Department of Neurobiology and Anatomy, Wake Forest School of Medicine, Winston-Salem, NC 27157.
Proc Natl Acad Sci U S A. 2014 Mar 11;111(10):3853-8. doi: 10.1073/pnas.1316594111. Epub 2014 Feb 24.
The prefrontal cortex continues to mature after puberty and into early adulthood, mirroring the time course of maturation of cognitive abilities. However, the way in which prefrontal activity changes during peri- and postpubertal cortical maturation is largely unknown. To address this question, we evaluated the developmental stage of peripubertal rhesus monkeys with a series of morphometric, hormonal, and radiographic measures, and conducted behavioral and neurophysiological tests as the monkeys performed working memory tasks. We compared firing rate and the strength of intrinsic functional connectivity between neurons in peripubertal vs. adult monkeys. Notably, analyses of spike train cross-correlations demonstrated that the average magnitude of functional connections measured between neurons was lower overall in the prefrontal cortex of peripubertal monkeys compared with adults. The difference resulted because negative functional connections (indicative of inhibitory interactions) were stronger and more prevalent in peripubertal compared with adult monkeys, whereas the positive connections showed similar distributions in the two groups. Our results identify changes in the intrinsic connectivity of prefrontal neurons, particularly that mediated by inhibition, as a possible substrate for peri- and postpubertal advances in cognitive capacity.
前额皮质在青春期后和成年早期继续成熟，反映了认知能力成熟的时间过程。然而，前额叶活动在围产期和青春期后皮质成熟过程中的变化方式在很大程度上尚不清楚。为了解决这个问题，我们通过一系列形态计量学、荷尔蒙和放射学测量来评估围产期恒河猴的发育阶段，并在猴子执行工作记忆任务时进行行为和神经生理学测试。我们比较了围产期和成年猴子之间神经元的放电率和内在功能连接的强度。值得注意的是，尖峰序列互相关分析表明，与成年猴子相比，围产期猴子前额叶皮层中测量的神经元之间功能连接的平均幅度总体上较低。这种差异是因为负功能连接（表明抑制相互作用）在围产期比成年猴子更强且更普遍，而正连接在两组中表现出相似的分布。我们的研究结果表明，前额叶神经元的内在连接性变化，特别是由抑制介导的连接性变化，可能是认知能力在围产期和青春期后进展的基础。
