4. Zinc accumulation in the midbrain following methamphetamine exposure as a potential biomarker for neurodegeneration

The illicit use of methamphetamine has been a rising concern in the United States, as there is a well-established association between methamphetamine intoxication and neurodegeneration. Many studies have suggested that the death of neurons is in part contributed to an overzealous response of the immune system following methamphetamine exposure. The immune system utilizes a variety of compounds to carry out its functions, including the element, zinc. Conversely, excessive buildup of zinc in the brain has been implicated in many neurodegenerative diseases. Similar to the damage that occurs following methamphetamine exposure, neurons are the primary cells that are involved in these terminal illnesses. Therefore, we hypothesize that accumulation of zinc in the brain could be resulting in neurodegeneration following methamphetamine intoxication. Briefly, mice were injected intraperitoneally with either sterile saline (n=6) or 5 mg/kg methamphetamine (n=6) for ten days. On day 10, the prefrontal cortex, midbrain, and striatum were isolated and sonicated. Total Reflection X-Ray Fluorescence Spectroscopy was used to measure zinc levels, which significantly increased in the midbrain of animals treated with methamphetamine compared to controls (