Locomotor patterns are mainly modulated by afferent feedback, but its actual contribution to spinal network activity during continuous passive limb training is still unexplored. To unveil this issue, we devised a robotic in vitro setup (Bipedal Induced Kinetic Exercise, BIKE) to induce passive pedaling, while simultaneously recording low-noise ventral and dorsal root (VR and DR) potentials in isolated neonatal rat spinal cords with hindlimbs attached. As a result, BIKE evoked rhythmic afferent volleys from DRs, reminiscent of pedaling speed. During BIKE, spontaneous VR activity remained unchanged, while a DR rhythmic component paired the pedaling pace. Moreover, BIKE onset rarely elicited brief episodes of fictive locomotion (FL) and, when trains of electrical pulses were simultaneously applied to a DR, it increased the amplitude, but not the number, of FL cycles. When BIKE was switched off after a 30-min training, the number of electrically induced FL oscillations was transitorily facilitated, without affecting VR reflexes or DR potentials. However, 90 min of BIKE no longer facilitated FL, but strongly depressed area of VR reflexes and stably increased antidromic DR discharges. Patch clamp recordings from single motoneurons after 90-min sessions indicated an increased frequency of both fast- and slow-decaying synaptic input to motoneurons. In conclusion, hindlimb rhythmic and alternated pedaling for different durations affects distinct dorsal and ventral spinal networks by modulating excitatory and inhibitory input to motoneurons. These results suggest defining new parameters for effective neurorehabilitation that better exploits spinal circuit activity.

Afferent Input Induced by Rhythmic Limb Movement Modulates Spinal Neuronal Circuits in an Innovative Robotic In Vitro Preparation / Dingu, Nejada; Deumens, Ronald; Taccola, Giuliano. - In: NEUROSCIENCE. - ISSN 0306-4522. - 394:(2018), pp. 44-59. [10.1016/j.neuroscience.2018.10.016]

Afferent Input Induced by Rhythmic Limb Movement Modulates Spinal Neuronal Circuits in an Innovative Robotic In Vitro Preparation

Dingu, Nejada;Taccola, Giuliano
2018-01-01

Abstract

Locomotor patterns are mainly modulated by afferent feedback, but its actual contribution to spinal network activity during continuous passive limb training is still unexplored. To unveil this issue, we devised a robotic in vitro setup (Bipedal Induced Kinetic Exercise, BIKE) to induce passive pedaling, while simultaneously recording low-noise ventral and dorsal root (VR and DR) potentials in isolated neonatal rat spinal cords with hindlimbs attached. As a result, BIKE evoked rhythmic afferent volleys from DRs, reminiscent of pedaling speed. During BIKE, spontaneous VR activity remained unchanged, while a DR rhythmic component paired the pedaling pace. Moreover, BIKE onset rarely elicited brief episodes of fictive locomotion (FL) and, when trains of electrical pulses were simultaneously applied to a DR, it increased the amplitude, but not the number, of FL cycles. When BIKE was switched off after a 30-min training, the number of electrically induced FL oscillations was transitorily facilitated, without affecting VR reflexes or DR potentials. However, 90 min of BIKE no longer facilitated FL, but strongly depressed area of VR reflexes and stably increased antidromic DR discharges. Patch clamp recordings from single motoneurons after 90-min sessions indicated an increased frequency of both fast- and slow-decaying synaptic input to motoneurons. In conclusion, hindlimb rhythmic and alternated pedaling for different durations affects distinct dorsal and ventral spinal networks by modulating excitatory and inhibitory input to motoneurons. These results suggest defining new parameters for effective neurorehabilitation that better exploits spinal circuit activity.
2018
394
44
59
Dingu, Nejada; Deumens, Ronald; Taccola, Giuliano
File in questo prodotto:
File Dimensione Formato  
NSC 2018_compressed.pdf

non disponibili

Tipologia: Versione Editoriale (PDF)
Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 605.82 kB
Formato Adobe PDF
605.82 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
MS_Dingu et al R2.pdf

Open Access dal 20/10/2019

Tipologia: Documento in Post-print
Licenza: Creative commons
Dimensione 1.75 MB
Formato Adobe PDF
1.75 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/88234
Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 3
  • ???jsp.display-item.citation.isi??? 3
social impact