Extended Data Figure 10: Overlap between spatial cell types and the SMT-modulated population.

a, Activity of spatial cell types that were also SMT-modulated. All plots are as in Fig. 2. b–e, Head direction cells overlap with SMT-modulated neurons, but head direction selectivity does not fully account for firing rate modulations in the SMT. This analysis was performed to account for the possibility that some SMT firing was due to subtle changes in head direction during the nosepoke or between the nosepoke and the lick-tube. b, Activity of all head direction cells that were also modulated in the SMT. c, Activity of all non-head direction cells that were also modulated in the SMT. d, Activity of three MEC cells in one rat. Cells 1 and 2 were simultaneously recorded. Left, activity in the SMT, plotted as in Fig. 3. Right, firing rate as a function of head direction during random foraging, plotted in polar coordinates. Each firing rate is scaled to its indicated maximum. Arrow, vector average of the head direction tuning curve. All three cells have a firing field at the release of the joystick. However, although cells 1 and 2 have similar head direction selectivity, cell 3 is not a head direction cell, suggesting that the firing field cannot be explained by head direction selectivity. e, Activity of two simultaneously recorded MEC cells, plotted as in d. Although the cells have similar head direction selectivity, they have highly dissimilar firing during the SMT. The total number of cells recorded in both tasks was 918 in CA1 and 881 in MEC, including 290 and 379 SMT-modulated cells, respectively. In CA1, there were 295 place cells, and in MEC there were 105 grid cells, 68 border cells, and 321 head direction cells. Overlaps of these cell types with SMT-modulated cells contained 74, 36, 42, and 163 cells, producing 104, 69, 78, and 295 firing fields, respectively.