TY - JOUR

T1 - Differences in backward and forward treadmill locomotion in decerebrated cats

AU - Merkulyeva, Natalia

AU - Lyakhovetskii, Vsevolod

AU - Gorskii, Oleg

AU - Musienko, Pavel

PY - 2022/4/19

Y1 - 2022/4/19

N2 - Locomotion in different directions is vital for animal life and requires fine-adjusted neural activity of spinal networks. To compare the levels of recruitability of the locomotor circuitry responsible for forward and backward stepping, several electromyographic and kinematic characteristics of the two locomotor modes were analysed in decerebrated cats. Electrical epidural spinal cord stimulation was used to evoke forward and backward locomotion on a treadmill belt. The functional state of the bilateral spinal networks was tuned by symmetrical and asymmetrical epidural stimulation. A significant deficit in the backward but not forward stepping was observed when laterally shifted epidural stimulation was used but was not observed with central stimulation: only half of the cats were able to perform bilateral stepping, but all the cats performed forward stepping. This difference was in accordance with the features of stepping during central epidural stimulation. Both the recruitability and stability of the EMG signals as well as inter-limb coordination during backward stepping were significantly decreased compared with those during forward stepping. The possible underlying neural mechanisms of the obtained functional differences of backward and forward locomotion (spinal network organisation, commissural communication and supraspinal influence) are discussed.

AB - Locomotion in different directions is vital for animal life and requires fine-adjusted neural activity of spinal networks. To compare the levels of recruitability of the locomotor circuitry responsible for forward and backward stepping, several electromyographic and kinematic characteristics of the two locomotor modes were analysed in decerebrated cats. Electrical epidural spinal cord stimulation was used to evoke forward and backward locomotion on a treadmill belt. The functional state of the bilateral spinal networks was tuned by symmetrical and asymmetrical epidural stimulation. A significant deficit in the backward but not forward stepping was observed when laterally shifted epidural stimulation was used but was not observed with central stimulation: only half of the cats were able to perform bilateral stepping, but all the cats performed forward stepping. This difference was in accordance with the features of stepping during central epidural stimulation. Both the recruitability and stability of the EMG signals as well as inter-limb coordination during backward stepping were significantly decreased compared with those during forward stepping. The possible underlying neural mechanisms of the obtained functional differences of backward and forward locomotion (spinal network organisation, commissural communication and supraspinal influence) are discussed.

KW - Spinal locomotor networks

KW - Forward and backward locomotion

KW - epidural stimulation

KW - Tonic drive

KW - Locomotion/physiology

KW - Biomechanical Phenomena

KW - Animals

KW - Electric Stimulation

KW - Epidural Space/physiology

KW - Electromyography

KW - Spinal Cord/physiology

KW - Hindlimb/physiology

UR - https://www.mendeley.com/catalogue/51e1d7bf-f3b6-353b-ab85-834a165a6fd0/

U2 - DOI: 10.1242/jeb.244210

DO - DOI: 10.1242/jeb.244210

M3 - Article

C2 - 35438747

VL - 225

JO - Journal of Experimental Biology

JF - Journal of Experimental Biology

SN - 0022-0949

IS - 9

M1 - jeb244210

ER -