Study of GABAergic modulation in the circuitry involved in analgesia induced by the electrical stimulation of the insular cortex

• Grant number: 17/25399-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: April 01, 2018
• End date: July 31, 2020
• Field of knowledge: Biological Sciences - Physiology
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Camila Squarzoni Dale
• Grantee: Heloísa Alonso Matielo
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 18/20702-3 - Optogenetic evaluation of the influence of gabaergic system in the antinociception induced by insular cortex electrical stimulation in neuropathic pain, BE.EP.MS

Abstract

Neuropathic pain is one of the most rebellious conditions to the analgesic treatment, making the search for new therapies for this type of pain extremely urgent. The protocol of the electrical stimulation of the insular cortex (ESI) standardized by our group was effective for the treatment of rats with neuropathic pain, which was also able to alter the neuronal activity of regions that are known to constitute endogenous modulation of pain, such as anterior cingulate cortex (ACC) and periaquedutal gray matter (PAG). The aim of this project is to evaluate the modulation promoted by the gabaergic system in the circuitry constituted by Insular Cortex-ACC-PAG- rostral ventromedial medulla (RVM)- spinal cord- dorsal root ganglion (DRG) in the analgesia induced by five ESI sessions in a neuropathic pain model induced by the chronic constriction of the sciatic nerve (CCI), as well as its influence on the endogenous control of pain mediated by encephalin in the spinal cord and DRG. Throughout this study, male rats, Sprague Dawley (280-340g; CEUA ICB/USP No. 3447131117), will be submitted to CCI in the right hindpaw and a concentric electrode will be implanted in the left insular cortex for subsequent consecutive daily electrical stimulation (15 min / session, 60 Hz , 210 ¼s, 1.0 V). Treatment with Bicuculina methiodide 0.01 ¼g (Tocris ®), a selective GABAA receptor antagonist, will be performed to evaluate the influence of the gabaergic system on the antinociceptive effect generated by the ESI, using the paw pressure test, and in the general locomotor activity of the animals, through the open field test. The levels of GAD67 will be analyzed by Immunofluorescence and Western Blotting in the regions of interest; and the levels of PENK (gene prepro-enkephalin) in the spinal cord and DRG quantified by rt-PCR. The results obtained will allow us to understand how the insula influences the nociceptive system and what neurophysiological mechanisms delineate the antinociceptive effect of ESI. (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)

ALONSO-MATIELO, HELOISA; DA SILVA OLIVEIRA, VICTORIA REGINA; DE OLIVEIRA, VICTHOR TEIXEIRA; DALE, CAMILA SQUARZONI. Pain in Covid Era. FRONTIERS IN PHYSIOLOGY, v. 12, FEB 2 2021. (17/25399-4, 18/18483-1)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

MATIELO, Heloísa Alonso. Study of GABAergic modulation in the circuitry involved in analgesia induced by electrical stimulation of the island cortex.. 2020. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) São Paulo.