scholarly journals Sound production in piranhas is associated with modifications of the spinal locomotor pattern

2021 ◽  
Vol 224 (9) ◽  
Author(s):  
Marine Banse ◽  
Boris P. Chagnaud ◽  
Alessia Huby ◽  
Eric Parmentier ◽  
Loïc Kéver
Keyword(s):  
Motor Neurons ◽  
Sound Production ◽  
Neural Circuit ◽  
Bladder Wall ◽  
Activation Pattern ◽  
Activation Patterns ◽  
Spinal Motor Neurons ◽  
Neuron Activation ◽  
Frequency Regime ◽  
Simultaneous Activation

ABSTRACT In piranhas, sounds are produced through the vibration of the swim bladder wall caused by the contraction of bilateral sonic muscles. Because they are solely innervated by spinal nerves, these muscles likely evolved from the locomotor hypaxial musculature. The transition from a neuromuscular system initially shaped for slow movements (locomotion) to a system that requires a high contraction rate (sound production) was accompanied with major peripheral structural modifications, yet the associated neural adjustments remain to this date unclear. To close this gap, we investigated the activity of both the locomotor and the sonic musculature using electromyography. The comparison between the activation patterns of both systems highlighted modifications of the neural motor pathway: (1) a transition from a bilateral alternating pattern to a synchronous activation pattern, (2) a switch from a slow- to a high-frequency regime, and (3) an increase in the synchrony of motor neuron activation. Furthermore, our results demonstrate that sound features correspond to the activity of the sonic muscles, as both the variation patterns of periods and amplitudes of sounds highly correspond to those seen in the sonic muscle electromyograms (EMGsonic). Assuming that the premotor network for sound production in piranhas is of spinal origin, our results show that the neural circuit associated with spinal motor neurons transitioned from the slow alternating pattern originally used for locomotion to a much faster simultaneous activation pattern to generate vocal signals.

scholarly journals Synergistic integration of Netrin and ephrin axon guidance signals by spinal motor neurons

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Sebastian Poliak ◽  
Daniel Morales ◽  
Louis-Philippe Croteau ◽  
Dayana Krawchuk ◽  
Elena Palmesino ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Molecular Mechanisms ◽  
Neural Circuit ◽  
Growth Cones ◽  
In Vitro Assays ◽  
Dependent Manner ◽  
Motor Axons ◽  
Spinal Motor Neurons ◽  
Spinal Motor

During neural circuit assembly, axonal growth cones are exposed to multiple guidance signals at trajectory choice points. While axonal responses to individual guidance cues have been extensively studied, less is known about responses to combination of signals and underlying molecular mechanisms. Here, we studied the convergence of signals directing trajectory selection of spinal motor axons entering the limb. We first demonstrate that Netrin-1 attracts and repels distinct motor axon populations, according to their expression of Netrin receptors. Quantitative in vitro assays demonstrate that motor axons synergistically integrate both attractive or repulsive Netrin-1 signals together with repulsive ephrin signals. Our investigations of the mechanism of ephrin-B2 and Netrin-1 integration demonstrate that the Netrin receptor Unc5c and the ephrin receptor EphB2 can form a complex in a ligand-dependent manner and that Netrin–ephrin synergistic growth cones responses involve the potentiation of Src family kinase signaling, a common effector of both pathways.

scholarly journals A Brainstem reticulotegmental neural ensemble drives acoustic startle reflexes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Weiwei Guo ◽  
Sijia Fan ◽  
Dan Xiao ◽  
Hui Dong ◽  
Guangwei Xu ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Neural Circuit ◽  
Acoustic Startle ◽  
Auditory Information ◽  
Spinal Motor Neurons ◽  
Glutamatergic Neurons ◽  
Spinal Motor ◽  
Neural Ensemble ◽  
Crucial Component

AbstractThe reticulotegmental nucleus (RtTg) has long been recognized as a crucial component of brainstem reticular formation (RF). However, the function of RtTg and its related circuits remain elusive. Here, we report a role of the RtTg in startle reflex, a highly conserved innate defensive behaviour. Optogenetic activation of RtTg neurons evokes robust startle responses in mice. The glutamatergic neurons in the RtTg are significantly activated during acoustic startle reflexes (ASR). Chemogenetic inhibition of the RtTg glutamatergic neurons decreases the ASR amplitudes. Viral tracing reveals an ASR neural circuit that the cochlear nucleus carrying auditory information sends direct excitatory innervations to the RtTg glutamatergic neurons, which in turn project to spinal motor neurons. Together, our findings describe a functional role of RtTg and its related neural circuit in startle reflexes, and demonstrate how the RF connects auditory system with motor functions.

scholarly journals Restoration of breathing after opioid overdose and spinal cord injury using temporal interference stimulation

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Michael D. Sunshine ◽  
Antonino M. Cassarà ◽  
Esra Neufeld ◽  
Nir Grossman ◽  
Thomas H. Mareci ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Neurons ◽  
Drug Overdose ◽  
Cervical Spinal Cord ◽  
Opioid Overdose ◽  
Electrode Position ◽  
Spinal Motor Neurons ◽  
Cord Injury ◽  
Low Amplitude

AbstractRespiratory insufficiency is a leading cause of death due to drug overdose or neuromuscular disease. We hypothesized that a stimulation paradigm using temporal interference (TI) could restore breathing in such conditions. Following opioid overdose in rats, two high frequency (5000 Hz and 5001 Hz), low amplitude waveforms delivered via intramuscular wires in the neck immediately activated the diaphragm and restored ventilation in phase with waveform offset (1 Hz or 60 breaths/min). Following cervical spinal cord injury (SCI), TI stimulation via dorsally placed epidural electrodes uni- or bilaterally activated the diaphragm depending on current and electrode position. In silico modeling indicated that an interferential signal in the ventral spinal cord predicted the evoked response (left versus right diaphragm) and current-ratio-based steering. We conclude that TI stimulation can activate spinal motor neurons after SCI and prevent fatal apnea during drug overdose by restoring ventilation with minimally invasive electrodes.

scholarly journals The atlas of RNase H antisense oligonucleotide distribution and activity in the CNS of rodents and non-human primates following central administration

2020 ◽  
Author(s):  
Paymaan Jafar-nejad ◽  
Berit Powers ◽  
Armand Soriano ◽  
Hien Zhao ◽  
Daniel A Norris ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Muscular Atrophy ◽  
Neurological Diseases ◽  
Cell Types ◽  
Rnase H ◽  
Central Administration ◽  
Spinal Motor Neurons ◽  
New Class ◽  
Wide Range ◽  
Therapeutic Development

Abstract Antisense oligonucleotides (ASOs) have emerged as a new class of drugs to treat a wide range of diseases, including neurological indications. Spinraza, an ASO that modulates splicing of SMN2 RNA, has shown profound disease modifying effects in Spinal Muscular Atrophy (SMA) patients, energizing efforts to develop ASOs for other neurological diseases. While SMA specifically affects spinal motor neurons, other neurological diseases affect different central nervous system (CNS) regions, neuronal and non-neuronal cells. Therefore, it is important to characterize ASO distribution and activity in all major CNS structures and cell types to have a better understanding of which neurological diseases are amenable to ASO therapy. Here we present for the first time the atlas of ASO distribution and activity in the CNS of mice, rats, and non-human primates (NHP), species commonly used in preclinical therapeutic development. Following central administration of an ASO to rodents, we observe widespread distribution and target RNA reduction throughout the CNS in neurons, oligodendrocytes, astrocytes and microglia. This is also the case in NHP, despite a larger CNS volume and more complex neuroarchitecture. Our results demonstrate that ASO drugs are well suited for treating a wide range of neurological diseases for which no effective treatments are available.

scholarly journals Translatomic analysis of regenerating and degenerating spinal motor neurons in injury and ALS

iScience ◽  
2021 ◽  
pp. 102700
Author(s):  
Jennifer L. Shadrach ◽  
Wesley M. Stansberry ◽  
Allison M. Milen ◽  
Rachel E. Ives ◽  
Elizabeth A. Fogarty ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Spinal Motor Neurons ◽  
Spinal Motor

A new method of isolating spinal motor neurons from fetal mouse

2017 ◽  
Vol 288 ◽  
pp. 57-61 ◽  
Author(s):  
Weifang Wang ◽  
Bao Qi ◽  
Hui Lv ◽  
Fei Wu ◽  
Lulu Liu ◽  
...  
Keyword(s):  
Motor Neurons ◽  
New Method ◽  
Fetal Mouse ◽  
Spinal Motor Neurons ◽  
Spinal Motor

scholarly journals Müllerian inhibiting substance contributes to sex-linked biases in the brain and behavior

2009 ◽  
Vol 106 (17) ◽  
pp. 7203-7208 ◽  
Author(s):  
Pei-Yu Wang ◽  
Anna Protheroe ◽  
Andrew N. Clarkson ◽  
Floriane Imhoff ◽  
Kyoko Koishi ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Reproductive Tract ◽  
Behavioral Traits ◽  
Spinal Motor Neurons ◽  
Müllerian Inhibiting Substance ◽  
Males And Females ◽  
Brain And Behavior ◽  
And Behavior ◽  
The Brain ◽  
Mullerian Inhibiting Substance

Many behavioral traits and most brain disorders are common to males and females but are more evident in one sex than the other. The control of these subtle sex-linked biases is largely unstudied and has been presumed to mirror that of the highly dimorphic reproductive nuclei. Sexual dimorphism in the reproductive tract is a product of Müllerian inhibiting substance (MIS), as well as the sex steroids. Males with a genetic deficiency in MIS signaling are sexually males, leading to the presumption that MIS is not a neural regulator. We challenge this presumption by reporting that most immature neurons in mice express the MIS-specific receptor (MISRII) and that male Mis−/− and Misrii−/− mice exhibit subtle feminization of their spinal motor neurons and of their exploratory behavior. Consequently, MIS may be a broad regulator of the subtle sex-linked biases in the nervous system.

Relevant Biophysical Parameters Discrimination along Corticospinal Tract in Patients with Stroke Using Convolutional Neural Networks

2021 ◽  
Vol 51 ◽  
pp. 95-103
Author(s):  
Abderrazek Zeraii ◽  
Amine Ben Slama ◽  
Lazhar Rmili ◽  
Cyrine Drissi ◽  
Mokhtar Mars ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Biophysical Parameters ◽  
Spinal Motor Neurons ◽  
Fiber Tracts ◽  
Subacute Stroke ◽  
Quantitative Metrics ◽  
White Matter Fiber Tracts

Stroke remains the leading source of long-term disability. As the only direct descending motor pathway, the corticospinal tract (CST) is the primary pathway to innervate spinal motor neurons and one of the most well studied tracts in human neuroanatomy. Its clinical significance can be demonstrated in many distinguished traumatic situations and diseases such as stroke. Along‐tract statistics analysis enables the extraction of quantitative diffusion metrics along specific white matter fiber tracts. Besides quantitative metrics derived from classical diffusion tensor imaging (DTI), such as fractional anisotropy and diffusivities. In this study, we extracted DTI derived quantitative microstructural diffusion metrics along the CST tract in patients with moderate to severe subacute stroke. Respectively DTI metric of individual patient's fiber tract was then plotted. This approach may be useful for future studies that may compare in two different time (acute and chronic). The contribution of this work presents a totally computerized method of DTI image recognition based on conventional neural network (CNN) in order to supply quantitative appraisal of clinical characteristics. The obtained results have achieved an important classification (Accuracy=94.12%) when applying the CNN. The proposed methodology enables us to assess the classification of the used DTI images database within a reduced processing time. Experimental results prove the success of the proposed rating system for a suitable analysis of microstructural diffusion when compared to previous work.

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