Thompson R R, Adkins-Regan E
Department of Psychology, Cornell University, Ithaca, NY 14853.
Brain Res. 1994 Dec 26;667(2):201-8. doi: 10.1016/0006-8993(94)91497-4.
Changes in the gross and cellular morphology of the nucleus preopticus medianus (POMn) were measured in response to changes in photoperiod in adult male Japanese quail (Coturnix japonica). POMn volume and the soma size of a dorsolateral population of neurons within POMn decreased when birds were moved from long day housing conditions (16L,8D) to short day housing conditions (8L,16D), and then increased again when birds were moved back to long day conditions, presumably as a function of the changes in circulating testosterone that accompanied changing daylengths. Male Japanese quail exhibit sexual behavior only when housed under long day housing conditions that approximate the photoperiod of the spring/summer breeding season, and do not exhibit sexual behavior when housed under short day conditions characteristic of fall/winter. Because POMn is known to be critically involved in the expression of male copulatory behavior, these morphological changes in the adult brain likely represent key functional events associated with the seasonal regulation of sexual behavior in male Japanese quail.
在成年雄性日本鹌鹑（Coturnix japonica）中，测量视前正中核（POMn）的大体和细胞形态变化，以响应光周期的变化。当鹌鹑从长日照饲养条件（16小时光照，8小时黑暗）转移到短日照饲养条件（8小时光照，16小时黑暗）时，POMn的体积以及POMn内背外侧一群神经元的胞体大小减小，而当鹌鹑再次转移回长日照条件时又增大，这可能是随着日照长度变化而循环的睾酮变化的结果。雄性日本鹌鹑仅在接近春/夏繁殖季节光周期的长日照饲养条件下才表现出性行为，而在秋/冬特征性的短日照条件下不表现出性行为。由于已知POMn在雄性交配行为的表达中起关键作用，成年大脑中的这些形态变化可能代表了与雄性日本鹌鹑性行为季节性调节相关的关键功能事件。
