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. 2020 Jan 7;11:72. doi: 10.1038/s41467-019-13809-8

Fig. 6. Chronic downregulation of GluN2B in prefrontal cortical SST interneurons and its behavioral consequences.

Fig. 6

a Coronal histological section, showing the extent of dsRed expression from bilateral injection of AAV1-CMV-dsRed-pSico-GluN2BshRNA into Cg1/M2 of a SST-IRES-Cre animal. b Fraction of time spent freezing during CS+ and trace period (if any), subtracted by that during CS− and trace period (if any), on the testing day. Freezing behavior for control SST-IRES-Cre animals in delay fear conditioning with no trace period (saline: 47 ± 6%, ketamine (10 mg/kg): 50 ± 5%, mean ± s.e.m.; P = 0.5, Wilcoxon rank-sum test; n = 8 and 12 animals for saline and ketamine, respectively), in trace fear conditioning (saline: 41 ± 7%, ketamine (10 mg/kg): 2 ± 4%, mean ± s.e.m.; P = 6 × 10−6, Wilcoxon rank-sum test; n = 8 animals each for saline and ketamine), and for GluN2B-SST KD animals in trace fear conditioning (saline: 33 ± 7%, ketamine (10 mg/kg): 43 ± 6%, mean ± s.e.m.; P = 0.2, Wilcoxon rank-sum test; n = 8 animals each for saline and ketamine). c Pre-pulse inhibition as a measure of sensorimotor gating. For control SST-IRES-Cre animals, a two-way within-subjects ANOVA with pre-pulse intensity (3, 6, and 9 dB) and drug (saline, ketamine (40 mg/kg)) as within-subjects factors found significant main effects of pre-pulse intensity (F(2,12) = 27.5, P = 4 × 10−6) and drug (F(1,24) = 2.0, P = 2 × 10−4), but a non-significant interaction (F(2,24) 1.8, P = 0.18). Post-hoc Tukey-Kramer’s tests for saline vs. ketamine were significant at 3 dB (40 ± 7%, 5 ± 6%, mean ± s.e.m., P = 0.01), at 6 dB (59 ± 5%, 17 ± 8%, mean ± s.e.m., P = 9 × 10−4), at 9 dB (67 ± 4%, 38 ± 6%, mean ± s.e.m., P = 0.003). n = 13 animals each for saline and ketamine. For GluN2B-SST KD animals, two-way within-subjects ANOVA revealed a significant main effect of pre-pulse intensity (F(2,24) = 6.3, P = 1.7 × 10−4), but non-significant drug effect (F(1,12) = 4.0, P = 0.93) or two-way interaction (F(2,24) = 1.4, P = 0.26). Saline vs. ketamine yielded no difference at 3 dB (32 ± 9%, 39 ± 6%, mean ± s.e.m.), at 6 dB (58 ± 6%, 56 ± 6%, mean ± s.e.m.), and at 9 dB (67 ± 6%, 63 ± 6%, mean ± s.e.m.). n = 13 animals each for saline and ketamine. d Open-field locomotor activity. Each trace comes from a single animal. For control SST-IRES-Cre animals, a two-way ANOVA was performed with epoch (pre-injection, 5–30 min post-injection, and 30–60 min post-injection) and drug (saline, ketamine (10 mg/kg)) as within-subjects factors. There were significant main effects of epoch (F(2,22) = 21.0, P = 7 × 10−5), drug (F(1,11) = 7.1, P = 0.02), and interaction (F(2,22) = 28.5, P = 7 × 10−5). Post-hoc Tukey-Kramer tests for saline vs. ketamine were significant for 5–30 min post-injection (P = 0.001), but non-significant for pre-injection (P = 0.07) and 30–60 min post-injection (P = 0.58). n = 12 animals each for saline and ketamine. For GluN2B-SST KD animals, two-way ANOVA revealed significant main effects of epoch (F(2,22) = 14.1, P = 0.002), drug (F(1,11) = 15.6, P = 0.002), and interaction (F(2,22) = 13.6, P = 0.003). Post-hoc Tukey-Kramer tests for saline vs. ketamine were significant for 5–30 min post-injection epoch (P = 0.003) and 30–60 min post-injection (P = 0.001), but non-significant for pre-injection (P = 1.0). n = 13 animals each for saline and ketamine. *P < 0.05; **P < 0.01; ***P < 0.001; n.s., not significant. Error bars, ± s.e.m.