Hyer Molly M, Glasper Erica R
Program in Neuroscience and Cognitive Sciences, University of Maryland, College Park, Maryland, United States of America.
Department of Psychology, University of Maryland, College Park, Maryland, United States of America.
PLoS One. 2017 Apr 13;12(4):e0175713. doi: 10.1371/journal.pone.0175713. eCollection 2017.
Individuals within monogamous species form bonds that may buffer against the negative effects of stress on physiology and behavior. In some species, involuntary termination of the mother-offspring bond results in increased symptoms of negative affect in the mother, suggesting that the parent-offspring bond may be equally as important as the pair bond. To our knowledge, the extent to which affect in paternal rodents is altered by involuntary termination of the father-offspring bond is currently unknown. Here, we investigated to what extent separation and paternal experience alters passive stress-coping behaviors and dendritic morphology in hippocampal subfields of California mice (Peromyscus californicus). Irrespective of paternal experience, separated mice displayed shorter latencies to the first bout of immobility, longer durations of immobility, and more bouts of immobility than control (non-separated) mice. This effect of separation was exacerbated by paternal experience in some measures of behavioral despair-separation from offspring further decreased the latency to immobility and increased bouts of immobility. In the dentate gyrus, separation reduced dendritic spine density regardless of paternal experience. Increased spine density was observed on CA1 basal, but not apical, dendrites following paternal experience. Regardless of offspring presence, fatherhood was associated with reduced apical dendritic spine density in area CA3 of the hippocampus. Separation enhanced complexity of both basal and apical dendrites in CA1, while fatherhood reduced dendritic complexity in this region. Our data suggest that forced dissolution of the pair bond induces passive stress-coping behaviors and contributes to region-specific alterations in hippocampal structure in California mouse males.
一夫一妻制物种中的个体形成的关系纽带可能会缓冲压力对生理和行为的负面影响。在某些物种中，母婴关系的非自愿终止会导致母亲出现更多负面影响症状，这表明亲子关系可能与配偶关系同样重要。据我们所知，父鼠与幼崽关系的非自愿终止对其情感的影响程度目前尚不清楚。在此，我们研究了分离和父性经历在多大程度上改变了加州小鼠（加州林鼠）海马亚区的被动应激应对行为和树突形态。无论父性经历如何，与对照组（未分离）小鼠相比，分离后的小鼠首次静止不动的潜伏期更短、静止不动的持续时间更长且静止不动的次数更多。在一些行为绝望指标中，父性经历加剧了这种分离效应——与后代分离进一步缩短了静止不动的潜伏期并增加了静止不动的次数。在齿状回中，无论父性经历如何，分离都会降低树突棘密度。父性经历后，CA1区基底树突而非顶端树突上的树突棘密度增加。无论后代是否存在，成为父亲都与海马体CA3区顶端树突棘密度降低有关。分离增强了CA1区基底和顶端树突的复杂性，而成为父亲则降低了该区域的树突复杂性。我们的数据表明，配偶关系的强制解除会诱发被动应激应对行为，并导致加州小鼠雄性海马结构出现区域特异性改变。
