title: Muscarinic depression of evoked surface-negative field potentials recorded from guinea-pig olfactory cortex in vitro.
abstract: The action of some cholinergic drugs has been studied on the field potentials evoked by orthodromic stimulation of the lateral olfactory tract (LOT) in guinea-pig olfactory cortex slices maintained in vitro. A reversible depression of the electrically evoked surface-negative field potential (N-wave) was seen following superfusion of muscarine (10-200 microM) or mixed-agonist choline esters but not nicotinic agonists. This depression was blocked by atropine and pirenzepine, but not d-tubocurarine or by antagonists active at gamma-aminobutyric acid or adenosine receptors. Little effect of muscarinic agonists was observed on the compound action potential recorded from the LOT, or on pial surface DC potential. A possible presynaptic site of action of muscarinic agonists in the olfactory cortex is discussed.
authors.forename: S H
authors.initials: SH
authors.lastname: Williams
authors.forename: A
authors.initials: A
authors.lastname: Constanti
authors.forename: D A
authors.initials: DA
authors.lastname: Brown
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002490:Central Nervous System / Q000187:drug effects*; D002540:Cerebral Cortex / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects*; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008688:Methacholine Compounds / Q000494:pharmacology; D009116:Muscarine / Q000494:pharmacology; D009833:Olfactory Pathways / Q000187:drug effects*; D010277:Parasympathomimetics / Q000494:pharmacology*; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
chemical_list: D005971:Glutamates; D008688:Methacholine Compounds; D010277:Parasympathomimetics; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D009116:Muscarine; D002217:Carbachol; D000109:Acetylcholine