Leptin receptor of the hind brain nuclei is involved in the conditioned taste preference of rats

Objective: Conditioned taste preference(CTP) is a taste learning reflex by which an animal learns to prefer a substance which tastes not well and has been studied with much interest in recent years. However, the neural substrates of CTP are less known. This study aimed to determine the possible neural pathways of CTP and whether serum leptin level and the leptin receptor(OB-Rb) in the hind brain are involved following CTP formation. Methods: We established CTP of quinine in rats with a 2-bottle preference test. The serum leptin concentrations were detected, the expression of c-fos in the rat brain was tested to determine the nuclei in relation with establishment of CTP. Finally, the OB-Rb m RNA expression was examined by RT-q PCR assay in parabrachial nucleus(PBN) and the nucleus of the solitary tract(NST) of the hind brain. Results: Compared with control group, the level of serum leptin was higher in the CTP group(4.58 ± 0.52 vs 1.67 ± 0.25 μg/L, P<0. 01); increased c-fos positive cells were found in the anterior hypothalamus(AH, 221.75 ± 4.96 vs. 178.50±6.63 cells/mm^2, P<0.05), the basal lateral amygdala(BLA, 70.75±6.17 vs 56.50±3.62 cells/mm^2, P<0.05) and the nucleus of the solitary tract(NST, 41.25±1.32 vs 32.50±1.02 cells/mm^2, P<0.05). But in ventromedial nucleus of the hypothalamus(VMH, 20.75±2.73 vs 38.5±1.54 per 1 mm^2, P<005), PBN(21.50 ±2.24 vs 36.25±1.49 cells/mm^2, P<0.05) and the central nucleus of the amygdala(Ce A, 22.25±1.53 vs 35.50 ±2.11 cells/mm^2, P<0.05), the number of c-fos positive cells was decreased in the CTP group. In addition, we found OB-Rb m RNA expression in PBN of CTP group rats was higher than that of control group(0.95±0.055 vs 0.57± 0.034, P<0.05), while there was no significant difference of OB-Rb m RNA expression in NST between the two groups. Conclusion: Nuclei AH, BLA, NST, VMH, PBN and Ce A participate in the formation of CTP. Leptin and its receptor in PBN may be involved in the formation and maintenance of CTP.

Distribution of IOP and its relationship with refractive error and other factors:the Anyang University Students Eye Study

AIM:To investigate the distribution of intraocular pressure(IOP)and its relationship with refractive error and other factors in university students from Anyang,China.METHODS:A university-based study was conducted.Subjects were invited to complete ophthalmic examinations,including visual acuity,noncontact tonometr y(NCT),cycloplegic autorefraction,and ocular biometry.Univariable and multivariable analyses were used to evaluate the associations between IOP and other factors.Only data from right eyes were used in analysis.RESULTS:A total of 7720 subjects aged 16 to 26 years old were included,and 2834(36.4%)of the participants were male.The mean IOP of the right eye for all subjects was 15.52±3.20 mm Hg(95%CI:15.45,15.59).Using multivariate linear regression analysis,IOP was found to correlate significantly with younger age(P<0.001;standardized regression coefficientβ,-0.061;regression coefficientβ,-0.139;95%CI:-0.18,-0.09),higher myopic refractive error(P=0.044;standardizedβ,-0.060;regression coefficientβ,-0.770;95%CI:-0.15,-0.002),higher central corneal thickness(P<0.001;standardizedβ,0.450;regression coefficientβ,0.044;95%CI:0.04,0.05),and shorter axial length(AL;P<0.001;standardizedβ,-0.061;regression coefficientβ,-0.163;95%CI:-0.25,-0.07).CONCLUSION:This study described the normal distribution of IOP.In Chinese university students aged 16-26 y,higherIOP is associated with younger age,higher myopic refractive error,higher thickness of the central cornea,and shorter AL.

Design, methodology, and preliminary results of the follow-up of a population-based cohort study in rural area of northern China:Handan Eye Study

Background:Handan Eye Study (HES),a large population-based cohort study in rural area of northern China,was one of the few studies focusing on the major eye diseases of rural Chinese population.The aim of this study was to introduce the design,methodology and to assess the data quality of the follow-up phase of HES.Methods:All participants were recruited in Yongnian county of Handan city between 2012 and 2013.Main outcomes were measured by visual quality scales and ocular examinations.We performed the Chi-square test to make comparison of categorical data among groups,One-way analysis of variance and Kruskal-Wallis test was applied to make comparison of continuous data among groups,a post-hoc test was done to make further pairwise comparison.Inter-class correlation coefficients (ICCs) and Kappa coefficients were used to evaluate the consistency between different operators.Logistic regression was used to explore the influence factors of death,odds ratio (OR) and 95% confidence interval (CI) were used to estimate the effect size of each influence factor.Results:The follow-up rate was 85.3%.Subjects were classified into three groups:the follow-up group (n =5394),the loss to follow-up group (n =929),and the dead group (n =507),comparison of their baseline information was done.Compared with the other two groups,age of the dead group (66.52 ± 10.31 years) was the oldest (Z =651.293,P < 0.001),male proportion was the highest (59.0 %)(x2 =42.351,P < 0.001),only 65.9 % of the dead finished middle school education (Z =205.354,P < 0.001).The marriage percentage,body mass index (BMI),best-corrected visual acuity (BCVA),and intra-ocular pressure of the dead group was the lowest either.Spherical equivalent error (SER) of the dead group was the highest.Besides,history of smoking,hypertension,diabetes,and heart disease were more common in the dead group.Multivariate analysis showed that age (OR =1.901,95% CI:1.074-1.108),gender (OR =0.317,95% CI:0.224-0.448),and BCVA (OR =0.282,95% CI:0.158-0.503) were associated with death.While between the follow-up group and the loss to follow-up group,there was only difference on age,gender,BMI,systolic blood pressure and SER.The Cronbach coefficients of all scales used in the follow-up were ≥0.63 and the cumulative variances were ≥0.61,indicating good reliability and validity.The ICCs and Kappa coefficients between different operators were ≥0.69.Conclusions:HES has a high follow-up rate and a low risk of loss to follow-up bias.Age,gender,and BCVA are influence factors of death.Specifically,male subjects are at a higher risk of death than female,age is a risk factor of death while BCVA is a protective factor for death.