Cellular compartment analysis of temporal activity by fluorescence in situ hybridization (catFISH).

This protocol describes a method (cellular compartment analysis of temporal activity by fluorescent in situ hybridization or catFISH) that uses fluorescent in situ hybridization to immediate-early gene RNAs and confocal microscopy to identify neuronal populations activated at two distinct times. The combination of cellular and temporal resolution makes catFISH a valuable tool for investigating the dynamic interactions of neuronal populations associated with different behaviors or cognitive challenges.