Acetylcholine induces neuritic outgrowth in rat primary olfactory bulb cultures

Citation
V. Coronas et al., Acetylcholine induces neuritic outgrowth in rat primary olfactory bulb cultures, NEUROSCIENC, 98(2), 2000, pp. 213-219
Citations number
48
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences & Behavoir
Journal title
NEUROSCIENCE
ISSN journal
0306-4522 → ACNP
Volume
98
Issue
2
Year of publication
2000
Pages
213 - 219
Database
ISI
SICI code
0306-4522(2000)98:2<213:AINOIR>2.0.ZU;2-4
Abstract
The rat olfactory bulb is innervated by basal forebrain cholinergic neurons and is endowed with both nicotinic and muscarinic receptors. The developme nt of this centrifugal cholinergic innervation occurs mainly in early postn atal stages. This developmental time-course and the demonstration that acet ylcholine can modulate some aspects of neuronal proliferation, differentiat ion or death, suggests the possible involvement of cholinergic afferents in the morphogenesis and/or plasticity of the olfactory bulb. The purpose of the present work was to assess whether acetylcholine could modulate neurona l morphogenesis in the olfactory bulb. Toward this aim, we developed a prim ary culture model of rat olfactory bulbs. Three major cell types were ident ified on the basis of their morphological and immunocytochemical phenotype: neuronal-shaped cells expressing the neuronal markers neuron specific enol ase, microtubule associated protein 2, neural cell adhesion molecule and be ta-tubulin III; glial-like cells immunoreactive for glial fibrillary acidic protein and flattened cells immunolabelled with antibodies against beta-tu bulin III and nestin, most likely neuronal precursors. After three to six d ays of treatment with 100-mu M carbachol, a cholinergic agonist, significan t increase in neuritic length was observed in cultured olfactory bulb neuro ns. The neurite outgrowth effect of carbachol was abolished by cotreatment with 1 mu M alpha-bungarotoxin, an alpha 7 subunit nicotinic receptor antag onist, but was not affected by the addition of 10 mu M atropine, a general muscarinic antagonist. The effect of carbachol was also mimicked by the nic otinic agonists, nicotine (100 mu M) and epibatidine (10 mu M) This pharmac ological profile suggested the involvement of nicotinic receptors of the al pha 7-like subtype as confirmed using I-125-alpha-bungarotoxin receptor aut oradiography. Taken together, these data argue for a role for nicotinic receptors in neur itic outgrowth in the rat olfactory bulb and provide a cellular support to the previously described effects of acetylcholine on olfactory bulb plastic ity in vivo. (C) 2000 IBRO. Published by Elsevier Science Ltd. All rights r eserved.