Kim Jin Su, Lee Hae-June, Lee Seonhwa, Lee Ho Sun, Jeong Ye Ji, Son Yeonghoon, Kim Jung Min, Lee Yong Jin, Park Min-Hyun
Division of RI Application, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea.
Radiological and Medico-Oncological Sciences, University of Science and Technology, Seoul, South Korea.
Front Neurosci. 2020 Aug 13;14:843. doi: 10.3389/fnins.2020.00843. eCollection 2020.
The study of cognitive impairment associated with hearing loss has recently garnered considerable interest. Epidemiological data have demonstrated that hearing loss is a risk factor for cognitive decline as a result of aging. However, no previous study has examined the effect of hearing loss in patients with cognitive problems such as Alzheimer's disease. Therefore, we investigated the effect of conductive hearing loss in an Alzheimer's mouse model. Positron emission tomography (PET) and magnetic resonance imaging (MRI) were used to evaluate changes in glucose metabolism and gray matter concentrations in the 5xFAD Alzheimer's Disease (AD) transgenic mouse model with and without conductive hearing loss (HL). Conductive hearing loss was induced using chronic perforation of the tympanic membrane. Behavioral data from the Y-maze and passive avoidance tests revealed greater memory deficits in the AD with HL (AD-HL) group than in the AD group. Following induction of hearing loss, lower cerebral glucose metabolism in the frontal association cortex was observed in the AD-HL group than in the AD group. Although lower glucose metabolism in the hippocampus and cerebellum was found in the AD-HL group than in the AD group at 3 months, the gray matter concentrations in these regions were not significantly different between the groups. Furthermore, the gray matter concentrations in the simple lobule, cingulate/retrosplenial cortex, substantia nigra, retrosigmoid nucleus, medial geniculate nucleus, and anterior pretectal nucleus at 7 months were significantly lower in the AD-HL group than in the AD group. Taken together, these results indicate that even partial hearing loss can aggravate memory impairment in Alzheimer's disease.
近期，与听力损失相关的认知障碍研究引发了广泛关注。流行病学数据表明，听力损失是衰老导致认知衰退的一个风险因素。然而，此前尚无研究探讨听力损失对患有诸如阿尔茨海默病等认知问题患者的影响。因此，我们在阿尔茨海默病小鼠模型中研究了传导性听力损失的影响。使用正电子发射断层扫描（PET）和磁共振成像（MRI）来评估在有和没有传导性听力损失（HL）的5xFAD阿尔茨海默病（AD）转基因小鼠模型中葡萄糖代谢和灰质浓度的变化。通过鼓膜慢性穿孔诱导传导性听力损失。Y迷宫和被动回避试验的行为数据显示，与AD组相比，伴有HL的AD（AD-HL）组存在更严重的记忆缺陷。在诱导听力损失后，观察到AD-HL组额叶联合皮质的脑葡萄糖代谢低于AD组。虽然在3个月时发现AD-HL组海马体和小脑的葡萄糖代谢低于AD组，但两组在这些区域的灰质浓度没有显著差异。此外，在7个月时，AD-HL组简单小叶、扣带/ retrosplenial皮质、黑质、乙状结肠后核、内侧膝状体核和前顶盖前核的灰质浓度显著低于AD组。综上所述，这些结果表明，即使是部分听力损失也会加重阿尔茨海默病的记忆障碍。
