Galvanic Redox Potentiometry Based Microelectrode Array for Synchronous Ascorbate and Single-Unit Recordings in Rat Brain

The scalp-recorded amplitude-modulation following response (AMFR)” is gaining recognition as an objective audiometric tool, but little is known about the neural sources that underlie this potential. We hypothesized, based on our human studies and single-unit recordings in animals, that the scalp-recorded AMFR reflects the interaction of multiple sources. We tested this hypothesis using an animal model, the unanesthetized rabbit. We compared AMFRs recorded from the surface of the brain at different locations and before and after the administration of agents likely to enhance or suppress neural generators. We also recorded AMFRs locally at several stations along the auditory neuraxis. We conclude that the surface-recorded AMFR is indeed a composite response from multiple brain generators. Although the response at any modulation frequency can reflect the activity of more than one generator, the AMFRs to low and high modulation frequencies appear to reflect a strong contribution from cortical and subcortical sources, respectively.

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Duplicate Detection of Spike Events: A Relevant Problem in Human Single-Unit Recordings

Brain Sciences ◽

10.3390/brainsci11060761 ◽

2021 ◽

Vol 11 (6) ◽

pp. 761

Author(s):

Gert Dehnen ◽

Marcel S. Kehl ◽

Alana Darcher ◽

Tamara T. Müller ◽

Jakob H. Macke ◽

...

Keyword(s):

Data Quality ◽

Single Unit ◽

Human Subjects ◽

External Noise ◽

Hospital Environment ◽

Noise Sources ◽

Recording Channels ◽

Waveform Similarity ◽

Therapeutic Procedures ◽

Single Unit Recordings

Single-unit recordings in the brain of behaving human subjects provide a unique opportunity to advance our understanding of neural mechanisms of cognition. These recordings are exclusively performed in medical centers during diagnostic or therapeutic procedures. The presence of medical instruments along with other aspects of the hospital environment limit the control of electrical noise compared to animal laboratory environments. Here, we highlight the problem of an increased occurrence of simultaneous spike events on different recording channels in human single-unit recordings. Most of these simultaneous events were detected in clusters previously labeled as artifacts and showed similar waveforms. These events may result from common external noise sources or from different micro-electrodes recording activity from the same neuron. To address the problem of duplicate recorded events, we introduce an open-source algorithm to identify these artificial spike events based on their synchronicity and waveform similarity. Applying our method to a comprehensive dataset of human single-unit recordings, we demonstrate that our algorithm can substantially increase the data quality of these recordings. Given our findings, we argue that future studies of single-unit activity recorded under noisy conditions should employ algorithms of this kind to improve data quality.

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A device enabling single unit recordings during head movements in cats

Brain Research Bulletin ◽

10.1016/0361-9230(82)90081-8 ◽

1982 ◽

Vol 8 (4) ◽

pp. 443-444 ◽

Cited By ~ 1

Author(s):

J.S. Schneider ◽

A.A. Castaldi ◽

T.I. Lidsky

Keyword(s):

Single Unit ◽

Head Movements ◽

Single Unit Recordings

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Single-unit recordings of arterial chemoreceptors from mouse petrosal ganglia in vitro

Journal of Applied Physiology ◽

10.1152/jappl.2000.88.4.1489 ◽

2000 ◽

Vol 88 (4) ◽

pp. 1489-1495 ◽

Cited By ~ 23

Author(s):

David F. Donnelly ◽

Ricardo Rigual

Keyword(s):

Mouse Model ◽

Carotid Body ◽

Unit Activity ◽

Action Potentials ◽

Single Unit ◽

Gene Deletions ◽

Suction Electrode ◽

Single Unit Recordings ◽

Unit Action

A preparation was developed that allows for the recording of single-unit chemoreceptor activity from mouse carotid body in vitro. An anesthetized mouse was decapitated, and each carotid body was harvested, along with the sinus nerve, glossopharyngeal nerve, and petrosal ganglia. After exposure to collagenase/trypsin, the cleaned complex was transferred to a recording chamber where it was superfused with oxygenated saline. The ganglia was searched for evoked or spontaneous unit activity by using a glass suction electrode. Single-unit action potentials were 57 ± 10 (SE) ( n = 16) standard deviations above the recording noise, and spontaneous spikes were generated as a random process. Decreasing superfusate[Formula: see text] to near 20 Torr caused an increase in spiking activity from 1.3 ± 0.4 to 14.1 ± 1.9 Hz ( n = 16). The use of mice for chemoreceptor studies may be advantageous because targeted gene deletions are well developed in the mouse model and may be useful in addressing unresolved questions regarding the mechanism of chemotransduction.

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INITIAL SURGICAL EXPERIENCE WITH A DENSE CORTICAL MICROARRAY IN EPILEPTIC PATIENTS UNDERGOING CRANIOTOMY FOR SUBDURAL ELECTRODE IMPLANTATION

Neurosurgery ◽

10.1227/01.neu.0000337575.63861.10 ◽

2009 ◽

Vol 64 (3) ◽

pp. 540-545 ◽

Cited By ~ 37

Author(s):

Allen Waziri ◽

Catherine A. Schevon ◽

Joshua Cappell ◽

Ronald G. Emerson ◽

Guy M. McKhann ◽

...

Keyword(s):

Local Field ◽

Single Unit ◽

Microelectrode Array ◽

Tissue Injury ◽

Local Field Potentials ◽

Microelectrode Arrays ◽

Field Potentials ◽

Surgical Experience ◽

Electrode Implantation ◽

Subdural Electrode

Abstract OBJECTIVE Detailed investigations of cortical physiology require the ability to record brain electrical activity at a submillimeter scale. Standard intracranial electrodes result in significant averaging of potentials generated by large numbers of neurons. In contrast, microelectrode arrays allow for recording of local field potentials and single-unit activity. We describe our initial surgical experience with the NeuroPort microelectrode array (Cyberkinetics Neurotechnology Systems, Inc., Salt Lake City, UT) in a series of patients undergoing subdural electrode implantation for epilepsy monitoring. METHODS Seven patients were implanted with and underwent semichronic recording from the NeuroPort array during standard subdural electrode monitoring for epilepsy. The electrode was placed according to company specifications in putative noneloquent epileptogenic cortex. After the monitoring period, microelectrode arrays were removed during explantation of subdural electrodes and resection of epileptogenic tissue. RESULTS Successful implantation of the microelectrode array was achieved in all patients, with minor operative difficulties. Robust and durable local field potentials and single-unit recordings were obtained from all implanted individuals. Implantation times ranged from 3 to 28 days; histological analysis of implanted tissue demonstrated no significant tissue injury or inflammatory response. There were no neurological complications or infections associated with electrode implantation or prolonged monitoring. Two patients developed postresection issues with wound healing at the site of scalp egress, with 1 requiring operative wound revision. CONCLUSION Our experience demonstrates that semichronic microelectroencephalographic recording can be safely and effectively achieved using the NeuroPort microarray. Although significant tissue injury, infection, or cerebrospinal fluid leak was not encountered, the large profile of the connection pedestal resulted in suboptimal wound closure and healing in several patients. We predict that this problem will be easily addressed in second-generation devices.

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Opportunities and Challenges for Single-Unit Recordings from Enteric Neurons in Awake Animals

10.20944/preprints201807.0631.v1 ◽

2018 ◽

Author(s):

Bradley Barth ◽

Hsin-I Huang ◽

Gianna Hammer ◽

Xiling Shen

Keyword(s):

Nervous System ◽

Single Unit ◽

Gastrointestinal System ◽

Enteric Neurons ◽

Unit Recording ◽

Neural Recordings ◽

Neuroscience Research ◽

Single Unit Recordings ◽

Excised Tissue ◽

Intrinsic Neurons

Advanced electrode designs have made single-unit neural recordings commonplace among modern neuroscience research. However, single-unit resolution remains out of reach for the intrinsic neurons of the gastrointestinal system. Single-unit recordings of the enteric (gut) nervous system have been conducted in anesthetized animal models and excised tissue, but there is a large physiological gap between awake and anesthetized animals, particularly for the enteric nervous system. Here, we describe the opportunity for advancing enteric neuroscience offered by single-unit recording capabilities in awake animals. We highlight the primary challenges to microelectrodes in the gastrointestinal system including structural, physiological, and signal quality challenges.

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Guest Editorial: Colour in a Larger Perspective: The Rebirth of Gestalt Psychology

Perception ◽

10.1068/p261341 ◽

1997 ◽

Vol 26 (11) ◽

pp. 1341-1352 ◽

Cited By ~ 7

Author(s):

Lothar Spillmann

Keyword(s):

Visual Perception ◽

Receptive Field ◽

Single Unit ◽

Guest Editorial ◽

Gestalt Psychology ◽

Future Developments ◽

The Past ◽

Classical Receptive Field ◽

Neuronal Mechanisms ◽

Single Unit Recordings

This overview takes the reader from the classical contrast and assimilation studies of the past to today's colour research, in a broad sense, with its renewed emphasis on the phenomenological qualities of visual perception. It shows how the shift in paradigm from local to global effects in single-unit recordings prompted a reappraisal of appearance in visual experiments, not just in colour, but in the perception of motion, texture, and depth as well. Gestalt ideas placed in the context of modern concepts are shown to inspire psychophysicists, neurophysiologists, and computational vision scientists alike. Feedforward, horizontal interactions, and feedback are discussed as potential neuronal mechanisms to account for phenomena such as uniform surfaces, filling-in, and grouping arising from processes beyond the classical receptive field. A look forward towards future developments in the field of figure–ground segregation (Gestalt formation) concludes the article.

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