Optimization of somatic inhibition at critical period onset in mouse visual cortex

Neuron. 2007 Mar 15;53(6):805-12. doi: 10.1016/j.neuron.2007.02.026.

Abstract

Local GABAergic circuits trigger visual cortical plasticity in early postnatal life. How these diverse connections contribute to critical period onset was investigated by nonstationary fluctuation analysis following laser photo-uncaging of GABA onto discrete sites upon individual pyramidal cells in slices of mouse visual cortex. The GABA(A) receptor number decreased on the soma-proximal dendrite (SPD), but not at the axon initial segment, with age and sensory deprivation. Benzodiazepine sensitivity was also higher on the immature SPD. Too many or too few SPD receptors in immature or dark-reared mice, respectively, were adjusted to critical period levels by benzodiazepine treatment in vivo, which engages ocular dominance plasticity in these animal models. Combining GAD65 deletion with dark rearing from birth confirmed that an intermediate number of SPD receptors enable plasticity. Site-specific optimization of perisomatic GABA response may thus trigger experience-dependent development in visual cortex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Animals
  • Animals, Newborn
  • Benzodiazepines / pharmacology
  • Critical Period, Psychological*
  • Dendrites / drug effects
  • Dendrites / physiology*
  • Dendrites / radiation effects
  • Dominance, Ocular / drug effects
  • Dominance, Ocular / genetics
  • Dominance, Ocular / radiation effects
  • Electric Stimulation / methods
  • GABA Agonists / pharmacology
  • Glutamate Decarboxylase / deficiency
  • In Vitro Techniques
  • Isoenzymes / deficiency
  • Membrane Potentials / drug effects
  • Membrane Potentials / genetics
  • Membrane Potentials / radiation effects
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neural Inhibition / genetics
  • Neural Inhibition / physiology*
  • Patch-Clamp Techniques / methods
  • Pyramidal Cells / cytology*
  • Pyramidal Cells / drug effects
  • Pyramidal Cells / radiation effects
  • Pyridines / pharmacology
  • Visual Cortex / cytology
  • Visual Cortex / physiology*
  • Zolpidem
  • gamma-Aminobutyric Acid / pharmacology

Substances

  • GABA Agonists
  • Isoenzymes
  • Pyridines
  • Benzodiazepines
  • gamma-Aminobutyric Acid
  • Zolpidem
  • Glutamate Decarboxylase
  • glutamate decarboxylase 2