Fast calcium and voltage-sensitive dye imaging in enteric neurones reveal calcium peaks associated with single action potential discharge.

Slow changes in [Ca(2+)](i) reflect increased neuronal activity. Our study demonstrates that single-trial fast [Ca(2+)](i) imaging ({\textgreater}/=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.     «

Slow changes in [Ca(2+)](i) reflect increased neuronal activity. Our study demonstrates that single-trial fast [Ca(2+)](i) imaging ({\textgreater}/=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...     »

Voltage-Sensitive Dye Imaging, Animals, Humans, Guinea Pigs, Tetrodotoxin/pharmacology, Calcium Channel Blockers/pharmacology, Male, Aniline Compounds/pharmacology, Excitatory Postsynaptic Potentials/physiology, Fluorescent Dyes/pharmacology, Ileum/physiology, Nicotine/pharmacology, Nicotinic Agonists/pharmacology, Pyridinium Compounds/pharmacology, Ruthenium Red/pharmacology, Xanthenes/pharmacology, omega-Conotoxins/pharmacology, Myenteric Plexus/*physiology, Neurons/*physiology, Action Potentials/*physiology, Calcium/*physiology     «

Voltage-Sensitive Dye Imaging, Animals, Humans, Guinea Pigs, Tetrodotoxin/pharmacology, Calcium Channel Blockers/pharmacology, Male, Aniline Compounds/pharmacology, Excitatory Postsynaptic Potentials/physiology, Fluorescent Dyes/pharmacology, Ileum/physiology, Nicotine/pharmacology, Nicotinic Agonists/pharmacology, Pyridinium Compounds/pharmacology, Ruthenium Red/pharmacology, Xanthenes/pharmacology, omega-Conotoxins/pharmacology, Myenteric Plexus/*physiology, Neurons/*physiology, Action Potenti...     »