Enhancement of spatial learning by predator odor in mice: Involvement of amygdala and hippocampus

• Published in: Neurobiology of learning and memory 2010-02, Vol.93 (2), p.196-202
• Main Authors: Galliot, Emmanuel, Levaillant, Maryline, Beard, Elidie, Millot, Jean-Louis, Pourié, Gregory
• Format: Article
• Language: English
• Subjects: Amygdala; Amygdala - drug effects; Amygdala - physiology; Animals; Behavioral psychophysiology; Biological and medical sciences; Brain; CA1 Region, Hippocampal - physiology; Escape Reaction - drug effects; Escape Reaction - physiology; Female; Fundamental and applied biological sciences. Psychology; Hippocampus; Hippocampus - physiology; Ibotenic Acid - toxicity; Learning - drug effects; Learning - physiology; Life Sciences; Maze Learning - physiology; Mice; Neurons and Cognition; Neuropsychological Tests; Neurotoxins - toxicity; Odorants; Odors; Olfactory Perception - physiology; Physical Stimulation; Predation; Predator odor; Predatory Behavior; Proto-Oncogene Proteins c-fos - metabolism; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rodents; Sensory perception; Smell; Space Perception - physiology; Spatial learning; Time Factors
• ISSN: 1074-7427; 1095-9564
• DOI: 10.1016/j.nlm.2009.09.011

Olfaction has particular links with learning and memory compared with other sensory cues, due to the interrelations between their neural circuitry. The present study deals with the effects of a putative stressor (i.e. a predator odor) on visuo-spatial learning in mice. Firstly, the results show that a predator odor spread during the Morris water maze task led to learning enhancement. In addition, a stereotaxic approach was used to investigate the involvement of the amygdala in this hippocampus-dependent type of learning. Thus, the performance of mice in visuo-spatial learning under predator odor conditions was dramatically reduced by an ibotenate bilateral amygdala lesion. The involvement of the amygdala was confirmed by a reduced expression of c-fos in the CA1 hippocampus of amygdala-lesioned mice at the end of the learning procedure. Mild exposure to a predator odor during hippocampus-dependent learning therefore leads to an enhancement of performance through the co-activation of the amygdala, probably by a stress mediated mechanism.