title: PACAP Modulates Acetylcholine-Elicited Contractions at Nicotinic Neuromuscular Contacts of the Land Snail.
abstract: In this study, we investigate the potentiating effect of PACAP27 on cholinergic neuromuscular transmission in the recently discovered flexor muscles of the land snail, Helix pomatia. Using immunohistochemistry, we show that PACAP and PAC1 receptors are present in nerve fibers innervating the flexor muscles but not in the muscle itself. We also observed that PACAP27 exerts both pre- and postsynaptic effects on the cholinergic synapse and performed tests using a broad spectrum of chemicals in order to explore the possible intracellular pathways through which PACAP mediates its stimulatory effect. Our pharmacological data demonstrate that PACAP27 presynaptically enhances the release of acetylcholine by activating the adenylate cyclase-cAMP-PKA pathway. Postsynaptically, PACAP27 was found to enhance muscle contractility by PKC-mediated signaling pathway resulting in an increased Ca(2+) release from intracellular stores. These findings suggest that regulation of Ca(2+) release may contribute to the stimulatory effect of PACAP. Our data are the first demonstration of the potentiating effect of PACAP27 at the molluscan excitatory neuromuscular contact.
authors.affiliation: Chemical Ecology and Neurobiology Research Group, Department of Experimental Zoology, Balaton Limnological Institute, Centre for Ecological Research, Hungarian Academy of Sciences, Klebelsberg Kuno u 3, H-8237, Tihany, Hungary.
authors.forename: Nóra
authors.initials: N
authors.lastname: Krajcs
authors.affiliation: Chemical Ecology and Neurobiology Research Group, Department of Experimental Zoology, Balaton Limnological Institute, Centre for Ecological Research, Hungarian Academy of Sciences, Klebelsberg Kuno u 3, H-8237, Tihany, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Hernádi
authors.affiliation: Chemical Ecology and Neurobiology Research Group, Department of Experimental Zoology, Balaton Limnological Institute, Centre for Ecological Research, Hungarian Academy of Sciences, Klebelsberg Kuno u 3, H-8237, Tihany, Hungary.|Adaptive Neuroethology Research Group, Department of Experimental Zoology, Balaton Limnological Institute, Centre for Ecological Research, Hungarian Academy of Sciences, Klebelsberg Kuno u 3, H-8237, Tihany, Hungary.|MTA-PTE "Momentum" PACAP Research Team, University of Pecs, Pecs, Hungary.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Pirger
authors.affiliation: MTA-PTE "Momentum" PACAP Research Team, University of Pecs, Pecs, Hungary.
authors.forename: Dóra
authors.initials: D
authors.lastname: Reglődi
authors.affiliation: Department of Medical Chemistry, University of Szeged, Szeged, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Tóth
authors.affiliation: Chemical Ecology and Neurobiology Research Group, Department of Experimental Zoology, Balaton Limnological Institute, Centre for Ecological Research, Hungarian Academy of Sciences, Klebelsberg Kuno u 3, H-8237, Tihany, Hungary. kiss.tibor@okologia.mta.hu.
authors.forename: Tibor
authors.initials: T
authors.lastname: Kiss
mesh_terms: D000109:Acetylcholine / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D059329:Cholinergic Neurons / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D009119:Muscle Contraction; D009469:Neuromuscular Junction / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism; D012908:Snails
chemical_list: D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011493:Protein Kinase C; D000109:Acetylcholine; D002118:Calcium
keywords: Cholinergic transmission; Muscle contraction; Neuromuscular contact; PACAP; Snail