title: Spatial memory extinction: a c-Fos protein mapping study.
abstract: While the neuronal basis of spatial memory consolidation has been thoroughly studied, the substrates mediating the process of extinction remain largely unknown. This study aimed to evaluate the functional contribution of selected brain regions during the extinction of a previously acquired spatial memory task in the Morris water maze. For that purpose, we used adult male Wistar rats trained in a spatial reference memory task. Learning-related changes in c-Fos inmunoreactive cells after training were evaluated in cortical and subcortical regions. Results show that removal of the hidden platform in the water maze induced extinction of the previously reinforced escape behavior after 16 trials, without spontaneous recovery 24h later. Extinction was related with significantly higher numbers of c-Fos positive nuclei in amygdala nuclei and prefrontal cortex. On the other hand, the lateral mammillary bodies showed higher number of c-Fos positive cells than the control group. Therefore, in contrast with the results obtained in studies of classical conditioning, we show the involvement of diencephalic structures mediating this kind of learning. In summary, our findings suggest that medial prefrontal cortex, the amygdala complex and diencephalic structures like the lateral mammillary nuclei are relevant for the extinction of spatial memory.
authors: Laboratory of Neuroscience, Department of Psychology, Instituto de Neurociencias del Principado de Asturias (INEUROPA), University of Oviedo, Plaza Feijóo s/n, 33003 Oviedo, Spain.
authors: M
authors: M
authors: Méndez-Couz
authors: Laboratory of Neuroscience, Department of Psychology, Instituto de Neurociencias del Principado de Asturias (INEUROPA), University of Oviedo, Plaza Feijóo s/n, 33003 Oviedo, Spain. Electronic address: conejonelida@uniovi.es.
authors: N M
authors: NM
authors: Conejo
authors: Methodology Area, Department of Psychology, Instituto de Neurociencias del Principado de Asturias (INEUROPA), University of Oviedo, Plaza Feijóo s/n, 33003 Oviedo, Spain.
authors: G
authors: G
authors: Vallejo
authors: Laboratory of Neuroscience, Department of Psychology, Instituto de Neurociencias del Principado de Asturias (INEUROPA), University of Oviedo, Plaza Feijóo s/n, 33003 Oviedo, Spain.
authors: J L
authors: JL
authors: Arias
mesh_terms: D000679:Amygdala / Q000502:physiology; D000818:Animals; D001921:Brain / Q000502:physiology*; D002452:Cell Count; D002467:Cell Nucleus / Q000378:metabolism; D004027:Diencephalon / Q000502:physiology; D005108:Extinction, Psychological / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology; D007150:Immunohistochemistry; D008297:Male; D008326:Mammillary Bodies / Q000502:physiology; D018782:Maze Learning / Q000502:physiology*; D008568:Memory / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013028:Space Perception / Q000502:physiology*; D013647:Task Performance and Analysis
chemical_list: D016760:Proto-Oncogene Proteins c-fos
keywords: ANOVA; Ba; CA1d; CA1v; CA3d; CA3v; CG; CS; Ce; DGd; DGv; EX; EXR; Extinction; FWE; IEGs; IL; LM; MM; MWM; Mammillary body; Me; Morris water maze; N; PBS; PBS solution containing triton; PBS-T; PL; Prefrontal cortex; RSA; RSG; Rat; Spatial memory; US; amygdala basal nucleus; amygdala central nucleus; amygdala medial nucleus; analysis of variance; c-Fos; cingulate cortex; conditioned stimulus; control naïve group; cornu ammonis 1 of the dorsal hippocampus; cornu ammonis 1 of the ventral hippocampus; cornu ammonis 3 of the dorsal hippocampus; cornu ammonis 3 of the ventral hippocampus; degrees of freedom; dentate gyrus of the dorsal hippocampus; dentate gyrus of the ventral hippocampus; df; extinction group; extinction plus retention probe group; familywise error rate; immediate early expression gene; infralimbic cortex; mammillary bodies lateral nucleus; mammillary bodies medial nucleus; phosphate-buffered saline; prelimbic cortex; retrosplenial agranular cortex; retrosplenial granular cortex; unconditioned stimulus