Effects of Enriched Housing on Functional Recovery After Spinal Cord Contusive Injury in the Adult Rat

Abstract

To date, most research performed in the area of spinal cord injury focuses on treatments designed to either prevent spreading lesion (secondary injury) or to enhance outgrowth of long descending and ascending fiber tracts around or through the lesion. In the last decade, however, several authors have shown that it is possible to enhance locomotor function after spinal cord injury in both animals and patients using specific training paradigms. As a first step towards combining such training paradigms with pharmacotherapy, we evaluated recovery of function in adult rats sustaining a spinal cord contusion injury (MASCIS device, 12.5 mm at T8), either housed in an enriched environment or in standard cages (n = 15 in both groups). The animals in the enriched environment were stimulated to increase their locomotor activity by placing water and food on opposite sides of the cage. As extra stimuli, a running wheel and several other objects were added to the cage. We show that exposure to the enriched environment improves gross and fine locomotor recovery as measured by the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale, the BBB subscale, the Gridwalk, and the Thoracolumbar height test. However, no group differences were found on our electrophysiological parameters nor on the amount of spared white matter. These data justify further studies on enriched housing and more controlled exercise training, with their use as potential additive to pharmacological intervention.

Progesterone Reduces Secondary Damage, Preserves White Matter, and Improves Locomotor Outcome after Spinal Cord Contusion

“…CatWalk measures a large number of both static and dynamic gait parameters and enables quantitative assessment of locomotion. 33,[35][36][37][38][39] Briefly, the CatWalk system consists of a glass runway that contains light from a fluorescent tube. Internal reflection causes the light to be restricted to the glass surface plate under normal circumstances.…”

Activity-dependent plasticity in spinal cord injury

“…This increased corticospinal drive could come from plasticity occurring in the cortex (see aforementioned data) or in the descending pathways themselves. In rodents after incomplete SCI, increased activity via enriched environment promotes plasticity in spared corticospinal but not raphespinal or rubrospinal axons [75]. * Based on studies in animal models, a possible molecular mechanism has been proposed for the neuroplasticity events known to occur because of voluntary exercise after SCI.…”

Functional Recovery in Rats With Chronic Spinal Cord Injuries After Exposure to an Enriched Environment

“…Lankhorst et al (36) found improvement in the Basso, Beattie and Bresnahan (BBB) locomotor test (37), BBB subscale, Gridwalk test, CatWalk test, and thoracolumbar height test in animals placed in an enriched environment immediately after SCI.…”