Neuroanatomical and neuropharmacological approaches to postictal antinociception-related prosencephalic neurons: the role of muscarinic and nicotinic cholinergic receptors

Author(s)

de Freitas, Renato Leonardo ^{[1, 2]} ; Bolognesi, Luana Iacovelo ^[1] ; Twardowschy, Andre ^[1] ; Aguiar Correa, Fernando Morgan ^[3] ; Sibson, Nicola R. ^[4] ; Coimbra, Norberto Cysne ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Farmacol, Lab Neuroanat & Neuropsicobiol, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Inst Neurosci & Behav, BR-14049900 Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Farmacol, Lab Cent Control Arterial Pressure, BR-14049900 Ribeirao Preto, SP - Brazil

^[4] Univ Oxford, Churchill Hosp, CR UK MRC Gray Inst Radiat Oncol & Biol, Expt Neuroimaging Grp, Oxford OX3 7LJ, Oxfordshire - England

• Document type: Journal article
• Source: BRAIN AND BEHAVIOR; v. 3, n. 3, p. 286-301, MAY 2013.
• Web of Science Citations: 10

Abstract

Several studies have suggested the involvement of the hippocampus in the elaboration of epilepsy. There is evidence that suggests the hippocampus plays an important role in the affective and motivational components of nociceptive perception. However, the exact nature of this involvement remains unclear. Therefore, the aim of this study was to determine the role of muscarinic and nicotinic cholinergic receptors in the dorsal hippocampus (dH) in the organization of postictal analgesia. In a neuroanatomical study, afferent connections were found from the somatosensory cortex, the medial septal area, the lateral septal area, the diagonal band of Broca, and the dentate gyrus to the dH; all these areas have been suggested to modulate convulsive activity. Outputs to the dH were also identified from the linear raphe nucleus, the median raphe nucleus (MdRN), the dorsal raphe nucleus, and the locus coeruleus. All these structures comprise the endogenous pain modulatory system and may be involved either in postictal pronociception or antinociception that is commonly reported by epileptic patients. dH-pretreatment with cobalt chloride (1.0 mmol/L CoCl2/0.2 mu L) to transiently inhibit local synapses decreased postictal analgesia 10 min after the end of seizures. Pretreatment of the dH with either atropine or mecamylamine (1.0 mu g/0.2 mu L) attenuated the postictal antinociception 30 min after seizures, while the higher dose (5.0 mu g/0.2 mu L) decreased postictal analgesia immediately after the end of seizures. These findings suggest that the dH exerts a critical role in the organization of postictal analgesia and that muscarinic and nicotinic cholinergic receptor-mediated mechanisms in the dH are involved in the elaboration of antinociceptive processes induced by generalized tonic-clonic seizures. (AU)

• FAPESP's process: 11/20381-3 - INVOLVEMENT OF SEROTONERGIC SYSTEM AND HIPPOCAMPAL NEUROGENESIS IN THE ANTIDEPRESSANT-LIKE EFFECT CAUSED BY ANTAGONISTS OF NOCICEPTIN RECEPTOR
• Grantee: Andre Twardowschy
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 08/00531-8 - Study of the interaction between Opioid and GABAergic mechanisms in the Dorsal Mesencephalon and its Role in the Modulation of Defensive Behaviour Organized in the Inferior Colliculus and Periaqueductal Grey Matter
• Grantee: Andre Twardowschy
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 07/01174-1 - Study of the Involvement of opioid-, serotonergic- and noradrenergic-mechanisms of the pain endogenous inhibitory system in antinociceptive processes induced by oriented escape reactions evoked by chemical stimulation of the merdial hypothalamus
• Grantee: Norberto Cysne Coimbra
• Support Opportunities: Regular Research Grants