OLIGODENDROCYTE PROLIFERATION IN THE AUDITORY BRAINSTEM OF FRAGILE X SYNDROME MICE

The auditory brainstem, specifically the medial nucleus of the trapezoid body (MNTB), possesses heavily myelinated neurons to aid in the rapid processing of sound location information. Myelin is formed by the oligodendrocytes (OLs), making them crucial to the temporal fidelity of this brain area and circuit. Studies have shown that deficits in myelination contribute to autism spectrum disorder (including Fragile X Syndrome - FXS) phenotypes. Thus, suggesting that brain areas that depend on the rapid processing of information, like the auditory brainstem, can be affected. A previous study by Lucas et al. showed an increase in both OLs and their precursor cells (OPCs) in the auditory brainstem, which may be related to a deficit in myelination and the function of OLs and overcompensation by OPCs. Twelve male animals (equal number of FXS and B6 control), between 60-100 days old were used. We used an EdU cell proliferation assay to assess DNA synthesis and cell proliferation compared to antibodies for OLs and OPCs to distinguish EdU incorporation in the two OL cell types. Using a confocal microscope to quantify OLs and OPCs in the auditory brainstem of FXS mice, we expect to see an increase in OLs and OPCs with EdU, suggesting higher turnover of these populations. Impairments in OLs can disrupt the proper myelination of neurons. Future research on how an imbalance of OLs and OPCs affects sound processing may further enhance treatment options for individuals with FXS.