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

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.

Author(s):  
Bradley Barth ◽  
Hsin-I Huang ◽  
Gianna Hammer ◽  
Xiling Shen

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.


Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 230-230
Author(s):  
B Lee

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.


Micromachines ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 428 ◽  
Author(s):  
Bradley Barth ◽  
Hsin-I Huang ◽  
Gianna Hammer ◽  
Xiling Shen

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.


1978 ◽  
Vol 41 (2) ◽  
pp. 260-267 ◽  
Author(s):  
P. B. Brown ◽  
H. R. Koerber

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.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Emily L. Mackevicius ◽  
Michael T. L. Happ ◽  
Michale S. Fee

Abstract How are brain circuits constructed to achieve complex goals? The brains of young songbirds develop motor circuits that achieve the goal of imitating a specific tutor song to which they are exposed. Here, we set out to examine how song-generating circuits may be influenced early in song learning by a cortical region (NIf) at the interface between auditory and motor systems. Single-unit recordings reveal that, during juvenile babbling, NIf neurons burst at syllable onsets, with some neurons exhibiting selectivity for particular emerging syllable types. When juvenile birds listen to their tutor, NIf neurons are also activated at tutor syllable onsets, and are often selective for particular syllable types. We examine a simple computational model in which tutor exposure imprints the correct number of syllable patterns as ensembles in an interconnected NIf network. These ensembles are then reactivated during singing to train a set of syllable sequences in the motor network.


Neurosurgery ◽  
2009 ◽  
Vol 65 (6) ◽  
pp. E1195-E1196 ◽  
Author(s):  
Gregory P. Lekovic ◽  
John F. Kerrigan ◽  
Scott Wait ◽  
Harold L. Rekate ◽  
Peter N. Steinmetz

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.


2002 ◽  
Vol 13 (04) ◽  
pp. 188-204 ◽  
Author(s):  
Shigeyuki Kuwada ◽  
Julia S. Anderson ◽  
Ranjan Batra ◽  
Douglas C. Fitzpatrick ◽  
Natacha Teissier ◽  
...  

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.


2021 ◽  
Vol 11 (6) ◽  
pp. 761
Author(s):  
Gert Dehnen ◽  
Marcel S. Kehl ◽  
Alana Darcher ◽  
Tamara T. Müller ◽  
Jakob H. Macke ◽  
...  

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.


2020 ◽  
Vol 16 ◽  
pp. 174480692092785 ◽  
Author(s):  
Mayumi Sonekatsu ◽  
Hiroshi Yamada ◽  
Jianguo G Gu

An electrophysiological technique that can record nerve impulses from a single nerve fiber is indispensable for studying modality-specific sensory receptors such as low threshold mechanoreceptors, thermal receptors, and nociceptors. The teased-fiber single-unit recording technique has long been used to resolve impulses that are likely to be from a single nerve fiber. The teased-fiber single-unit recording technique involves tedious nerve separation procedures, causes nerve fiber impairment, and is not a true single-fiber recording method. In the present study, we describe a new and true single-fiber recording technique, the pressure-clamped single-fiber recording method. We have applied this recording technique to mouse whisker hair follicle preparations with attached whisker afferents as well as to skin-nerve preparations made from mouse hindpaw skin and saphenous nerves. This new approach can record impulses from rapidly adapting mechanoreceptors (RA), slowly adapting type 1 mechanoreceptors (SA1), and slowly adapting type 2 mechanoreceptors (SA2) in these tissue preparations. We have also applied the pressure-clamped single-fiber recordings to record impulses on Aβ-fibers, Aδ-fibers, and C-fibers. The pressure-clamped single-fiber recording technique provides a new tool for sensory physiology and pain research.


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