Abstract

Circadian clocks are a ubiquitous feature of the mammalian brain, yet whether they regulate how neural circuits encode and transmit information remains largely unknown. Here, we address this question in the mouse visual thalamus (dLGN), a key relay between retina and cortex that provides a tractable model for studying sensory information transfer. Using wireless electrophysiological recordings from awake, behaving mice, we show that spontaneous dLGN activity is under circadian control, peaking during the late subjective day. Combining visual stimulation, information-theoretic analyses, and optogenetic interrogation of retinogeniculate transmission, we demonstrate that circadian phase selectively reconfigures the visual code. Although fundamental tuning properties remain largely stable, the impact of circadian phase on information transfer depends on visual scene statistics, promoting a more efficient coding strategy at night under high-contrast conditions. Together, these findings identify circadian clocks as dynamic regulators of neuronal communication that actively reshape sensory information processing across the day-night cycle.