DOI: 10.5061/dryad.bk3j9kdp4
title: Data from: Operation of spinal sensorimotor circuits controlling phase durations during tied-belt and split-belt locomotion after a lateral thoracic hemisection

description: Locomotion is controlled by spinal circuits that interact with supraspinal
 drives and sensory feedback from the limbs. These sensorimotor
 interactions are disrupted following spinal cord injury. The thoracic
 lateral hemisection represents an experimental model of an incomplete
 spinal cord injury, where connections between the brain and spinal cord
 are abolished on one side of the cord. To investigate the effects of such
 an injury on the operation of the spinal locomotor network, we used our
 computational model of cat locomotion recently published in eLife (Rybak
 et al., 2024) to investigate and predict changes in cycle and phase
 durations following a thoracic lateral hemisection during treadmill
 locomotion in tied-belt (equal left-right speeds) and split-belt (unequal
 left-right speeds) conditions. In our simulations, the “hemisection” was
 always applied to the right side. Based on our model, we hypothesized that
 following hemisection, the contralesional (“intact”, left) side of the
 spinal network  is mostly controlled by supraspinal drives,
 whereas the ipsilesional (“hemisected”, right) side is mostly controlled
 by somatosensory feedback. We then compared the simulated results with
 those obtained during experiments in adult cats before and after a
 mid-thoracic lateral hemisection on the right side in the same locomotor
 conditions. Our experimental results confirmed many effects of hemisection
 on cat locomotion predicted by our simulations. We show that having the
 ipsilesional hindlimb step on the slow belt, but not the fast belt, during
 split-belt locomotion substantially reduces the effects of lateral
 hemisection. The model provides explanations for changes in temporal
 characteristics of hindlimb locomotion following hemisection based on
 altered interactions between spinal circuits, supraspinal drives, and
 somatosensory feedback.
description: During experiments, two cameras (Basler AcA640-100gm) captured
 videos from the left and right sides of the animal (60 frames per second;
 640 × 480 pixels spatial resolution). A custom-made LabVIEW program
 acquired the images. We analyzed kinematic data from videos off-line with
 a deep learning approach (DeepLabCut<sup>TM</sup>; Mathis et
 al<em>.</em>, 2018), which we recently validated in our cat
 model (Lecomte et al., 2021). We determined contact of the left and right
 hindlimbs by visual inspection. Paw contact was defined as the first frame
 where the paw made visible contact with the treadmill surface. We measured
 cycle duration from successive paw contacts, while stance duration
 corresponded to the interval of time from foot contact to the most caudal
 displacement of the toe relative to the hip (Halbertsma, 1983). We
 calculated swing duration as cycle duration minus stance
 duration.
description: # Data from: Operation of spinal sensorimotor circuits controlling phase
 durations during tied-belt and split-belt locomotion after a lateral
 thoracic hemisection
 [https://doi.org/10.5061/dryad.bk3j9kdp4](https://doi.org/10.5061/dryad.bk3j9kdp4) ## Description of the data and file structure The file shows data (cycle, stance, and swing durations) in three locomotor conditions (tied belt, Left fast/Right slow, Left slow/Right fast) before (INTACT) and eight weeks after a lateral spinal hemisection (H1_S8) at different speeds in m/s. During experiments, two Basler AcA640-100gm cameras recorded video of the animal from the left and right sides (60 fps, 640 × 480 resolution). A custom LabVIEW program acquired the images, and we analyzed kinematics off-line using a deep learning approach, recently validated in our cat model. Paw contact was determined by the first visible frame of contact with the treadmill. Cycle duration was calculated from successive paw contacts, stance duration from foot contact to the most caudal toe displacement (Halbertsma, 1983), and swing duration as the difference between cycle and stance durations. ### Files and variables #### File: EXPERIMENTAL\_DATA\_FOR\_ELIFE\_PAPER.xlsx **Description:** Cycle and phase durations ##### Variables * Cycle and phase durations ## Code/software MS Excel can be used to view the file.