Genesis of dendritic spines: Insights from ultrastructural and imaging studies

Dendritic spines are small protrusions from many types of neuron, which receive most of the excitatory inputs to the cell. Spines are thought to have important roles in neural information processing and plasticity, yet we still have a poor understanding of how they emerge during development. Here, we review the developmental generation of dendritic spines, covering recent live imaging experiments and older ultrastructural data. We address the potential role of dendritic filopodia in spine development and recent findings of spinogenesis in adult animals, and conclude by discussing three potential models of spinogenesis.