1. Differential dynamics of amino acid release in the amygdala and olfactory cortex during odor fear acquisition as revealed with simultaneous high temporal resolution microdialysis
- Author
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Hegoburu, Chloé, Sevelinges, Yannick, Thevenet, Marc, Gervais, Rémi, Parrot, Sandrine, Mouly, Anne-Marie, Thévenet, M., Centre de recherche en neurosciences de Lyon (CRNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Neurosciences Sensorielles Comportement Cognition, Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Recherche en Génie Industriel alimentaire (LRGIA), and Université de Lyon-Université de Lyon
- Subjects
Male ,Olfactory system ,Time Factors ,Microdialysis ,Cognitive Neuroscience ,Conditioning, Classical ,Sensory system ,Amygdala ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Piriform cortex ,medicine ,Animals ,Rats, Long-Evans ,Fear conditioning ,Amino Acids ,Freezing Reaction, Cataleptic ,030304 developmental biology ,Fear processing in the brain ,Analysis of Variance ,Electroshock ,0303 health sciences ,Classical conditioning ,Neurochemistry ,Fear ,Olfactory Pathways ,Rats ,Neuropsychology and Physiological Psychology ,medicine.anatomical_structure ,Nonlinear Dynamics ,Odorants ,[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] ,Psychology ,Neuroscience ,psychological phenomena and processes ,030217 neurology & neurosurgery ,Basolateral amygdala - Abstract
International audience; Although the amygdala seems to be essential to the formation and storage of fear memories, it might store only some aspects of the aversive event and facilitate the storage of more specific sensory aspects in cortical areas. We addressed the time course of amygdala and cortical activation in the context of odor fear conditioning in rats. Using high temporal resolution (1-min sampling) intracerebral microdialysis, we investigated the dynamics of glutamate and GABA fluctuations simultaneously in basolateral amygdala (BLA) and posterior piriform cortex (pPCx) during the course of the acquisition session, which consisted of six odor (conditioned stimulus)-footshock (unconditioned stimulus) pairings. In BLA, we observed a transient increase in amino acid concentrations following the first odor-shock pairing, after which concentrations returned to baseline levels or slightly below. In pPCx, transient increases were seen after each pairing and were also observed after the last odor-shock pairing, corresponding to the predicted times of anticipated trials. Furthermore, we observed that for the first pairing, the increase in BLA occurred earlier than the increase in pPCx. These data suggest that the amygdala is engaged early during acquisition and precedes the activation of the olfactory cortex, which is maintained until the end of the session. In addition, our data raise the challenging idea that the olfactory cortex might store certain aspects of fear conditioning related to the timing of the associations.
- Published
- 2009