Figure 3.

Interlocking Gaps Do Not Alter Hippocampal Place Coding

(A) Left, normalized firing rate map of two representative place cells that have place fields around gap locations in the hippocampal CA1 on the square-shaped maze configuration. Right, normalized firing rate maps of 65 hippocampal place cells simultaneously monitored from a rat (ζA) ordered by the latency of their peak firing rates. Each line is a single unit. Gap locations are indicated at the top. Red indicates maximum firing rates, and blue indicates silent.

(B) Distribution of the average width of place fields randomly shuffled from the original sample covering the gaps (3,000 shuffles). Red line indicates the average width of the place fields on the gaps. Dotted lines indicate 5^th and 95^th percentiles for the shuffled data.

(C and D) Left, the number of place fields (C) and the firing rate of multi-unit activity (MUA) in the hippocampal CA1 (D) as a function of linearized location on the square-shaped maze. Right, the average number of place fields (C) (z = 0.14, p = 0.89) and the average firing rate of MUA (z = −1.51, p = 0.13) on the gaps (#3, 4, 9, 10) (green shaded area) and between them (orange shaded area).

(E) Representative posterior probability of locations decoded by the Bayesian decoder from 89 simultaneously monitored cells. Values are indicated by the color bar (right).

(F) Left, the difference between actual and decoded locations as a function of linearized location on the square-shaped maze. Right, the average difference between actual and decoded locations on the gaps (#3, 4, 9, 10) (green shaded area) and between them (orange shaded area) (z = 1.34, p = 0.18). Bin width is set at 3 cm.

All error bars indicate SEM. All were from two-tailed Wilcoxon rank-sum test, n.s.: p > 0.05.