Hormone‐mediated modulation of the electromotor CPG in pulse‐type weakly electric fish. Commonalities and differences across species

Developmental Neurobiology, Journal Year: 2020, Volume and Issue: 80(1-2), P. 70 - 80

Published: Jan. 1, 2020

Abstract Like stomatogastric activity in crustaceans, vocalization teleosts and frogs, locomotion mammals, the electric organ discharge (EOD) of weakly fish is a rhythmic stereotyped electromotor pattern. The EOD, which functions both perception communication, controlled by two‐layered central pattern generator (CPG), CPG, modifies its basal output response to environmental social challenges. Despite major anatomo‐functional commonalities CPG across species, we show that Gymnotus omarorum Brachyhypopomus gauderio have evolved divergent neural processes transiently modify outputs through descending fast neurotransmitter inputs generate communication signals. We also present two examples behavioral displays it possible separately analyze effects neuropeptides (mid‐term modulation) gonadal steroid hormones (long‐term upon CPG. First, nonbreeding territorial aggression G. has been an advantageous model status‐dependent modulation excitability neuronal components vasotocin. Second, seasonal sexually dimorphic courtship signals B. useful understand sex steroids on responses glutamatergic Overall, regime safeguards EOD waveform. However, prepacemaker influences hormonal enable enormous versatility allows adapt functional state species‐, sex‐, context‐specific manners.

Language: Английский

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The execution of movement: a spinal affair

Journal of Neurophysiology, Journal Year: 2020, Volume and Issue: 125(2), P. 693 - 698

Published: Dec. 23, 2020

In this tribute to Reggie Edgerton, I briefly review the spinal mechanisms that coordinate locomotion and interaction between different sensory help locomotor movements central network. The step cycle has four distinct parts, support phase, lift off, flexion and, most complex, touch down, when limb makes a smooth contact with ground again. Each of these phases is affected by mechanisms, which interact network [central pattern generator (CPG)] generating basic its components. Conversely, CPG also gates reflex pathways, so they are active only in given phase cycle, or even produces opposite effects parts cycle. These examples from mammals likely important consider for human particular, patients cord injury, partial complete.

Language: Английский

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Flexor and Extensor Ankle Afferents Broadly Innervate Locomotor Spinal Shox2 Neurons and Induce Similar Effects in Neonatal Mice

Frontiers in Cellular Neuroscience, Journal Year: 2019, Volume and Issue: 13

Published: Oct. 9, 2019

Central pattern generators (CPGs) in the thoracolumbar spinal cord generate basic hindlimb locomotor pattern. The CPG integrates descending commands and sensory information from periphery to activate, modulate halt rhythmic program. General function response perturbations are well described cat rat models. In mouse, roles for many genetically identified interneurons have been inferred alterations following population deletion or modulation. However, organization of afferent input specific populations mouse remains comparatively less resolved. Here, we focused on a neurons marked by transcription factor Shox2. To directly test integration signaling Shox2 neurons, afferents were stimulated during patch clamp recordings isolated preparations neonatal mice. broadly displayed afferent-evoked currents at multiple segmental levels, particularly caudal dorsal roots innervating distal joints. As root stimulation may activate both flexor- extensor-related afferents, preserving peripheral nerves used provide more activation ankle afferents. We found that likely evoke similar given neuron, as assessed polarity, latency, duration amplitude. It has proposed can be divided into which contribute rhythm generation premotor absence presence V2a marker Chx10, respectively. Response did not differ based Chx10 expression. Although evoked flexor extensor follow expected functional antagonism, they consistent with observation reset phase ongoing fictive locomotion flexion Together, data suggest interposed pathways low threshold proprioceptive reinforces perturbation similarly activating inhibiting patterning layers CPG.

Language: Английский

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Identification of adult spinal Shox2 neuronal subpopulations based on unbiased computational clustering of electrophysiological properties

Frontiers in Neural Circuits, Journal Year: 2022, Volume and Issue: 16

Published: Aug. 4, 2022

Spinal cord neurons integrate sensory and descending information to produce motor output. The expression of transcription factors has been used dissect out the neuronal components circuits underlying behaviors. However, most canonical populations interneurons are heterogeneous require additional criteria determine functional subpopulations. Neurons expressing factor Shox2 can be subclassified based on co-expression Chx10 each subpopulation is proposed have a distinct connectivity different role in locomotion. Adult recently shown diverse their firing properties. Here, order subclassify adult mouse neurons, we performed multiple analyses data collected from whole-cell patch clamp recordings visually-identified lumbar spinal slices. A smaller set was included for validation. We k-means hierarchical unbiased clustering approaches, considering electrophysiological variables. Unlike categorizations by type, clusters displayed properties that could differentiate between neurons. presence consisting exclusively both techniques suggests it possible distinguish Shox2+Chx10- Shox2+Chx10+ alone. Computational were further validated immunohistochemistry with accuracy small subset Thus, cluster analysis using tool enhance current interneuronal subclassifications complement groupings molecular expression.

Language: Английский

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Modular organization of locomotor networks in people with severe spinal cord injury

Frontiers in Neuroscience, Journal Year: 2022, Volume and Issue: 16

Published: Dec. 7, 2022

Introduction Previous studies support modular organization of locomotor circuitry contributing to the activation muscles in a spatially and temporally organized manner during locomotion. Human spinal may reorganize after cord injury; however, it is unclear if reorganization post-injury affects organization. Here we characterize synergy muscle activity expressed assisted stepping subjects with complete incomplete injury (SCI) varying chronicity, before any explicit training regimen. We also investigated whether characteristics changed two who achieved independent walking epidural stimulation. Methods To capture structures stepping, individuals SCI were stepped on body-weight supported treadmill manual facilitation, while electromyography (EMGs) recorded from bilateral leg muscles. EMGs analyzed using non-negative matrix factorization (NMF) component analysis (ICA) identify patterns. Synergy patterns compared across different clinical non-disabled (NDs). Results for both NMF ICA indicated that similar among themselves, but greater variability number synergies criterion variance NDs, weaker correlation NDs. yielded than NMF. Further, chronicity did not predict significant differences spatial despite neuroplastic changes. post-training become closer ND individuals. Discussion These findings suggest fundamental between motor modules SCIs as well striking level temporal stability population, absent application specific interventions.

Language: Английский

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