Figure 4.

Arc palmitoylation is required for MEF2-dependent synapse depression. (A) Simultaneous dual-patch mEPSC recordings from untransfected (U) Arc KO neurons and neighboring Arc KO neurons transfected (T) with MEF2-VP16 and MRE-mCherry with a vector (top), the coding region of Arc^WT (middle), or a nonpalmitoylatable Arc mutant (Arc^C94,96,98S, bottom). The dot plots show individual cell pairs in gray with means ± the standard error of the mean in black. Bar graphs represent data from 13–22 cell pairs. Representative mEPSC traces and averaged mEPSC waveforms for untransfected (gray) and transfected (black) neurons are shown at the right. (B and C) Representative immunohistochemistry images for Arc and mCherry (transfection marker) indicate that Arc^WT and Arc^C94,96,98S are similarly expressed in the (B) soma and (C) dendrites of transfected Arc KO neurons (n = 8–14, for Arc^WT and Arc^C94,96,98S, respectively). Bar graphs of fluorescence intensity normalized to background are shown as means ± the standard error of the mean.