Clayton N S, Reboreda J C, Kacelnik A
Section of Neurobiology, Physiology and Behavior, Briggs Hall, University of California, Davis, CA 95616, USA.
Instituto de Biologı́a y Medicina Experimental-CONICET, Vuelta de Obligado 2490, 1428 Buenos Aires, Argentina.
Behav Processes. 1997 Dec;41(3):237-43. doi: 10.1016/s0376-6357(97)00050-8.
Avian brain plasticity has been demonstrated by seasonal variations in neuroanatomy correlated with changes in singing and hoarding behaviour. We report a new instance of plasticity. Brood parasitism in South American cowbirds involves memory for location of hosts' nests, and is associated with an enlarged hippocampus relative to telencephalon size. This effect holds between sexes and species during the breeding season. We report that for two parasitic species, relative hippocampal volume is smaller during the non-breeding than the breeding season, and that sexual dimorphism present in summer in one of the species is not found in winter. These results support the hypothesis that the avian hippocampal formation shows neuroanatomical plasticity associated with seasonal changes in spatial memory demands.
鸟类大脑的可塑性已通过与鸣叫和贮藏行为变化相关的神经解剖学季节性变化得到证明。我们报告了一个可塑性的新实例。南美褐头牛鹂的巢寄生涉及对宿主巢穴位置的记忆，并且相对于端脑大小，其海马体增大。在繁殖季节，这种效应在不同性别和物种之间都存在。我们报告，对于两种寄生性物种，非繁殖季节的相对海马体体积比繁殖季节小，并且其中一个物种在夏季出现的两性差异在冬季未被发现。这些结果支持了这样的假设，即鸟类海马结构表现出与空间记忆需求的季节性变化相关的神经解剖学可塑性。
