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

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.

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

Micromachines ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 428 ◽  
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 in 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, and we provide design criteria recommendations for enteric microelectrodes.

Midbrain Periaqueductal Gray and Vocal Patterning in a Teleost Fish

2006 ◽  
Vol 96 (1) ◽  
pp. 71-85 ◽  
Author(s):  
J. Matthew Kittelberger ◽  
Bruce R. Land ◽  
Andrew H. Bass
Keyword(s):  
Single Unit ◽  
Activity Patterns ◽  
Periaqueductal Gray ◽  
Social Contexts ◽  
Tract Tracing ◽  
Temporal Dimension ◽  
Unit Recording ◽  
Motor Circuits ◽  
Call Production ◽  
Single Unit Recordings

Midbrain structures, including the periaqueductal gray (PAG), are essential nodes in vertebrate motor circuits controlling a broad range of behaviors, from locomotion to complex social behaviors such as vocalization. Few single-unit recording studies, so far all in mammals, have investigated the PAG's role in the temporal patterning of these behaviors. Midshipman fish use vocalization to signal social intent in territorial and courtship interactions. Evidence has implicated a region of their midbrain, located in a similar position as the mammalian PAG, in call production. Here, extracellular single-unit recordings of PAG neuronal activity were made during forebrain-evoked fictive vocalizations that mimic natural call types and reflect the rhythmic output of a known hindbrain–spinal pattern generator. The activity patterns of vocally active PAG neurons were mostly correlated with features related to fictive call initiation. However, spike trains in a subset of neurons predicted the duration of vocal output. Duration is the primary feature distinguishing call types used in different social contexts and these cells may play a role in directly establishing this temporal dimension of vocalization. Reversible, lidocaine inactivation experiments demonstrated the necessity of the midshipman PAG for fictive vocalization, whereas tract-tracing studies revealed the PAG's connectivity to vocal motor centers in the fore- and hindbrain comparable to that in mammals. Together, these data support the hypotheses that the midbrain PAG of teleosts plays an essential role in vocalization and is convergent in both its functional and structural organization to the PAG of mammals.

Single Units and Sensation: 25 Years on

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 230-230
Author(s):  
B Lee
Keyword(s):  
Visual System ◽  
Single Unit ◽  
Single Units ◽  
Single Unit Recording ◽  
Unit Recording ◽  
Visual Neuroscience ◽  
Neurophysiological Data ◽  
20Th Anniversary ◽  
Single Unit Recordings ◽  
Perceptual Psychology

In 1972 Horace Barlow (“Single units and sensation: a neuron doctrine for perceptual psychology?” Perception1 371 – 394) proposed a set of dogmas to guide vision scientists in interpreting neurophysiological data. The 20th anniversary of ECVP is an appropriate occasion to ask if single-unit recordings have really helped us understand the visual system. The answer may be affirmative, but interpreting single-unit data has proved to be much more of a challenge than was anticipated in that early and optimistic era of single-unit recording. I review data from retinal and cortical experiments to illustrate this thesis, and ask if Barlow's dogmas are still relevant to current visual neuroscience.

Cat hindlimb tactile dermatomes determined with single-unit recordings

1978 ◽  
Vol 41 (2) ◽  
pp. 260-267 ◽  
Author(s):  
P. B. Brown ◽  
H. R. Koerber
Keyword(s):  
Dorsal Root ◽  
Single Unit ◽  
Field Size ◽  
Width Ratio ◽  
Single Unit Recording ◽  
Unit Recording ◽  
Length Width ◽  
Low Threshold ◽  
Single Unit Recordings ◽  
Different Parts

1. Single-unit recording from dorsal root ganglia was used to determine the dermatomes of L4-S2 segments in the cat. Dermatomes for low-threshold myelinated mechanoreceptor afferents are smaller than those reported in earlier studies of whole-root dermatomes. There are also sufficient discrepancies among earlier studies and with the present data to merit reexamination of hindlimb whole-root dermatomes. 2. Receptive-field size varies directly with distance from toes. Length/width ratio is essentially constant for different parts of the hindlimb. 3. Estimates of innervation density verify the long-standing assumption that innervation density is greater for foot and toes than for proximal hindlimb, at least for low-threshold cutaneous myelinated afferents.

Reverse-correlation methods in auditory research

1983 ◽  
Vol 16 (3) ◽  
pp. 341-414 ◽  
Author(s):  
J. J. Eggermont ◽  
P. I. M. Johannesma ◽  
A. M. H. J. Aertsen
Keyword(s):  
Nervous System ◽  
Single Unit ◽  
Frequency Tuning ◽  
Reverse Correlation ◽  
Tuning Curves ◽  
Auditory Nervous System ◽  
Nervous System Activity ◽  
Single Unit Recordings ◽  
Stimulus Time ◽  
Auditory Research

Single unit recordings have provided us with a basis for understanding the auditory system, especially about how it behaves under stimulation with simple sounds such as clicks and tones. The experimental as well as the theoretical approach to single unit studies has been dichotomous. One approach, the more familiar, gives a representation of nervous system activity in the form of peri-stimulus-time (PST) histograms, period histograms, iso-intensity rate curves and frequency tuning curves. This approach observes the neural output of units in the various nuclei in the auditory nervous system, and, faced with the random way in which the neurons respond to sound, proceeds by repeatedly presenting the same stimulus in order to obtain averaged results. These are the various histogram procedures (Gerstein & Kiang, 1960; Kiang et al. 1965).

IN SITU SINGLE-UNIT RECORDING OF HYPOTHALAMIC HAMARTOMAS UNDER ENDOSCOPIC DIRECT VISUALIZATION

Neurosurgery ◽  
2009 ◽  
Vol 65 (6) ◽  
pp. E1195-E1196 ◽  
Author(s):  
Gregory P. Lekovic ◽  
John F. Kerrigan ◽  
Scott Wait ◽  
Harold L. Rekate ◽  
Peter N. Steinmetz
Keyword(s):  
Single Unit ◽  
Intractable Epilepsy ◽  
Direct Visualization ◽  
Cellular Mechanisms ◽  
Unit Recording ◽  
Field Recordings ◽  
Hypothalamic Hamartomas ◽  
Neuron Spike ◽  
Single Unit Recordings

Abstract OBJECTIVE Hypothalamic hamartomas (HHs) are associated with refractory epilepsy and are amenable to surgical treatment. The gelastic seizures associated with HHs originate within the HH lesion, but the responsible cellular mechanisms are unknown. Microelectrode patch-clamp recordings from HH neurons in resected slice preparations show that small HH neurons spontaneously fire with intrinsic pacemaker-like activity. We questioned whether spontaneous firing of HH neurons was present in situ, and we hypothesized that single-unit field recordings from HH tissue could be obtained with instrumentation passed through the endoscope before surgical resection. TECHNIQUE After informed consent was obtained, patients undergoing transventricular, endoscopic resection of an HH for intractable epilepsy were eligible for study. After placement of the endoscope, a bundled microwire (total of 9 contacts) was placed into the HH under direct visualization. Spontaneous activity was recorded for two or three 5-minute epochs, under steady-state general anesthesia. The wire was advanced 0.5 to 1 mm within the lesion between recording epochs. RESULTS A total of thirteen 5-minute recordings were obtained from 5 patients. Noise levels were comparable to extraoperative microwire recordings for temporal lobe epilepsy. Single-neuron spike activity was isolated from a total of 5 channels obtained during recording of 3 sessions in 3 patients. CONCLUSION We have shown that single-unit recordings from HH lesions can be successfully obtained in situ under direct endoscopic visualization. We believe that this is the first report using the working channel of a neuroendoscope to make physiological recordings of deep structures in humans.

Sources of the Scalp-Recorded Amplitude-Modulation Following Response

2002 ◽  
Vol 13 (04) ◽  
pp. 188-204 ◽  
Author(s):  
Shigeyuki Kuwada ◽  
Julia S. Anderson ◽  
Ranjan Batra ◽  
Douglas C. Fitzpatrick ◽  
Natacha Teissier ◽  
...  
Keyword(s):  
Animal Model ◽  
Amplitude Modulation ◽  
Single Unit ◽  
Modulation Frequency ◽  
Multiple Sources ◽  
High Modulation ◽  
Before And After ◽  
Single Unit Recordings ◽  
Composite Response ◽  
The 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.

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

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.

scholarly journals Long range synchronization within the enteric nervous system underlies propulsion along the large intestine in mice

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Nick J. Spencer ◽  
Lee Travis ◽  
Lukasz Wiklendt ◽  
Marcello Costa ◽  
Timothy J. Hibberd ◽  
...  
Keyword(s):  
Nervous System ◽  
Smooth Muscle ◽  
Enteric Nervous System ◽  
Lymphatic Vessels ◽  
Distal Colon ◽  
Distal Region ◽  
Proximal Colon ◽  
Synchronous Firing ◽  
Electrophysiological Recordings ◽  
Intrinsic Neurons

AbstractHow the Enteric Nervous System (ENS) coordinates propulsion of content along the gastrointestinal (GI)-tract has been a major unresolved issue. We reveal a mechanism that explains how ENS activity underlies propulsion of content along the colon. We used a recently developed high-resolution video imaging approach with concurrent electrophysiological recordings from smooth muscle, during fluid propulsion. Recordings showed pulsatile firing of excitatory and inhibitory neuromuscular inputs not only in proximal colon, but also distal colon, long before the propagating contraction invades the distal region. During propulsion, wavelet analysis revealed increased coherence at ~2 Hz over large distances between the proximal and distal regions. Therefore, during propulsion, synchronous firing of descending inhibitory nerve pathways over long ranges aborally acts to suppress smooth muscle from contracting, counteracting the excitatory nerve pathways over this same region of colon. This delays muscle contraction downstream, ahead of the advancing contraction. The mechanism identified is more complex than expected and vastly different from fluid propulsion along other hollow smooth muscle organs; like lymphatic vessels, portal vein, or ureters, that evolved without intrinsic neurons.

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