University of California at Irvine researchers have found that short-term stress lasting as little as a few hours can impair brain-cell communication in areas associated with learning and memory.

The acute-stress-activated selective corticotropin molecules released hormones (CRH), which disrupted the process the brain uses to collect and stores memories.

In rat and mouse studies, the researchers found that the release of CRH in the hippocampus led to rapid disintegration of dendritic spines on neurons, which theb limited the ability of synapses to collect and store memories. The spines appeared to grow back once the CRH was removed.