Bondan Eduardo Fernandes, Cardoso Carolina Vieira, Martins Maria de Fátima Monteiro, Otton Rosemari
Universidade Paulista, Programa de Pós-Graduação em Patologia Ambiental e Experimental, São Paulo SP, Brasil.
Universidade Cruzeiro do Sul, Escola de Medicina Veterinária, São Paulo SP, Brasil.
Arq Neuropsiquiatr. 2019 Sep 23;77(9):601-608. doi: 10.1590/0004-282X20190091. eCollection 2019.
Hypothalamic inflammation and glial fibrillary acidic protein (GFAP) overexpression in astrocytes are well described in obese animals, as are some cognitive and memory deficits. As the hippocampus plays important roles in the consolidation of information, this investigation aimed to observe the memory function and the astrocyte expression of GFAP in the hippocampus of rats that received either a hypercaloric or a normocaloric diet.
Adult male Wistar rats received a high-fat (cafeteria) or a standard diet for 60 days. On the 61st day, the rats were submitted to the novel object recognition (NOR) test at three and 24 hours after the first contact with objects, to assess short-term and long-term memory, respectively. Thereafter, the rats were euthanized and their brains were collected for GFAP immunohistochemical investigation in the hippocampus (CA1, CA2, CA3 areas) and hypothalamus (periventricular and arcuate nuclei). Astrocytic reactivity was assessed by morphometry. Different white adipose tissue depots and brown adipose tissue were weighed to calculate the adiposity index.
The hypercaloric diet increased body weight gain, adiposity index, white adipose tissue weight (epididymal, subcutaneous and retroperitoneal) and brown adipose tissue weight. Rats fed with the hypercaloric diet showed short-term and long-term memory impairments in the NOR test, as well as increased GFAP expression in astrocytes from all analyzed hypothalamic and hippocampal areas.
This astrogliosis suggests that the neuroinflammatory response also occurs in the hippocampus and may be involved in the memory losses observed in obese/overweight animals.
肥胖动物中，下丘脑炎症以及星形胶质细胞中胶质纤维酸性蛋白（GFAP）的过表达已被充分描述，一些认知和记忆缺陷也是如此。由于海马体在信息巩固中发挥重要作用，本研究旨在观察接受高热量或正常热量饮食的大鼠海马体中的记忆功能以及GFAP的星形胶质细胞表达。
成年雄性Wistar大鼠接受高脂（自助餐式）或标准饮食60天。在第61天，大鼠在首次接触物体后3小时和24小时分别接受新物体识别（NOR）测试，以分别评估短期和长期记忆。此后，将大鼠安乐死并收集其大脑，用于海马体（CA1、CA2、CA3区）和下丘脑（室周核和弓状核）的GFAP免疫组织化学研究。通过形态计量学评估星形胶质细胞反应性。称量不同的白色脂肪组织库和棕色脂肪组织以计算肥胖指数。
高热量饮食增加了体重增加、肥胖指数、白色脂肪组织重量（附睾、皮下和腹膜后）和棕色脂肪组织重量。喂食高热量饮食的大鼠在NOR测试中表现出短期和长期记忆障碍，以及所有分析的下丘脑和海马体区域中星形胶质细胞的GFAP表达增加。
这种星形胶质细胞增生表明神经炎症反应也发生在海马体中，并且可能与肥胖/超重动物中观察到的记忆丧失有关。
