Dominant Negative Suppression of Kv12 Channels in Transgenic Mice

Open Access
Author:
Ackerman, Colin Thomas
Area of Honors:
Biology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Timothy J Jegla, Thesis Supervisor
  • Dr Gong Chen, Honors Advisor
Keywords:
  • Kv12
  • Potassium
  • Transgenic
  • Mice
  • Dominant Negative
Abstract:
Neuronal hyperexcitability is a characteristic feature of many nervous system diseases, such as epilepsy. It is therefore critical to understand how excitability is regulated in the brain. Subthreshold voltage-gated K+ channels (such as EAG family channels) provide a critical buffer against hyperexcitability, and knockout of these channels in the forebrain of mice leads to epilepsy. A dominant negative (DN) transgenic strategy was designed to inducibly knockout Kv12 potassium channels (which are known to limit excitability of pyramidal neurons) in individual neurons to understand how loss of these channels leads to hyperexcitability and epileptogenesis. Additionally, the transgenic mice will be used to test the role of Kv12 channels in learning and memory. Transgenic mice were created to couple DN suppression of Kv12 channels with a switch in fluorescent protein marker expression from green to red. The ability to compare the function of hyperexcitable (red) neurons to normal (green) neurons in the same animal will help us to better understand how epileptogenesis occurs. The transgene has been successfully inserted into mice, and we have verified that DN expression correlates with a green to red color change in forebrain neurons upon induction of Cre-recombinase. These mice should allow for direct electrophysiological comparison of the contributions of neighboring wild type and hyperexcitable (DN) neurons to circuit function in living brain slices. Future experiments included a detailed characterization of the expression pattern and behavioral analysis of the mice in hope of answering the questions: Can one titrate induction? And if so what degree or pattern of DN expression leads to epileptogenesis?