Brain derived neurotrophic factor keeps pattern electroretinogram from dropping after superior colliculus lesion in mice.

AIM: To determine if brain-derived neurotrophic factor (BDNF) could offer protention to retinal ganglion cells following a superior colliculus (SC) lesion in mice using pattern electroretinogram (PERG) and optical coherence tomography (OCT) as a measures of ganglion cell response and retinal health. METHODS: Seven C57BL/6J mice with BDNF protection were tested with PERG and OCT before and after SC lesions. RESULTS: Compared with baseline PERG, the amplitude of PERG decreased 11.7% after SC lesions, but not significantly (P>0.05). Through fast Fourier transform (FFT) analysis of the PERGs before and after SC lesions, it was found that dominant frequency of PERGs stayed unchanged, suggesting that the ganglion cells of the retina remained relatively healthy inspite of damage to the ends of the ganglion cell axons. Also, OCT showed no changes in retinal thickness after lesions. CONCLUSION: It was concluded that BDNF is essential component of normal retinal and helps retina keeping normal function. While retina lack of BDNF, ex vivo resource of BDNF provides protection to the sick retina. It implies that BDNF is a kind therapeutic neurotrophic factor to retina neurodegeneration diseases, such as glaucoma, age related macular degeneration.

[Genetic structure of wild Macrobrachium nipponense populations in Taihu Lake based on microsatellite analysis].

By using eight highly polymorphic microsatellite DNA loci, this paper analyzed the genetic structure of wild Macrobrachium nipponense populations in Taihu Lake. For the 15 M. nipponense populations in the Lake, there were at least three of the loci presenting heterozygosity deficiency and obvious deviation from Hardy-Weinberg equilibrium after Bonferroni correction. The observed heterozygosity values of the 15 populations were all above 0. 683, displaying a high genetic diversity, but the diversity varied obviously with site. For example, the genetic diversity of the eastern and southern populations at Dukou and Luxiang was higher than that of the western and northern populations at Huazhuang and Yangzhu. For the 15 populations, parts of the loci showed heterozygote excess and departure from mutation-drift equilibrium, suggesting that the population structure had experienced bottleneck effect and the population amount had declined. The AMOVA analysis across all the populations and loci showed that the genetic divergence among the 15 populations was at a lower level (F(ST) = 0.011 ). 98.9% of the genetic variation came from intra-population, and 1.1% came from inter-population, suggesting that all the M. nipponense populations in the Lake could be protected and managed as a single unit in genetic resource. However, the genetic distance between Huazhuang and Wutangmen populations reached 0.206, being close to the delimitation of species identification. Further studies would be needed for the sustainable utilization of the genetic resource of M. nipponense in Taihu Lake.

[Characteristics of the action potentials and the underlying ionic mechanisms in the cardiomyocytes from rabbit pulmonary vein sleeves].

To investigate the characteristics of action potentials and their ionic mechanism in cardiomyocytes from rabbit pulmonary vein sleeves (PVC), and to compare them with those in left atrial cardiomyocytes (LAC), the technique of whole-cell patch clamp was applied. We used current-clamp technique to record action potentials, and voltage-clamp technique to record ionic currents. PVC had longer action potential duration (APD) than LAC, and therefore a second plateau response could be induced easily, suggesting a strong tendency of early afterdepolarization (EAD) genesis in PVC. Non-selective cation current (I(NSCC)) was first recorded in both LAC and PVC. This I(NSCC)was permeable to K(+), Na(+) and Cs(+), sensitive to GdCl3 but not sensitive to 4-AP. The current densities of inward rectifier potassium current (I(K1)), transient outward potassium current (I(To)) and I(NSCC) were all significantly less in PVC than those in LAC. These differences in repolarizing ionic currents between PVC and LAC form a basis of the differences in their action potential configurations and might be an important ionic mechanism of the arrhythmogenic characteristics of pulmonary vein muscle sleeves.