Fig. 1

Evaluation of anxiety-like behavior and striatal MSN excitability 3 weeks after adolescent or adult treatment by CIW vs. CIE. a Experimental timeline for Fig. 1, Figs. 2–4. b–e Increased anxiety-like behavior 3 weeks after adolescent but not adult CIE. Representative maps in the light compartment of LDT test, surrounded by black lines (indicating the walls of light compartment) and white bars (indicating the tunnel to the dark compartment), on rats treated by CIW vs. CIE during adolescent (Ado) vs. adult (Adu) stage (b). Summarized results showing that relative to CIW group, CIE treatment in the adolescent stage specifically decreased the crossover latency from light to dark compartment, indicating a higher anxiety level in the early adult stage induced by adolescent CIE treatment (CIW/CIE × adolescent/adult interaction F_1,36 = 9.9, p < 0.01) (c). Summarized results showing that average speed (d, CIW/CIE × adolescent/adult interaction F_1,48 = 0.2, p = 0.66) and total distance traveled (e, CIW/CIE × adolescent/adult interaction F_1,48 = 0.2, p = 0.65) were not affected by CIE treatment in either adolescent or adult stage. f–j Increased excitability of MSNs in the NAcS 3 weeks after adolescent, but not adult, CIE. Example DIC image of coronal section at a low magnification (through ×4 objective) showing the anatomical boundaries used to collect data from the NAcS (f). Example traces showing action potentials elicited by 200 and 400 pA current injections in NAcS MSNs from rats treated with CIW (left in each panel) and CIE (right in each panel) during the adolescent (g) or the adult (i) stage. Summarized data showing that excitability of NAcS MSNs is increased in rats with a CIE vs. CIW history during their adolescent stage (h, Ado::CIW/Ado::CIE × I_inj interaction, F₇₂₀₃ = 6.7, p < 0.01, cell based; F_7,91 = 10.2, p < 0.01, animal based) but not adult stage (j, Adu::CIW/Adu::CIE × I_inj interaction, F₇₂₅₂ = 1.0, p = 0.44, cell based; F₇₁₀₅ = 1.1, p = 0.37, animal based). k–o Increased excitability of MSNs in the NAcC 3 weeks after both adolescent and adult CIE. Example DIC image of coronal section at a low magnification (through ×4 objective) showing the anatomical boundaries used to collect data from the NAcC (k). Example traces showing action potentials elicited by 200 and 400 pA current injections in NAcC MSNs from rats treated with CIW (left in each panel) and CIE (right in each panel) during the adolescent (l) or the adult (n) stage. Summarized data showing significant injected current-dependent differences in excitability of NAcC MSNs from rats treated with CIW vs. CIE during both their adolescent (m, Ado::CIW/Ado::CIE × I_inj interaction F₇₁₂₆ = 4.1, p < 0.01, cell based; F_7,49 = 2.9, p = 0.01, animal based) and adult (o, Adu::CIW/Adu::CIE × I_inj interaction, F₇₁₁₉ = 3.7, p < 0.01, cell based; F_7,42 = 2.4, p = 0.03, animal based) stage. p–t No changes in excitability of DLS MSNs 3 weeks after either adolescent or adult CIE. Example DIC image of coronal section at a low magnification (through ×4 objective) showing the anatomical boundaries used to collect data from the DLS (p). Example traces showing action potentials elicited by 200 and 400 pA current injections in DLS MSNs from rats treated with CIW (left in each panel) and CIE (right in each panel) during the adolescent (q) or the adult (s) stage. Summarized data showing no injected current-dependent difference in excitability of DLS MSNs from rats treated with CIW vs. CIE during their adolescent (r, Ado::CIW/Ado::CIE × I_inj interaction F₇₁₈₂ = 1.0, p = 0.41, cell based; F_7,63 = 1.3, p = 0.27, animal based), or adult (t, Adu::CIW/Adu::CIE × I_inj interaction F₇₂₃₁ = 0.6, p = 0.79, cell based; F_7,56 = 0.6, p = 0.75, animal based) stage. The animal number (i.e., n in c–e) or cell number/animal number (i.e., m/n in h, i, m, o, r, t) is shown in parentheses for each group. Data were analyzed by two-way ANOVA (c–e) or two-way ANOVA with repeated measures (h, i, m, o, r, t), followed by Bonferroni post test. *p < 0.05