Astrocytic gap junctions contribute to potassium redistribution over the neocortex

25^th World Congress on Neurology and Neurodisorders

July 16-17, 2018 Melbourne, Australia

Azin Ebrahim Amini

University of Toronto, Canada

Scientific Tracks Abstracts: J Neurol Disord

Abstract :

Extracellular potassium ion concentration ([K]e) is tightly regulated throughout the brain because it has a major impact on brain functionality. Potassium concentration is disrupted in many brain diseases such as stroke and epilepsy. My project is designed base on a well-developed experimental platform to investigate the effects of extracellular potassium redistribution in physiological states. All experiments were conducted in vivo in mouse neocortex. 2 double-barreled K-sensitive electrodes coupled with Local Field Potential (LFP) electrodes were placed 4 mm apart. 50 mM KCl solution was injected focally closer to one of the K-LFP electrodes. [K]e levels and LFP were measured in two different scenarios: (1) Pharmacological intervention (gap junction blockage) and (2) optical intervention (optogentics). Focally increased [K]e was associated with a transient depolarization which in turn spreads into neighboring tissues so called spreading depolarization. Gap junctional blockade in the peri-injection site simultaneously increased the amplitude and duration of the local [K]e response and the local field response was greatly prolonged. While in the remote injection site, [K]e response was decreased after gap junctional blockage application. Optical stimulation decreased the [K]e both in the peri-injection and remote site. Our preliminary results are evidence of slow K redistribution (take for minutes) throughout the astrocytic syncytium which is partly mediated via astrocytic gap junctions. Potassium redistribution across a large area of the cortex is not a well-studied area because most studies have limited their focus on focal potassium dynamics. In this project we are addressing this gap using novel tools to elucidate potassium redistribution dynamics.

Biography :

Azin Ebrahim Amini is pursuing her Masters from University of Toronto in the Department of Biomedical Engineering within Neuroscience platform. She has completed her Bachelors at University of Toronto where she double majored in Neuroscience and Physiology. Her interest to multidisciplinary sciences motivated her to learn advanced programming software along with designing a new method for recording intracranial brain activities. Along with being active in academic world she also takes on community service responsibility and engages in leadership and mentorship programs.

E-mail: azin.amini@mail.utoronto.ca