Fig. 5. Inhibition of EC-6b neurons affects spatial information processing and memory formation.

a Representative parasagittal section showing specific expression of ArchT-EGFP in layer 6b and the location of the optic fiber in a Ctgf-2A-dgCre crossed with an ArchT-EGFP (Ai40) cre reporter mouse. b Representative position plots for the three consecutive exposure sessions (top) and corresponding firing-rate maps of 12 representative units, ranked by their spatial information score in S3. Numbers above each plot note the peak firing rate (Hz). c A summary plot showing the average spatial information for CA1 pyramidal cells within the illuminated quadrant (green) relative to the rest of the arena (gray) in each exposure session (left) alongside a box plot showing the median change in SI between S2-S1 and S3-S1 for cells inside and outside of the target region (right). Boxplot center, bounds of box and whiskers represent the median, top and bottom 25th and top and bottom 10th percentile, respectively. A total of 184 units from 4 animals were included in the analysis. Single (*) and triple asterisks (***) indicate P < 0.05 and P < 0.001, respectively. d Representative images of the hippocampus of a Ctgf-2A-dgCre crossed with a Rosa(stop)DTA mice, immunolabeled for CPLX3, either without (top left) or 9 days following administration of TMP (top right) with representative STED images taken from the CA3 S.M. below demonstrate the density of VGluT1 and eCPLX3 at each time point. Changes in density of both VGluT1 and eCPLX3/VGluT1 are quantified for CA1 and CA3 S.M. at different time points following administration of TMP, with each dot representing an individual animal (n = 3 animals per group) and lines represent the average for each condition (bottom plot). e Schematic diagram of the experimental protocol in the intellicage. f Time plot of the average group error rate during each of the experimental days. TMP was administered on experimental day 0, indicated by a black arrow. g Scatter plot between the density of surviving eCPLX3 terminals in the CA3 S.M., calculated from STED images, and the error rate for each animal in the TMP group, on experimental days 8 and 9, corresponding to the last day of the final novel location (D) and the first day of the return to the familiar location (A*), respectively. One-tailed Spearman’s rank correlation coefficient (r_s) with its corresponding P value indicated below and dashed regression lines shown for each group. Data in (c, left) and f is shown as mean and SEM and scale bars on images represent 200 µm.