德国马克斯·普朗克大脑研究所Moritz Helmstaedter小组发现，小鼠桶状皮质抑制产后结缔组织的发育。该研究于2020年12月3日发表于《科学》杂志。

研究人员量化了发育过程中的小鼠体感皮层抑制性中间神经元突触发生的电路模式。研究人员利用3D电子显微镜观察了出生后前4周（出生后5至28天）小鼠细胞体、顶突和轴突初始节段的突触神经支配。研究发现顶端树突神经支配发生在早期，特别是目标偏好性在产后第五天（P5）几乎与成人水平一致。

另一方面，轴突神经细胞体可能通过突触过量和随后抗特异性突触去除逐渐从P5到P9获得特异性。枝形吊灯轴突揭示了P14的第一个靶标优先选择，但P28几乎形成了完整的靶标特异性，这与轴突生长和脱靶突触去除的组合相一致。这种结缔组织发育概况揭示了小鼠皮质中抑制性轴突在发育过程中如何建立大脑回路。

研究人员表示，新皮层中大脑回路是由迁移并能形成突触的多种神经元发育而成。

附：英文原文

Title: Postnatal connectomic development of inhibition in mouse barrel cortex

Author: Anjali Gour, Kevin M. Boergens, Natalie Heike, Yunfeng Hua, Philip Laserstein, Kun Song, Moritz Helmstaedter

Issue&Volume: 2020/12/03

Abstract: Brain circuits in the neocortex develop from diverse types of neurons that migrate and form synapses. Here we quantify the circuit patterns of synaptogenesis for inhibitory interneurons in the developing mouse somatosensory cortex. We studied synaptic innervation of cell bodies, apical dendrites and axon initial segments using 3D electron microscopy focusing on the first four weeks postnatally (postnatal days 5 to 28). We found that innervation of apical dendrites occurs early and specifically: target preference is already almost at adult levels at the fifth postnatal day (P5). Axons innervating cell bodies, on the other hand, gradually acquire specificity from P5 to P9 likely via synaptic overabundance followed by antispecific synapse removal. Chandelier axons show first target preference by P14 but develop full target specificity almost completely by P28, consistent with a combination of axon outgrowth and off-target synapse removal. This connectomic developmental profile reveals how inhibitory axons in mouse cortex establish brain circuitry during development.

DOI: 10.1126/science.abb4534

Source: https://science.sciencemag.org/content/early/2020/12/02/science.abb4534