The compass within

Abstract

Head direction cells have been hypothesized to form representations of an animal’s spatial orientation through internal network interactions. New data from mice show the predicted signatures of these internal dynamics.

Figure 1

The attractor-network model of the head direction system produces a coherent head direction representation even in the absence of external inputs. (a) The ring attractor network. Each cell is positively coupled (blue) to its representational neighbors and negatively coupled (red) to the entire ring, which produces a structure of local excitation amidst global inhibition. (b) Even in the absence of external inputs, the internal dynamics of the ring network settles to a ‘bump’ or ‘activity packet’ (red, high activity; blue, low activity). This specific simulation was generated using code from ref. , but all ring attractor models produce equivalent dynamics. (c) An activity packet seen by Peyrache et al. during sleep states, showing the ‘virtual gaze’ of the mouse (reprinted from ref. with permission).