Abstract Introduction Sleep disruption leads to attention impairments, excessive daytime sleepiness, and is a major contributor to accident rates and decreased workplace productivity. The basal forebrain (BF) region has long been associated with promoting cortical arousal and wakefulness. Recently, selective excitation of BF parvalbumin (PV) GABAergic neurons has been shown to produce high frequency cortical activation and brief periods of wakefulness. Here we test the hypothesis that BF PV neurons are involved in vigilant attention using bidirectional optogenetic manipulations in a signaled reaction time task. Methods Brief optogenetic excitation (ChR2) and inhibition (ArchT) of BF PV neurons was applied during a lever release version of the rodent psychomotor vigilance task (rPVT). Mice were trained to hold a lever down to initiate a trial and after a random delay, a 200ms cue light signaled the mouse to quickly release the lever within 1s to receive a sucrose pellet reward. The reaction time between cue light onset and lever release was the primary measure of attentional performance. Sleep deprivation (8h) produced by gentle handling was also investigated. Laser parameters: brief (1s) of continuous (non-pulsatile) laser stimulation was delivered beginning 500ms prior to cue light onset (5mW 473nm blue light for ChR2-mediated excitation; 10mW 530nm green light for ArchT-mediated inhibition). Results BF PV excitation led to faster reactions times (N=6, 14% faster, p<.001), interpreted as an enhancement of attention. Sleep deprivation slowed reaction times (20% slower, p<.01) and BF PV excitation rescued the sleep deprivation induced impairments. BF PV inhibition significantly slowed reaction times (25% slower, p<.02), an effect that resembled the effects of sleep deprivation. Conclusion This is the first demonstration of a role for BF PV neurons in attention and in the attention deficits produced by sleep deprivation. Support T32 HL007901, I01 BX002774, P01 HL095491, R01 MH039683, I01 BX004500, IK2 BX002130, Stonehill College SURE program, I01 BX001356