Study of the structures involved in orofacial pain and perspectives of combined treatment of low level laser and B vitamins in a model of trigeminal neuralgia

• Grant number: 15/24256-0
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): August 01, 2016
• Effective date (End): July 31, 2019
• Field of knowledge: Biological Sciences - Morphology
• Principal Investigator: Marucia Chacur
• Grantee: Daniel de Oliveira Martins
• Home Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The trigeminal neuralgia (TN) is a common cause of facial pain. It has a significant impact on quality of life and socioeconomic functioning of the patient. The International Association for the Study of Pain (IASP) defines the TN as a unilateral painful disorder characterized by brief episodes of pain, electric shock type that both your beginning and end can be abrupt. Among the various models of neuropathy using body nerve damage, the trigeminal nerve has also been an important target. Since the trigeminal nerve is largely responsible for conducting sensory information arising from the face and neck. In rats, the infraorbital nerve, maxillary division, greater emphasis has to be composed almost by sensory fibers and is responsible for supplying the set of whiskers. The chronic constriction injury of the infraorbital nerve (CCI-NIO) which results in a chronic pain model that can be applied to the study of orofacial neuropathic pain has been described by VOS et al. (1994) subsequently being used in other studies, becoming a well-established model for the study of TN. The current TN treatment is not satisfactory, and pain control is the most widely used solution, and some severe cases you can choose to remove or destroy the trigeminal ganglion (TG). The multifactorial etiology of orofacial pain hinders diagnosis and impairs the proper choice of drug therapy. According to some studies, vitamin B complex (VBC) exhibit neuroprotective effects, which may be related to its analgesic action in various models of neuropathic pain. And among the main non-pharmacological techniques used for the treatment of neuropathies, we can highlight the low level laser therapy (LLLT). In this study we propose a combination treatment using LLLT, GaAs (904 nm) with VBC, to evaluate the cellular and molecular changes in TG and caudalis subnucleus spinal trigeminal nucleus (Sc-STN) after CCI-NiO, as well as the control of the symptomatology painful and NIO repair. To do so, we use analytical techniques such as immuno-histochemistry, immunoblottig and real-time PCR, besides behavioral and electrophysiological test to assess the pain symptomatology. Still, we will evaluate the expression of molecules associated with pain process in GT and Sc-STN. And also study proteins related to the microenvironment of the injury and that work in the repair of nerve tissue. (AU)