Distinct Morphological Stages of Dentate Granule Neuron Maturation in the Adult Mouse Hippocampus

Adult neurogenesis in the dentate gyrus may contribute to hippocampus-dependent functions, yet little is known about when and how newborn neurons are functional because of limited information about the time course of their connectivity. By using retrovirus-mediated gene transduction, we followed the dendritic and axonal growth of adult-born neurons in the mouse dentate gyrus and identified distinct morphological stages that may indicate different levels of connectivity. Axonal projections of newborn neurons reach the CA3 area 10-11 d after viral infection, 5-6 d before the first spines are formed. Quantitative analyses show that the peak of spine growth occurs during the first 3-4 weeks, but further structural…

• MF
  Milken Family Foundation
• AE
  American Epilepsy Society
• EF
  Epilepsy Foundation
• ES
  Epilepsy Society
• NI
  National Institutes of Health