Figure 2.

Inactivation of PV Interneurons Impairs Speed Coding in Speed Cells

(A) Firing rate map (top), map of spike locations on trajectory (middle), and normalized firing rate as a function of speed (bottom) for a representative MEC speed cell from a mouse with hM4D-mCitrine in PV interneurons. Left, before CNO; middle, 30 min after; right, 12 hr after.

(B) Cumulative frequency diagrams showing significant decrease in speed-rate correlation (speed score) of speed cells after inactivation of PV interneurons (top). The mean firing rate of the speed cells showed a small but significant decrease (bottom). See Figure S4 for absolute scores.

(C) Speed-rate relationship in layer II (left) and III (right) speed cells from animals with hM4D-mCitrine in MEC-PV interneurons (five representative pairs of layer II and III speed cells with approximately similar baseline speed scores). Symbols as in (A). Speed scores (s) are indicated at the top of each panel. Animal and cell numbers are indicated to the left.

See also Figures S1, S2, S4, and S5.