Three-dimensional kinematic and kinetic analysis of quadrupedal walking in the common marmoset (Callithrix jacchus)

The common marmoset as a translational model of age-related osteoarthritis

Age-related osteoarthritis (OA) is a degenerative joint disease characterized by pathological changes in nearly every intra- and peri-articular tissue that contributes to disability in older adults. Studying the etiology of age-related OA in humans is difficult due to an unpredictable onset and insidious nature. A barrier in developing OA modifying therapies is the lack of translational models that replicate human joint anatomy and age-related OA progression. The purpose of this study was to determine whether the common marmoset is a faithful model of human age-related knee OA. Semi-quantitative microCT scoring revealed greater radiographic OA in geriatric versus adult marmosets, and the age-related increase in OA prevalence was similar between marmosets and humans. Quantitative assessments indicate greater medial tibial cortical and trabecular bone thickness and heterogeneity in geriatric versus adult marmosets which is consistent with an age-related increase in focal subchondral bone sclerosis. Additionally, marmosets displayed an age-associated increase in synovitis and calcification of the meniscus and patella. Histological OA pathology in the medial tibial plateau was greater in geriatric versus adult marmosets driven by articular cartilage damage, proteoglycan loss, and altered chondrocyte cellularity. The age-associated increase in medial tibial cartilage OA pathology and meniscal calcification was greater in female versus male geriatric marmosets. Overall, marmosets largely replicate human OA as evident by similar 1) cartilage and skeletal morphology, 2) age-related progression in OA pathology, and 3) sex differences in OA pathology with increasing age. Collectively, these data suggest that the common marmoset is a highly translatable model of the naturally occurring, age-related OA seen in humans.

Non-human primate models and systems for gait and neurophysiological analysis

Brain-computer interfaces (BCIs) have garnered extensive interest and become a groundbreaking technology to restore movement, tactile sense, and communication in patients. Prior to their use in human subjects, clinical BCIs require rigorous validation and verification (V&V). Non-human primates (NHPs) are often considered the ultimate and widely used animal model for neuroscience studies, including BCIs V&V, due to their proximity to humans. This literature review summarizes 94 NHP gait analysis studies until 1 June, 2022, including seven BCI-oriented studies. Due to technological limitations, most of these studies used wired neural recordings to access electrophysiological data. However, wireless neural recording systems for NHPs enabled neuroscience research in humans, and many on NHP locomotion, while posing numerous technical challenges, such as signal quality, data throughout, working distance, size, and power constraint, that have yet to be overcome. Besides neurological data, motion capture (MoCap) systems are usually required in BCI and gait studies to capture locomotion kinematics. However, current studies have exclusively relied on image processing-based MoCap systems, which have insufficient accuracy (error: ≥4° and 9 mm). While the role of the motor cortex during locomotion is still unclear and worth further exploration, future BCI and gait studies require simultaneous, high-speed, accurate neurophysiological, and movement measures. Therefore, the infrared MoCap system which has high accuracy and speed, together with a high spatiotemporal resolution neural recording system, may expand the scope and improve the quality of the motor and neurophysiological analysis in NHPs.

Competing Models of Work in Quadrupedal Walking: Center of Mass Work is Insufficient to Explain Stereotypical Gait

The walking gaits of cursorial quadrupedal mammals tend to be highly stereotyped as a four-beat pattern with interspersed periods of double and triple stance, often with double-hump ground reaction force profiles. This pattern has long been associated with high energetic economy, due to low apparent work. However, there are differing ways of approximating the work performed during walking and, consequently, different interpretations of the primary mechanism leading to high economy. A focus on Net Center of Mass (COM) Work led to the claim that quadrupedal walking is efficient because it effectively trades potential and kinetic energy of the COM. Individual Limbs COM Work instead focuses on the ability of the limbs to manage the trajectory of the COM to limit energetic losses to the ground ("collisions"). By focusing on the COM, both these metrics effectively dismiss the importance of rotation of the elongate quadrupedal body. Limb Extension Work considers work required to extend and contract each limb like a strut, and accounts for the work of body pitching. We tested the prescriptive ability of these approximations of work by optimizing them within a quadrupedal model with two approximations of the body as a point-mass or a rigid distributed mass. Perfect potential-kinetic energy exchange of the COM was possible when optimizing Net COM Work, resulting in highly compliant gaits with duty factors close to one, far different than observed mammalian gaits. Optimizing Individual Limbs COM Work resulted in alternating periods of single limb stance. Only the distributed mass model, with Limb Extension Work as the cost, resulted in a solution similar to the stereotypical mammalian gait. These results suggest that maintaining a near-constant limb length, with distributed contacts, are more important mechanisms of economy than either transduction of potential-kinetic energy or COM collision mitigation for quadrupedal walking.

Treadmill Training for Common Marmoset to Strengthen Corticospinal Connections After Thoracic Contusion Spinal Cord Injury

Spinal cord injury (SCI) leads to locomotor dysfunction. Locomotor rehabilitation promotes the recovery of stepping ability in lower mammals, but it has limited efficacy in humans with a severe SCI. To explain this discrepancy between different species, a nonhuman primate rehabilitation model with a severe SCI would be useful. In this study, we developed a rehabilitation model of paraplegia caused by a severe traumatic SCI in a nonhuman primate, common marmoset (Callithrix jacchus). The locomotor rating scale for marmosets was developed to accurately assess the recovery of locomotor functions in marmosets. All animals showed flaccid paralysis of the hindlimb after a thoracic contusive SCI, but the trained group showed significant locomotor recovery. Kinematic analysis revealed significantly improved hindlimb stepping patterns in trained marmosets. Furthermore, intracortical microstimulation (ICMS) of the motor cortex evoked the hindlimb muscles in the trained group, suggesting the reconnection between supraspinal input and the lumbosacral network. Because rehabilitation may be combined with regenerative interventions such as medicine or cell therapy, this primate model can be used as a preclinical test of therapies that can be used in human clinical trials.

A Comparison of Two-Dimensional and Three-Dimensional Techniques for Kinematic Analysis of the Sagittal Motion of Sheep Hindlimbs During Walking on a Treadmill

Compared to rodents, sheep offer several attractive features as an experimental model for testing different medical and surgical interventions related to pathological gait caused by neurological diseases and injuries. To use sheep for development of novel treatment strategies in the field of neuroscience, it is key to establish the relevant kinematic features of locomotion in this species. To use sheep for development of novel treatment strategies in the field of neuroscience, it is crucial to understand fundamental baseline characteristics of locomotion in this species. Despite their relevance for medical research, little is known about the locomotion in the ovine model, and next to nothing about the three-dimensional (3D) kinematics of the hindlimb. This study is the first to perform and compare two-dimensional (2D) and 3D hindlimb kinematics of the sagittal motion during treadmill walking in the ovine model. Our results show that the most significant differences took place throughout the swing phase of the gait cycle were for the distal joints, ankle and metatarsophalangeal joint, whereas the hip and knee joints were much less affected. The results provide evidence of the inadequacy of a 2D approach to the computation of joint kinematics in clinically normal sheep during treadmill walking when the interest is centered on the hoof's joints. The findings from the present investigation are likely to be useful for an accurate, quantitative and objective assessment of functionally altered gait and its underlying neuronal mechanisms and biomechanical consequences.

Spectral Power in Marmoset Frontal Motor Cortex during Natural Locomotor Behavior

During primate arboreal locomotion, substrate orientation modifies body axis orientation and biomechanical contribution of fore- and hindlimbs. To characterize the role of cortical oscillations in integrating these locomotor demands, we recorded electrocorticographic activity from left dorsal premotor, primary motor, and supplementary motor cortices of three common marmosets moving across a branch-like small-diameter pole, fixed horizontally or vertically. Animals displayed behavioral adjustments to the task, namely, the horizontal condition mainly induced quadrupedal walk with pronated/neutral forelimb postures, whereas the vertical condition induced walk and bound gaits with supinated/neutral postures. Examination of cortical activity suggests that β (16–35 Hz) and γ (75–100 Hz) oscillations could reflect different processes in locomotor adjustments. During task, modulation of γ ERS by substrate orientation (horizontal/vertical) and epoch (preparation/execution) suggests close tuning to movement dynamics and biomechanical demands. β ERD was essentially modulated by gait (walk/bound), which could illustrate contribution to movement sequence and coordination. At rest, modulation of β power by substrate orientation underlines its role in sensorimotor processes for postural maintenance.

Spatiotemporal quantification of gait in common marmosets

BACKGROUND

Objective gait evaluation in humans is used as a predictive disability outcome measure as well as an indicator for intervention effectiveness. Parallel methods of gait analysis in nonhuman primate models are essential for clinical translation. The goal of this study was to first assess whether marmosets' gait data could be reliably collected in a Noldus CatWalk XT10.6 and second, establish a testing protocol to assess gait and the intraindividual variability during repeated testing.

NEW METHOD

The CatWalk, originally developed for rodents, was modified and used to assess gait in eight adult common marmoset monkeys across multiple days and trials. Data was first analyzed to identify valid runs. Repeated measures ANOVA was completed for the following gait measures: mean base of support, average stride length, average swing time, and average stance time.

RESULTS

Raters had a high level of concurrence of usable data across all trials with successful trials including four consecutive hindfoot footfalls, during a continuous, uninterrupted segment of walking. A significant main effect of time (p < 0.000) but not rater (p = 0.98) was present with significant interactions for time by subject (p < 0.000), but not rater per subject (p = 0.538), time (p = 0.186), or three-way interaction (p = 0.297).

COMPARISON WITH EXISTING METHOD(S)

Gait has been assessed using force-plate and video data. The CatWalk allowed reproducible, automated and translational locomotor data to be collected at multiple time points with detailed analyses that identified a diagonal gait pattern.

CONCLUSIONS

The CatWalk system, similar to those used in humans, can be effectively used to quantify spatiotemporal characteristics of gait in the common marmoset.

High-speed tracking of fast chemical precipitations

Heterogeneous reactions taking place in the aqueous phase bear significant importance both in applied and fundamental research. Among others, producing solid catalysts, crystallizing biomorphs or pharmaceutically relevant polymorphs, and yielding bottom-up synthesised precipitate structures are prominent examples. To achieve a better control on product properties, reaction kinetics and mechanisms must be taken into account especially in dynamic systems where transport processes are coupled to chemistry. Since the characteristic time scale of numerous precipitation reactions falls below 1 s within the relevant concentration range, unique experimental protocols are needed. Herein we present a high-speed camera supported experimental procedure capable of determining such characteristic time scales in the range of 10 ms to 1 s. The method is validated both experimentally and by performing 3D hydrodynamic simulations.