Low level laser therapy in neuroplasticity and functional recovery after spinal cord injury

• Grant number: 12/24680-8
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2013
• End date: June 30, 2015
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Carla Christina Medalha
• Grantee: Carla Christina Medalha
• Host Institution: Instituto de Saúde e Sociedade (ISS). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil
• Associated researchers: Ana Claudia Muniz Renno

Abstract

Low Level Laser Therapy (LLLT) has been proposed as a potential treatment agent after lesions of the Central and Peripheral Nervous System. The aim of this study is to investigate the effects of laser therapy in regeneration and plasticity after spinal cord injury. Sprague Dawley rats at 8 weeks of age will be undergone to a spinal cord injury, a contusion, and studied in two experiments. In experiment 1, the goal is to obtain the best parameter of the laser on the modulation of inflammatory response and spinal glial scar formation. Three groups of animals (n = 10) will be lesioned by the equipment impactor, at 150Kdin. A control group and two treated with 100 J/cm2 or 200 J/cm2 of LLLT of gallium arsenide and aluminum (GaAlAs) with a wavelength of 808nm, power of 100 mW for 15 days will be studied. The dose with best results will be used in experiment 2. In the second experiment the aim will be to identify effects of LLLT on the plasticity of the spinal cord at various time windows after injury. Six groups of animals (n = 10 each) will be harmed and divided as follows: Group 1: Control 4 weeks (CTR4) - Animals injured, sacrificed after 4 weeks, Group 2: Treated and sacrificed after 4 weeks (LLLT4) - Animals injured, treated with laser 15 days, sacrificed after 4 weeks, Group 3: Control 8 weeks (CTR8) - Animals injured, euthanized after 8 weeks, Group 4: Treated and sacrificed after 8 weeks (LLLT8) - Animals injured, treated with laser 15 days, sacrificed after 8 weeks, Group 5: Control 12 weeks (CTR12) - Animals lesioned, sacrificed after 12 weeks; Group 6: Treated and sacrificed after 12 weeks (LLLT12) - Animals injured, treated with laser 15 days, sacrificed after 12 weeks. In both experiments the morphological and functional changes at the injury site and in the lumbar region will be followed by analysis and immunohistochemical staining of Nissl-mielin. Functional analyzes will be carried out by Basso, Beattie and Bresnahan (BBB) scale for general motor activity, Grid Test for coordination, Von Frey filaments (tactile) for sensory assessment, and the hot plate test for thermal sensitivity and painful. Gait kinematic analysis will be also performed. (AU)