Holtmaat Anthony J G D, Trachtenberg Joshua T, Wilbrecht Linda, Shepherd Gordon M, Zhang Xiaoqun, Knott Graham W, Svoboda Karel
Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Neuron. 2005 Jan 20;45(2):279-91. doi: 10.1016/j.neuron.2005.01.003.
Dendritic spines were imaged over days to months in the apical tufts of neocortical pyramidal neurons (layers 5 and 2/3) in vivo. A fraction of thin spines appeared and disappeared over a few days, while most thick spines persisted for months. In the somatosensory cortex, from postnatal day (PND) 16 to PND 25 spine retractions exceeded additions, resulting in a net loss of spines. The fraction of persistent spines (lifetime > or = 8 days) grew gradually during development and into adulthood (PND 16-25, 35%; PND 35-80, 54%; PND 80-120, 66%; PND 175-225, 73%), providing evidence that synaptic circuits continue to stabilize even in the adult brain, long after the closure of known critical periods. In 6-month-old mice, spines turn over more slowly in visual compared to somatosensory cortex, possibly reflecting differences in the capacity for experience-dependent plasticity in these brain regions.
在体内对新皮层锥体神经元（第5层和第2/3层）顶端树突丛中的树突棘进行了长达数天至数月的成像。一部分细树突棘在几天内出现和消失，而大多数粗树突棘持续数月。在体感皮层中，从出生后第16天（PND）到第25天，树突棘的回缩超过增加，导致树突棘净损失。持续存在的树突棘（寿命≥8天）的比例在发育过程中逐渐增加并持续到成年期（PND 16 - 25，35%；PND 35 - 80，54%；PND 80 - 120，66%；PND 175 - 225，73%），这表明即使在成年大脑中，在已知关键期结束很久之后，突触回路仍在继续稳定。在6个月大的小鼠中，与体感皮层相比，视觉皮层中的树突棘周转更慢，这可能反映了这些脑区在经验依赖性可塑性能力方面的差异。
