Department of Biology, University of Nevada, Reno, Nevada, USA.
Dev Neurobiol. 2010 Jun;70(7):538-47. doi: 10.1002/dneu.20795.
Brain plasticity and adult neurogenesis may play a role in many ecologically important processes including mate recognition, song learning and production, and spatial memory processing. In a number of species, both physical and social environments appear to influence attributes (e.g., volume, neuron number, and neurogenesis) of particular brain regions. The hippocampus in particular is well known to be especially sensitive to such changes. Although social grouping in many taxa includes the formation of male and female pairs, most studies of the relationship between social environment and the hippocampus have typically considered only solitary animals and those living in same-sex groups. Thus, the aim of this study was to compare the volume of the hippocampal formation, the total number of hippocampal neurons, and the number of immature neurons in the hippocampus (as determined by doublecortin expression) in mountain chickadees (Poecile gambeli) housed in groups of males and females, male-female pairs, same sex pairs of either males or females, and as solitary individuals. The different groups were visually and physically, but not acoustically, isolated from each other. We found no significant differences between any of our groups in hippocampal volume, the total number of hippocampal neurons, or the number of immature neurons. Our results thus provided no support to the hypothesis that social group composition and/or size have an effect on hippocampal morphology and neurogenesis.
大脑的可塑性和成年神经发生可能在许多生态重要的过程中发挥作用，包括配偶识别、歌曲学习和产生，以及空间记忆处理。在许多物种中，物理和社会环境似乎都影响特定脑区的属性（例如体积、神经元数量和神经发生）。特别是海马体，它对这些变化特别敏感。尽管许多类群的社会群体包括雌雄配对，但大多数关于社会环境与海马体关系的研究通常只考虑了独居动物和生活在同性群体中的动物。因此，本研究的目的是比较雄性和雌性群体、雌雄对、同性对（雄性或雌性）以及独居个体中饲养的山雀（Poecile gambeli）的海马体结构体积、海马体神经元总数和海马体中未成熟神经元（通过双皮质蛋白表达确定）的数量。不同的群体在视觉和物理上相互隔离，但在声学上没有隔离。我们在海马体体积、海马体神经元总数或未成熟神经元数量方面没有发现任何组间存在显著差异。因此，我们的结果不支持社会群体组成和/或大小对海马体形态和神经发生有影响的假设。
