University Honors

Fragile X syndrome is the most common inherited contributor to intellectual disability and autismspectrum disorder. Fragile X syndrome is caused by the mutation of the Fmr1 gene, which iscrucial for producing the Fragile X Messenger Ribonucleoprotein 1 protein (FMRP) and isinvolved in proper synaptic development and function. Some of the phenotypic effects of thismutation include increased repetitive behavior, anxiety, social communication deficits, andcognitive decline. Based on the current literature, Fmr1 knockout mouse models have shown anenhanced N-methyl-D-aspartate receptors (NMDAR) receptor activity, contributing to thesymptoms we see in Fragile X syndrome, such as anxiety and increased repetitive behavior. N-methyl-D-aspartate receptors play a crucial role in glutamate binding and neuronal excitability.When glutamate binds to the N-methyl-D-aspartate receptor, it will open the ion channel, whichreleases more excitatory neurotransmitters and increases neuronal excitability. This cascade maycontribute to the anxiety and cognitive deficit phenotypes we observe. Memantine is anuncompetitive N-methyl-D-aspartate receptor inhibitor that reduces the N-methyl-D-aspartatereceptor activity. By reducing the elevated N-methyl-D-aspartate receptor activity, a therapeuticeffect may be seen due to the reduction in the cellular excitability and neurotransmitters, whichwould rescue the abnormal behavioral phenotypes caused by Fragile X syndrome.