Extended Data Fig. 7: Time-cells (as measured during motionless hanging) and place-cells (as measured in-flight) represent a largely overlapping population of cells – but there was no clear relation between their preferred-time and preferred-place.

(a) Top view of the experimental room (2.35 × 2.69 m, with 2.56 m height). Three landing-balls were positioned inside the room, designated as locations ‘Start’, ‘A’ and ‘B’. (b) Five examples of dorsal hippocampal CA1 neurons which were place-cells when the observer bat was flying (left), and were time-cells when the observer bat was motionlessly hanging from one of the landing balls (right). These examples demonstrate two things: First, that time cells and place cells are overlapping populations of cells (see also main Fig. 1h for a population analysis). Second, these examples demonstrate that the place-field and time-field of the same neuron are not necessarily related to each other in a simple way: The top 2 examples are cells whose place-fields were on opposite sides from the location of the time-field; and the bottom 3 examples demonstrate the lack of clear relation between preferred-time and preferred-place – for example late time-field for a cell whose place-field was early along the flight (third from the top), or vice versa (fourth from the top). First example: Left, place-cell firing rate map (top view) for flights from landing balls A and B to the Start ball. Right, time-cell raster for landing ball A. Note that the place-field is located on the flight path from ball B to the Start ball, whereas the time-field is on the other side – on ball A. Second example: Left, place-cell firing rate map for flights from the Start ball to balls A and B. Right, time-cell raster for ball A. Note that the place-field is located on the side of B, while the time-field is on the other side – on ball A. Third example: Left, place-cell firing rate map for flights from the Start ball to balls A and B. Right, time-cell raster for ball B. Note that the place-field is located close to the Start ball – early in the flight to B, while the time-field when the bat was on B occurs late in time. Fourth example: Left, Place-cell firing rate map for flights from landing balls A and B to the Start ball. Right, time-cell raster for ball B. Note that the place-field is located mid-way during the flight from B to Start, while the time-field occurs early in time. Fifth example: Left, place-cell firing rate map for flights from the Start ball to balls A and B. Right, time-cell raster on ball A. Note that the place-field is located mid-way during the flight, while the time-field occurs relatively early in time. (c) Population analysis. No significant correlation was found between the preferred time of firing after landing (x-axis) and the distance of the place-field peak from the takeoff-ball (y-axis) (Pearson r = –0.03, P = 0.64; Spearman ρ = –0.04, P = 0.54; two-sided tests). Plotted here are all the cells which were both significant place-cells when the bat was flying and significant time-cells when the bat was hanging motionlessly on one of the landing balls (n = 135 cells; note the number of dots plotted here [n = 194] is larger than the number of cells [n = 135] because neurons that had significant place-fields in the two flight-directions have contributed two dots to this scatter, and likewise for cells with significant time-fields in multiple locations [multiple balls]). Overall, there was no strong systematic relation between the preferred-time and preferred-place of firing for bat dorsal CA1 neurons.