Ambeskovic Mirela, Soltanpour Nasrin, Falkenberg Erin A, Zucchi Fabiola C R, Kolb Bryan, Metz Gerlinde A S
Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, CanadaT1K 3M4.
Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada T1K 3M4.
Cereb Cortex. 2017 Mar 1;27(3):2126-2138. doi: 10.1093/cercor/bhw063.
In a continuously stressful environment, the effects of recurrent prenatal stress (PS) accumulate across generations and generate new behavioral traits in the absence of genetic variation. Here, we investigated if PS or multigenerational PS across 4 generations differentially affect behavioral traits, laterality, and hemispheric dominance in male and female rats. Using skilled reaching and skilled walking tasks, 3 findings support the formation of new behavioral traits and shifted laterality by multigenerational stress. First, while PS in the F1 generation did not alter paw preference, multigenerational stress in the F4 generation shifted paw preference to favor left-handedness only in males. Second, multigenerational stress impaired skilled reaching and skilled walking movement abilities in males, while improving these abilities in females beyond the levels of controls. Third, the shift toward left-handedness in multigenerationally stressed males was accompanied by increased dendritic complexity and greater spine density in the right parietal cortex. Thus, cumulative multigenerational stress generates sexually dimorphic left-handedness and dominance shift toward the right hemisphere in males. These findings explain the origins of apparently heritable behavioral traits and handedness in the absence of DNA sequence variations while proposing epigenetic mechanisms.
在持续紧张的环境中，反复的产前应激（PS）效应会跨代累积，并在没有基因变异的情况下产生新的行为特征。在此，我们研究了PS或四代间的多代PS是否会对雄性和雌性大鼠的行为特征、偏侧性及半球优势产生不同影响。通过熟练抓握和熟练行走任务，有三项发现支持多代应激会形成新的行为特征并改变偏侧性。第一，虽然F1代的PS未改变爪偏好，但F4代的多代应激仅使雄性的爪偏好转向更倾向于左利手。第二，多代应激损害了雄性的熟练抓握和熟练行走运动能力，却提高了雌性这些能力至超过对照组的水平。第三，多代应激雄性中向左利手的转变伴随着右顶叶皮质中树突复杂性增加和棘密度增大。因此，累积的多代应激在雄性中产生了性二态性左利手和向右侧半球的优势转移。这些发现解释了在没有DNA序列变异的情况下明显可遗传的行为特征和利手性的起源，同时提出了表观遗传机制。
