The hypnotic zolpidem increases the synchrony of BOLD signal fluctuations in widespread brain networks during a resting paradigm

► Synchronized BOLD fluctuations contain information about functional connectivity. ► We challenged spontaneous brain activity using the GABAergic hypnotic zolpidem. ► Zolpidem increased functional connectivity in sensory, motor, and limbic networks. ► Effects were consistent with other GABA-related increases in BOLD signal synchrony. ► Functional connectivity may reveal network substrates of sedative drug effects.