Peremans Kathelijne, Audenaert Kurt, Blanckaert Peter, Jacobs Filip, Coopman Frank, Verschooten Francis, Van Bree Henri, Van Heeringen Cornelis, Mertens John, Slegers Guido, Dierckx Rudi
Department of Medical Imaging, Faculty of Veterinary Medicine, Ghent University Salisburylaan 133, B-9820 Merelbeke, Belgium.
Prog Neuropsychopharmacol Biol Psychiatry. 2002 Dec;26(7-8):1393-404. doi: 10.1016/s0278-5846(02)00306-8.
Normal aging is associated with a decrease in number and size of neurons, loss of synapses and neuronal branching and with a reduced functioning neurotransmitter systems, such as the serotonergic system. These structural and functional alterations have important impact on the behavioural, cognitive and affective status of the individual. With the introduction of functional brain imaging in veterinary medicine, the canine brain can be examined in vivo, evaluating changes in perfusion, metabolism and neurotransmitter systems. Since cognitive decline is recognised in the aging dog, it was our aim to investigate whether age related changes concerning cerebral perfusion and binding index of the selective 5-HT2A receptor ligand 123I-5-I-R91150 could be found in the canine brain. A group of twelve normal, aging dogs, older than 96 months, was compared to a normal reference group (n = 12), younger than 96 months. SPET images were obtained, using the radiopharmaceutical 99mTc-N,N''-1,2-ethylene-diylbis-L-cysteine diethylester dihydrochloride (99mTc-ECD) for evaluation of the regional perfusion and the selective radioligand 123I-5-I-R91150 for visualization of the 5-HT2A receptor. Regional decrease of cerebral blood-flow was noted in the fronto- and temporocortical area and in the subcortical region. Age was negatively correlated with perfusion in the left and right fronto-cortical region. The binding index of the neuroreceptor radioligand was decreased in the fronto-cortical region, with a significant negative correlation with age in the right fronto-cortical area. No correlation was found between alteration of perfusion and binding index of the receptor ligand, suggesting that age related perfusion differences do not influence the binding of this radioligand. These results suggest that age related effects should be considered in functional canine brain imaging.
正常衰老与神经元数量和大小的减少、突触和神经元分支的丧失以及神经递质系统(如血清素能系统)功能的降低有关。这些结构和功能的改变对个体的行为、认知和情感状态有重要影响。随着功能性脑成像技术在兽医学中的引入,可以对犬脑进行活体检查,评估灌注、代谢和神经递质系统的变化。由于老龄犬存在认知衰退,我们的目的是研究在犬脑中是否能发现与年龄相关的脑灌注变化以及选择性5-HT2A受体配体123I-5-I-R91150的结合指数变化。将一组12只年龄超过96个月的正常老龄犬与一个年龄小于96个月的正常参照组(n = 12)进行比较。使用放射性药物99mTc-N,N''-1,2-乙二基双-L-半胱氨酸二乙酯二盐酸盐(99mTc-ECD)获得单光子发射计算机断层扫描(SPET)图像,以评估区域灌注,并使用选择性放射性配体123I-5-I-R91150来显示5-HT2A受体。在额叶和颞叶皮质区域以及皮质下区域发现脑血流量有区域性减少。年龄与左右额叶皮质区域的灌注呈负相关。神经受体放射性配体的结合指数在额叶皮质区域降低,在右侧额叶皮质区域与年龄呈显著负相关。未发现灌注改变与受体配体结合指数之间存在相关性,这表明与年龄相关的灌注差异不会影响这种放射性配体的结合。这些结果表明,在犬脑功能成像中应考虑与年龄相关的影响。