Gómez-Chacón B, Morillas E, Gallo M
Department of Psychobiology, Institute of Neurosciences, Centre for Biomedical Research (CIBM), University of Granada, Campus Cartuja, Granada-18071, Spain.
Department of Psychobiology, Institute of Neurosciences, Centre for Biomedical Research (CIBM), University of Granada, Campus Cartuja, Granada-18071, Spain.
Behav Brain Res. 2015 Mar 15;281:245-9. doi: 10.1016/j.bbr.2014.12.020. Epub 2014 Dec 20.
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.
嗅周皮质（PRh）病理改变和化学感觉识别功能障碍是阿尔茨海默病的早期迹象。我们以c-Fos免疫反应性作为神经元活动的标志物，评估了正常衰老对风味识别记忆过程中PRh活性的影响。成年（5个月大）和老年（24个月大）雄性Wistar大鼠每天接触醋溶液，持续6天。行为评估表明，两个年龄组的表现相似，但老年大鼠对新事物的恐惧消退较慢。关于c-Fos免疫反应性，随着风味变得熟悉，在首次（新奇）、第二次（熟悉I）或第六次（熟悉II）接触风味溶液时，成年组和老年组饮用风味溶液期间发现PRh活性呈现相反的模式。成年大鼠在呈现新奇风味时PRh c-Fos阳性神经元的数量高于第二次和第六次呈现时，而老年大鼠在最后一次呈现熟悉风味时PRh c-Fos阳性神经元的数量高于第一次和第二次。结果表明，PRh的作用在衰老过程中发生变化，有助于区分神经退行性疾病引起的PRh功能障碍和正常衰老。
