Objective To explore the influence of gender and age on auditory startle reflex in healthy adults.Methods A total of 150 healthy volunteers (92 males and 58 females) aged from 18 to 60 years were recruited for this study.A modified startle reflex paradigm was adopted.Furthermore,gender-age differences on startle magnitude,habituation,perceived spatial co-location induced prepulse inhibition (PSC-PPI) and perceived spatial separation-induced prepulse inhibition (PSS-PPI) in healthy volunteers were analyzed.Results ① There was no significant difference in amplitude and habituation of startie reflex between males and females (F=0.29,P=0.593;F=1.57,P=0.212).PSC-PPI and PSS-PPI were significantly higher in males (PSC-PPI:(34.68± 20.81) ％,PSS-PPI:(44.56 ± 23.19) ％) than those in females (PSC-PPI:(23.11±22.43)％,PSS-PPI:(35.21±25.09)％) (F=9.48,P=0.002;F=4.76,P=0.031).② There was a negative correlation between startle magnitude and age (r=-0.29,P＜0.01),however,no obvious correlations between age and PSC-PPI or PSS-PPI as well as habituation were observed.③Bivariate analysis of variance showed that no interaction between gender and age was found to the indexes of startle reflex(F=0.71-1.36,all P＞0.05).Conclusions There are differences for gender and age in the indexes of startle reflex.In detail,age chiefly influences startle magnitude,while gender mainly affects the prepulse inhibition.

Objective:To explore differences of resting brain regional homogeneity (ReHo) between patients with major depressive disorder (MDD) and their siblings.Methods:From January to December 2013, the resting-state functional magnetic resonance imaging (fMRI) data of 87 patients with MDD and 21 healthy siblings were collected.DPABI v5.1 software was used to preprocess the resting-state fMRI data, and ReHo maps of each subject was obtained. A two-sample t-test was used to compare differences between the patients with MDD and their siblings in ReHo values throughout the brain. ReHo values within the significant brain regions were extracted out, and used to calculate Spearman correlation with the total score of 17-items Hamilton depression rating scale(HAMD-17) in the patients with MDD and their siblings respectively.The software of SPSS 20.0 was used for statistical analysis. Results:The patients with MDD exhibited lower ReHo values in the precuneus extending to the posterior cingulate cortex (PCu/PCC) compared with their siblings (cluster-size=126 voxel, cluster-level PFDR=0.033; MNI: x=-4, y=-58, z=38, t=4.30). ReHo values of the PCu/PCC in patient with MDD were positively correlated with the severity of depressive symptoms ( r=0.255, P=0.021). Conclusion:Compared with the siblings, local brain activity of the PCu/PCC in the patients with MDD was decreased, and related to the severity of depressive symptoms. It is helpful to further reveal the intrinsic neural mechanism of MDD.

The research on clinical high-risk for psychosis is a hotspot in recent years, which is helpful to the early identification and early intervention of psychosis. White matter fibers are the important structural basis of complex information transmission function among brain regions. The existing literatures show that there are abnormal white matter microstructures in individuals at clinical high-risk for psychosis, which is related to their clinical symptoms and social function. Diffusion tensor imaging is the only non-invasive technique to study the microstructure of brain white matter. This paper reviews the existing evidences of microstructural abnormalities of white matter at clinical high-risk for psychosis by diffusion tensor imaging, in order to comprehensively analyze the potential neurobiomarkers in the early stage of the disease and the pathological evolution characteristics in the development of the disease.