title: Altered perirhinal cortex activity patterns during taste neophobia and their habituation in aged rats.
abstract: Perirhinal cortex (PRh) pathology and chemosensory identification dysfunction are early signs of Alzheimer's disease. We have assessed the impact of normal aging on PRh activity during flavor recognition memory using c-Fos immunoreactivity as a marker for neuronal activity. Adult (5-month-old) and aged (24-month-old) Wistar male rats were exposed to a vinegar solution on a daily basis for a period of six days. Behavioral assessment indicated similar performance in both age groups but suggested slower attenuation of neophobia in aged rats. Regarding c-Fos immunoreactivity, an opposite pattern of PRh activity was found in adult and aged groups drinking the flavor solution during the first (Novel), second (Familiar I) or sixth (Familiar II) exposure as the flavor became familiar. While adult rats exhibited a higher number of PRh c-Fos-positive neurons during the presentation of the novel flavor than during the second and sixth presentation, in aged rats the number of PRh c-Fos-positive neurons was higher during the presentation of the familiar flavor in the last session than in the first and second. The results suggest that the role of the PRh changes during aging and can help to dissociate PRh dysfuntions induced by neurodegenerative diseases and normal aging.
authors.affiliation: Department of Psychobiology, Institute of Neurosciences, Centre for Biomedical Research (CIBM), University of Granada, Campus Cartuja, Granada-18071, Spain. Electronic address: bgomezchacon@ugr.es.
authors.forename: B
authors.initials: B
authors.lastname: Gómez-Chacón
authors.affiliation: Department of Psychobiology, Institute of Neurosciences, Centre for Biomedical Research (CIBM), University of Granada, Campus Cartuja, Granada-18071, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Morillas
authors.affiliation: Department of Psychobiology, Institute of Neurosciences, Centre for Biomedical Research (CIBM), University of Granada, Campus Cartuja, Granada-18071, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Gallo
mesh_terms: D019342:Acetic Acid; D000375:Aging / Q000523:psychology*; D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D004327:Drinking Behavior / Q000502:physiology; D005106:Exploratory Behavior / Q000502:physiology*; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D008297:Male; D008568:Memory / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D021641:Recognition, Psychology / Q000502:physiology; D013649:Taste; D013997:Time Factors
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D019342:Acetic Acid
keywords: Aging; Attenuation of neophobia; Memory; Perirhinal cortex; Rat; Taste