title: Effects of inactivation of the magnocellular preoptic nucleus of olfactory bulb processing.
abstract: The magnocellular nucleus (MCPO) was inactivated in anaesthetized rats, using muscimol, a gamma-amino butyric acid ergic agonist, in order to examine the effect of suppression of its tonic activity on extracellular unit firing in the granular (GRL), mitral (MCL) and external plexiform (EPL) layers of the olfactory bulb (OB). In GRL there was a significant increase in unit activity during the first hour after muscimol injection (30 ng), followed by a significant decrease in activity during the following hour. No effect on activity in MCL was seen after muscimol injection into the MCPO. Unit activity in EPL increased during the second hour post-injection. It was concluded that MCPO plays an important part in regulating the balance between granule and tufted cell activity.
authors.affiliation: Department of Otolaryngology, University of Melbourne, Royal Victorian Eye and Ear Hospital, Australia.
authors.forename: A G
authors.initials: AG
authors.lastname: Paolini
authors.forename: J S
authors.initials: JS
authors.lastname: McKenzie
mesh_terms: D000818:Animals; D001931:Brain Mapping; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D008297:Male; D008845:Microinjections; D009118:Muscimol / Q000008:administration & dosage / Q000494:pharmacology*; D009830:Olfactory Bulb / Q000187:drug effects / Q000502:physiology*; D011301:Preoptic Area / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013238:Stereotaxic Techniques; D013377:Substantia Innominata / Q000187:drug effects / Q000502:physiology*
chemical_list: D009118:Muscimol