Zhang Na, Zhang Jianfen, Du Songming, Ma Guansheng
Department of Nutrition and Food Hygiene, School of Public Health, Peking University, Beijing, China.
Laboratory of Toxicological Research and Risk Assessment for Food Safety, Peking University, Beijing, China.
Front Nutr. 2022 Sep 23;9:906088. doi: 10.3389/fnut.2022.906088. eCollection 2022.
The effects of dehydration and rehydration on brain regional density and homogeneity are unknown and have been infrequently studied. In this pilot self-control study, twelve participants aged 18-25 years were recruited and the brain was scanned using magnetic resonance imaging for three tests under different hydration statuses. In three tests, urine osmolality was determined to assess hydration status. Test 1 was conducted after 12 h of overnight fasting. Test 2 was conducted in a dehydration state induced by 36 h of water deprivation. Test 3 was conducted in a rehydration state, which was induced by 1.5 L of purified water supplementation. Compared with test 1, participants under the dehydration state in test 2 had higher cerebrospinal fluid density ( < 0.001). Compared with test 2, participants under the rehydration state in test 3 showed an extensive increase in gray matter density in widespread brain regions, mainly involving the left middle temporal gyrus, cuneus, right thalamus, left rolandic opercula, Brodmann area 39, right precentral, left postcentral gyrus, and cingulate gyrus ( < 0.001); a higher white matter density in the temporal lobe, sub-lobar, and sub-gyral areas; and a lower cerebrospinal fluid density ( < 0.001). The multimodal, multiscale neuroimaging marker of the human brain connection-the regional homogeneity (ReHo) index-was used for evaluating the connectivity of nodes in the brain. Compared with test 1, participants in test 2 had a lower ReHo value in the right amygdala, left occiput median, right lingual, opercula part of right inferior frontal gyrus, and right precuneus ( < 0.01). Compared with test 2, participants in test 3 had a higher ReHo value in the right amygdala, right lingual, opercula part of the right inferior frontal gyrus, and right precuneus ( < 0.01). Dehydration state increased cerebrospinal fluid density, decreased brain regional homogeneity. Rehydration state increased brain gray matter and white matter density widespreadly, and increased brain regional homogeneity.
脱水和补液对脑区密度及同质性的影响尚不清楚，且相关研究较少。在这项初步的自我对照研究中，招募了12名年龄在18至25岁之间的参与者，并在不同的水合状态下，使用磁共振成像对大脑进行了三次扫描测试。在这三次测试中，通过测定尿渗透压来评估水合状态。测试1在禁食12小时后进行。测试2在通过禁水36小时诱导的脱水状态下进行。测试3在通过补充1.5升纯净水诱导的补液状态下进行。与测试1相比，测试2中处于脱水状态的参与者脑脊液密度更高（<0.001）。与测试2相比，测试3中处于补液状态的参与者在广泛的脑区灰质密度有广泛增加，主要涉及左侧颞中回、楔叶、右侧丘脑、左侧中央沟盖、布罗德曼区39、右侧中央前回、左侧中央后回和扣带回（<0.001）；颞叶、脑叶下和脑回下区域的白质密度更高；脑脊液密度更低（<0.001）。使用人类脑连接的多模态、多尺度神经影像标记——局部一致性（ReHo）指数来评估大脑中节点的连通性。与测试1相比，测试2中的参与者在右侧杏仁核、左侧枕叶中部、右侧舌回、右侧额下回岛盖部和右侧楔前叶的ReHo值较低（<0.01）。与测试2相比，测试3中的参与者在右侧杏仁核、右侧舌回、右侧额下回岛盖部和右侧楔前叶的ReHo值较高（<0.01）。脱水状态增加了脑脊液密度，降低了脑区同质性。补液状态广泛增加了脑灰质和白质密度，并增加了脑区同质性。
