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Undergraduate Researchers

David Eisen

David Eisen, Computer Engineering

“Mid-IR Optical Stimulation of Nerve Cells”

Neuron excitation and inhibition have been previously studied as they have important applications to bio-medical fields, particularly in human prosthetics, as well as in audio and visual assist devices. Optical stimulation via high power mid-IR (MIR) quantum cascade lasers (QCLs) coupled with a MIR fiber provides a non-contact method of stimulus delivery direct to the neural site. It offers possible advantages over traditional electrical stimulation techniques, which can lead to either electrode or cellular damage. By using cultivated rat nerve cells on a multi-electrode array circuit board we can configure MIR optical fiber coupled QCLs to deliver signals in the 3 μm wavelength range. The focus will be on examining the range of excitation energy per unit area, possible excitation rates, wavelength dependence of the excitation and inhibition characteristics around the main peaks of the neuron absorption spectra, and identifying optical stimulation/inhibition thresholds as well as damage thresholds at these wavelengths. We will also apply similar studies to plants and insect subjects such as Venus Fly Traps, and fruit flies and hope that this will eventually lead to in vivo studies of small-animal brains with our collaborators at NIH NIDA lab., Baltimore, who are interested in applying MIR techniques to the studies of brain circuitry, chemical pathways, and drug effects.

How did you find your mentor for your research?
I was lucky and found my mentor and learned about the URA program by chance really. I was required to join an engineering professional society for one of my classes and was having difficulty with the UMBC IEEE website so I contacted Professor Fow-Sen Choa, who oversees the UMBC chapter. I explained I was a computer engineering major and as a professor of the department, he asked if I was interested in doing undergraduate research. We set up a meeting and discussed the different opportunities available.

How did you know this was the project you wanted to do?
Admittedly, when I went to meet with my mentor for the first time I didn't know what to expect. However, after hearing about the projects he was working on, including using lasers as part of brain controlled robotic arm, I couldn't resist finding out more about this research area. We are currently working on using cultured rat neurons for mid-IR optical stimulation and inhibition testing.

What academic background did you have before you started?

As an engineering major I had a fairly strong background in general math and science courses including physics, chemistry, calculus, and computer programming. However, I had no background whatsoever in photonics, which is now my area of research. This was okay though as my mentor as well as graduate students in the research group, were able to explain the basics so I could get a hands-on learning experience right away.

How much time do you put into it?
During the semester I try to put in 5-8 hours a week in order to complete about 70 hours of work per semester. Scheduling work hours is very flexible so I can accommodate my schedule of classes. I also do work during the summer and over winter break where I can put in more time without classes.

Was the application difficult to do?
The application is not long and is very straight forward. If you have some background in your research area, you will be in great shape and even if you do not, you can always get help from your mentor. That is, after all, what they are there for.

How much did your mentor help you with the application?
My mentor helped a lot with the application. As I had no background on the subject, he was very willing to offer other technical papers on the material, as well as help fill in any parts that I was unable to answer due to my lack of knowledge in the field of photonics and the finer details of the project.

What is your advice to other students about getting involved in research?
Do not hesitate to get involved. If you have a particular subject or idea you want to explore, you should pursue it but even if you do not and just know you would like to get involved in some project speak with your advisor, professor's in your department, and the Shriver Center for opportunities that interest you. Even if you do not have a background in the field, as I did not, you should still investigate it as the professors on campus are very helpful in getting you up to speed and involved in work you enjoy. Remember, the idea is to investigate a subject or problem you are interested in, so you don't need to already be an expert coming into the game.