Activity-dependent changes in gene-expression are believed to underlie the 
molecular representation of memory. In this study, we report that in vivo 
activation of neurons rapidly induces the CREB-regulated microRNA miR-132. To 
determine if production of miR-132 is regulated by neuronal activity its 
expression in mouse brain was monitored by quantitative RT-PCR (RT-qPCR). 
Pilocarpine-induced seizures led to a robust, rapid, and transient increase in 
the primary transcript of miR-132 (pri-miR-132) followed by a subsequent rise in 
mature microRNA (miR-132). Activation of neurons in the hippocampus, olfactory 
bulb, and striatum by contextual fear conditioning, odor-exposure, and 
cocaine-injection, respectively, also increased pri-miR-132. Induction kinetics 
of pri-miR-132 were monitored and found to parallel those of immediate early 
genes, peaking at 45 min and returning to basal levels within 2 h of 
stimulation. Expression levels of primary and mature-miR-132 increased 
significantly between postnatal Days 10 and 24. We conclude that miR-132 is an 
activity-dependent microRNA in vivo, and may contribute to the long-lasting 
proteomic changes required for experience-dependent neuronal plasticity.