Fig. 4: Inactivation of IL→NAcSh neurons activated by a familiar mouse impairs social recognition.
From: Hippocampal-cortical interactions in the consolidation of social memory
a TRAP tagging of IL→NAcSh neurons. b TRAP-mCherry expression in the mPFC after exposure to a familiar conspecific. ACC, anterior cingulate cortex; PL, prelimbic cortex; IL, infralimbic cortex. Scale: 500 μm, 100 μm. c TRAP labeling of familiar conspecific-dependent neurons. Day 1: A subject mouse was familiarized with a social target. Day 2: The subject mouse interacted with the familiarized target, followed by tamoxifen (4-OHT) injection. Days 9-10: The subject mouse underwent social familiarization/recognition task. d Both groups showed reduced interaction times during familiarization (left). Two-way RM ANOVA: mCherry CNO/hM4Di CNO, n = 18/22 mice; F2,76 = 0.1825, p = 0.8336. CNO-injected hM4Di group did not distinguish social targets, whereas mCherry-CNO mice interacted longer with novel conspecifics (right). CNO or saline was injected 40 min before recognition. Two-way RM ANOVA; F2,76 = 5.170, **p = 0.0079. e Induction of cFos in TRAP-labeled (TRAPed) mice in response to novel conspecifics or littermates. BL, baseline; N, novel mouse; L, littermate. f Mice exposed to novel conspecifics showed longer interaction times than those to littermates. Two-tailed unpaired t-test: TRAPed mice with littermates/novel conspecifics, n = 4/5; t7 = 3.571, **p = 0.0091. g IL sections showing TRAPed neurons (mCherry) and cFos (green) with DAPI (blue). Scale: 50 μm. h TRAPed neurons in littermate-exposed mice showed more overlap with cFos than those in baseline or novel conspecific-exposed mice. One-way ANOVA: Baseline/Novel/Littermate, n = 3/5/4 mice; F2,9 = 9.531, **p = 0.0060. i Comparable numbers of TRAPed neurons were observed across conditions. One-way ANOVA: F2,9 = 0.6061, p = 0.5663. Data presented as mean ± SEM; One dot represents one mouse. Statistics were made using either two-sided unpaired t-test, ordinary one- or two-way RM ANOVA with two-sided Tukey-corrected post hoc comparisons. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Source data are provided as a source data file. The schematic drawing of the brain in (a) and the mouse illustrations in (c) and (e) are reprinted from Cell Reports, Volume 35, Issue 6, Park, et al., Social isolation impairs the prefrontal-nucleus accumbens circuit subserving social recognition in mice, 109104, Copyright (2021), with permission from Elsevier.
