Fig. 2.

Exogenously applied Aβ increases PV interneuron but not pyramidal neuron excitability in hippocampal slices of wild-type mice. Passive and active membrane properties were measured 1 h after Aβ application. a PV interneuron resting membrane potential was not affected by Aβ (Student’s t test: n = 17/10 cells from 4/3 mice per group, p = 0.180) but membrane input resistance (b) was significantly increased in PV interneurons that were incubated in 1 μM Aβ peptides compared with cells that were incubated with control peptides (Student’s t test: n = 17/10 cells from 4/3 mice per group, *p < 0.05). c Voltage responses to 1 s hyperpolarizing or depolarizing current steps from a PV interneuron recorded from slices incubated with control peptides (gray) or with 1 μM Aβ (red). d AP frequency in response to 0–250 pA depolarizing current steps showing a significant increase in PV interneuron excitability in slices incubated in 1 μM Aβ compared with control slices (genotype × current two-way repeated measures ANOVA: n = 17/10 cells from 4/3 mice per group, F_10,250 = 4.50, p = 0.006). e Application of 1 μM Aβ peptides did not alter resting membrane potential and (f) did not affect membrane input resistance in pyramidal neurons (Student’s t test: n = 13/16 cells from four mice per group; p = 0.449 and p = 0.195). g Voltage responses to 1 s hyperpolarizing or depolarizing current steps from a pyramidal neuron recorded from slices incubated with control peptides (gray) or with 1 μM Aβ (red). h AP frequency in response to 0–250 pA depolarizing current steps showing no significant change in pyramidal neuron excitability in slices incubated in 1 μM Aβ compared with control slices (genotype × current two-way repeated measures ANOVA: n = 13/16 cells from four mice per group, F_10,250 = 4.98, p = 0.494)