Effect of environmental enrichment associated or not with physical activity on nociceptive and motor functions in an animal model of fibromyalgia

Abstract

BACKGROUND AND OBJECTIVES: Fibromyalgia is a complex syndrome, characterized by chronic widespread musculoskeletal pain and the reduction of physical/functional performance as a major comorbidity. Pharmacological treatment of fibromyalgia has limited effectiveness, making it important to study non-pharmacological therapies, emphasizing physical activity, cognitive behavioral therapy and distracting techniques. Environment enrichment and physical activity have been used in the treatment of diseases associated with increases in peripheral and central nociceptive activity. The objective of this study was the investigation of environmental enrichment, a technique based on physical, sensory and cognitive stimulation, and voluntary physical activity for hyperalgesia prevention in an experimental model of fibromyalgia. METHODS: Twenty-four male Wistar rats were split into four groups: 1. environmental enrichment, 2. physical activity, 3. environmental enrichment plus physical activity and 4. control and kept in these protocols for 4 weeks. Next, diffuse chronic muscle pain was induced by a double injection of acidic saline in the left gastrocnemius muscle. Mechanical paw withdrawal threshold, thermal latency, neuromuscular activity and ambulation in six different moments were assessed: baseline, after the 1 st , 2 nd , 3 rd and 4 th weeks and 24 hours after chronic muscle pain induction.