Fig. 1
Higher incidence and rate of disinhibition-induced spfps in VH compared with DH. a Schematic drawing of the hippocampus where the cutting plane directions and the extent of sliced structure are indicated by the solid lines. Dotted line indicates the longitudinal axis of the structure. b Fast sweep speed record of a single spontaneous field potential (spfp) induced under blockade of GABAARs by their antagonist SR 95531. Recording was made in the CA3 stratum pyramidale of a VH slice. c Continuous recordings from the CA3 stratum pyramidale illustrating that at the low concentration of 0.1 μM the antagonist of GABAARs SR 95531 induced spfps in VH but not DH. Even at the highest concentration of SR 95531 used (10 μM) the rate of spfps was higher in VH than in DH. d Histogram of percentages of DH and VH slices displaying spfps under different concentrations of SR 95531 (plot on the left) and the cumulative results for all concentrations (plot on the right) are shown. The number of slices examined under the six different drug concentrations are given in the main text. e Histogram of the rate of spfps in DH and VH under the various SR 95531 concentrations and the cumulative mean values for all concentrations are shown in the left and right graph, respectively. Asterisks in all graphs denote statistically significant differences between DH and VH at *p < 0.05 or **p < 0.01 (Mann–Whitney U test). Statistical comparison at 0.1 μM was not possible because of the absence of spfps in DH slices