Figure 7

Induction of LTP in the hippocampus of 3MST-KO, TRPA1-KO, 3MST/TRPA1-double-KO and the wild-type rats. a and b. LTP induced by high-frequency stimulation (100 pulses at 100 Hz) in the wild-type in the presence (closed circles, n = 4) or absence (open circles, n = 5) of 20 μM Na₂S₂. Time course of changes in the fEPSP slope (a). The data in (a) were summarized by calculating the average of fEPSP slopes 30–60 min after high-frequency stimulation as an index of LTP magnitude (b). c and d. LTP induced in 3MST-KO in the presence or absence of 20 μM Na₂S₂ (Wild: open circles, n = 11; 3MST-KO: closed circles, n = 11; 3MST-KO + Na₂S₂: gray triangles, n = 11) and 10 μM 5,7-dichlorokynurenic acid (DCKA) (3MST-KO + Na₂S₂ + DCKA: gray squares, n = 11). Time course of changes in the fEPSP slope (c). The data in (c) was summarized as an index of LTP magnitude (d). One-way ANOVA followed by Tukey’s test (F₃, ₄₀ = 18.232, P < 0.001). e and f. LTP induced in TRPA1-KO in the presence or absence of 10 μM d-serine (Wild: open circles, n = 10; TRPA1-KO: closed circles, n = 10; TRPA1-KO + d-serine: gray triangles, n = 10). Time course of changes in the fEPSP slope (e). The data in (e) was summarized as an index of LTP magnitude (f). One-way ANOVA followed by Tukey’s test (F₂, ₂₇ = 8.997, P = 0.001). g and h. LTP induced in 3MST/TRPA1-double KO in the presence or absence of 20 μM Na₂S₂ (3MST/TRPA1-DKO: closed circles, n = 11; 3MST/TRPA1-DKO + Na₂S₂: gray triangles, n = 11) and 10 μM d-serine (Wild: open circles, n = 11; 3MST/TRPA1-DKO + d-serine: gray inverted triangles, n = 11). Time course of changes in the fEPSP slope (g). The data in (g) was summarized as an index of LTP magnitude (h). Kruskal–Wallis ANOVA on Ranks followed by Tukey’s test (H = 26.727, P < 0.001).