Involvement of the opioid system in the analgesia induced by the electrical stimulation of the insular cortex

• Grant number: 17/07411-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2017
• End date: December 31, 2017
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal Investigator: Camila Squarzoni Dale
• Grantee: Elizamara Santos Gonçalves
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The insular cortex has connections with the analgesic downward pathway of pain and is the place where a painful sensation is interpreted by its intensity, in addition to being in contact with the emotional aspect of chronic pain. Neuropathic pain resulting from peripheral nerve injury is characterized by the presence of allodynia and hyperalgesia. Treatments for this type of pain are constantly ineffective due to misunderstanding of the molecular and cellular mechanisms involved. The encephalic electrical estimation induces mechanisms of pain suppression and endogenous analgesics, being, therefore, an alternative for patients refractory to conventional treatments. However, little is known about the mechanisms that involve this effect, proving a need for studies that go deeper in this field. Data obtained by our group demonstrate that an electrical estimate of the acute insular cortex (ECC) (only a 15 minute estimation session) induces antinociception in rats submitted to a neuropathic pain model, and this effect is dependent on opioid and cannabinoid receptors of the type I. In addition, a chronic ECM is capable of generating a mechanical antinociception that lasts for less than 24 hours after a last stimulation session without generating effects on a general locomotor activity of the animals. Thus, this project aims to investigate the effect of chronic ECSI (5 consecutive daily sessions of 15 minutes of estimation) on a mechanical pain sensitivity and to perform tests with a naloxone - a nonselective opioid antagonist to verify the involvement of the opioidergic system No antinociceptive effect induced by chronic ECSS in animals submitted to a peripheral neuropathy model. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ALONSO-MATIELO, HELOISA; GONCALVES, ELIZAMARA S.; CAMPOS, MARIANA; OLIVEIRA, VICTORIA R. S.; TONIOLO, ELAINE F.; ALVES, ADILSON S.; LEBRUN, IVO; DE ANDRADE, DANIEL C.; TEIXEIRA, MANOEL J.; BRITTO, LUIZ R. G.; et al. Electrical stimulation of the posterior insula induces mechanical analgesia in a rodent model of neuropathic pain by modulating GABAergic signaling and activity in the pain circuitry. Brain Research, v. 1754, MAR 1 2021. (17/25399-4, 15/17136-8, 18/18483-1, 17/07411-7, 15/23522-8)