The kinematic recovery process of rhesus monkeys after spinal cord injury

Abstract

After incomplete spinal cord injury (SCI), neural circuits may be plastically reconstructed to some degree, resulting in extensive functional locomotor recovery. The present study aimed to observe the post-SCI locomotor recovery of rhesus monkey hindlimbs and compare the recovery degrees of different hindlimb parts, thus revealing the recovery process of locomotor function. Four rhesus monkeys were chosen for thoracic hemisection injury. The hindlimb locomotor performance of these animals was recorded before surgery, as well as 6 and 12 weeks post-lesion. Via principal component analysis, the relevant parameters of the limb endpoint, pelvis, hindlimb segments, and joints were processed and analyzed. Twelve weeks after surgery, partial kinematic recovery was observed at the limb endpoint, shank, foot, and knee joints, and the locomotor performance of the ankle joint even recovered to the pre-lesion level; the elevation angle of the thigh and hip joints showed no obvious recovery. Generally, different parts of a monkey hindlimb had different spontaneous recovery processes; specifically, the closer the part was to the distal end, the more extensive was the locomotor function recovery. Therefore, we speculate that locomotor recovery may be attributed to plastic reconstruction of the motor circuits that are mainly composed of corticospinal tract. This would help to further understand the plasticity of motor circuits after spinal cord injury.

MRI metrics at the epicenter of spinal cord injury are correlated with the stepping process in rhesus monkeys

“…A reflective marker was fixed on the second metatarsophalangeal joint, and its spatial location was recorded through multiple cameras in real time (recording frequency: 100 Hz). The animals were allowed to walk on a treadmill bipedally with their upper body restrained (speed: 0.2 m s −1 ), and successive stepping (>10 steps) data were captured for subsequent analysis [ 26 , 27 , 28 , 29 ].…”

“…The gait cycle was first divided automatically [ 31 ]. Then, the step height, stride length, direction and acceleration of the limb endpoint velocity at swing onset, and path length of the limb endpoint trajectory of each gait cycle were computed [ 28 ]. The PS and GS were set to decrease the effect of individual variability and to reflect gait performance comprehensively.…”

Neuromuscular control pattern in rhesus monkeys during bipedal walking

“…The joint angles of the hip, knee, and ankle were calculated based on the coordinate position of each marker. The methods used to calculate gait parameters were previously described [37].…”

Application of non-human primates’ behavioral research in the study of spinal cord injury

“…[89] . Yaguchi等人 [90] 针对颈髓挫伤的狨猴 数, 涉及到了描述步行运动的所有关键特征 [73,97] ; 肌肉 活动数据则包括动物双下肢腓肠肌、胫骨前肌、股直 肌和半腱肌的表面肌电幅值、频率、功率等8个参 数 [100,101]…”