title: Association of an odor with activation of olfactory bulb noradrenergic beta-receptors or locus coeruleus stimulation is sufficient to produce learned approach responses to that odor in neonatal rats.
abstract: These experiments examined the sufficiency of pairing an odor with either intrabulbar activation of noradrenergic beta-receptors or pharmacological stimulation of the locus coeruleus to support learned odor preferences in Postnatal Day 6-7 rat pups. The results showed that pups exposed to odor paired with beta-receptor activation limited to the olfactory bulb (isoproterenol, 50 microM) displayed a conditioned approach response on subsequent exposure to that odor. Furthermore, putative stimulation of the locus coeruleus (2 microM idazoxan or 2 mM acetylcholine) paired with odor produced a subsequent preference for that odor. The effects of locus coeruleus stimulation could be blocked by a pretraining injection of the beta-receptor antagonist propranolol (20 mg/kg). Together these results suggest that convergence of odor input with norepinephrine release from the locus coeruleus terminals within the olfactory bulb is sufficient to support olfactory learning.
authors.affiliation: Department of Zoology, University of Oklahoma, Norman 73019, USA. rsullivan@ou.edu
authors.forename: R M
authors.initials: RM
authors.lastname: Sullivan
authors.forename: G
authors.initials: G
authors.lastname: Stackenwalt
authors.forename: F
authors.initials: F
authors.lastname: Nasr
authors.forename: C
authors.initials: C
authors.lastname: Lemon
authors.forename: D A
authors.initials: DA
authors.lastname: Wilson
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology*; D007858:Learning / Q000187:drug effects* / Q000502:physiology*; D008125:Locus Coeruleus / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D009812:Odorants; D009830:Olfactory Bulb / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D020318:Rats, Long-Evans; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D012903:Smell / Q000187:drug effects* / Q000502:physiology*
chemical_list: D000318:Adrenergic beta-Agonists; D011943:Receptors, Adrenergic, beta; D007545:Isoproterenol