Reduced perineuronal net expression in Fmr1 KO mice auditory cortex and amygdala is linked to impaired fear -associated memory.

Reduced perineuronal net expression in Fmr1 KO mice auditory cortex and amygdala is linked to impaired fear -associated memory. Neurobiol Learn Mem. 2019 Jul 18;:107042 Authors: Reinhard SM, Rais M, Afroz S, Hanania Y, Pendi K, Espinoza K, Rosenthal R, Binder DK, Ethell IM, Razak KA Abstract Fragile X syndrome (FXS) is a leading cause of heritable intellectual disability and autism. Humans with FXS show anxiety, sensory hypersensitivity and impaired learning. The mechanisms of learning impairments can be studied in the mouse model of FXS, the Fmr1 KO mouse, using tone-associated fear memory paradigms. Our previous study reported impaired development of parvalbumin (PV) positive interneurons and perineuronal nets (PNN) in the auditory cortex of Fmr1 KO mice. A recent study suggested PNN dynamics in the auditory cortex following tone-shock association is necessary for fear expression. Together these data suggest that abnormal PNN regulation may underlie tone-fear association learning deficits in Fmr1 KO mice. We tested this hypothesis by quantifying PV and PNN expression in the amygdala, hippocampus and auditory cortex of Fmr1 KO mice following fear conditioning. We found impaired tone-associated memory formation in Fmr1 KO mice. This was paralleled by impaired learning-associated regulation of PNNs in the superficial layers of auditory cortex in Fmr1 KO mice. PV cell density decreased in the auditory cortex in response to fear conditi...
Source: Neurobiology of Learning and Memory - Category: Neurology Authors: Tags: Neurobiol Learn Mem Source Type: research