title: The role of norepinephrine in the expression of learned olfactory neurobehavioral responses in infant rats.
abstract: In neonatal rats, norepinephrine (NE) is necessary and sufficient for the acquisition of an olfactory preference and its associated olfactory bulb neural modifications as assessed by [(14)C] 2-deoxyglucose (2-DG) and electrophysiology. In the present studies, we assessed the influence of NE on the expression of a conditioned odor preference and its associated olfactory bulb neural modifications in neonatal rats. On Postnatal Day 5 (PN 5), pups were trained to prefer an odor in a 1-h classical conditioning paradigm. Experimental paired odor-stroke pups received 20 forward pairings of a 10-sec peppermint odor and a 9-sec reinforcing tactile stimulation (stroking). Control pups received either random stroke-odor pairings or were naive (received neither the odor nor stroking). The next day (PN 6), the pups were injected with either an NE β-receptor antagonist, (propranolol or timolol) or saline, 1 h prior to testing. The pups were tested for a behavioral olfactory preference and assessed for differential olfactory bulb activity with [(14)C] 2-DG autoradiography. The results indicate that NE is not necessary for the expression of the learned neurobehavioral response.
authors.affiliation: University of Oklahoma, Norman, Oklahoma.
authors.forename: R M
authors.initials: RM
authors.lastname: Sullivan
authors.forename: D A
authors.initials: DA
authors.lastname: Wilson