Experience-induced changes of dendritic spine densities in the prefrontal and sensory cortex: Correlation with developmental time windows
Experience-induced changes of dendritic spine densities in the prefrontal and sensory cortex: Correlation with developmental time windows
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DOI：
10.1093/cercor/bhh181
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发表时间：
2005-06-01
期刊：
影响因子：
3.7
通讯作者：
Braun, K
中科院分区：
文献类型：
--
作者：
Bock, J;Gruss, M;Braun, K
本研究提供了证据的假设，即经验引起的突触变化的程度和方向与神经元和内分泌发育的时间窗口相关的皮层区。在下丘脑-垂体-肾上腺（HPA）轴的应激低反应期（SHRP）之前，反复短暂暴露于母体分离诱导21日龄大鼠前扣带皮层（ACd）第II/III层锥体神经元树突棘密度显著降低（-16%），而SHRP终止后分离导致该神经元类型的树突棘密度增加（+16%）。此外，两组大鼠在此年龄段的基础血浆皮质酮水平升高。分离期间SHRP（出生后第5-7天）并没有影响脊柱密度的ACD，和基础皮质酮水平保持不变。与此相反，锥体神经元的躯体感觉皮层（SSC）显示出显着增强的棘密度（高达52%的增长）独立于分离的时间。这些结果表明，在边缘系统和感觉皮层区域的突触平衡的变化，以响应早期的情绪体验是区域特异性的，并与内分泌和神经系统的成熟阶段。
The present study provides evidence for the hypothesis that the extent and the direction of experience-induced synaptic changes in cortical areas correlates with time windows of neuronal as well as endocrine development. Repeated brief exposure to maternal separation prior to the stress hyporesponsive period (SHRP) of the hypothalamic-pituitary-adrenal (HPA) axis induced significantly reduced dendritic spine density (-16%) in layer II/III pyramidal neurons of the anterior cingulate cortex (ACd) of 21-day-old rats, whereas separation after termination of the SHRP resulted in increased spine densities (+16%) in this neuron type. In addition, rats of both groups displayed elevated basal plasma levels of corticosterone at this age. Separation during the SHRP (postnatal days 5-7) did not influence spine density in the ACd, and basal corticosterone levels remained unchanged. In contrast, pyramidal neurons in the somatosensory cortex (SSC) displayed significantly enhanced spine densities (up to 52% increase) independent from the time of separation. These results indicate that alterations in the synaptic balance in limbic and sensory cortical regions in response to early emotional experience are region-specific and related to the maturational stage of endocrine and neuronal systems.