title: The use of the rat isolated vagus nerve for functional measurements of the effect of drugs in vitro.
abstract: In this article we describe how to dissect, set up and use the rat isolated vagus nerve in a 'grease gap' apparatus which provides a simple and practical method for measuring the effects of drugs on the membrane potential of axons in the nerve in vitro. Some discussion of the origins and development of the technique as well as the strengths and disadvantages of the preparation as a neuropharmacological tool are included. The vagus nerve conducts action potentials in at least three distinct types of axons that can be measured extracellularly as compound action potentials and distinguished on the basis of their conduction velocity and excitability. Activity in myelinated A fibres and unmyelinated C fibres can be measured separately easily. The axons express receptors for a wide range of putative neurotransmitter agents including 5-HT, GABA and ATP as well as other agents such as capsaicin, anandamide, bradykinin and prostanoids. Responses to all of these chemicals can be measured as a depolarization of the nerve fibres. The vagus nerve is an important target for a wide range of drugs and the isolated preparation provides a fairly simple preparation for studying their effects. The isolated vagus nerve is also a convenient system in which the effects of drugs that have been discovered using heterologous expression systems can be assayed on receptors and ion channels that are expressed in a native neural system.
authors.affiliation: Centre for Neuroscience Research, GKT School of Biomedical Sciences, King's College London, Guy's Campus, London Bridge, London SE1 9RT, United Kingdom. reginald.docherty@kcl.ac.uk
authors.forename: R J
authors.initials: RJ
authors.lastname: Docherty
authors.forename: G
authors.initials: G
authors.lastname: Charlesworth
authors.forename: K
authors.initials: K
authors.lastname: Farrag
authors.forename: A
authors.initials: A
authors.lastname: Bhattacharjee
authors.forename: S
authors.initials: S
authors.lastname: Costa
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004594:Electrophysiology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000502:physiology; D009412:Nerve Fibers / Q000187:drug effects; D009431:Neural Conduction / Q000187:drug effects; D009467:Neuromuscular Depolarizing Agents / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D051381:Rats; D011955:Receptors, Drug; D017981:Receptors, Neurotransmitter / Q000187:drug effects; D013779:Tetrodotoxin / Q000494:pharmacology; D014630:Vagus Nerve / Q000166:cytology / Q000187:drug effects* / Q000502:physiology
chemical_list: D009467:Neuromuscular Depolarizing Agents; D011955:Receptors, Drug; D017981:Receptors, Neurotransmitter; D013779:Tetrodotoxin