Figure 2

Basal synaptic transmission and LTP in the hippocampus of dnRAR mice. (A) The input-output relationships of AMPA receptor-mediated EPSP in WT (n = 9) and dnRAR H06 (n = 8) mice. The sample traces in the inset represent the responses evoked with the five different stimulus intensities and the stimulus artifacts were truncated. The data were first sorted by the amplitude range of the fiber volleys, and then the EPSP slopes were averaged within each range. (B) PPF induced by stimulating afferent fibers twice at intervals of 50, 100, 200, and 300 ms in WT (n = 9) and dnRAR H06 (n = 8) mice. (C) PTP induced by high-frequency stimulation (one 100 Hz, 1 s train) in the presence of D-APV (50 μM) in WT (139.2 ± 3.5% of baseline; n = 12) and dnRAR H06 (137.2 ± 4.1% of baseline; n = 10) mice. (D) LTP induced by single conditioning stimulation (one 100 Hz, 1 s train) in WT (n = 30) and dnRAR H06 (n = 16) mice. The initial EPSP slopes were measured, and the values were normalized in each experiment to the averaged slope value measured during the control period (-30 to 0 min). Conditioning stimulation was applied at 0 min. The sample traces in the inset represent the EPSPs (average of 10 consecutive responses) of WT and H06 mice recorded at the times indicated by the letters. The stimulus artifacts were truncated. (E) Summary of LTP induced by single conditioning stimulation in WT and dnRAR H06 mice (21-30 min: WT, 149.5 ± 2.0%; H06, 143.9 ± 3.5%; 51-60 min: WT, 144.1 ± 2.4%; H06, 133.6 ± 3.8%; 111-120 min: WT, 133.3 ± 2.9%; H06, 118.6 ± 3.6%; 171-180 min: WT, 125.0 ± 3.3%; H06, 106.0 ± 4.2% of baseline) (t test, *p < 0.05). (F) LTP induced by strong conditioning stimulation (four 100 Hz, 1 s trains at 5 min intervals) in WT (n = 6) and dnRAR H06 (n = 9) mice. The initial EPSP slopes were measured, and the values were normalized in each experiment to the averaged slope value measured during the control period (-30 to 0 min). Conditioning stimulation was applied at 0 min. The sample traces in the inset represent the EPSPs (average of 10 consecutive responses) of WT and H06 mice recorded at the times indicated by the letters. The stimulus artifacts were truncated. (G) Summary of normalized LTP induced by strong conditioning stimulation in WT and dnRAR H06 mice (21-30 min: WT, 181.4 ± 3.6%; H06, 179.2 ± 3.9%; 51-60 min: WT, 169.9 ± 4.6%; H06, 169.0 ± 3.6%; 111-120 min: WT, 155.3 ± 5.3%; H06, 151.9 ± 5.5%; 171-180 min: WT, 141.7 ± 7.7%; H06, 136.3 ± 6.6% of baseline). (H) STP induced by short conditioning stimulation (one 100 Hz, 100 ms train) in WT (116.2 ± 5.1% of baseline; n = 5) and dnRAR H06 (120.6 ± 8.1% of baseline; n = 5) mice. The initial EPSP slopes were measured, and the values were normalized in each experiment to the averaged slope value measured during the control period (-30 to 0 min). Conditioning stimulation was applied at 0 min. Error bars indicate SEM.