Extended Data Figure 8: A large fraction of CA1 and MEC cells with activity at the cue port were place cells and grid cells, respectively.

a, Spatial distribution of firing in example cells with cue-port activity recorded in dCA1, pCA1, LEC or MEC in either the odour–cue association task (top) or a random foraging task in a 1 m square box (bottom). Each column shows results for one representative cell. For each cell, spike position (red) is overlaid on the trajectory of the rat (grey) at the top and a colour-coded frequency map is shown at the bottom. Red is maximum firing rate, as indicated by the scale bar. Rat number, tetrode number (t) and cell number (c) are indicated above each path diagram. Peak frequencies are indicated at the top right of the colour map. Note that dCA1/pCA1 and MEC cells had clearly distinguishable place fields or grid fields in the foraging task, whereas the LEC cell showed no clear spatial modulation. b, Top, distribution of spatial information scores calculated from firing rate distributions in the random foraging task for cells with cue-port activity in dCA1, pCA1, LEC and MEC. Results in dCA1 are shown for both microdrive (MD) and hyperdrive (HD) implants. Bottom, distribution of shuffled data based on 100 permutations per cell. Red lines indicate 95th percentile value (chance level) for a distribution based on all permutations in each area. 95th percentile value is indicated in red. Percentage of cells that exceeded chance level is shown for each region. Note that 74% and 81% of the cue-port cells were spatially modulated in dCA1 and pCA1, respectively, that is, they were place cells⁴⁵. c, As in b, but for the distribution of gridness scores. Note that 89% of cue port cells in MEC had gridness scores that exceeded chance level and so were defined as grid cells⁴⁵.