ABSTRACT
The present study was aimed to investigate the electrophysiological characteristics of hippocampal postnatal early development mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in rats. Forty-eight Wistar rats were divided into postnatal 0.5-, 1-, 2- and 3-month groups (n = 12). Spontaneous excitatory postsynaptic currents (sEPSCs) and field excitatory postsynaptic potentials (fEPSPs) mediated by AMPA receptors were recorded to evaluate the changes in the intrinsic membrane properties of hippocampal CA1 pyramidal neurons by using patch-clamp and MED64 planar microelectrode array technique respectively. The results showed that, during the period of postnatal 0.5-3 months, some of the intrinsic membrane properties of hippocampal CA1 pyramidal neurons, such as the membrane capacitance (Cm) and the resting membrane potential (RMP), showed no significant changes, while the membrane input resistance (Rin) and the time constant (τ) of the cells were decreased significantly. The amplitude, frequency and kinetics (both rise and decay times) of sEPSCs were significantly increased during the period of postnatal 0.5-1 month, but they were all decreased during the period of postnatal 1-3 months. In addition, the range of evoked fEPSPs in hippocamal CA1 region was significantly expanded, but the fEPSP amplitudes were decreased significantly during the period of postnatal 0.5-3 months. Furthermore, the evoked fEPSPs could be significantly inhibited by extracellular application of the AMPA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). These results suggest that AMPA receptor may act as a major type of excitatory receptor to regulate synaptic transmission and connections during the early stage of hippocampal postnatal development, which promotes the development and functional maturation of hippocampus in rats.
ABSTRACT
Background Glaucoma is one of the leading causes of blindness worldwide;while the different types of glaucoma is vary from different region. Objective Present study was to survey the prevalence and types of glaucoma among peasants of Uigur adults in Kuche county and offer the basis for the prevent and treatment of glaucoma in Uigur nationanlity. Methods 4191 Uigur peasants aged 40 years or above were collected in Kuche county for the survey of prevalence and types of glaucoma by randomized cluster sampling in March and April of 2009. The subjects were grouped into 40-,50-,60- and ≥70 years groups according to the distribution of age. The disease history of glaucoma, regular eye examination, funds examination and measurement of the anterior chamber depth, gonioscope were performed in the all subjects. Darkroom prone test and mydriasis test were carried out in suspicious glaucomous patients. The depth of periphery anterior chamber was assessed based on van Herick' s criteria, and the width of chamber angle was graded based on Scheie' s method. The standardized training was performed. This survey approved by Xinjiang Medical Ethics Committee, all subjects signed the informed consent before the examination. Results 4191 of 4873 subjects finished all the examinations with the response rate 86%. All the subjects showed a good compliance. The prevalence of glaucoma was 3. 79% , and the prevalence of primary angle-closed glaucoma(PACG) .primary angle-open glaucoma (PAOG) and secondary glaucoma was 2.22% ,0.26% and 1. 31% respectively, showing a significant difference among the different types of glaucoma( P<0. 05). The prevalence of glaucoma was elevated with aging (χ2 - 116. 69 ,P<0. 05) and presented a high rate in male subjects compared with female ones(χ2 = 7. 34, P<0. 05 ). Bilateral blindness was found in 19.75% glaucoma peasants, in which 25.3% glaucoma peasants received anti-glaucoma surgery. The distribution of visual acuity of patients was of significant difference among different age groups(χ2 = 37. 69 ,P<0. 05 ) . Conclusions The prevalence of the glaucoma among Uigur peasants in Kuche county was higher than most area no matter inland or overseas. PACG still is the common type in those people.