A multichannel neural probe with embedded microfluidic channels for simultaneous in vivo neural recording and drug delivery

Hyunjoo J. Lee, Yoojin Son, Jeongyeon Kim, C. Justin Lee, Eui Sung Yoon, Il Joo Cho

    Research output: Contribution to journalArticlepeer-review

    80 Citations (Scopus)

    Abstract

    Multi-functional neural probes integrated with various stimulation modalities are becoming essential tools in neuroscience to study the brain more effectively. In this paper, we present a new multi-functional neural probe that allows chemical stimulation through drug delivery and simultaneous recording of individual neuron signals through a microelectrode array. By embedding microchannels in silicon using a proposed glass reflow process, we successfully fabricated 40 μm thick silicon neural probes suitable for small animal experiments. The electrochemical impedance spectroscopy confirms that impedance of iridium microelectrodes is low enough (<1 MΩ at 1 kHz) to measure neural signals. Flow rate characterization in a 0.9% w/v agarose gel shows the capability to deliver a small volume of drugs (<1 μl) at a controlled flow rate. We demonstrate the viability and potential of this new probe by conducting in vivo experiments on mice. Because of the proposed compact structure, both action potentials of individual neurons and local field potentials (LFP) at the thalamus region of a mouse brain were successfully detected with a noise level of ~30 μVpp. Furthermore, we successfully induced absence seizure by injecting seizure-inducing drugs (baclofen) at a local target region and observed distinctive changes in neural signal patterns. Specifically, spike-wave discharge (SWD), which is an indicative signal pattern of absence seizure, was successfully recorded. These signals were also directly compared to SWD detected after inducing absence seizure through direct injection of baclofen through the abdomen. This work demonstrates the potential of our multi-functional neural probes for use in effective investigation of brain functions and disorders by using widely available mouse models.

    Original languageEnglish
    Pages (from-to)1590-1597
    Number of pages8
    JournalLab on a Chip
    Volume15
    Issue number6
    DOIs
    Publication statusPublished - 2015 Mar

    Bibliographical note

    Publisher Copyright:
    © 2015 The Royal Society of Chemistry.

    ASJC Scopus subject areas

    • Bioengineering
    • Biochemistry
    • General Chemistry
    • Biomedical Engineering

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