Faculty of Veterinary Medicine, Okayama University of Science, Ehime, Japan.
Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan.
J Vet Med Sci. 2023 Jan 6;85(1):30-39. doi: 10.1292/jvms.22-0103. Epub 2022 Nov 18.
Social anhedonia is a psychological state with difficulty in experiencing pleasure from social interactions and is observed in various diseases, such as depressive disorders. Although the relationships between social reward responses and anxiety- and depression-like behaviors have remained unclear, a social reward conditioned place preference (SCPP) test can be used to analyze the rewarding nature of social interactions. To elucidate these relationships, we used 5-week-old male mice of AKR, BALB/c, and C57BL/6J strains and conducted behavioral tests in the following order: elevated plus-maze test (EPM), open field test (OFT), SCPP, saccharin preference test (SPT), and passive avoidance test. The nucleus accumbens of these mice were collected 24 hr after these behavioral tests and were used for western blotting to determine the levels of receptors for brain-derived neurotrophic factors and glucocorticoids. BALB/c mice displayed the highest levels of anxiety-like behavior in EPM and OFT as well as physical anhedonia-like behaviors in SPT. They also showed increased responses to social rewards and huddling behaviors in SCPP, with downregulated glucocorticoid receptor (GR). Regression analysis results revealed positive influences of anxiety- and physical anhedonia-like behaviors and expressions of GR on social reward responses. Collectively, temperament associated with anxiety and physical anhedonia may affect social reward responses, which possibly is influenced by the expression of GR that can modify these psychological traits.
社交快感缺失是一种难以从社交互动中体验到愉悦的心理状态，在各种疾病中都有观察到，如抑郁症。虽然社交奖励反应与焦虑和抑郁样行为之间的关系仍不清楚，但社交奖励条件位置偏好（SCPP）测试可用于分析社交互动的奖励性质。为了阐明这些关系，我们使用了 5 周龄的 AKR、BALB/c 和 C57BL/6J 品系的雄性小鼠，并按以下顺序进行行为测试：高架十字迷宫测试（EPM）、旷场测试（OFT）、SCPP、蔗糖偏好测试（SPT）和被动回避测试。这些行为测试后 24 小时，收集这些小鼠的伏隔核，并进行 Western blot 以确定脑源性神经营养因子和糖皮质激素受体的水平。BALB/c 小鼠在 EPM 和 OFT 中表现出最高水平的焦虑样行为以及 SPT 中的躯体快感缺失样行为。它们还表现出对 SCPP 中社会奖励的反应增加和挤在一起的行为，同时糖皮质激素受体（GR）下调。回归分析结果表明，焦虑和躯体快感缺失样行为以及 GR 的表达对社会奖励反应有积极影响。总的来说，与焦虑和躯体快感缺失相关的气质可能会影响社会奖励反应，这可能受到可以改变这些心理特征的 GR 表达的影响。
