title: Fast calcium and voltage-sensitive dye imaging in enteric neurones reveal calcium peaks associated with single action potential discharge.
abstract: Slow changes in [Ca(2+)](i) reflect increased neuronal activity. Our study demonstrates that single-trial fast [Ca(2+)](i) imaging (≥200 Hz sampling rate) revealed peaks each of which are associated with single spike discharge recorded by consecutive voltage-sensitive dye (VSD) imaging in enteric neurones and nerve fibres. Fast [Ca(2+)](i) imaging also revealed subthreshold fast excitatory postsynaptic potentials. Nicotine-evoked [Ca(2+)](i) peaks were reduced by -conotoxin and blocked by ruthenium red or tetrodotoxin. Fast [Ca(2+)](i) imaging can be used to directly record single action potentials in enteric neurones. [Ca(2+)](i) peaks required opening of voltage-gated sodium and calcium channels as well as Ca(2+) release from intracellular stores.
authors: Human Biology, Technische Universität München, Freising, Germany.
authors: K
authors: K
authors: Michel
authors: M
authors: M
authors: Michaelis
authors: G
authors: G
authors: Mazzuoli
authors: K
authors: K
authors: Mueller
authors: P
authors: P
authors: Vanden Berghe
authors: M
authors: M
authors: Schemann
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000814:Aniline Compounds / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D005456:Fluorescent Dyes / Q000494:pharmacology; D006168:Guinea Pigs; D006801:Humans; D007082:Ileum / Q000502:physiology; D008297:Male; D009197:Myenteric Plexus / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D009538:Nicotine / Q000494:pharmacology; D018722:Nicotinic Agonists / Q000494:pharmacology; D011726:Pyridinium Compounds / Q000494:pharmacology; D012430:Ruthenium Red / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D056969:Voltage-Sensitive Dye Imaging; D014966:Xanthenes / Q000494:pharmacology; D020960:omega-Conotoxins / Q000494:pharmacology
chemical_list: C089669:1-(3-sulfonatopropyl)-4-(beta-(2-(di-n-octylamino)-6-naphthyl)vinyl)pyridinium betaine; D000814:Aniline Compounds; D002121:Calcium Channel Blockers; C409648:Fluo 4; D005456:Fluorescent Dyes; D018722:Nicotinic Agonists; D011726:Pyridinium Compounds; D014966:Xanthenes; D020960:omega-Conotoxins; D012430:Ruthenium Red; D013779:Tetrodotoxin; D009538:Nicotine; D002118:Calcium