Nkemdilim Ndubuizu

Major: Biological Sciences
“Cannabis use in Relation to Gaba and Glutamate Levels in Schizophrenia”

Nkemdilim Ndubuizu

Marijuana is the most widely used illicit drug. Heavy cannabis use can lead to brain alterations and early adolescent use is a risk factor for the development of schizophrenia. The purpose of this ongoing project is to investigate the relationship between marijuana use and gamma-aminobutyric acid (GABA) and glutamate levels, major neurotransmitters involved in the pathophysiology of schizophrenia. It is hypothesized there will be lower levels of GABA and glutamate in patients with schizophrenia who have used marijuana.

One hundred and four subjects were recruited in this study (44 schizophrenia and 60 healthy controls). Magnetic Resonance Spectroscopy was used to determine anterior cingulate concentrations of GABA and glutamate during rest. Marijuana use history, working memory, processing speed, and functional capacity were obtained on all subjects. Subjects with schizophrenia were assessed for psychiatric symptom severity.

Anterior cingulate GABA levels were lower in healthy subjects who reported cannabis use compared to nonusers at trend level (t(58)=1.76,p=0.08). GABA levels were not significantly different between users and nonusers in the schizophrenia group (p=0.6). However, age of first cannabis use was positively correlated with anterior cingulate GABA in the schizophrenia group (r(23)=0.42,p=0.04) but not in the control group (p=0.6). Glutamine levels were higher in previous users than nonusers at trend level (F(1,58)=3.40, p=0.07). There were no significant differences between users and nonusers on cognitive and psychiatric symptom measures, glutamate, and combined glutamate and glutamine measures.

Three main findings emerged from these preliminary results. First, GABA levels are higher in healthy persons who have never tried marijuana, possibly reflecting personality traits of greater inhibition and less risk taking behavior. Second, the younger the age of first marijuana use, the lower the GABA levels in persons with schizophrenia It is unknown whether the amount of marijuana use contributed to lower GABA levels or first psychotic break, but this relationship will be explored in future studies. Third, glutamine levels were higher in those who have used marijuana across diagnosis group but highest in the schizophrenia group. Higher glutamine levels in schizophrenia is consistent with previous research and raises the question if marijuana use further impacts the glutamatergic system resulting in an illness+marijuana use summation effect.

This investigation was sponsored by National Institutes of Health (R01MH094520 to LMR, R01MH085646 and R01DA027680 to LEH) and NIH/NIGMS MARC U*STAR T3408663 National Research Service Award to UMBC.

How did you find out about the MARC U*STAR Program? When did you join?
I found out about the MARC program by word of mouth from upperclassmen I viewed as peer mentors and then through a letter that was sent to my house about the upcoming application opening. I applied during the spring semester of my sophomore year, inducted that May, and became an official member the summer before my junior year.

What have you gained from being a MARC scholar?
I have gained a variety of skills, including presentation skills and communication skills in general. I have learned how to really make myself an appealing applicant to graduate schools and research opportunities as well as how to conduct myself in professional networking events.

What is your most recent independent research project?
My most recent project in on the relationship between cannabis use and GABA and glutamate levels in people with schizophrenia.

How did you find your mentor for this project?
I looked into research mentors at the Maryland Psychiatric Research Center and local mentors that were studying topics that interested me and I stumbled upon Dr. Laura M. Rowland’s information. She became my research mentor.

How did you know this was the project you wanted to do?
When I started working in Dr. Rowland’s lab, she offered a few different potential projects and this one was the one that interested both of us the most, so I decided to work on it.

How much time do you put into it?
Over the summer I worked in my lab full-time for about 10 weeks, and during the semester I work in my lab for about eight hours per week.

What academic background did you have before you started?
I had completed a few Biology major requirements. Dr. Rowland is also a professor, so any questions I had about the topics or concepts, she was more than willing to answer.

How much did your mentor help you with your research?
My mentor was instrumental in my research experience. She provided me with background information on what her lab studied and the experiment procedures. We had weekly meeting to discuss whatever readings I did over the week about schizophrenia basics, cannabinoid receptors, or even the about the data collection techniques used in the lab. We still meet regularly to talk, but not as formally. I appreciate how our mentoring relationship has developed.

What did you gain from participating in the 2014 Annual Biomedical Research Conference for Minority Students (ABRCMS) conference?
This conference has given me the much needed boost of confidence to settle my insecurities about excelling in STEM research. This realization came about soon after I presented my poster. Participating in the conference reassured me that research is really something that I want to pursue as a career.

What has been the hardest part about your research?
Processing and analyzing the data was the hardest part for me. I have yet to take a formal class on computers so a lot of the programs I was using were new or I had used sparingly before. Data processing required me to use computer programs such as Microsoft Excel and SPSS in addition to program I have never worked with such as MATLAB and LCModel.

What was the most unexpected thing?
The most unexpected thing was that my mentor was so willing to teach me what I did not know. I assumed that she would expect me to know everything about her research and how to do research but that was not the case at all. She was really eager to have a new undergraduate student in her lab.

How does your research relate to your work in other classes?
A lot of the data processing I do involves spectroscopy and it is interesting to see the real-world applications of what I learned in organic chemistry. I was familiar with the neurotransmitters glutamate and GABA from my psychology courses and it was nice to see how these impact mental disorders like schizophrenia.

What else are you involved in on campus, outside of the MARC program?
I am involved in the Shriver Center and am a Student Coordinator for the Choice Program’s College Night. The Choice Program encourages youth to make positive choices in their lives. At College Night, Baltimore youth come to campus and we play games and talk about how fun college can be. Simply being on a college campus can influence a child to come to college. I am also a France & Merrick Scholar, which is given to students for community service involvement, and an active member in Black Student Union.

What is your advice to other students about getting involved in research?
Be open-minded to new experiences and in finding a research mentor. Simply Googling faculty researchers and emailing them about your interests is a good way to start a conversation.

What are your career goals?
I plan to pursue a Ph.D. in neuroscience.

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