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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)


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de Freitas, Renato Leonardo ; Medeiros, Priscila ; da Silva, Juliana Almeida ; de Oliveira, Rithiele Cristina ; de Oliveira, Ricardo ; Ullah, Farhad ; Khan, Asmat Ullah ; Coimbra, Norberto Cysne
Total Authors: 8
Document type: Journal article
Source: Neuroscience; v. 336, p. 133-145, NOV 12 2016.
Web of Science Citations: 4

It has been proposed that the post-ictal state is associated with the expression of hypoalgesia. It is clear that the projections among the periaqueductal gray matter (PAG), dorsal raphe nucleus (DRN) and locus coeruleus (LC) play a role in pain management. These mesencephalic structures have direct reciprocal opioid and monoaminergic projections to the LC that can possibly modulate post-ictal hypoalgesia. The goal of this study was to examine if LC-opioid and serotonergic/noradrenergic mechanisms signal the post-ictal hypoalgesic responses to tonic clonic seizures produced by intraperitoneal administration of pentylenetetrazole (PTZ at 64 mg/kg), causing an ionophore gamma-aminobutyric acid (GABA)-mediated CI- influx antagonism. The rodents' nociceptive threshold was measured by the tail-flick test. Intra-LC cobalt chloride (1.0 nM/0.2 mu L microinjections produced intermittent local synaptic inhibition and were able to reduce post-ictal hypoalgesia. Central administration of naltrexone (a non-selective antagonist for opioid receptors), naloxonazine (a selective antagonist for mu(1)-opioid-receptors), methysergide (a non-selective antagonist for serotonergic receptors) or ketanserin (an antagonist for both alpha(1)-noradrenergic and 5-Hydroxytryptamine(HT)(2A/2C) receptors) at 5.0 mu g/0.2 mu L, R-96544 (a 5-HT2A receptor selective antagonist) at 10 nM/0.2 mu L, or RS-102221 (a 5-HT2c receptor selective antagonist) at 0.15 mu g/0.2 mu L into the LC also decreased post-ictal hypoalgesia. The data presented here suggest that the post-ictal antinociception mechanism involves the mu(1)-opiod, 5-HT2A- and 5-HT2c-serotonergic, and alpha(1)-noradrenergic receptors in the LC. (C) 2016 IBRO. Published by Elsevier Ltd. All rights reserved. (AU)

FAPESP's process: 11/09850-1 - study of serotoninergic pathways that connect the dorsal raphe nucleus to the Lateral Septal Area on the Modulation of Defensive Behavior Organized by periaqueductal gray performed by the prefrontal cortex
Grantee:Ricardo de Oliveira
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 09/02458-9 - Neuropharmacological study of the interaction between cannabinoid and opioid circuits of the substantia nigra, pars reticulata, on the activity of the nigrotectal GABAergic pathways, and of its role in the modulation of the innate fear-induced analgesia
Grantee:Juliana Almeida da Silva
Support type: Scholarships in Brazil - Master
FAPESP's process: 13/12916-0 - Role of endocannabinoid, glutamatergic and endovanilloid systems of medial prefrontal cortex in neuropathic pain model and investigation of neurological disorders and chronic pain comorbidity
Grantee:Renato Leonardo de Freitas
Support type: Research Grants - Young Investigators Grants
FAPESP's process: 09/17258-5 - Study of the involvement of nitrergic system and of glutamatergic and cannabinoid-mediated neurotransmission from the medial prefrontal cortex in the analgesia induced by elaborated escape reactions evoked by GABAergic blockade in the medial hypothalamus
Grantee:Renato Leonardo de Freitas
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 12/25167-2 - Role of glutamatergic, endocannabinoid and endovaniloid systems of medial pre-frontal cortex in neurophatic pain model: Investigation of panic and chronic pain comorbidity
Grantee:Priscila de Medeiros
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 14/11869-0 - Multi-use equipment approved in grant 2013/12916-0: deep brain stimulation (DBS) (Thomas mini matrix system - Thomas recording GmbH® - Winchester Strasse - Giessen - Germany)
Grantee:Renato Leonardo de Freitas
Support type: Multi-user Equipment Program
FAPESP's process: 09/00668-6 - Study of the involvement of cholinergic pathways form tegmentar pedunculopontine nucleus to monoaminergic nuclei of the pain endogenous inhibitory system in the post-ictal antinociception
Grantee:Norberto Cysne Coimbra
Support type: Regular Research Grants
FAPESP's process: 15/10313-1 - Study of nigro-tectal GABAergic pathways activity during the elaboration of defensive behaviour: role of endocannabinoid mediated neuromodulation in the caudatum putamen of the GABAergic disinhibitory neostriatum-nigral inhibitory nigro-collicular pathways
Grantee:Juliana Almeida da Silva
Support type: Scholarships in Brazil - Post-Doctorate