Plasticity of dendritic spine formation: A state dependent stochastic process

Abstract

This study proposes that plasticity of dendritic spine formation may be modeled as distribution patterns imbedded in a spine length-dependent and density-dependent stochastic process. Modeling the jewel fish tectal interneuron revealed a critical 10-36 fim region where spine length plasticity was predicted to be most detectable. This hypothesis was tested by comparing neurons sampled from jewel fish reared for 4 years in a crowded environment (1 fish/6.64 /) with uncrowded controls (1 fish/25 /). The interaction between fish groups and the location of spine length differences was significant O<0.01) within the basal 10-30/xm dendritic segment. Spine head widths were also significantly smaller (p<0.0l) in the crowded fish over the entire dendrite. These findings suggest two modes of neuronal plasticity: (1) plasticity of spine length during formation, and (2) plasticity in spine head width after the spine is formed.