RNA FISH analysis of L1Cam and ActB mRNA localization throughout rat hippocampal neuron maturation

Neurons contain thousands of distinct mRNAs that are targeted to specific subcellular regions. Past research has shown that this spatial organization enables localized protein synthesis, allowing neurons to respond autonomously to local stimuli. However, current understanding of mRNA localization does not account for how these patterns change over the course of neuronal development. In this study, we examine two SFARI-classified mRNAs associated with autism spectrum disorders: ActB and L1Cam. Using RNA FISH, immunofluorescence, fluorescence microscopy and quantitative analysis, the distribution of ActB and L1Cam mRNA in the soma and dendrites was quantified across three stages of neuronal development and maturation. It was observed that somatic levels of both mRNAs was substantially higher than dendritic levels, and that ActB was consistently more abundant in dendrites than L1Cam. These findings contribute to a broader understanding of how these mRNAs are distributed during maturation.