Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Paradoxical effect of noradrenaline-mediated neurotransmission in the antinociceptive phenomenon that accompanies tonic-clonic seizures: Role of locus coeruleus neurons and alpha(2)- and beta-noradrenergic receptors

Full text
Author(s):
Felippotti, Tatiana Tocchini [1] ; dos Reis Ferreira, Celio Marcos [1] ; de Freitas, Renato Leonardo [1] ; de Oliveira, Rithiele Cristina [1] ; de Oliveira, Ricardo [1] ; Paschoalin-Maurin, Tatiana [1] ; Coimbra, Norberto Cysne [1]
Total Authors: 7
Affiliation:
[1] Univ Sao Paulo, FMRP, Lab Neuroanat & Neuropsicobiol, Ribeirao Preto Med Sch, Dept Farmacol, BR-14049900 Ribeirao Preto, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Epilepsy & Behavior; v. 22, n. 2, p. 165-177, OCT 2011.
Web of Science Citations: 15
Abstract

The postictal state is generally followed by antinociception. It is known that connections between the dorsal raphe nucleus, the periaqueductal gray matter, and the locus coeruleus, an important noradrenergic brainstem nucleus, are involved in the descending control of ascending nociceptive pathways. The aim of the present study was to determine whether noradrenergic mechanisms in the locus coeruleus are involved in postictal antinociception. Yohimbine (an alpha(2)-receptor antagonist) or propranolol (a beta-receptor antagonist) was microinjected unilaterally into the locus coeruleus, followed by intraperitoneal administration of pentylenetetrazole (PTZ), a noncompetitive antagonist that blocks GABA-mediated Cl(-) influx. Although the administration of both yohimbine and propranolol to the locus coeruleus/subcoeruleus area resulted in a significant decrease in tonic or tonic clonic seizure-induced antinociception, the effect of yohimbine restricted to the locus coeruleus was more distinct compared with that of propranolol, possibly because of the presynaptic localization of alpha(2)-noradrenergic receptors in locus coeruleus neurons. These effects were related to the modulation of noradrenergic activity in the locus coeruleus. Interestingly, microinjections of noradrenaline into the locus coeruleus also decrease the postictal antinociception. The present results suggest that the mechanism underlying postictal antinociception involves both alpha(2)- and beta-noradrenergic receptors in the locus coeruleus, although the action of noradrenaline on these receptors causes a paradoxical effect, depending on the nature of the local neurotransmission. (C) 2011 Elsevier Inc. All rights reserved. (AU)

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 Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 08/09897-5 - Psychopharmacological study of opioid disinhibitory and GABAergic inhibitory links between the amygdaloid complex and the substantia nigra, pars lateralis: Role on fear eliciated by electrical and chemical stimulation of the inferior colliculus
Grantee:Ricardo de Oliveira
Support Opportunities: Scholarships in Brazil - Doctorate