Jacob Blickenstaff and Dr. Jeffrey Edwards, Physiology and Developmental Biology

Gap junctions play a critical role in controlling the rhythmic patterns of electrical oscillations in the brain, particularly in the hippocampus. These ion channels which connect neighboring cells allow electrical signals to be conducted rapidly and in a synchronized manner over a localized area.

I began my research project with the intent of imaging calcium currents in the hippocampus. We planned to run experiments in normal physiological conditions as a control to establish baseline hippocampal oscillatory activity, and then compare the data to experiments involving anesthetic drugs. We had hoped to see the effect of anesthesia on electrical circuitry and gap junctions in the brain.

However, scientific research is not without setbacks. Our early attempts to image were difficult and unfruitful. After acquiring a high resolution charge coupled device for bioimaging, we began staining hippocampal slices with voltage-sensitive dye. Our hope was that, by stimulating the brain, we would invoke calcium currents through gap junctions. These calcium currents would fluoresce when excited due to the voltage-sensitive dye, and we would be able to record intensities of calcium currents through gap junctions and analyze their strength, oscillatory patterns, etc.

We ran into major obstacles with our electrophysiological equipment, which was not properly assembled for the experiment we had in mind. There were also other difficulties, including uncertainties of dealing with concentrations of a new dye, and unfamiliarity with the imaging software. We continued experiments on the setup for a number of months, and tried addressing several problematic factors. We varied the concentrations of dye, in an attempt to more clearly see the effects of the concentration on fluorescence. We changed our light source, from a halogen lamp to a laser beam to a monochromatic laser source. We also tried moving to a different area of the lab to account for possible electric noise. None of our efforts yielded results, and after about four months of research and experimentation, we had made little progress with our project. We did have a better understanding of fluorescent imaging and the properties of the charge coupled device, however we were not beginning experiments with drugs like we had hoped.

I met with my mentor, Dr. Edwards, and we agreed that I could better use my time by practicing electrophysiological techniques in his lab and learning how to record and analyze field potentials. I soon became proficient in field techniques, and while continuing correspondence with the gap junction team, I began to do field experiments in Dr. Edwards lab. Besides the anesthesia/gap junction project, Dr. Edwards is also researching the role of transient receptor potential vanilloid type 1 (TRPV1) in synaptic plasticity in the hippocampus.

My attention shifted quickly to the new research hypothesis, as I was interested in contributing to something after months of setbacks. Briefly stated, Dr. Edwards is researching what specific role the TRPV1 receptor plays in learning and memory formation in the hippocampus. By specifically activating and/or blocking the receptor during field experiments, we can observe its role in electrical activity and synaptic plasticity in the hippocampus.

Over a period of months I acquired enough experimental data to contribute to the lab research poster regarding TRPV1. My electrophysiological data became part of the poster that was taken to a conference held by the Society for Neuroscience. Our research abstract was published in a catalog that outlined the proceedings of the Neuroscience 2009 conference. It is entitled TRPV1 mediates synaptic plasticity in the hippocampus. This year, I actually had the opportunity to attend the neuroscience conference along with Dr. Edwards and present our poster.

Overall, it was an incredible learning experience. I am still in contact with the group that is working on the gap junction project, and things are still slow and unfruitful in their lab. Things did not quite turn out the way I expected. However, I have been able to contribute to a great research project and my focus has shifted to a new line of research regarding memory and learning. Even though research doesn’t always go as planned, there is always an opportunity to make the best of your circumstances. This coming year I hope to further elucidate the specific mechanism of TRPV1 in its mediation of synaptic plasticity.