Project description:Purpose: The goal of this study was to determine the gene expression changes that occur over 7 days in parralyzed muscle in response to isometric contraction elicited by electrical stimulation initiated 4 months after spinal cord injury and to compare such changes to those observed in a normal muscle subjected to overload. Methods: Electrical stimulation of the soleus and plantaris muscle was stimulated in female rats with complete transection of the spinal cord at the interspace between the 9th and 10th thoracic vertebrae. Stimulation was begun 16 weeks after spinal cord transection and produced near-isometric contraction of soleus, plantaris and tibialis anterior. Muscle was analyzed at 1, 2 and 7 days after starting exercise with electrical stimulation. To provide a baseline reference for gene expression at 16 weeks after spinal cord injury, muscle was also analysed from an additional group of spinal cord transected animals. One additional group of animals with a sham-spinal cord injury was included to provide information about gene expression in neurologically intact animals of similar age. In parallel studies, rats underwent bilateral gastrocnemius ablation to overload soleus and plantaris, or a sham ablation as a control. Muscle was analyzed at 1, 3 and 7 days after gastrocnemius ablation or sham-ablation. Gene expression was determined using Affymetrix Rat Exon microarrays. For each group of animals, microarray analysis was performed for soleus muscle for each of 3 separate animals, using one array per animal. Control sammples for the spinal cord injured groups included a group of animals with a Sham-spinal cord injury, and a group of spinal cord injured animals that did not get electrical stimulation. The comparator for determining fold-change expression values was the spinal cord injured group that did not receive electrical stimulation. For each day after gastrocnemius ablation, a control was included that received all procedures needed for this ablation except cutting the distal insertion of the gastrocnemius into the Achilles tendon to control for effects of the surgery on gene expression.
Project description:Summary: Spinal cord injury (SCI) is a damage to the spinal cord induced by trauma or disease resulting in a loss of mobility or feeling. SCI is characterized by a primary mechanical injury followed by a secondary injury in which several molecular events are altered in the spinal cord often resulting in loss of neuronal function. Analysis of the areas directly (spinal cord) and indirectly (raphe and sensorimotor cortex) affected by injury will help understanding mechanisms of SCI. Hypothesis: Areas of the brain primarily affected by spinal cord injury are the Raphe and the Sensorimotor cortex thus gene expression profiling these two areas might contribute understanding the mechanisms of spinal cord injury. Specific Aim: The project aims at finding significantly altered genes in the Raphe and Sensorimotor cortex following an induced moderate spinal cord injury in T9.
Project description:Skeletal Muscle Contraction Reduces Effects of Unloading on Bone Independently from the Central Nervous System: Studies Using Functional Electrical Stimulation after Spinal Cord Transection