title: Post-training gamma irradiation-enhanced contextual fear memory associated with reduced neuronal activation of the infralimbic cortex.
abstract: The brain might be exposed to irradiation under a variety of situations, including clinical treatments, nuclear accidents, dirty bomb scenarios, and military and space missions. Correctly recalling tasks learned prior to irradiation is important but little is known about post-learning effects of irradiation. It is not clear whether exposure to X-ray irradiation during memory consolidation, a few hours following training, is associated with altered contextual fear conditioning 24h after irradiation and which brain region(s) might be involved in these effects. Brain immunoreactivity patterns of the immediately early gene c-Fos, a marker of cellular activity was used to determine which brain areas might be altered in post-training irradiation memory retention tasks. In this study, we show that post-training gamma irradiation exposure (1 Gy) enhanced contextual fear memory 24h later and is associated with reduced cellular activation in the infralimbic cortex. Reduced GABA-ergic neurotransmission in parvalbumin-positive cells in the infralimbic cortex might play a role in this post-training radiation-enhanced contextual fear memory.
authors.affiliation: Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239, USA.
authors.forename: Tara
authors.initials: T
authors.lastname: Kugelman
authors.affiliation: Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239, USA.
authors.forename: Damian G
authors.initials: DG
authors.lastname: Zuloaga
authors.affiliation: Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239, USA.
authors.forename: Sydney
authors.initials: S
authors.lastname: Weber
authors.affiliation: Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239, USA; Oregon Health and Science University, Portland, OR 97239, USA; Division of Neuroscience, ONPRC, Oregon Health and Science University, Portland, OR 97239, USA. Electronic address: raberj@ohsu.edu.
authors.forename: Jacob
authors.initials: J
authors.lastname: Raber
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000503:physiopathology / Q000528:radiation effects*; D003213:Conditioning, Psychological / Q000502:physiology / Q000528:radiation effects; D005239:Fear / Q000502:physiology / Q000528:radiation effects*; D005720:Gamma Rays / Q000009:adverse effects*; D007150:Immunohistochemistry; D008297:Male; D008568:Memory / Q000502:physiology / Q000528:radiation effects*; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000502:physiology / Q000528:radiation effects*; D010320:Parvalbumins / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D011897:Random Allocation; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D010320:Parvalbumins; D016760:Proto-Oncogene Proteins c-fos; D005680:gamma-Aminobutyric Acid
keywords: Contextual; Fear memory; Infralimbic; Irradiation; Parvalbumin; c-Fos