Cunningham Miles Gregory, Bhattacharyya Sujoy, Benes Francine Mary
Laboratory of Structural Neuroscience, McLean Hospita,; Program in Neuroscience and Department of Psychiatry, Harvard Medical School, Boston, Massachusetts 02478, USA.
J Comp Neurol. 2002 Nov 11;453(2):116-30. doi: 10.1002/cne.10376.
Adolescence is a critical stage for the development of emotional maturity and diverse forms of psychopathology. The posterior basolateral nucleus of the amygdala is known to mediate fear and anxiety and is important in assigning emotional valence to cognitive processes. The medial prefrontal cortex, a homologue of the human anterior cingulate cortex, mediates emotional, attentional, and motivational behaviors at the cortical level. We postulate that the development of connectivity between these two corticolimbic regions contributes to an enhanced integration of emotion and cognition during the postnatal period. In order to characterize the development of this relay, injections of the anterograde tracer biocytin were stereotaxically placed within the posterior basolateral nucleus of the amygdala of rats at successive postnatal time points (postnatal days 6-120). Labeled fibers in the medial prefrontal cortex were evaluated using a combination of brightfield, confocal, and electron microscopy. We found that the density of labeled fibers originating from the posterior basolateral nucleus shows a sharp curvilinear increase within layers II and V of the anterior cingulate cortex and the infralimbic subdivisions of medial prefrontal cortex during the late postweanling period. This increase was paralleled by a linear rise in the number of axospinous and axodendritic synapses present in the neuropil. Based on these results, we propose that late maturation of amygdalo-cortical connectivity may provide an anatomical basis for the development and integration of normal and possibly abnormal emotional behavior during adolescence and early adulthood.
青春期是情绪成熟和多种精神病理学形式发展的关键阶段。杏仁核的后基底外侧核已知可介导恐惧和焦虑，并且在为认知过程赋予情绪效价方面很重要。内侧前额叶皮质是人类前扣带回皮质的同源物，在皮质水平介导情绪、注意力和动机行为。我们推测，这两个皮质边缘区域之间连接性的发展有助于在出生后时期增强情绪与认知的整合。为了描述这种中继的发展，在连续的出生后时间点（出生后第6 - 120天）将顺行示踪剂生物胞素立体定位注射到大鼠杏仁核的后基底外侧核内。使用明场、共聚焦和电子显微镜相结合的方法评估内侧前额叶皮质中的标记纤维。我们发现，源自后基底外侧核的标记纤维密度在断奶后期在前扣带回皮质的II层和V层以及内侧前额叶皮质的边缘下亚区呈急剧的曲线增加。这种增加与神经毡中轴棘突触和轴树突触数量的线性增加并行。基于这些结果，我们提出杏仁核 - 皮质连接性的后期成熟可能为青春期和成年早期正常以及可能异常的情绪行为的发展和整合提供解剖学基础。
