Fig. 5.

TORC1 is involved in L-LTP maintenance in the Schaffer collateral–CA1 pathway. (A) Transduction of the recombinant TORC dominant-negative protein (TORC-DN-EGFP-11R) or the control recombinant protein (NLS-EGFP-11R) in hippocampal slices. Many cells contain recombinant protein in the nucleus, as evidenced by the colocalization of EGFP and DAPI staining. (B) Effect of TORC-DN-EGFP-11R on L-LTP induced by three trains of 100-Hz pulses (1-s duration) separated by 5-min intervals (HFS). Seventy-five minutes after the tetanic stimulation, LTP became significantly smaller in slices treated with TORC- DN-EGFP-11R (n = 7, 7 rats) than in control slices (n = 9, 9 rats) treated with NLS-EGFP-11R (t test; P < 0.05). An arrow indicates a stimulation of a 1-s train at 100 Hz. Traces show examples of postsynaptic responses before (preHFS; black) and 180 min after (180 min postHFS; red) the tetanic stimulation. [Scales for these traces: 1 mV (vertical), 10 ms (horizontal).] HFS was applied ≈1.5 h after the end of the incubation with the recombinant proteins. (C) Transduction of TORC-DN-EGFP-11R did not have any significant effect on the input/output curve. There was no significant effect of treatment after a two-way ANOVA on postsynaptic responses with treatment as an independent variable and concentration as a repeated measure (P > 0.05). N as in B. (D) Transduction of TORC-DN-EGFP-11R did not interfere with the presynaptic function as evidenced by unchanged paired-pulse facilitation (t test; P > 0.05). N as in B.