Strategies for improving neural signal detection using a neural-electronic interface

Abstract

Abstract-There have been various theoretical and experi mental studies presented in the literature that focus on interfacing neurons with discrete electronic devices, such as transistors. From both a theoretical and experimental perspective, these studies have emphasized the variability in the characteristics of the detected action potential from the nerve cell. The demonstrated lack of reproducible fidelity of the nerve cell action potential at the device junction would make it impractical to implement these devices in any neural prosthetic application where reliable detection of the action potential was a prerequisite. In this study, the effects of several different physical parameters on the fidelity of the de tected action potential at the device junction are investigated and discussed. The impact of variations in the extracellular resistivity, which directly affects the junction seal resistance, is studied along with the impact of variable nerve cell membrane capacitance and variations in the injected charge. These parameters are discussed in the context of their suitability to design manipulation for the purpose of improving the fidelity of the detected neural action potential. In addition to investigating the effects of variations in these parameters, the applicability of the linear equivalent circuit approach to calculating the junction potential is investigated.Index Terms-Nervous system, neural systems, neural elec tronics, neuron transistor interfacing, neuron transistor.

Burst firing transitions in two-compartment pyramidal neuron induced by the perturbation of membrane capacitance

“…A large number of factors can take part in the generation and propagation of action potential, such as: external stimulus [1], noise (internal or external) [2,3], specific ion channels [4], membrane capacitance [5], and temperatures [6], etc. Membrane capacitance (C m ) as one of the factors may be defined as:…”

“…Amzica et al [27] investigated the role of membrane capacitance in sleep oscillations and spike-wave seizures. Szlavik [5] gave a detailed analysis of the impact of variations in membrane capacitance on the detected neuralelectronic signal, and concluded that larger values of membrane capacitance results in smaller initial changes in potential across the cell membrane, while smaller values of membrane capacitance yield larger initial changes in transmembrane potential that can be sufficient to generate an action potential. These studies are helpful and instructive, but seldom discussed the exact role of C m in burst firing patterns, especially the transitions among these patterns.…”

Neural-electronic inhibition simulated with a neuron model implemented in SPICE

“…Some of these studies include simulations of neural detection using synthetic electronic circuitry [2], [3]. Additional studies include simulations of neural excitation using external electronics [4], [5].…”

“…The simplicity of the overall circuit topology is a common feature of the simulations pre sented in the above literature. The approach adopted in some of these studies involves solution of the circuit equations using conventional numerical ordinary differential equation solvers or circuit simulation software [3], [5]- [7]. Algebraic manip ulation involves rewriting these equations in a form whereby the first derivatives are isolated on one side.…”

Varying the time delay of an action potential elicited with a neural-electronic stimulator

“…The modeling approach adopted in this study is analogous to the approach taken in Szlavik [5]. The physical parameters related to the membrane and the transistor are shown in Table 1., along with the definition of the circuit components.…”