title: Delayed Intervention with Intermittent Hypoxia and Task Training Improves Forelimb Function in a Rat Model of Cervical Spinal Injury.
abstract: The reduction of motor, sensory and autonomic function below the level of an incomplete spinal cord injury (SCI) has devastating consequences. One approach to restore function is to induce neural plasticity as a means of augmenting spontaneous functional recovery. Acute intermittent hypoxia (AIH-brief exposures to reduced O2 levels alternating with normal O2 levels) elicits plasticity in respiratory and nonrespiratory somatic spinal systems, including improvements in ladder walking performance in rats with incomplete SCI. Here, we determined whether delayed treatment with AIH, with or without concomitant motor training, could improve motor recovery in a rat model of incomplete cervical SCI. In a randomized, blinded, sham-controlled study, rats were exposed to AIH for 7 days beginning at 4 weeks post-SCI, after much spontaneous recovery on a horizontal ladder-crossing task had already occurred. For up to 2 months post-treatment, AIH-treated rats made fewer footslips on the ladder task compared with sham-treated rats. Importantly, concomitant ladder-specific motor training was needed to elicit AIH-induced improvements, such that AIH-treated SCI rats receiving no motor training or nontask-specific treadmill training during the treatment week did not show improvements over sham-treated rats with SCI. AIH treatment combined with task-specific training did not improve recovery on two different reach-to-grasp tasks, however, nor on tasks involving unskilled forepaw use. In brief, our results indicate that task-specific training is needed for AIH to improve ladder performance in a rat model of incomplete cervical SCI.
authors: 1 Biomedical Sciences, WCVM, University of Saskatchewan , Saskatoon, Saskatchewan, Canada .
authors: Erin J
authors: EJ
authors: Prosser-Loose
authors: 1 Biomedical Sciences, WCVM, University of Saskatchewan , Saskatoon, Saskatchewan, Canada .
authors: Atiq
authors: A
authors: Hassan
authors: 2 Comparative Biosciences, University of Wisconsin-Madison , Madison, Wisconsin.
authors: Gordon S
authors: GS
authors: Mitchell
authors: 1 Biomedical Sciences, WCVM, University of Saskatchewan , Saskatoon, Saskatchewan, Canada .
authors: Gillian D
authors: GD
authors: Muir
mesh_terms: D000818:Animals; D002574:Cervical Vertebrae / Q000293:injuries*; D005081:Exercise Therapy; D005552:Forelimb; D007839:Functional Laterality; D018737:Hand Strength; D002534:Hypoxia, Brain / Q000503:physiopathology*; D008297:Male; D009473:Neuronal Plasticity; D011597:Psychomotor Performance; D051381:Rats; D011917:Rats, Inbred Lew; D020127:Recovery of Function; D013119:Spinal Cord Injuries / Q000628:therapy*; D016138:Walking
keywords: behavioral assessments; locomotor function; spinal cord injury