Figure 2.

High [Ca²⁺]_o partially antagonizes HP depression of single MPP fEPSP. (A) fEPSPs, recorded at the inner dendritic area of the dentate gyrus, showing the effects of pressure (0.1, 5.1, 10.1 MPa) at 2 mM [Ca²⁺]_o, and the partial restoration of fEPSPs at HP by 4 mM [Ca²⁺]_o. (B) Statistical analysis of the above experiments. fEPSPs are depressed in a pressure-dependent manner. At 10.1 MPa the fEPSP's slope is significantly increased at 4 mM [Ca²⁺]_o (p < 0.0001, n = 8). Further increasing [Ca²⁺]_o to 6 mM paradoxically resulted in reduction of fEPSP's slopes (p < 0.05, n = 2). Scatter bars indicate mean ± SE.