Magnocellular neurons of the rat supraoptic nucleus are endowed with functional nicotinic acetylcholine receptors

Autor: Daniel Bertrand, Mario Raggenbass, Christophe Blanchet, Eliane Tribollet, M. Zaninetti
Rok vydání: 1999
Předmět:
Male
alpha7 Nicotinic Acetylcholine Receptor
Pyridines
Vasodilator Agents
Nicotinic Antagonists
Supraoptic Nucleus/ cytology
Receptors
Nicotinic
Supraoptic nucleus
Membrane Potentials
Nicotinic Antagonists/pharmacology
Iodine Radioisotopes
Rats
Sprague-Dawley
Radioligand Assay
Ganglion type nicotinic receptor
Muscarinic acetylcholine receptor
Nicotinic Agonists
Nicotinic Antagonist
Neurons
Acetylcholine/pharmacology
Nicotine/pharmacology
General Neuroscience
Receptors
Nicotinic/ physiology
Bungarotoxins/metabolism/pharmacology
Electrophysiology
Nicotinic agonist
Epibatidine
Alpha-4 beta-2 nicotinic receptor
Dihydro-beta-Erythroidine/pharmacology
Supraoptic Nucleus
Membrane Potentials/drug effects/physiology
Nicotinic Agonists/pharmacology
Acetylcholine
medicine.drug
Nicotine
medicine.medical_specialty
In Vitro Techniques
Biology
Tritium
Pyridines/metabolism/pharmacology
Internal medicine
Neurons/ chemistry/ physiology
medicine
Animals
Vasodilator Agents/pharmacology
Dose-Response Relationship
Drug
Iodine Radioisotopes/diagnostic use
Bicyclo Compounds
Heterocyclic/metabolism/pharmacology
Dihydro-beta-Erythroidine
Bridged Bicyclo Compounds
Heterocyclic
Bungarotoxins
ddc:616.8
Rats
Tritium/diagnostic use
Endocrinology
Zdroj: Neuroscience, Vol. 95, No 2 (1999) pp. 319-323
ISSN: 0306-4522
DOI: 10.1016/s0306-4522(99)00477-7
Popis: Acetylcholine can stimulate the release of vasopressin. In organ-cultured hypothalamo-neurohypophyseal systems, acetylcholine enhanced vasopressin release by acting in or near the supraoptic nucleus Extracellular recordings suggested that acetylcholine can increase supraoptic neuron excitability. These effects could be mimicked, in part, by nicotine or blocked by nicotinic antagonists, suggesting that they might be mediated by nicotinic acetylcholine receptors. Autoradiography indicated that alpha-bungarotoxin binding sites are present in the supraoptic nucleus; however, neither acetylcholine nor nicotine binding sites could be detected. Thus, the existence, let alone the nature, of nicotinic receptors in the supraoptic nucleus has so far remained elusive. The present work attempts to determine: (i) whether functional nicotinic receptors are present in this nucleus; (ii) whether they are located on neurosecretory magnocellular cells or at presynaptic sites; (iii) what their pharmacological and biophysical properties are; (iv) whether they influence the activity of all or only part of supraoptic neurons. Whole-cell recordings were performed in hypothalamic slices or in acutely dissociated supraoptic neurons and the effect of nicotinic agonists was tested under voltage-clamp conditions. Autoradiography was done in coronal hypothalamic sections, using [3H]epibatidine and [125I]alpha-bungarotoxin as ligands. Our results indicate that supraoptic neurons possess functional nicotinic receptors containing the alpha7 subunit.
Databáze: OpenAIRE
Externí odkaz: