Characterization of a cerebral palsy‐like model in rats: Analysis of gait pattern and of brain and spinal cord motor areas

Abstract

In an attempt to propose an animal model that reproduces in rats the phenotype of cerebral palsy, this study evaluated the effects of maternal exposure to bacterial endotoxin associated with perinatal asphyxia and sensorimotor restriction on gait pattern, brain and spinal cord morphology. Two experimental groups were used: Control Group (CTG) − offspring of rats injected with saline during pregnancy and Cerebral Palsy Group (CPG) − offspring of rats injected with lipopolysaccharide during pregnancy, submitted to perinatal asphyxia and sensorimotor restriction for 30 days. At 29 days of age, the CPG exhibited coordination between limbs, weight‐supported dorsal steps or weight‐supported plantar steps with paw rotation. At 45 days of age, CPG exhibited plantar stepping with the paw rotated in the balance phase. An increase in the number of glial cells in the primary somatosensory cortex and dorsal striatum were observed in the CPG, but the corpus callosum thickness and cross‐sectional area of lateral ventricle were similar between studied groups. No changes were found in the number of motoneurons, glial cells and soma area of the motoneurons in the ventral horn of spinal cord. The combination of insults in the pre, peri and postnatal periods produced changes in hindlimbs gait pattern of animals similar to those observed in diplegic patients, but motor impairments were attenuated over time. Besides, the greater number of glial cells observed seems to be related to the formation of a glial scar in important sensorimotor brain areas.

The Subdivided Driving System Used in Stepping Motor

“…Subdivided driving control technology is also called micro-step control technology. The essence of this technology is to input step-by-step change direction current into the winding of the stepping motor, so that the step angle can be reduced when each step rotates, thereby improving the resolution of the motor [6][7][8]. The subdivided driving control technology reduces the step angle of each step of the motor, improves the inherent resolution of the motor, and has a good restraining effect on the low frequency oscillation, step loss, and large noise that are common in most motors.…”

Synaptophysin and caspase-3 expression on lumbar segments of spinal cord after sensorimotor restriction during early postnatal period and treadmill training

“…Animal models of SR usually try to mimic the immobility imposed by spasticity and has been already shown to be a valuable model to understand underlying mechanisms of neural adaptations occurred in response to immobility. A series of studies using the SR procedure showed that SR impact proprioceptive feedback from the hind limbs during development and affects cortical structural and functional organization ( Coq et al, 2008 ; dos Santos et al, 2017 ; Marcuzzo et al, 2010 ; Strata et al, 2004 ). Although central effects of disuse are evident, the functional impairment in motor tasks could be resulted by the combination of both central and peripheral factors.…”