National Centre for Biological Sciences, Bangalore, 560065, India; Manipal University, Manipal, India.
National Centre for Biological Sciences, Bangalore, 560065, India; Dept. of Behavioral Neuroscience, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands.
Behav Brain Res. 2021 Jan 15;397:112940. doi: 10.1016/j.bbr.2020.112940. Epub 2020 Oct 27.
There are large individual differences in the way animals, including humans, behaviorally and physiologically cope with environmental challenges and opportunities. Rodents with either a proactive or reactive coping style not only differ in their capacity to adapt successfully to environmental conditions, but also have a differential susceptibility to develop stress-related (psycho)pathologies when coping fails. In this study, we explored if there are structural neuronal differences in spine density in brain regions important for the regulation of stress coping styles. For this, the individual coping styles of wild-type Groningen (WTG) rats were determined using their level of offensive aggressiveness assessed in the resident-intruder paradigm. Subsequently, brains from proactive (high-aggressive) and reactive (low-aggressive) rats were Golgi-cox stained for spine quantification. The results reveal that dendritic spine densities in the dorsal hippocampal CA1 region and basolateral amygdala are similar in rats with proactive and reactive coping styles. Interestingly, however, dendritic spine density in the medial amygdala (MeA) is strikingly reduced in the proactive coping rats. This brain region is reported to be strongly involved in rivalry aggression which is the criterion by which the coping styles in our study are dissociated. The possibility that structural differences in spine density in the MeA are involved in other behavioral traits of distinct coping styles needs further investigation.
动物（包括人类）在行为和生理上应对环境挑战和机遇的方式存在很大的个体差异。具有主动或被动应对方式的啮齿动物不仅在成功适应环境条件的能力上有所不同，而且在应对失败时也具有不同的易患与压力相关的（心理）病理的倾向。在这项研究中，我们探讨了在调节压力应对方式的重要脑区中，神经元结构是否存在差异。为此，我们使用常驻入侵者范式评估了野生型 Groningen (WTG) 大鼠的个体应对方式，确定了它们的攻击性水平。随后，对具有主动（高攻击性）和被动（低攻击性）应对方式的大鼠进行 Golgi-cox 染色以进行棘突定量。结果表明，具有主动和被动应对方式的大鼠背侧海马 CA1 区和基底外侧杏仁核的树突棘密度相似。然而，有趣的是，主动应对大鼠的内侧杏仁核（MeA）的树突棘密度明显降低。据报道，该脑区强烈参与竞争攻击，这是我们研究中区分应对方式的标准。在 MeA 中，棘突密度的结构差异是否参与不同应对方式的其他行为特征，需要进一步研究。
