Presentation Title

Impaired PV and PNN Expression in CA1 Hippocampus May Underlie Contextual Recall Deficits After Auditory Fear Conditioning In FMR1 Knockout Mice

Faculty Mentor

Iryna Ethell, Khaleel Abdulrazak

Start Date

18-11-2017 2:15 PM

End Date

18-11-2017 3:15 PM

Location

BSC-Ursa Minor 126

Session

Poster 3

Type of Presentation

Poster

Subject Area

interdisciplinary

Abstract

Impaired PV and PNN Expression in CA1 Hippocampus May Underlie Contextual Recall Deficits After Auditory Fear Conditioning In FMR1 Knockout Mice

Authors: Sonia Afroz, Sarah Reinhard, Kasim Pendi, Yasmien Hanania (University of California, Riverside School of Medicine)

Mentors: Iryna M. Ethell, Khaleel A. Razak (University of California, Riverside School of Medicine)

Fragile X Syndrome (FXS) is a genetic condition known to cause intellectual disabilities and autistic behavior due to silencing the Fragile X Mental Retardation 1 (Fmr1) gene. We are interested in understanding cellular mechanisms of impaired spatial learning, working memory, and attention deficits associated with FXS. In this study we used Fmr1 KO mouse, a FXS mouse model, to study the underlying mechanisms using auditory fear conditioning paradigm. This fear conditioning protocol included habituation, training, and extinction in conditioned and un-conditioned contexts. Contextual learning was studied by comparing the freezing behaviors of WT to Fmr1 mice using Freeze frame and TopScan Lite software. While there was no difference in freezing behavior detected between the two groups during tone recall, contextual recall was significantly impaired in Fmr1 KO mice. During fear conditioning learning and recall we also observed significant changes in Parvalbumin (PV) inhibitory interneuron density and the organization of Perineuronal nets (PNNs) in the CA2 and CA1 areas of the hippocampus. Fmr1 KO mice showed a post-conditioning decrease in PNNs around CA1 hippocampal pyramidal neurons when compared to WT mice. We also detected a significant increase in PV expression in WT following the training but saw a decrease in PV expression in Fmr1 KO. These results show that a reduced density of PV inhibitory interneurons in the CA1 hippocampus may be responsible for contextual memory deficits in Fmr1 KO mice.

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Nov 18th, 2:15 PM Nov 18th, 3:15 PM

Impaired PV and PNN Expression in CA1 Hippocampus May Underlie Contextual Recall Deficits After Auditory Fear Conditioning In FMR1 Knockout Mice

BSC-Ursa Minor 126

Impaired PV and PNN Expression in CA1 Hippocampus May Underlie Contextual Recall Deficits After Auditory Fear Conditioning In FMR1 Knockout Mice

Authors: Sonia Afroz, Sarah Reinhard, Kasim Pendi, Yasmien Hanania (University of California, Riverside School of Medicine)

Mentors: Iryna M. Ethell, Khaleel A. Razak (University of California, Riverside School of Medicine)

Fragile X Syndrome (FXS) is a genetic condition known to cause intellectual disabilities and autistic behavior due to silencing the Fragile X Mental Retardation 1 (Fmr1) gene. We are interested in understanding cellular mechanisms of impaired spatial learning, working memory, and attention deficits associated with FXS. In this study we used Fmr1 KO mouse, a FXS mouse model, to study the underlying mechanisms using auditory fear conditioning paradigm. This fear conditioning protocol included habituation, training, and extinction in conditioned and un-conditioned contexts. Contextual learning was studied by comparing the freezing behaviors of WT to Fmr1 mice using Freeze frame and TopScan Lite software. While there was no difference in freezing behavior detected between the two groups during tone recall, contextual recall was significantly impaired in Fmr1 KO mice. During fear conditioning learning and recall we also observed significant changes in Parvalbumin (PV) inhibitory interneuron density and the organization of Perineuronal nets (PNNs) in the CA2 and CA1 areas of the hippocampus. Fmr1 KO mice showed a post-conditioning decrease in PNNs around CA1 hippocampal pyramidal neurons when compared to WT mice. We also detected a significant increase in PV expression in WT following the training but saw a decrease in PV expression in Fmr1 KO. These results show that a reduced density of PV inhibitory interneurons in the CA1 hippocampus may be responsible for contextual memory deficits in Fmr1 KO mice.