Fig. 6: Cells recruited in the acute vs. repeated ensembles exhibit different intrinsic excitability.
From: Cocaine-context memories are transcriptionally encoded in nucleus accumbens Arc ensembles
a Experimental design for ensemble tagging and ex vivo electrophysiology study of Arc-CreERT2::Ai14 mice. 4-OHT 4-Hydroxytamoxifen. Whole cell patch clamp recordings of Tom+ cells (n = 34 neurons, acute; n = 30 neurons, repeated) were performed in ArcCreERT2::Ai14 male mice (n = 8, acute; n = 7, repeated). For controls, recordings from naive D1-tdTomato male mice (n = 11) allowed for patching neurons (n = 33) in fixed relative proportions (70% D1+ / 30% D1-) matching those of Arc ensembles (Supplementary Fig. 9) b Representative wide-field (top) and close-up (bottom) views of patched MSNs. Scale bars 20 µm. c Resting membrane potential. LMM-ANOVA: F2,13.668 = 1.88, p = 0.1897. Acu. Acute, Rep. Repeated. d Rheobase. LMM-ANOVA: F2,20.96 = 1.7497, p = 0.1983. e Representative membrane responses from a Tom+ neuron in response to a 280 pA current injection from an acutely (top) or chronically (bottom) treated mouse. f Number of evoked action potentials (APs) in response to increasing depolarizing current steps. LMM-ANOVA: interaction group x current, F30,1410.4 = 9.72, ***p < 0.001; main effect of group, F2,20.3 = 4.85, *p = 0.0190; main effect of current, F15,1410.4 = 525.56, ***p < 0.001; followed by Šidák post hoc tests (repeated vs acute: *p < 0.05, **p < 0.01, ***p < 0.001; repeated vs naive: &p < 0.05, &&p < 0.01, & & &p > 0.001; acute vs naive: #p < 0.05). g Representative voltage-clamp recordings of Tom+ neurons held at -70 mV. h Spontaneous excitatory synaptic currents (sEPSC) frequency. LMM-ANOVA: F2,14.12 = 0.026, p = 0.9749. i sEPSC amplitude. LMM-ANOVA: F2,12.96 = 0.17, p = 0.8453. Bar and line graphs are expressed as means ± SEM. Source data are provided as a Source Data File. Created in BioRender. Parise, E. (2025) https://BioRender.com/voi7l54.
