Figure 2. Dopamine retroactively converts t-LTD into t-LTP.

(A) DA applied immediately after the pairing protocol with Δt = −20 ms converted t-LTD into t-LTP (+Pairing +Stim; red). If the pathway was not stimulated following the pairing protocol until after DA washout, t-LTD was induced (+Pairing −Stim; black). In the absence of the pairing protocol, DA had no effect on baseline EPSPs (−Pairing +Stim; blue). Traces show an EPSP before (1) and 40 min after (2) pairing. (B) Summary of results. Error bars represent s.e.m. Significant difference (**p < 0.01, ***p < 0.001) compared with the baseline (one-sample two-tailed Student's t-test). The number of cells is shown in parentheses.

DOI: http://dx.doi.org/10.7554/eLife.09685.005