Transient and persistent dendritic spines in the neocortex in vivo.
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.
Holtmaat
Anthony J G D
AJ
Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Trachtenberg
Joshua T
JT
Wilbrecht
Linda
L
Shepherd
Gordon M
GM
Zhang
Xiaoqun
X
Knott
Graham W
GW
Svoboda
Karel
K
D000375:Aging / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D002454:Cell Differentiation / Q000502:physiology*; D049229:Dendritic Spines / Q000502:physiology / Q000648:ultrastructure*; D049452:Green Fluorescent Proteins; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D019579:Neocortex / Q000254:growth & development* / Q000648:ultrastructure*; D009434:Neural Pathways / Q000254:growth & development / Q000648:ultrastructure; D009473:Neuronal Plasticity / Q000502:physiology; D017966:Pyramidal Cells / Q000502:physiology / Q000648:ultrastructure*; D013003:Somatosensory Cortex / Q000254:growth & development / Q000648:ultrastructure; D013569:Synapses / Q000502:physiology / Q000648:ultrastructure; D014793:Visual Cortex / Q000254:growth & development / Q000648:ultrastructure
D049452:Green Fluorescent Proteins