“Think like a proton and stay positive.”
Amanda is currently a fourth year graduate student in the Lunte group at the University of Kansas. She received her B.S. in Chemistry and B.A. in Spanish at a tiny private university in Iowa that no one has ever heard of. Her current research is an in vivo study of epilepsy using microdialysis sampling to induce seizures and collect extracellular fluid for analysis. She is hoping to graduate soon-ish and move on to learn more about pharmacokinetic and pharmacodynamics things. When not in lab, she enjoys watching Netflix and drinking wine.
Neurochemical Investigation of Multiple Locally-Induced Seizures
using Microdialysis Sampling
Epilepsy is a well-known neurological disease that results in seizures. In approximately 70% of epileptic patients, these seizures occur in specific regions of the brain. Since patients are only diagnosed with epilepsy after experiencing two or more unprovoked seizures, an animal model for local epilepsy was developed. In this model, multiple seizures are induced to a living animal within one experiment to more accurately represent the disease in comparison to previous studies. Microdialysis was used to administer an epileptic agent, 3-mercaptapropionic acid (3-MPA), locally to the hippocampus of rats in two, 30 minutes intervals. The time between the two administrations of 3-MPA was varied to allow 40, 60, or 180 minutes of recovery before the next dose was given, while simultaneously collecting dialysate for analysis. Glutamate and GABA concentrations were determined in the dialysate samples using liquid chromatography with fluorescence detection flowing derivatization with NDA/CN. Depending on the length of recovery time between seizures, a 60-80% attenuation in glutamate concentration was observed in response to the second epileptic event. It is hypothesized that during the first seizure the mitochondria are being deprived of nutrients and therefore unable to produce glutamate for release in the second seizure. Therefore the effect of the 3-MPA on glutamate metabolic pathways was investigated in a series of experiments. Glucose or lactate was supplemented in the perfusate to promote the KREB cycle production of glutamate. In a separate experiment, glutamate transporters were inhibited with dihydrokainic acid, to determine the amount of glutamate released in the region of interest. The goal of these experiments was to determine the cause of the attenuation in the second seizure in hopes to further develop the animal model for local epilepsy.