To explore the expression of brain-derived neurotrophic factor (BDNF) and specific receptor tyrosine kinase receptor B (TrkB) in the primary visual cortex of young and old cats, especially to reveal the age-related differences in the mediating mechanism of BDNF-TrkB signaling pathway in cats’ visual cortex and their possible effects on synaptic plasticity, Nissl staining was used to display neurons in each layer of cats’ primary visual cortex, and immunohistochemical ABC method was used to label BDNF and TrkB immunopositive cells in each layer of cats’ primary visual cortex. The BDNF and TrkB receptor immunoreactive neurons and non-neurons were observed and photographed. Their density and immunoreactive intensity were measured. Results showed that BDNF and TrkB were widely expressed in all layers of visual cortex in young and old cats. Compared with the young group, the density and intensity of BDNF and TrkB positive cells in each layer of primary visual cortex in the old group decreased significantly (P < 0.01). The findings indicate that the expression levels of BDNF and TrkB in the primary visual cortex of cats decrease with age, suggesting that the change of BDNF-TrkB signal pathway caused by the weakening of brain-derived neurotrophic factor activity may be one of the important reasons for the decline of visual function.
Chemical analysis of the aerial parts of Artemisia argyi H. Lév. & Vaniot led to the isolation of 6 lignans, including a new lignan glycoside, artemisiaside A, using various chromatographic techniques. Detailed spectroscopic (including 1D, 2D- nuclear magnetic resonance) and high resolution mass spectroscopy procedures, and electronic circular dichroism were used to ascertain the structural orientations of these compounds. The anti-inflammatory activities of compounds 1 to 6 were evaluated by measuring their inhibitory effects on lipopolysaccharide (LPS) -induced nitric oxide (NO) production in RAW264.7 LPS-activated macrophages. At 50 μM, compound 1 showed moderate anti-inflammatory activity with an inhibition rate of 61.2%.
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