title: Cholinergic modulation during acquisition of olfactory fear conditioning alters learning and stimulus generalization in mice.
abstract: We investigated the role of cholinergic neurotransmission in olfactory fear learning. Mice receiving pairings of odor and foot shock displayed fear to the trained odor the following day. Pretraining injections of the nicotinic antagonist mecamylamine had no effect on subsequent freezing, while the muscarinic antagonist scopolamine significantly reduced freezing. To test whether cholinergic manipulation affected fear generalization, mice were presented with odors similar to the trained odor. Generalization was increased following pretraining scopolamine, while the muscarinic agonist oxotremorine decreased generalization. These results suggest that muscarinic neurotransmission during the acquisition of olfactory association modulates both the strength and specificity of learning.
authors.affiliation: Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
authors.forename: Eloisa
authors.initials: E
authors.lastname: Pavesi
authors.forename: Allison
authors.initials: A
authors.lastname: Gooch
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Lee
authors.forename: Max L
authors.initials: ML
authors.lastname: Fletcher
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D018678:Cholinergic Agents / Q000378:metabolism*; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology*; D003463:Cues; D004597:Electroshock / Q000009:adverse effects; D005239:Fear; D005260:Female; D046352:Freezing Reaction, Cataleptic / Q000502:physiology; D005793:Generalization, Psychological / Q000502:physiology*; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D018727:Muscarinic Antagonists / Q000494:pharmacology; D018733:Nicotinic Antagonists / Q000494:pharmacology; D009812:Odorants; D009833:Olfactory Pathways / Q000502:physiology*; D012601:Scopolamine / Q000494:pharmacology; D012903:Smell / Q000502:physiology*
chemical_list: D018678:Cholinergic Agents; D018727:Muscarinic Antagonists; D018733:Nicotinic Antagonists; D008464:Mecamylamine; D012601:Scopolamine