University Honors

Fragile X syndrome (FXS) is often accompanied by sensory hyperarousal andhypersensitivity, leading to cognitive impairments in attention, learning, and memory. To betterunderstand the neural mechanisms underlying hypersensitivity to sensory stimuli, weinvestigated how these atypical sensory processes influence goal-directed behavior by using ananimal model of FXS- Fmr1 Knockout (FMR1 KO) mice. Compared to wild-type (WT) mice,Fmr1 KO mice displayed greater vulnerability to distracting auditory and visual stimuli whenperforming the same visual discrimination task, suggesting hypersensitivity and inability toignore distractors. Prior studies have found that the anterior cingulate cortex (ACC) is involvedin increasing cortical responses to behaviorally relevant information (Zhang et al, 2014; Fiser etal., 2016; Norman et al. 2021). We propose that dysfunction in inputs from ACC→V1 maycontribute to the ability to ignore sensory distractors and selectively attend to behaviorallyrelevant stimuli in Fmr1 KO mice. This is supported by in vivo two-photon calcium imaging ofACC axon terminals in V1, which shows reduced modulation of ACC→V1 input duringdistractor susceptibility in Fmr1 KO. Inactivation of ACC prevents WT mice from overcomingdistractors and elevating ACC function using Methylphenidate showed trends for reduceddistractibility in Fmr1 KO mice. Identifying disruptions in these long-range inputs to V1 willprovide knowledge about the mechanistic understanding of sensory hypersensitivity in a range ofneurodevelopmental disorders.