Retinotopic map refinement requires spontaneous retinal waves during a brief critical period of development

Neuron. 2003 Dec 18;40(6):1147-60. doi: 10.1016/s0896-6273(03)00790-6.

Abstract

During retinocollicular map development, spontaneous waves of action potentials spread across the retina, correlating activity among neighboring retinal ganglion cells (RGCs). To address the role of retinal waves in topographic map development, we examined wave dynamics and retinocollicular projections in mice lacking the beta2 subunit of the nicotinic acetylcholine receptor. beta2(-/-) mice lack waves during the first postnatal week, but RGCs have high levels of uncorrelated firing. By P8, the wild-type retinocollicular projection remodels into a refined map characterized by axons of neighboring RGCs forming focal termination zones (TZs) of overlapping arbors. In contrast, in P8 beta2(-/-) mice, neighboring RGC axons form large TZs characterized by broadly distributed arbors. At P8, glutamatergic retinal waves appear in beta2(-/-) mice, and later, visually patterned activity appears, but the diffuse TZs fail to remodel. Thus, spontaneous retinal waves that correlate RGC activity are required for retinotopic map remodeling during a brief early critical period.

Publication types

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

MeSH terms

  • Action Potentials / physiology*
  • Animals
  • Animals, Newborn
  • In Vitro Techniques
  • Mice
  • Mice, Knockout
  • Neural Pathways / growth & development
  • Neural Pathways / metabolism
  • Receptors, Nicotinic / deficiency
  • Receptors, Nicotinic / genetics
  • Retina / growth & development*
  • Retina / metabolism
  • Retinal Ganglion Cells / physiology
  • Superior Colliculi / growth & development*
  • Superior Colliculi / metabolism
  • Time Factors

Substances

  • Receptors, Nicotinic
  • nicotinic receptor beta2