Gaze shifts in freely moving mice comprise distinct head-eye coordination motifs

Abstract

Freely moving mice are generally thought to redirect gaze mainly through head-coupled movements, with eye movements stabilizing the retinal image or resetting eye position. This reflexive view leaves unresolved whether gaze shifts also include active coordination modes. Here we show that a single gaze-shift class resolves into multiple distinct head-eye coordination motifs. Using high-resolution head and eye tracking in freely moving mice, we identified four reproducible motifs: Head-before-Eye (HbE), Head-with-Eye (HwE), Head-Dominant (HD), and Eye-Dominant (ED). The motifs differed in head-eye timing, locomotor context, and pre-onset visual-behavioral structure. Their short-timescale sequential organization was non-random: HD formed alternating side-to-side head movements, whereas HwE-HbE-ED formed a directed transition chain preserved within each movement direction. Simultaneous neural recordings further revealed motif-dependent responses in primary visual cortex (V1) and superficial superior colliculus (sSC), with stronger sSC than V1 modulation for the three motifs distinguished by pre-onset visual-behavioral structure (all but HbE). HwE showed the clearest signature of active orienting, combining near-synchronous head-eye onset, strong relevance to visual-behavioral features, and the largest pre-onset and earliest peri-onset responses in sSC. These results expand a unitary view of gaze shifts in freely moving mice into a diverse, structured repertoire of coordination motifs, and identify HwE as a candidate active gaze-shift mode during natural behavior.