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Yingying Geng

Date of Award


Document Type

Restricted Thesis: Campus only access

Degree Name

Bachelor of Science


Biochemistry & Molecular Biol.

First Advisor

Dr. Krista Stenger


Vesicular monoamine transporter-1 (VMAT-1) is involved in transporting monoamines (serotonin, dopamine, norepinephrine) into storage vesicles within cells. Single nucleotide polymorphisms (SNPs) within the human VMAT-1 (hVMAT-1) gene SLC18A1 have been associated with neuropsychiatric disorders. This research project aims to better understand the biochemical and physiological effects of these polymorphisms on VMAT-1 protein expression and function. We used SDS-PAGE, western blotting, and a serotonin transport assay to show tha although VMAT-1 with a threonine at position 136 had no effect on protein expression, it reduced the protein’s monoamine transport activity by 20-25% when compared to the 136-Ile form. Studies have also begun to address the behavioral consequences of knocking out the VMAT-1 gene in mice. These results revealed a cognitive deficit in mice lacking the VMAT-1 gene. A biochemical assay has also demonstrated that young female VMAT-1 knockout mice have increased corticosterone (CORT) levels when compared to wild type mice. As the mice aged, this difference in CORT levels was no longer present.