Dorsal raphe nucleus acetylcholine-mediated neurotransmission modulates post-ictal antinociception: The role of muscarinic and nicotinic cholinergic receptors
| Autor: | Norberto Cysne Coimbra, Ricardo de Oliveira, Luiz Luciano Falconi-Sobrinho, Rithiele Cristina de Oliveira, Audrey Francisco Biagioni |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Atropine Dorsal Raphe Nucleus Male Pain Threshold Muscarinic Antagonists Nicotinic Antagonists Mecamylamine Receptors Nicotinic Synaptic Transmission RAFE 03 medical and health sciences 0302 clinical medicine Dorsal raphe nucleus Muscarinic acetylcholine receptor medicine Animals Nicotinic Antagonist Cholinergic neuron GABAergic Neurons Rats Wistar Molecular Biology Pain Measurement Analgesics Chemistry General Neuroscience Receptors Muscarinic Acetylcholine nervous system diseases Rats Stroke 030104 developmental biology Nicotinic agonist nervous system Cholinergic Neurology (clinical) Epilepsy Tonic-Clonic Neuroscience 030217 neurology & neurosurgery Developmental Biology medicine.drug Serotonergic Neurons |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 1872-6240 |
| Popis: | The dorsal raphe nucleus (DRN) is a key structure of the endogenous pain inhibitory system. Although the DRN is rich in serotoninergic neurons, cholinergic neurons are also found in that nucleus. Both ictal and inter-ictal states are followed by post-ictal analgesia. The present study investigated the role of cholinergic mechanisms in postictal antinociceptive processes using microinjections of atropine and mecamylamine, muscarinic and nicotinic cholinergic receptor antagonists, respectively, in the DRN of rats. Intraperitoneal injection of pentylenetetrazole (PTZ) (at 64mg/kg) caused tonic and tonic-clonic seizures. The convulsive motor reactions were followed by an increase in pain thresholds, a phenomenon known as post-ictal analgesia. Pre-treatment of the DRN with atropine or mecamylamine at 1µg, 3µg and 5µg/0.2µL decreased the post-ictal antinociceptive phenomenon. The present results showed that the post-ictal analgesia was mediated by muscarinic and nicotinic cholinergic receptors in the DRN, a structure crucially involved in the neural network that organises post-ictal hypoalgesia. |
| Databáze: | OpenAIRE |
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