Figure 7.

Theta rhythmic spiking modestly reduced following scopolamine administration. A. Phase locking histograms for a representative grid cell, plotting the mean spike rate at each phase of theta, for the pre-injection, scopolamine and 6 hour recovery trials. Little change is observable. B. Standardized spike time autocorrelation for the same cell as shown in A showing theta rhythmic spiking in all three trial types. A modest reduction in theta rhythmicity can be seen during the scopolamine trial by the reduced difference between the standardized spike rate at 0.06 and 0.12 s, corresponding to the half and full period of a theta cycle. C. Average phase locking observed over trials for both the saline and scopolamine conditions as quantified by mean resultant length of the phase locking histograms (as shown in A). No significant differences were observed over trial types in either condition. D. Average theta rhythmicity over trials in both conditions. A trend toward a decrease can be seen between the pre-injection and baseline trials. Error bars on C and D reflect standard error on the mean.