Interactions between Dorsal and Ventral Root Stimulation on the Generation of Locomotor-Like Activity in the Neonatal Mouse Spinal Cord
| Autor: | Dvir Blivis, Avinash Pujala, Michael J. O'Donovan |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Sacrum
Nerve root Sensory Receptor Cells Efferent ventral root Models Neurological dorsal root Stimulation Stimulus (physiology) Biology Tissue Culture Techniques Mice Postsynaptic potential Interneurons Neural Pathways medicine Animals Motor Neurons Lumbar Vertebrae General Neuroscience Central pattern generator spinal cord General Medicine Anatomy New Research musculoskeletal system Spinal cord Axons Electric Stimulation central pattern generator locomotion medicine.anatomical_structure Animals Newborn Excitatory postsynaptic potential Central Pattern Generators Sensory and Motor Systems Spinal Nerve Roots Neuroscience Brain Stem |
| Zdroj: | eNeuro |
| ISSN: | 2373-2822 |
| Popis: | We investigated whether dorsal (DR) and ventral root (VR) stimulus trains engage common postsynaptic components to activate the central pattern generator (CPG) for locomotion in the neonatal mouse spinal cord. VR stimulation did not activate the first order interneurons mediating the activation of the locomotor CPG by sacrocaudal afferent stimulation. Simultaneous stimulation of adjacent dorsal or ventral root pairs, subthreshold for evoking locomotor-like activity, did not summate to activate the CPG. This suggests that locomotor-like activity is triggered when a critical class of efferent or afferent axons is stimulated and does not depend on the number of stimulated axons or activated postsynaptic neurons. DR- and VR-evoked episodes exhibited differences in the coupling between VR pairs. In DR-evoked episodes, the coupling between the ipsilateral and contralateral flexor/extensor roots was similar and stronger than the bilateral extensor roots. In VR-evoked episodes, ipsilateral flexor/extensor coupling was stronger than both the contralateral flexor/extensor and the bilateral extensor coupling. For both types of stimulation, the coupling was greatest between the bilateral L1/L2 flexor-dominated roots. This indicates that the recruitment and/or the firing pattern of motoneurons differed in DR and VR-evoked episodes. However, the DR and VR trains do not appear to activate distinct CPGs because trains of DR and VR stimuli at frequencies too low to evoke locomotor-like activity did so when they were interleaved. These results indicate that the excitatory actions of VR stimulation converge onto the CPG through an unknown pathway that is not captured by current models of the locomotor CPG. |
| Databáze: | OpenAIRE |
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