Total and dendritic RNA-sequencing from primary mouse cortical neurons

Activity-dependent protein synthesis is critical for determining changes in dendritic proteomes underlying brain function, yet the mechanisms governing these changes are lacking. Here, we combined proximity-based labeling of dendritic transcriptome, translatome, and proteome to study the dynamics of RNA regulation in activated synapses. We discovered that depolarization leads to a switch from RNAs translated under basal conditions to new translation of previously unrecognized subsets of depolarization-dependent transcripts. Dynamically regulated RNAs bound by specific regulatory proteins, including NOVA1, FMRP, and ELAVLs, rapidly generate proteins with roles in mitochondrial regulation, RNA metabolism, translational control, and synaptic signaling in dendrites. Knockdowns of activity-induced dendritic RNAs altered neuronal physiology, underscoring how dynamic switches in the regulation of RNAs encoding coordinated sets of proteins underlie synaptic plasticity.