Mecp2-deficient mice (Mecp2(-/y)) normally breathe at birth but develop first altered breathing regulations, thereafter erratic breathing with severe apnoeas, aggravating until respiratory distress and premature death. Mecp2(-/y) mice also develop early GABA deficits. To examine whether GABA deficits contributed to breathing defects of Mecp2(-/y) mice, mice were subjected to acute administration of Midazolam, a benzodiazepine of clinical use known to enhance GABA effects. For the first time, we showed that Midazolam abolished, although transiently, the breathing defects of Mecp2(-/y) mice, confirming a crucial role of GABA deficits in their breathing defects.