Figure 2. Dopamine retroactively converts acetylcholine-facilitated t-LTD into t-LTP.
(a) Application of muscarinic acetylcholine receptor antagonist, 100 nM atropine, following acetylcholine (ACh; 1 μM) washout after the pre-before-post pairing protocol with Δt = +10 ms did not affect the development of ACh-facilitated t-LTD (black). Dopamine (DA; 100 μM) applied, together with atropine, immediately after ACh washout at the end of the same pairing protocol, converted ACh-facilitated t-LTD into t-LTP (red). Traces show an EPSP before (1) and 40 min after pairing (2) in the two conditions. (b) Forskolin (50 μM), applied together with atropine, converted ACh-facilitated t-LTD into t-LTP, mimicking the effect of DA. Traces are presented as in a. (c) Summary of results from a and b. In the absence of the pairing protocol, atropine had no significant effect on baseline EPSPs (blue). Error bars represent s.e.m. Significant difference (*p<0.05) compared with the baseline or between the indicated two groups (two-tailed Student’s t-test). The total numbers of individual cells (blue data points) are shown in parentheses.
DOI: http://dx.doi.org/10.7554/eLife.27756.008
Figure 2—figure supplement 1. Acetylcholine applied after the pairing protocol does not affect t-LTP.
