Department of Physiology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Chicago, IL, 60611, USA.
Department of Neurobiology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL, 60208, USA.
Sci Rep. 2020 Oct 16;10(1):17522. doi: 10.1038/s41598-020-74385-2.
GABA is a key regulator of adult-born dentate granule cell (abDGC) maturation so mapping the functional connectivity between abDGCs and local interneurons is required to understand their development and integration into the hippocampal circuit. We recorded from birthdated abDGCs in mice and photoactivated parvalbumin (PV) and somatostatin (SST) interneurons to map the timing and strength of inputs to abDGCs during the first 4 weeks after differentiation. abDGCs received input from PV interneurons in the first week, but SST inputs were not detected until the second week. Analysis of desynchronized quantal events established that the number of GABAergic synapses onto abDGCs increased with maturation, whereas individual synaptic strength was constant. Voluntary wheel running in mice scaled the GABAergic input to abDGCs by increasing the number of synaptic contacts from both interneuron types. This demonstrates that GABAergic innervation to abDGCs develops during a prolonged post-mitotic period and running scales both SST and PV synaptic afferents.
GABA 是调节成年海马齿状回颗粒细胞（abDGC）成熟的关键因子，因此需要绘制 abDGC 与局部中间神经元之间的功能连接图谱，以了解它们的发育和整合到海马回路的情况。我们在出生后不久的小鼠中记录 abDGC 的电活动，并通过光激活 parvalbumin（PV）和 somatostatin（SST）中间神经元，以在分化后的头 4 周内绘制 abDGC 输入的时间和强度图谱。abDGC 在第一周接收来自 PV 中间神经元的输入，但直到第二周才检测到 SST 输入。去同步量子事件的分析表明，随着成熟， GABA 能突触传入到 abDGC 的数量增加，而单个突触强度保持不变。小鼠的自愿轮跑通过增加来自两种中间神经元类型的突触接触数量来调节 GABA 能传入到 abDGC。这表明 GABA 能传入到 abDGC 的发育发生在一个延长的有丝分裂后时期，而跑步会调节 SST 和 PV 突触传入。
