Neural compass in the sky

Abstract

Head-direction cells are neurons in the brain that increase their firing rates when animals face specific directions. The head-direction network serves as an internal compass, converting sensory cues into an instantaneous estimate of head direction to support navigation. Decades of laboratory and theoretical work have generated a sophisticated understanding of the mammalian head-direction network, including how external cues and internal self-motion cues contribute to precise head-direction coding. Yet most evidence comes from animals confined to small, laboratory environments, typically ~1 to 2 m² in area. On page 259 of this issue, Palgi et al. (1) present recordings of the activity of head-direction cells from Egyptian fruit bats made as the bats flew over large areas on a small, remote island. The data show that preferred firing directions of head-direction cells remain stable and anchored to a global reference frame in this large, natural environment just as they do in the laboratory.