My research focuses on the involvement of two voltage-gated calcium channel mutations in epilepsy. Epilepsy is a neurological disorder characterized by spontaneous seizures that can cause brain damage. In epilepsy, the normal pattern of neuronal activity becomes disturbed, causing convulsions, muscle spasms, and the loss of consciousness. Epilepsy may develop because of an abnormality in brain wiring, an imbalance in neurotransmitters, changes in ion channels, or some combination of these factors.
Ion channels are cell membrane proteins that allow the passage of ions, such as calcium, into or out of the cell, which generates the electrical signals of neural networks. Voltage-gated calcium channels are a type of ion channel, which allows the passage of calcium ions into the cell. They have a pore through which calcium passes, and one or more auxiliary subunits that regulate pore opening and closing. The auxiliary subunit my research focuses on is the β subunit. The β subunit functions in delivering the calcium channel to the cell membrane and regulating activation and inactivation kinetics of the ion channel. The two mutations in the β subunit that I studied are E53K and Q131L. These mutations were found in a cohort of epileptic patients, but not in unaffected individuals.
In order to study how both of these mutations alter β subunit function and thus voltage-gated calcium channel function, site-directed mutagenesis was performed with QuickChange II XL kit to introduce the desired mutation into the wild-type β subunit. Once we obtained the desired mutation, we synthesized RNA. The RNA, along with the RNA for the other necessary subunits, were injected into Xenopus laevis oocytes. The RNA forms into a calcium channel protein and then we recorded currents using the two-electrode voltage clamp (TEVC). This is done by inserting two glass microelectrodes into the oocyte. One electrode applies the voltage to activate the voltage-gated calcium channel and the other electrode records the resulting currents. Interestingly, we found that the E53K mutant channels had significantly decreased current amplitude when compared to the wild-type and the Q131L mutant channels. This means that not enough calcium ions are able to flow into the cell. We hypothesize that the E53K mutation is causing a decrease in current amplitude by altering channel trafficking. This can lead to various problems such as neurotransmitter imbalance, which is one of the causes of epilepsy.
This research can eventually lead to more personalized and specific treatment that will be more beneficial in treating epilepsy than what is currently available. Performing such research really impacted me and made me feel really happy to discover something that no one has discovered before that can eventually help people and society. I presented my research at two conferences, the NEURON Conference and the Eastern Colleges Science Conference (ECSC). In both conferences my research won an award. I won an Honorable Mention for the Suzannah Bliss Tieman Outstanding Poster Award at the NEURON Conference and I won an award for Outstanding Presentation in Genetics/Molecular Biology at ECSC. While I don’t do research to win awards, it made me feel proud to know that my hard work was recognized by the community and made a significant impact on those who I had presented to.
Overall, I really enjoyed this experience and it is one of the highlights of my four years at Pace. I realized how much I enjoyed being in the lab, constantly learning new things, and doing something that is beneficial to society. Even though I plan to go to medical school in hopes to pursue a career in neurosurgery, I want to incorporate doing research as well in my plans for the future. I am very thankful to my research mentor, Dr. Buraei, and to this program for supporting this research and providing me with this valuable experience.