Objective:To investigate the changes in structural and functional connectivity of different hippocampal subregions in courses of Alzheimer's disease (AD).Methods:One hundred and seventeen subjects from Sino Longitudinal Study on Cognitive Decline (SILCODE) were chosen; their cognitive functions were assessed using neuropsychological tests, and brain beta-amyloid (Aβ) levels were measured using PET-MRI. These patients were divided into group of normal cognitive function and negative Aβ ( n=68), group of normal cognitive function and positive Aβ ( n=29), and group of cognitive impairment and positive Aβ ( n=20); neuropsychological characteristics and changes in volume, structural connectivity and functional connectivity of hippocampal subareas were compared among the 3 groups. Results:Compared with group of normal cognitive function and negative Aβ and group of normal cognitive function and positive Aβ, group of cognitive impairment and positive Aβ had significantly decreased scores of Mini-mental State Examination (MMSE), Montreal Cognitive Assessment-Basic Version (MoCA-B), Auditory Verbal Learning Test (AVLT)-Short-term Delayed Recall (SR), AVLT-Long-term Delayed Recall (LR), Animal Fluency Test (AFT) and Boston Naming Test (BNT), and statistically increased Shape Trails Test B (STT-B) scores ( P<0.05). Compared with group of normal cognitive function and negative Aβ and group of normal cognitive function and positive Aβ, group of cognitive impairment and positive Aβ had significantly decreased volumes of the left and right hippocampal CA1, CA2, CA3, dentate gyrus (DG), entolorhinal cortex (EC) and inferior support area (Sub, P<0.05). Compared with group of normal cognitive function and negative Aβ, group of normal cognitive function and positive Aβ had increased or decreased structural connectivity, and almost all increased functional connectivity of each hippocampal subregion; compared with group of normal cognitive function and negative Aβ, group of cognitive impairment and positive Aβ had almost all increased structural connectivity, and almost all decreased functional connectivity of each hippocampal subregion. Conclusion:Changes in gray matter volume and structural and functional connectivity in various hippocampal subregions are different in courses of AD.

Objective:To investigate the effect of Shentai Tea Polyphenols on memory and its underlying mechanism in healthy elderly adults.Methods:According to the randomized, double blind and placebo-controlled prospective experimental design, 240 healthy middle-aged or elderly subjects with normal objective cognition were recruited in our hospital from April to December 2019 through advertising, and they were randomly divided into an experimental group ( n=120) and a control group ( n=120). Oral administration of Shentai Tea Polyphenols or placebo capsules (lasting for 90 d, 2 times/d, 2 capsules/time) was given to subjects in the two groups. The neuropsychological scale scores and near-infrared brain imaging data of all subjects were collected before and after intervention, and the mean time from baseline data collection before intervention to follow-up data collection after medication was controlled within 6 months. Results:In patients from the experimental group, as compared with those before intervention, scores of delayed recall and recognition memory in the auditory verbal learning test (Huashan version) and Boston naming test, scores of Montreal cognitive assessment scale (basis version) were significantly higher, and scores of Hamilton anxiety scale, shape trails test A and rapid-eye-movement sleep behavior disorder screening questionnaire were significantly lower after intervention ( P<0.05); however, only scores of delayed recall in the auditory verbal learning test (Huashan version) were significantly increased in the control group ( P<0.05). A total of 23 pairs of differences of brain function connection before and after intervention in the experimental group were significantly higher than those in the control group ( P<0.05), mainly involving the function connection of forehead peak network (FPN), and function connection of FPN-default network, function connection of FPN-somatosensory movement network, function connection of FPN-dorsal attention network and function connection of FPN-visual network, as well as the function connection of default network and somatosensory movement network. Conclusion:Shentai Tea Polyphenols can improve cognitive performances including memory, language and executive function, anxiety mood and sleep quality in healthy middle aged or elderly subjects by affecting the functional connections of the networks in the brain.