Meloni, EdwardGillis, Timothy E.Manoukian, JasmineKaufman, Marc2014-09-082014Meloni, Edward G., Timothy E. Gillis, Jasmine Manoukian, and Marc J. Kaufman. 2014. “Xenon Impairs Reconsolidation of Fear Memories in a Rat Model of Post-Traumatic Stress Disorder (PTSD).” PLoS ONE 9 (8): e106189. doi:10.1371/journal.pone.0106189. http://dx.doi.org/10.1371/journal.pone.0106189.1932-6203http://nrs.harvard.edu/urn-3:HUL.InstRepos:12785926Xenon (Xe) is a noble gas that has been developed for use in people as an inhalational anesthestic and a diagnostic imaging agent. Xe inhibits glutamatergic N-methyl-D-aspartate (NMDA) receptors involved in learning and memory and can affect synaptic plasticity in the amygdala and hippocampus, two brain areas known to play a role in fear conditioning models of post-traumatic stress disorder (PTSD). Because glutamate receptors also have been shown to play a role in fear memory reconsolidation – a state in which recalled memories become susceptible to modification – we examined whether Xe administered after fear memory reactivation could affect subsequent expression of fear-like behavior (freezing) in rats. Male Sprague-Dawley rats were trained for contextual and cued fear conditioning and the effects of inhaled Xe (25%, 1 hr) on fear memory reconsolidation were tested using conditioned freezing measured days or weeks after reactivation/Xe administration. Xe administration immediately after fear memory reactivation significantly reduced conditioned freezing when tested 48 h, 96 h or 18 d after reactivation/Xe administration. Xe did not affect freezing when treatment was delayed until 2 h after reactivation or when administered in the absence of fear memory reactivation. These data suggest that Xe substantially and persistently inhibits memory reconsolidation in a reactivation and time-dependent manner, that it could be used as a new research tool to characterize reconsolidation and other memory processes, and that it could be developed to treat people with PTSD and other disorders related to emotional memory.en-USBiology and Life SciencesAnatomyNervous SystemNeuroanatomyNeural PathwaysNeuroscienceCellular NeuroscienceSynaptic PlasticityCognitive ScienceCognitionMemoryCognitive PsychologyLearningBehavioral NeuroscienceCognitive NeuroscienceLearning and MemoryMedicine and Health SciencesMental Health and PsychiatryJournal Article2014-09-0810.1371/journal.pone.0106189