Transient and persistent dendritic spines in the neocortex in vivo

Neuron. 2005 Jan 20;45(2):279-91. doi: 10.1016/j.neuron.2005.01.003.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging / physiology*
  • Animals
  • Animals, Newborn
  • Cell Differentiation / physiology*
  • Dendritic Spines / physiology
  • Dendritic Spines / ultrastructure*
  • Green Fluorescent Proteins
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Microscopy, Fluorescence
  • Neocortex / growth & development*
  • Neocortex / ultrastructure*
  • Neural Pathways / growth & development
  • Neural Pathways / ultrastructure
  • Neuronal Plasticity / physiology
  • Pyramidal Cells / physiology
  • Pyramidal Cells / ultrastructure*
  • Somatosensory Cortex / growth & development
  • Somatosensory Cortex / ultrastructure
  • Synapses / physiology
  • Synapses / ultrastructure
  • Visual Cortex / growth & development
  • Visual Cortex / ultrastructure

Substances

  • Green Fluorescent Proteins