March 10: Susan Rivera, Dept. of Psychology, UC Davis

Investigating Gene-Brain Relationships Across the Lifespan in the fragile X spectrum of Disorders
Mutations of the fragile X mental retardation 1 (FMR1) gene are the genetic cause of fragile X syndrome (FXS), the most common inherited form of mental retardation. Large expansions of the CGG trinucleotide repeat in the full mutation range (> 200 CGG repeats) consequently result in transcriptional silencing of the FMR1 gene and deficiency or absence of the FMR1 protein. Smaller expansions (~ 55 to 200 repeats)are referred to as the premutation (FXPM). My laboratory has been investigating individuals across the fragile X spectrum of involvement (including both premutation carriers and individuals with the full mutation) using both infrared eyetracking and brain imaging techniques. We have gathered data from individual across the life span, from infants to aging adults, and are converging on a consistent pattern of results which suggests that alterations in a fronto-parietal circuit may underly many of the observed cognitive deficits seen across the fragile X spectrum (especially, difficulty with spatial and numerical processing and attentive tracking). Furthermore, across these multiple studies, we have observed correlations between level of impairment on these tasks and molecular variables such as CGG repeat size and protein expression, suggesting a dosage effect of FMR1 mutations on cortical functioning in this prefrontal-parietal network.

Room 1111 Tolman Hall
12:00-1:30p.m.