The human cortex, particularly the prefrontal cortex, decreases in volume during adolescence which indicates considerable pruning. There is consistent evidence from human, monkey and rat tissue that synapses, dendritic spines and dendrites are pruned during this time. However, our work with a rat model of adolescence shows that other cellular components are remodeling at this time as well. Neurons are also pruned and we have found that in female rats, puberty is a key signal for this process. Other critical developmental events occur that are not detectable in gross size changes including the growth of dopaminergic inputs. The changes in the inhibitory GABAergic system, especially the parvalbumin-expressing neuronal subtype, are an essential part of the maturation of the prefrontal cortex. This involves the formation of perineuronal nets around parvalbumin interneurons that allow mature fast spiking. We have found a large increase in perineuronal nets from early adolescence to adulthood in both sexes. We also have seen a temporary pause in this increase at the time of puberty in females. These complicated events cannot be deduced from MRI. The cellular reorganization that is indicated by size changes in the human cortex during adolescence can be informed by work from rodent models.

人的皮层，特别是前额叶皮层，在青春期的体积减少，这表明可修剪的程度很大。来自人，猴子和大鼠组织的一致证据表明，在此期间，突触，树突棘和树突被修剪。但是，我们对大鼠青春期模型的研究表明，此时其他细胞成分也在重塑。神经元也被修剪，我们发现在雌性大鼠中，青春期是该过程的关键信号。发生了其他重大发育事件，这些变化在总大小变化中无法检测到，包括多巴胺能输入的增长。抑制性GABA能系统的变化，尤其是表达小白蛋白的神经元亚型，是前额叶皮质成熟的重要组成部分。这涉及在小白蛋白中间神经元周围形成神经周围网，从而允许成熟的快速突刺。我们发现，从青春期早期到成年，男女的神经周神经网都有大量增加。在女性青春期时，这种增加也有短暂的停顿。这些复杂的事件无法从MRI推论出来。可以通过啮齿动物模型的工作来了解青春期人类皮层大小变化所指示的细胞重组。