Locomotor recovery after spinal cord hemisection/contusion injures in bonnet monkeys: Footprint testing—a minireview

Abstract

Spinal cord injuries usually produce loss or impairment of sensory, motor and reflex function below the level of damage. In the absence of functional regeneration or manipulations that promote regeneration, spontaneous improvements in motor functions occur due to the activation of multiple compensatory mechanisms in animals and humans following the partial spinal cord injury. Many studies were performed on quantitative evaluation of locomotor recovery after induced spinal cord injury in animals using behavioral tests and scoring techniques. Although few studies on rodents have led to clinical trials, it would appear imperative to use nonhuman primates such as macaque monkeys in order to relate the research outcomes to recovery of functions in humans. In this review, we will discuss some of our research evidences concerning the degree of spontaneous recovery in bipedal locomotor functions of bonnet monkeys that underwent spinal cord hemisection/contusion lesions. To our knowledge, this is the first report to discuss on the extent of spontaneous recovery in bipedal locomotion of macaque monkeys through the application of footprint analyzing technique. In addition, the results obtained were compared with the published data on recovery of quadrupedal locomotion of spinally injured rodents. We propose that the mechanisms underlying spontaneous recovery of functions in spinal cord lesioned monkeys may be correlated to the mature function of spinal pattern generator for locomotion under the impact of residual descending and afferent connections. Moreover, based on analysis of motor functions observed in locomotion in these subjected monkeys, we understand that spinal automatism and development of responses by afferent stimuli from outside the cord could possibly contribute to recovery of paralyzed hindlimbs. This report also emphasizes the functional contribution of progressive strengthening of undamaged nerve fibers through a collateral sprouts/synaptic plasticity formed in partially lesioned cord of monkeys.

Histamine Promotes Locomotion Recovery After Spinal Cord Hemisection via Inhibiting Astrocytic Scar Formation

“…It has been reported that following incomplete SCI a large cyst with amorphous material, trabeculae and liquid surrounded by a glial scar has formed at 4 weeks, and remained stable even at 8 and 16 weeks after SCI . Moreover, many studies have shown a strong relationship between the severity of SCI and the recovery of motor functions based on behavioral assessments . So, the histological outcomes and functional recovery were assessed at 4 weeks after SCI.…”

A simplified method of walking track analysis to assess short-term locomotor recovery after acute spinal cord injury caused by thoracolumbar intervertebral disc extrusion in dogs

“…A decrease in SL of the PL is therefore an expected finding in SCI-affected dogs, and may be due to loss of supraspinal excitatory input to motor neurons innervating the pelvic limb extensor muscles. This leads to paraparesis, decreased weight support in the affected limbs, reduced limb propulsion, and decreased stance or swing duration (Hamers et al, 2001; McEwen and Springer, 2006; Collazos-Castro et al, 2006; Rangasamy, 2013). …”

“…Walking track analysis has been used previously to assess return of pelvic limb function following animal models of nerve injury and traumatic SCI (de Medinaceli et al, 1982; Kunkel-Bagden et al, 1993; Cheng et al, 1997; Klapdor et al, 1997; Varejao et al, 2004; Hamers et al, 2001; Hamers et al, 2006; Gordon-Evans et al, 2009, Rangasamy, 2013). Measurements such as base of support (BS), stride length (SL), inter-limb coordination, regularity of step patterns and paw position can provide valuable information regarding the animal's pattern of locomotion in both the thoracic limbs (TL) and pelvic limbs (PL) which may reflect the injury type, severity of injury, and specific spinal tracts affected by the lesion (Kunkel-Bagden et al, 1993; Klapdor et al, 1997; Hamers et al, 2001; Hamers et al, 2006; Rangasamy, 2013).…”

“…Measurements such as base of support (BS), stride length (SL), inter-limb coordination, regularity of step patterns and paw position can provide valuable information regarding the animal's pattern of locomotion in both the thoracic limbs (TL) and pelvic limbs (PL) which may reflect the injury type, severity of injury, and specific spinal tracts affected by the lesion (Kunkel-Bagden et al, 1993; Klapdor et al, 1997; Hamers et al, 2001; Hamers et al, 2006; Rangasamy, 2013). Dogs with spinal cord disease exhibit an uncoordinated gait that is quantifiably different using instrumented gait analysis from dogs with lameness due to orthopedic disease (Gordon-Evans et al, 2009).…”

A bipedal mammalian model for spinal cord injury research: The tammar wallaby

“…The only eutherian bipedal models available are some species of non-human primates (see Alexander, 2004; Babu & Namasivayam, 2008); however most primates are not truly bipedal, are expensive to study and are not readily accessible. Very few studies of SCI in primate species that are truly bipedal have been published ( Rangasamy, 2013). Macropodid marsupials are the only other major group of mammals that are substantially bipedal.…”