ObjectiveTo investigate the effect of neuregulin1β (NRG1β) on the learning memory abilities and the neuronal apoptosis and the expressions of nuclear factor kappa B (NFκB) in experimental Alzheimer's disease model in rats induced with beta-amyloid protein1-40 (Aβ1-40) injection.To explore the mechanisms of NRG in improving the capabilities of learning and memory.MethodsThirty adult healthy male wistar rats were randomly divided into control group (n =10),model group (n =10) and treated group (n =10).Alzheimer's disease models were established by stereotactically injecting Aβ1-40 into the left lateral ventricle,and treated by injecting NRG1β(0.3 μg · kg-1 ) into the right lateral ventricle.The learning and memory abilities of rats were evaluated with Y-electric maze before the experiment and 7 days after making Alzheimer's disease models and 14 days after treatment.HE staining was used to observe the structure of hippocampal neurons.The neuronal apoptosis of hippocampus was investigated by TUNEL assay.The expressions of NFκB in hippocampal neurons were determined with immunohistochemistry technique.ResultsCompared with control group (57.50 ± 1.58,7.20 ±1.03 ),the model group rats ( 59.50 ± 2.79,7.50 ± 1.08 ) showed low cognitive ability ( t =20.36,5.28,P ＜0.05 ),the hippocampal pyramidal cells of rats in the model group were sparse and disturbed pyramidal cells,noticeable neuron loss.The number of neuronal apoptosis and the expressions of NFκB increased significantly than those in control group (P＜0.05).Compared with model group (79.10 ±4.12,4.40 ±0.69),NRG1β strikingly improved cognitive ability ( 67.70 ± 4.90,5.80 ± 0.63 ) and normal cell structure ( t =5.63,4.69,P ＜ 0.05 ).The expressions of NFκB (25.90 ± 6.67 ) reduced while the number of neuronal apoptosis ( 23.50 ± 3.89 ) decreased markablely than those ( 41.10 ±7.95,29.30 ± 7.24) in model group(t =4.63,2.23,P ＜ 0.05).ConclusionNRG1β might decrease the neuronal apoptosis by inhibiting NFκB expressions,so that to improve the learning and memory abilities of experimental dementia rats.

Objective To investigate the habits of eye rubbing and sleeping posture of patients with keratoconus(KC)and analyze the correlation of the onset and severity of KC with eye rubbing and sleeping posture.Methods In this retrospective case-control study,KC patients who received diagnosis and treatment in the Eye Hospital of Shandong First Medical University from January 2018 to June 2022 were collected as the KC group,and myopia patients with matching ages and sexes who visited our hospital from February to June 2022 were recruited as the control group.All patients were inves-tigated by questionnaire and the details of eye rubbing,sleeping posture and related habits were recorded.According to the severity of the disease(corneal curvature),KC patients were divided into different stages,and the eye rubbing and sleep-ing posture of KC patients in different stages were compared.Results In this study,406 KC patients and 394 myopia pa-tients were included.It was found that 67.98％of KC patients and 24.87％of myopia patients rubbed their eyes,with a sig-nificant difference(P＜0.001);45.32％of KC patients and 24.87％of myopia patients were accustomed to sleeping on their side or stomach,with a significant difference(P＜0.001).The multivariate binary logistic regression analysis indica-ted that the following variables showed significant differences:patients with eyes at the later stages(steeper eyes)were more likely to rub eyes[odds ratio(OR)=3.547,95％CI:2.02-6.24,P＜0.001],sleep on side or stomach(OR=10.725,95％CI:5.77-19.94,P＜0.001),and turn head to the steeper eye when sleeping(OR=12.171,95％CI:7.23-20.49,P＜0.001).The statistical analysis demonstrated that the proportion of KC patients at the IV stage who were habitu-ated to rub their steeper eyes and turn their heads to the steeper eyes when sleeping was significantly higher than that of pa-tients at stages Ⅰ to Ⅲ(all P＜0.001).Conclusion Eye rubbing and sleeping on the side or stomach are risk factors for the onset of KC and are related to the severity of the disease.