Predator (cat hair)-induced enhancement of hippocampal long-term potentiation in rats: involvement of acetylcholine.
Extensive literature has demonstrated that arousal and fear modify memory acquisition and consolidation. Predator hair and odors increase arousal in rats and, therefore, may influence information encoding and synaptic plasticity in the rodent nervous system. In behavioral experiments, we confirm that laboratory-bred Long Evans rats avoid cat hair. Electrophysiological work in vivo showed that long-term potentiation (LTP) in the dentate gyrus induced by perforant path stimulation was enhanced for 5-7 days when LTP induction occurred in the presence of cat hair relative to fake hair. The muscarinic receptor antagonist scopolamine (i.p.) reversed the cat hair-elicited LTP enhancement without affecting weaker LTP elicited in the presence of fake hair. Thus, exposure to a predator stimulus elicits a cholinergically-dependent state of heightened plasticity that may serve to facilitate information storage in hippocampal circuits.
Dringenberg
Hans C
HC
Department of Psychology, Queen's University, Kingston, Ontario K7L 3N6, Canada. dringenb@queensu.ca
Oliveira
Daniel
D
Habib
Diala
D
D000109:Acetylcholine / Q000502:physiology*; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D002415:Cats / Q000523:psychology; D018891:Dentate Gyrus / Q000502:physiology; D004594:Electrophysiology; D006197:Hair; D006624:Hippocampus / Q000502:physiology*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009473:Neuronal Plasticity / Q000502:physiology; D019580:Perforant Pathway / Q000502:physiology; D011235:Predatory Behavior; D051381:Rats / Q000502:physiology* / Q000523:psychology; D020318:Rats, Long-Evans; D012601:Scopolamine / Q000494:pharmacology
D018727:Muscarinic Antagonists; D012601:Scopolamine; D000109:Acetylcholine