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Summary Sleep is regulated by homeostatic process and circadian clock. Light indirectly modulates sleep by entraining the circadian clock to the solar day. Light can also influence sleep independent of photo-entrainment [ 1 ]. An acute light exposure could induce sleep, and an acute dark pulse could increase wakefulness in nocturnal animals [ 1, 2 ]. The photoreceptors and cell types in the retina that mediate light and dark effects on sleep are well characterized [ 1–4 ]. A few studies have explored the brain region involved in acute light induction of sleep. Fos expression and nonspecific lesions suggest that the superior colliculus (SC) may play a role in acute light induction of sleep [ 2, 5 ]. In contrast, the brain area and neural circuits mediating acute dark induction of wakefulness are unknown. Here, we demonstrated that retina ganglion cells (RGCs) had direct innervations on the GABAergic neurons in the mouse SC, and the activities of these cells were inhibited by an acute dark pulse, but not influenced by a light pulse. Moreover, ablating SC GABAergic neurons abolished the acute dark induction of wakefulness, but not light induction of sleep. Based on optogenetic and electrophysiological experiments, we found that SC GABAergic neurons formed monosynaptic functional connections with dopaminergic neurons in the ventral tegmental area (VTA). Selective lesions of VTA dopaminergic cells totally abolished acute dark induction of wakefulness without affecting the light induction of sleep. Collectively, our findings uncover a fundamental role for a retinal-SC GABAergic-VTA dopaminergic circuit in acute dark induction of wakefulness and indicate that the dark and light signals affect sleep-wake behaviors through distinct pathways. Graphical Abstract Highlights • GABAergic neurons in the SC receive direct input from RGCs • Acute dark induction of wakefulness requires SC GABAergic neurons • VTA dopaminergic neurons receive direct innervations from GABAergic neurons in the SC • VTA dopaminergic neurons are necessary for acute dark induction of wakefulness Zhang et al. reveal that lesions of SC GABAergic neurons, which receive direct input from RGCs, abolish acute dark induction of wakefulness in mice. They also demonstrate that VTA dopaminergic neurons form monosynaptic connections with SC GABAergic neurons and ablating of VTA dopaminergic cells also abolishes acute dark induction of wakefulness. [ABSTRACT FROM AUTHOR]