Effects of prolonged selenium deficiency on synaptic structures in CA3 area of hippocampus in the third generation rats / 中华病理学杂志

<p><b>OBJECTIVE</b>The relationship between selenium deficiency and the changes of synaptic structure in the CA3 area of hippocampus were studied in the third generation rats.</p><p><b>METHODS</b>A selenium deficiency model was established by feeding rats with selenium-deficient food. The rats were divided into 4 groups: control (Se+I+), selenium deficiency (Se-I+), iodine deficiency (Se+I-), and both deficient group (Se-I-). The hippocampuses were dissected from the third generation rats on the 21st gestational day and the ultrastructural features of hippocampal synapses were observed with electron microscope. The length of active zone, synaptic curvatures, post-synaptic density (PSD) and synaptic cleft were quantitatively described.</p><p><b>RESULTS</b>Compared with the control, the length of active zone and the thickness of PSD were significantly decreased in Se-I+, Se+I- and Se-I- groups [(261.7 +/- 50.1) nm, (286.7 +/- 41.6) nm and (220.8 +/- 61.6) nm contrast to (312.4 +/- 47.7) nm, P < 0.01], so were the synaptic curvatures in Se-I+, Se+I- and Se-I- groups [(22.9 +/- 6.3) nm, (27.5 +/- 8.6) nm and (25.2 +/- 6.5) nm contrast to (48.1 +/- 12.3) nm, P < 0.01]; the width of synaptic cleft were also decreased significantly in Se-I- [(11.1 +/- 3.3) nm contrast to (16.1 +/- 4.0) nm, P < 0.01].</p><p><b>CONCLUSION</b>Selenium deficiency might cause changes of neuronal functions at the synaptic level, and furthermore, affect learning and memory.</p>

Effects of selenium and B-27 supplements on viability and differentiation of neural stem cell in newborn rat / 中华预防医学杂志

<p><b>OBJECTIVE</b>To assess how trace element selenium and B27 supplements affect the neural stem cell (NSc) differentiation in vitro.</p><p><b>METHODS</b>The development and differentiation of NSc from the newborn rat were observed with primary culture and subculture during treating by sodium-selenite, and selenium-methyl-cysteine (SMC). The immunocytochemistry techniques were used to identify the NSc and mature protein expression with neuron marker beta-tubulin, astrocyte marker GFAP, and oligodendrocyte marker CNPase. The neurosphere morphology and neurite outgrowth were observed.</p><p><b>RESULTS</b>Adding the complete B-27 serum-free supplement, Selenium could promote the neurosphere viability, development and differentiation. Without selenium and B-27, neurosphere could not survive and differentiate. Without B-27 in the medium but there containing selenium, the neurosphere could promote the viability and development into neuron, astrocyte and oligodendrocyte, as compared with the no-containing B-27 and selenium groups, these differentiated cells might have more quantity, more branches and better morphological nerve net. The count of the neuron, astrocyte and oligodendrocyte was 11.2/Hp, 16.1/Hp and 9.3/Hp.</p><p><b>CONCLUSIONS</b>The selenium should be very important for neural stem cells' survival. Selenium could promote the neurosphere cells differentiation and development.</p>