Institute for Systems Medicine and Department of Human Medicine, MSH Medical School Hamburg, Hamburg, Germany.
Department of Psychology, Medical School Hamburg, Hamburg, Germany.
J Neural Transm (Vienna). 2023 Sep;130(9):1153-1165. doi: 10.1007/s00702-023-02610-z. Epub 2023 Feb 26.
The brain is built with hemispheric asymmetries in structure and function to enable fast neuronal processing. In neuroimaging studies, several mental disorders have been associated with altered or attenuated hemispheric asymmetries. However, the exact mechanism linking asymmetries and disorders is not known. Here, studies in animal models of mental disorders render important insights into the etiology and neuronal alterations associated with both disorders and atypical asymmetry. In this review, the current literature of animal studies in rats and mice focusing on anxiety and fear, anhedonia and despair, addiction or substance misuse, neurodegenerative disorders as well as stress exposure, and atypical hemispheric asymmetries is summarized. Results indicate overall increased right-hemispheric neuronal activity and a left-sided behavioral bias associated with symptoms of anxiety, fear, anhedonia, behavioral despair as well as stress exposure. Addiction behavior is associated with right-sided bias and transgenic models of Alzheimer's disease indicate an asymmetrical accumulation of fibrillar plaques. Most studies focused on changes in the bilateral amygdala and frontal cortex. Across studies, two crucial factors influencing atypical asymmetries arose independently of the disorder modeled: sex and developmental age. In conclusion, animal models of mental disorders demonstrate atypical hemispheric asymmetries similar to findings in patients. Particularly, increased left-sided behavior and greater right-hemispheric activity were found across models applying stress-based paradigms. However, sex- and age-dependent effects on atypical hemispheric asymmetries are present that require further investigation. Animal models enable the analysis of hemispheric changes on the molecular level which may be most effective to detect early alterations.
大脑在结构和功能上具有半球不对称性，以实现快速的神经元处理。在神经影像学研究中，几种精神障碍与改变或减弱的半球不对称性有关。然而，将不对称性与障碍联系起来的确切机制尚不清楚。在这里，精神障碍动物模型的研究为理解与障碍和非典型不对称性相关的病因和神经元变化提供了重要的见解。在这篇综述中，总结了目前关于焦虑和恐惧、快感缺失和绝望、成瘾或物质滥用、神经退行性疾病以及应激暴露与非典型半球不对称性的动物研究的文献。结果表明，与焦虑、恐惧、快感缺失、行为绝望以及应激暴露相关的症状总体上与右半球神经元活动增加和左侧行为偏向有关。成瘾行为与右侧偏向有关，阿尔茨海默病的转基因模型表明纤维状斑块的不对称积累。大多数研究都集中在双侧杏仁核和前额皮质的变化上。跨研究发现，有两个独立于所模拟障碍的关键因素影响非典型的不对称性：性别和发育年龄。总之，精神障碍动物模型表现出与患者相似的非典型半球不对称性。特别是，在应用基于应激的范式的模型中发现了更多的左侧行为和更大的右半球活动。然而，存在与性别和年龄相关的非典型半球不对称性影响，需要进一步研究。动物模型能够分析分子水平上的半球变化，这可能是检测早期变化最有效的方法。
