title: Exogenous ciliary neurotrophic factor (CNTF) reduces synaptic depression during repetitive stimulation.
abstract: It has been shown that ciliary neurotrophic factor (CNTF) has trophic and maintenance effects on several types of peripheral and central neurons, glia, and cells outside the nervous system. Both CNTF and its receptor, CNTF-Rα, are expressed in the muscle. We use confocal immunocytochemistry to show that the trophic cytokine and its receptor are present in the pre- and post-synaptic sites of the neuromuscular junctions (NMJs). Applied CNTF (7.5-200 ng/ml, 60 min-3 h) does not acutely affect spontaneous potentials (size or frequency) or quantal content of the evoked acetylcholine release from post-natal (in weak or strong axonal inputs on dually innervated end plates or in the most mature singly innervated synapses at P6) or adult (P30) NMJ of Levator auris longus muscle of the mice. However, CNTF reduces roughly 50% the depression produced by repetitive stimulation (40 Hz, 2 min) on the adult NMJs. Our findings indicate that, unlike neurotrophins, exogenous CNTF does not acutely modulate transmitter release locally at the mammalian neuromuscular synapse but can protect mature end plates from activity-induced synaptic depression.
authors.affiliation: Unitat d'Histologia i Neurobiologia (UHN), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, Reus, Spain. ngs@fmcs.urv.es
authors.forename: Neus
authors.initials: N
authors.lastname: Garcia
authors.forename: Manel M
authors.initials: MM
authors.lastname: Santafé
authors.forename: Marta
authors.initials: M
authors.lastname: Tomàs
authors.forename: Mercedes
authors.initials: M
authors.lastname: Priego
authors.forename: Teresa
authors.initials: T
authors.lastname: Obis
authors.forename: Maria A
authors.initials: MA
authors.lastname: Lanuza
authors.forename: Nuria
authors.initials: N
authors.lastname: Besalduch
authors.forename: Josep
authors.initials: J
authors.lastname: Tomàs
mesh_terms: D000818:Animals; D020934:Ciliary Neurotrophic Factor / Q000096:biosynthesis* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation / Q000379:methods; D036881:Long-Term Synaptic Depression / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051379:Mice; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D009469:Neuromuscular Junction / Q000187:drug effects / Q000378:metabolism; D013569:Synapses / Q000187:drug effects* / Q000378:metabolism
chemical_list: D020934:Ciliary Neurotrophic Factor