For five of these cells, hyperpolarizing holding current was applied (−0.009 to −0.040 nA), and for one cell the holding current was not recorded. Four of these recordings were histologically verified to be from CA1 pyramidal cells. Most of the eighteen GDC-0973 purchase recordings were used

in a previous study (Epsztein et al., 2010). All procedures were performed according to German guidelines on animal welfare. All analysis was done using custom-written programs in Matlab. All values are reported as mean ± SEM unless otherwise noted. All place versus silent and active versus nonactive comparisons were done using the unpaired t test assuming unequal variances unless otherwise noted, in which case the nonparametric Mann-Whitney U test was used. Pearson’s linear correlation coefficient was used to assess correlations (ρ) between features, with significance determined with respect to the hypothesis that there was no correlation. All p values reported are two sided. The following procedure

(Epsztein et al., 2010) was used to determine whether a cell has a place field in a given direction. Only directions in which the animal sampled each location in ≥2 different laps were considered. The locations in the maze were collapsed onto an ∼2 m long curve that went around the “O”-shaped track, giving a one-dimensional representation of animal location. The beginning (position selleck compound 0) and end of this curve were arbitrary and identified as the same location, preserving the maze’s cyclical structure. The curve was divided Bcl-2 cancer into 4 cm wide segments. Only time periods when the animal’s head faced within 75 degrees of the given direction (CW or CCW) were considered. The AP

firing rate as a function of the animal’s one-dimensional location in the given direction (Figures 2D, 3D, 4A, and 6E, red) was computed as the number of APs that occurred when the head of the animal was within a given pair of adjacent segments divided by the total amount of time the animal’s head was there, and this rate was assigned to the location at the middle of the segment pair. Thus the rate was computed every 4 cm with 8 cm wide boxcar smoothing. If the total duration that the head was within a pair of segments was <0.2 s, no rate was assigned to that location. Then (1) the baseline firing rate was set as the mean rate of the 10% of lowest rate positions, (2) the position of the peak rate was determined, (3) the full session candidate (place) field around the peak was determined by adding any continguous positions (called the “inside” of the field) where the rate was ≥ the baseline rate plus 20% of the difference between the peak and baseline rates, and (4) the peak rate outside of the candidate field was also determined.