High-throughput Electrophysiology for Pathway Identification
(NIH R01 EB005459-01)

James J. Hickman: PI
Peter Molnar: Co-PI
Vaibhav Thakore: Ph. D. student
IDEA


 

 

 

Action potential generation is a complex process, depends on the status of several ion channels in the cell membrane. Drugs, toxins or other factors which have a direct or indirect effect on these ion channels, might affect the shape of the action potentials. Using a data-true mathematical model of action potential generation of the cell ion channel parameters can be calculated based on action potential shape recordings. Drug effects can be characterized and discriminated based on changes in ion channel parameters.
Moreover, if the cell-electrode interface is optimized and mathematically characterized, high throughput, non-invasive, extracellular recordings can be used to obtain action potential shape data.

GOAL   Development of a high-throughput toxin / drug / warfare agent detection and discrimination system based on extracellularly recorded action potential shape analysis
APPROACH  

A mathematical model of action potential generation in NG108-15 neuroblastoma / glioma cells will be created based on patch-clamp recordings. Using this model ion channel parameters will be derived from action potential shape data before and after drug administration. After the determination of the transfer characteristics of the cell-electrode interface action potential shapes will be derived from the extracellular signal. The system will be validated with known toxins.

RESULTS   We have shown that there is a characteristic change in the extracellular action potential amplitude upon toxin administration (Toxicology.pdf)

Percent Change in Amplitude before and after pyrethroid addition (Error bars from standard error of mean)


We have created a mathematical model of action potential generation in NG108-15 cells and demonstrated that ion channel parameters can be extracted from action potential data, and toxins have a characteristic and distinct effect on the extracted ion channel parameters (Shape analysis.pdf).

 

 


In a separate project we have developed the methods for the non-parametric nonlinear characterization of the cell-electrode interface (Electrode.htm).
WORK IN PROGRESS   Parametric characterization of the interface
Characterization of toxin effects on the intracellular and extracellular AP shapes
Optimization of the cell-electrode interface using surface chemistry