This study evaluated the spectral characteristics of neuronal discharges in the caudal hypoglossal nucleus and their physiological relevance in adult, male Sprague Dawley rats which were anaesthetized and maintained with pentobarbital sodium. Based on auto-spectral analysis of extracellular single-neuron activity, three spectral patterns were identified in the spontaneous discharges of hypoglossal neurons. Neurons that exhibited a rhythmic pattern manifested a concentrated peak in the auto-spectrogram that corresponded to the mean discharge rate. A majority of hypoglossal neurons displayed the modulated pattern, which was manifested either as scattered power densities (wide-band modulated pattern) or with a peak frequency component that was different from the mean discharge rate (narrow-band modulated pattern). Neurons that exhibited a mixed pattern displayed both rhythmic and modulated spectral patterns. Cross-spectral analysis further revealed that respiratory modulation constituted a major physiological influence on caudal hypoglossal neurons. The respiratory modulated pattern, however, could be converted to a mixed pattern in the presence of a central dipsogen, angiotensin III. The results suggest that the spectral patterns of neuronal discharges in caudal hypoglossal neurons represent manifestations of multiple physiological information, including that regarding respiration and dipsogenesis, which is encoded in these neurons. It was also shown that this information may only be revealed by auto-spectral and cross-spectral analysis of neuronal discharge signals.
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http://dx.doi.org/10.1016/s0306-4522(96)00515-5 | DOI Listing |
Heliyon
January 2025
Department of Neurology, Xinhua Hospital Affiliated with Dalian University, Dalian, Liaoning Province, China.
Wallerian degeneration (WD) was first discovered by Augustus Waller in 1850 in a transection of the glossopharyngeal and hypoglossal nerves in frogs. Initial studies suggested that the formation mechanism of WD is related to the nutrition of neuronal cell bodies to axons. However, with the wide application of transgenic mice in experiments, the latest studies have found that the mechanism of WD is related to axonal degeneration, myelin clearance and extracellular matrix.
View Article and Find Full Text PDFEpilepsia
January 2025
Division of Pediatric Neurology and Developmental Medicine, Department of Pediatrics, Duke University, Durham, North Carolina, USA.
Objective: This study was undertaken to test the following hypotheses in the Atp1a3 mouse (which carries the most common human ATP1A3 (the major subunit of the neuronal Na/K-adenosine triphosphatase [ATPase]) mutation, D801N): sudden unexpected death in epilepsy (SUDEP) occurs during seizures and is due to terminal apneas in some and due to lethal cardiac arrhythmias in others; and Atp1a3 mice have central cardiorespiratory dysregulation and abnormal respiratory drive.
Methods: Comparison was made of littermate wild-type and Atp1a3 groups using (1) simultaneous in vivo video-telemetry recordings of electroencephalogram, electrocardiogram, and breathing; (2) whole-body plethysmography; and (3) hypoglossal nerve recordings.
Results: In Atp1a3 mice, (1) SUDEP consistently occurred during seizures that were more severe than preterminal seizures; (2) seizure clustering occurred in periods preceding SUDEP; (3) slowing of breathing rate (BR) and heart rate was observed preictally before preterminal and terminal seizures; and (4) the sequence during terminal seizures was as follows: bradypnea with bradycardia/cardiac arrhythmias, then terminal apnea, followed by terminal cardiac arrhythmias.
Brain Res
February 2025
Beijing Key Laboratory of Central Nervous System Injury, Beijing Neurosurgical Institute, Capital Medical University, Beijing 10070, China; Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing 10070, China; U1195, Inserm et Universite Paris-Saclay, 94276 Le Kremlin-Bicetre, France. Electronic address:
Objective: Peripheral nerve injury results in functional alterations of the corresponding active brain areas, which are closely related to functional recovery. Whether such functional plasticity induces relative anatomical structural changes remains to be investigated.
Methods: In this study, we investigated the changes in brain cortical thickness in patients with facial paralysis following neurorrhaphy treatment at different follow-up times.
J Neurophysiol
January 2025
Department of Physiology, College of Graduate Studies, Midwestern University, Glendale, Arizona, United States.
Respiration is governed by a central rhythm and pattern generator, which has the pre-Bötzinger complex as the inspiratory oscillator initiating the coordinated activity of several respiratory muscles, including the diaphragm, intercostals, and upper airway muscles. The diaphragm is the main inspiratory pump muscle driving inflow, whereas dilator upper airway muscles, such as tongue muscles, reduce airway resistance during inspiration. Breathing exhibits a marked state-dependent pattern attributed to changes in neuromodulatory tone in respiratory-related brain regions, including decreases in noradrenaline and serotonin and increases in acetylcholine levels during rapid eye movement (REM) sleep.
View Article and Find Full Text PDFFront Physiol
August 2024
Department of Pediatrics, Division of Pulmonary and Sleep Medicine, Duke University Medical Center, Durham, NC, United States.
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