Exploring the Meth-Parkinson’s Link

Wednesday, November 20, 2019

Loss of sense of smell may be part of puzzle

Up to 90 percent of Parkinson’s disease patients exhibit some loss of their sense of smell prior to developing motor deficits. Brinda Bradaric, PhD, assistant professor in the Department of Health Sciences in the College of Health Sciences at Rush University, wants to know whether those changes can shed light on the connection between methamphetamine abuse and the development of Parkinson’s-like symptoms.

Intrigued by epidemiological findings showing that people who abuse meth are three times more likely to develop Parkinson’s disease later in life, Bradaric and colleagues at Rush created a longitudinal study in which rats self-administered meth via intravenous catheters. “Our model of meth self-administration emulates human drug taking,” Bradaric explains

In addition to Bradaric, the research team includes Amanda Lee Persons, PhD, assistant professor of health sciences; T. Celeste Napier, PhD, a professor in Rush Medical College’s Department of Psychiatry and Behavioral Sciences, and director of the department’s Center for Compulsive Behavior and Addiction; and Daphne Calma, one of Napier’s graduate college PhD candidates.

In order to emulate successful abstinence by human meth abusers, the rats then underwent periods of time when they no longer had access to meth. Calma discovered that the longer rats were abstinent from meth, the greater the expression of Parkinson’s-like motor deficits.

Bradaric, Persons and Napier extended these behavioral findings to study biomarkers of colon pathology that may correlate with early stages of Parkinson’s disease. In 2017, they coauthored a presentation, “Parkinson’s Disease-like Pathology in the Brain and Colon Following Methamphetamine Self-Administration,” that won a blue ribbon at the 21st International Congress of Parkinson’s Disease and Movement Disorders.

Bradaric is now extending this research a step farther by looking at two neuropathological hallmarks of Parkinson’s disease: a decrease in an enzyme called tyrosine hydroxylase, and an increase of the protein alpha-synuclein – which, in abnormal amounts, make up clumps in the brain known as Lewy bodies, which contribute to Parkinson’s disease.

“We’re exploring whether similar changes occur in the olfactory bulb (a neural structure involved in the sense of smell) of the meth-treated rats,” Bradaric explains. If they are, she and her colleagues would have further evidence of the connection between meth abuse and development of Parkinson’s later in life.

Research also is giving students experience

Bradaric, who’s also the associate discipline director of pharmacology in Rush Medical College, has significant teaching and administrative responsibilities. They limit the amount of time she can spend on research, so the opportunity to work in Napier’s lab is critical to her scholarship.

This relationship also provides a place for Bradaric’s College of Health Sciences (CHS) students to gain firsthand experience in biomedical research.

“Dr. Napier’s team-based lab helps young investigators like me advance our careers,” says Bradaric, who also sits on several MS thesis committees in the CHS and the Graduate College at Rush University. “I share my expertise with students, and they help me out by conducting some of the daily assays. It’s a great relationship that benefits everyone.”

Patryk Czyzewski wasn’t sure which health care field he wanted to enter when he enrolled in the Rush BS in health science program — but he made up his mind along the way. A 2018 graduate of the program, Czyzewski is currently volunteering in the Napier/Bradaric lab while he prepares to apply for medical school.

“The farther I went into the program and the more clinical hours I completed, the more I gained the confidence to pursue a medical career,” says Czyzewski, who’s learning a variety of research tasks as he assists with Bradaric’s study of olfactory bulb changes in rats.