Electrophysiology and Neural Electronics Laboratory (ENEL)

Location: ATL, St. Jude Lab

The advancement of the state of the art in the simulation, modeling and experimental application of biological neural systems and integrated neural-electronic systems for the benefit of medicine, national defense and the space sciences.

The Electrophysiology and Neural Electronics Research Group at California Polytechnic State University has extensive expertise in the simulation and modeling of neurological systems. This simulation and modeling expertise includes simulation of linear as well as non-linear neurological systems. A principal recent focus of the group has been the development of Hodgkin-Huxley based equivalent circuit models to study the characteristics of neural-electronic systems. Consequently, there is extensive in house experience related to combining simulations of excitable cells, through the use of Hodgkin-Huxley active membrane equivalent circuit models, with models of electronic devices. Additional research efforts have been focused on developing improved, physiologically relevant, models based on the Hodgkin-Huxley excitable membrane framework for implementation in SPICE-based simulation programs. These efforts are ongoing and have included successful implementation of the models in SPICE circuit description programs or (netlist) code as well as hard coding Hodgkin-Huxley equivalent circuit models within public domain versions of the SPICE program.

Recently the group has been extensively involved in the development of hybrid nerve conduction velocity techniques based on the spectral group delay characteristics associated with compound evoked potential measurements of peripheral nerve. These techniques facilitate the determination of peripheral nerve fiber diameter distributions associated with the fibers that contribute to the propagated evoked potential. If successfully implemented, the group delay techniques could provide an alternative and more robust diagnostic tool for neurologists in the diagnosis of pathologies of the peripheral nervous system.

The group has an extensive empirical and theoretical program focused on studying the impact of organophosphate based neural toxins on the electrophysiology of the neuromuscular junction. Detailed mathematical models of the processes involved in conduction of neural activity across the motor end-plate have been developed. These simulation studies are currently being validated empirically through electrophysiology based empirical investigations of the leech neuromuscular junction exposed to organophosphate based neural toxins.

The Electrophysiology and Neural Electronics Laboratory features state of the art electrophysiology instrumentation for sharp electrode and patch clamp experiments. A Molecular Devices/Axon Instruments MultiClamp 700B sharp electrode/patch clamp amplifier is the main instrumentation platform for intracellular studies. This platform is supported by advanced digital sampling/data collection capabilities with the Molecular Devices/Axon Instruments Digidata 1440A Digitizer and the supporting PClamp 10 Electrophysiology Software Suite. Customizable data acquisition capabilities are further enhanced by the availability of a high speed National Instruments PCI-6259, M Series data acquisition system capable of 1.25 MS/s. Intracellular electrophysiology studies are supported by a Nikon Eclipse FN1 fixed state microscope with a Gibraltar x-y stage platform. The facility is housed in a radio frequency screen room located within the St. Jude Biomedical Engineering Laboratory in the Advanced Technology Laboratory at California Polytechnic State University.