Microinjectrode System for Combined Drug Infusion and Electrophysiology

作者： M. Isabel Vanegas1, Kenneth R. Hubbard1,2, Rahim Esfandyarpour3,4, Behrad Noudoost1 1Department of Ophthalmology and Visual Sciences,University of Utah, 2Department of Biomedical Engineering,University of Utah, 3Department of Electrical Engineering and Computer Science,University of California, Irvine, 4Department of Biomedical Engineering,University of California, Irvine

简介：

Overview

This study presents a microinjectrode system tailored for drug infusion, electrophysiology, and the delivery of experimental probes like microelectrodes and nanosensors. The system minimizes tissue damage, allowing for repeated use in awake, behaving animals. A protocol for constructing the microinjectrode and results from a muscimol infusion in macaque cortex are detailed.

Key Study Components

Area of Science

• Electrophysiology
• Neuroscience
• Microfluidics

Background

• Traditional methods may compromise fragile probes when penetrating the dura mater.
• Existing techniques can cause significant tissue damage during insertion.
• Repeated use of microinjectrodes is critical for longitudinal studies in living animals.
• Microfluidics allows precise delivery of small volumes, essential for drug infusion strategies.

Purpose of Study

• To develop a versatile microinjectrode system for various applications.
• To facilitate the safe delivery of probes into brain tissue.
• To enable controlled drug infusion with minimal tissue impact.

Methods Used

• The study utilizes a custom microinjectrode system involving a cannula and microfluidic components.
• It employs a biological model using macaque cortex for drug infusion experiments.
• The protocol outlines detailed assembly and insertion procedures of the microinjectrode.
• Key steps include preparing the microelectrode, verifying leak-free assembly, and conducting drug infusions.

Main Results

• Successful infusion of a GABA A agonist resulted in reversible inactivation of the frontal eye field, monitoring the effects during a memory-guided saccade task.
• The microinjectrode maintained structural integrity while allowing precise probe placement.
• The microfluidic system effectively delivered drugs in the nanoliter scale.
• Key findings highlight the improved application of microinjectrodes for various electrophysiological experiments.

Conclusions

• This microinjectrode system demonstrates enhanced capabilities for drug delivery and electrophysiological measurements in vivo.
• The adaptations allow researchers to explore neuronal mechanisms with less tissue damage and improved data integrity.
• The findings have significant implications for future studies on neuronal activities and drug effects in behaving animals.

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