Toscano J E, Bauman M D, Mason W A, Amaral D G
Department of Psychiatry and Behavioral Sciences, 2230 Stockton Blvd. Sacramento, CA 95817, USA.
Neuroscience. 2009 Sep 15;162(4):881-91. doi: 10.1016/j.neuroscience.2009.05.056. Epub 2009 May 29.
Previous research in our laboratory has shown that damage to the amygdala in neonatal rhesus monkeys profoundly alters behaviors associated with fear processing, while leaving many aspects of social development intact. Little is known, however, about the impact of neonatal lesions of the amygdala on later developing aspects of social behavior. A well-defined phenomenon in the development of young female rhesus monkeys is an intense interest in infants that is typically characterized by initiating proximity or attempting to hold them. The extent to which young females are interested in infants may have important consequences for the development of species-typical maternal behavior. Here we report the results of a study that was designed to assess interest in infants by female rhesus monkeys that received neonatal lesions to the amygdala, hippocampus or a sham surgical procedure. Subjects were first paired with pregnant "stimulus" females to assess social interactions with them prior to the birth of the infants. There were few behavioral differences between lesion groups when interacting with the pregnant females. However, following the birth of the infants, the amygdala-lesioned females showed significantly less interest in the infants than did control or hippocampus-lesioned females. They directed fewer affiliative vocalizations and facial expressions to the mother-infant pair compared to the hippocampus-lesioned and control females. These findings suggest that neonatal damage to the amygdala, but not the hippocampus, impairs important precursors of non-human primate maternal behavior.
我们实验室之前的研究表明,新生恒河猴的杏仁核受损会深刻改变与恐惧处理相关的行为,而社会发展的许多方面则保持完好。然而,关于杏仁核新生期损伤对后期社会行为发展方面的影响,我们知之甚少。年轻雌性恒河猴发育过程中一个明确的现象是对婴儿有着浓厚兴趣,其典型表现是主动接近或试图抱起婴儿。年轻雌性对婴儿感兴趣的程度可能对物种典型的母性行为发展具有重要影响。在此,我们报告一项研究结果,该研究旨在评估接受杏仁核、海马体新生期损伤或假手术的雌性恒河猴对婴儿的兴趣。首先将实验对象与怀孕的“刺激”雌性配对,以评估在婴儿出生前它们与这些雌性的社会互动。在与怀孕雌性互动时,损伤组之间几乎没有行为差异。然而,在婴儿出生后,杏仁核损伤的雌性对婴儿的兴趣明显低于对照组或海马体损伤的雌性。与海马体损伤和对照组雌性相比,它们对母婴对发出的亲和叫声和面部表情更少。这些发现表明,新生期杏仁核损伤而非海马体损伤会损害非人类灵长类动物母性行为的重要先兆。