Fig. 1: The two-dimensional active avoidance paradigm and recording of prefrontal population activity.

a, Task schematic and time course of the 11-day learning paradigm. Tasks 1 and 2 are defined by shuttling along the x and y axes of the shuttle box, respectively. b, Trial structure and illustration of the different trial types (avoid and error). c, Percentage of successful avoid trials per active avoidance session (n = 12 mice, mean ± s.e.m.). d, Shuttle rates for X shuttle (solid line) and Y shuttle (dashed line) across 11 days of learning (n = 12 mice, mean ± s.e.m.). e, Miniaturized (single photon) population calcium imaging in freely behaving mice. GCaMP6m was genetically expressed in pyramidal neurons, and a GRIN lens was implanted above the PL. Scale bar: 1 mm. f, Cell map of an example animal. Scale bar: 100 μm. g, Calcium fluorescence traces of ten example neurons on days 1, 6 and 11. h, Top, mouse speed for five exemplary avoid trials including markers for three reference time points (tone start, shuttle start and tone end). Bottom, distributions of latencies from tone start to shuttle start and shuttle start to tone end over all avoid trials (days 2–9, 12 mice). i, Top, calcium fluorescence traces of one example neuron aligned to tone start (left) or shuttle start (right). Trials are sorted according to trial length. Bottom, trial-averaged neuronal activity of the same neuron. j, Percentage of trial-responsive neurons across 11 days of learning (n = 12 mice, mean ± s.e.m.). See Methods for the definition of trial-responsiveness. k, Overlap of trial-responsive subpopulations across 11 days, where the overlap between days i and j is defined as n_{i and j}/((n_i + n_j)/2). l, Trial-averaged response of four example neurons aligned to tone start (left) or shuttle start (right). OFC, orbitofrontal cortex; IL, infralimbic cortex; PL, prelimbic cortex; D1, day 1; D2–D4, days 2–4; D5–D9, days 5–9; D10–D11, days 10–11.