Biology subjects

Driscoll, N.

Publications and source records attributed to Driscoll, N..

5 recordsLinked to original sources

bioRxiv2024

Fiber-based Probes for Electrophysiology, Photometry, Optical and Electrical Stimulation, Drug Delivery, and Fast-Scan Cyclic Voltammetry In Vivo

Recording and modulation of neuronal activity enables the study of brain function in health and disease. While translational neuroscience relies on electrical recording and modulation techniques, mechanistic studies in rodent models leverage genetic precision of optical methods, such as optogenetics and imaging of fluorescent indicators. In addition to electrical signal transduction, neurons produce and receive diverse chemical signals which motivate tools to probe and modulate neurochemistry. Although the past decade has delivered a wealth of technologies for electrophysiology, optogenetics, chemical sensing, and optical recording, combining these modalities within a single platform remains challenging. This work leverages materials selection and convergence fiber drawing to permit neural recording, electrical stimulation, optogenetics, fiber photometry, drug and gene delivery, and voltammetric recording of neurotransmitters within individual fibers. Composed of polymers and non-magnetic carbon-based conductors, these fibers are compatible with magnetic resonance imaging, enabling concurrent stimulation and whole-brain monitoring. Their utility is demonstrated in studies of the mesolimbic reward pathway by simultaneously interfacing with the ventral tegmental area and nucleus accumbens in mice and characterizing the neurophysiological effects of a stimulant drug. This study highlights the potential of these fibers to probe electrical, optical, and chemical signaling across multiple brain regions in both mechanistic and translational studies.

neuroscience↗

bioRxiv2023

Magnetoelectric Nanodiscs Enable Wireless Transgene-Free Neuromodulation

Deep-brain stimulation (DBS) with implanted electrodes revolutionized treatment of movement disorders and empowered neuroscience studies. Identifying less invasive alternatives to DBS may further extend its clinical and research applications. Nanomaterial-mediated transduction of magnetic fields into electric potentials offers an alternative to invasive DBS. Here, we synthesize magnetoelectric nanodiscs (MENDs) with a core-double shell Fe3O4-CoFe2O4-BaTiO3 architecture with efficient magnetoelectric coupling. We find robust responses to magnetic field stimulation in neurons decorated with MENDs at a density of 1 {micro}g/mm2 despite individual-particle potentials below the neuronal excitation threshold. We propose a model for repetitive subthreshold depolarization, which combined with cable theory, corroborates our findings in vitro and informs magnetoelectric stimulation in vivo. MENDs injected into the ventral tegmental area of genetically intact mice at concentrations of 1 mg/mL enable remote control of reward behavior, setting the stage for mechanistic optimization of magnetoelectric neuromodulation and inspiring its future applications in fundamental and translational neuroscience.

bioengineering↗

bioRxiv2022

An Open-Source Rodent Chronic EEG Array System with High Density MXene-Based Skull Surface Electrodes

Electroencephalography (EEG) is an indispensable tool in epilepsy, sleep, and behavioral research. In rodents, EEG recordings are typically performed with metal electrodes that traverse the skull into the epidural space. In addition to requiring a major surgery, this intracranial EEG technique is difficult to perform for more than a few electrodes, is time-intensive, and confounds experiments studying traumatic brain injury. Here, we describe an open-source cost-effective refinement of this technique for chronic mouse EEG recording. Our alternative two channel (EEG2) and sixteen channel high-density EEG (HdEEG) arrays use electrodes made of the novel, flexible 2D nanomaterial titanium carbide (Ti3C2Tx) MXene. The MXene electrodes are placed on the surface of the intact skull and establish electrical connection without conductive gel or paste. Fabrication and implantation times of MXene EEG electrodes are significantly shorter than the standard approach and recorded resting baseline and epileptiform EEG waveforms are similar to those obtained with traditional epidural electrodes. Applying HdEEG to a mild traumatic brain injury (mTBI) model in mice of both sexes revealed that mTBI significantly altered awake resting state spectral density with a spatiospectral region of interest in the {beta} spectral band (12-30 Hz) in the central and posterior regions. These findings indicate that fabrication of MXene electrode arrays is a cost effective, efficient technology for multichannel EEG recording in rodents that obviates the need for skull-penetrating surgery. Moreover, increased {beta} spectral power may contribute to the development of early post-mTBI seizures. Significance StatementElectroencephalography (EEG) is a critical technique used to study neurological activity in rodents. Commonly used EEG procedures require time-consuming skull-penetrating surgeries that may confound the experiments. Here we provide a cost-effective solution for obtaining two channel (EEG2) and high-density EEG (HdEEG) recordings on the skull surface thus avoiding major surgery. We compared this HdEEG system to traditional EEG recordings and then used it to determine the effects of mild traumatic brain injury on awake resting state spectral density. This novel open-source EEG system will contribute the electrophysiological characterization of rodent behaviors and seizure activity.

neuroscience↗

bioRxiv2021

MXtrodes: MXene-infused bioelectronic interfaces for multiscale electrophysiology and stimulation

Soft bioelectronic interfaces for mapping and modulating excitable networks at high resolution and at large scale can enable paradigm-shifting diagnostics, monitoring, and treatment strategies. Yet, current technologies largely rely on materials and fabrication schemes that are expensive, do not scale, and critically limit the maximum attainable resolution and coverage. Solution processing is a cost-effective manufacturing alternative, but biocompatible conductive inks matching the performance of conventional metals are lacking. Here, we introduce MXtrodes, a novel class of soft, high-resolution, large-scale bioelectronic interfaces enabled by Ti3C2 MXene and scalable solution processing. We show that the electrochemical properties of MXtrodes exceed those of conventional materials, and do not require conductive gels when used in epidermal electronics. Furthermore, we validate MXtrodes in a number of applications ranging from mapping large scale neuromuscular networks in humans to delivering cortical microstimulation in small animal models. Finally, we demonstrate that MXtrodes are compatible with standard clinical neuroimaging modalities.

bioengineering↗

bioRxiv2020

Multimodal in vivo recording using transparent graphene microelectrodes illuminates spatiotemporal seizure dynamics at the microscale

Neurological disorders such as epilepsy arise from disrupted brain networks. Our capacity to treat these disorders is limited by our inability to map these networks at sufficient temporal and spatial scales to target interventions. Current best techniques either sample broad areas at low temporal resolution (e.g. calcium imaging) or record from discrete regions at high temporal resolution (e.g. electrophysiology). This limitation hampers our ability to understand and intervene in aberrations of network dynamics. Here we present a technique to map the onset and spatiotemporal spread of acute epileptic seizures in vivo by simultaneously recording high bandwidth microelectrocorticography and calcium fluorescence using transparent graphene microelectrode arrays. We integrate dynamic data features from both modalities using non-negative matrix factorization to identify sequential spatiotemporal patterns of seizure onset and evolution, revealing how the temporal progression of ictal electrophysiology is linked to the spatial evolution of the recruited seizure core. This integrated analysis of multimodal data reveals otherwise hidden state transitions in the spatial and temporal progression of acute seizures. The techniques demonstrated here may enable future targeted therapeutic interventions and novel spatially embedded models of local circuit dynamics during seizure onset and evolution.

neuroscience↗