Membránové vlastnosti gliových buněk po ischemii in vivo

• Main Author: Pivoňková, Helena
• Other Authors: Anděrová, Miroslava
• Format: Doctoral Thesis
• Language: Czech
• Published: 2011
• Online Access: http://www.nusl.cz/ntk/nusl-308919

In my PhD thesis, I aimed to characterize the membrane properties of astrocytes and NG2 glia during the acute and chronic phases of the ischemic injury in the central nervous system with a focus on the expression and activity of K+ ion channels. Two ischemia models in rats were used for the experiments - global cerebral ischemia 5 causing selective neuronal loss and astrogliosis in the CA1 region of the hippocampus, and incubation of spinal cord segments in a solution with high K+ concentration. We found that hippocampal astrocytes depolarize starting 3 days after ischemia, and demonstrate an increase in the inward rectification of their whole cell currents 1 month after ischemia. The Kir4.1 channel expression in the hippocampal tissue was downregulated starting 3 days after ischemia, while the expression of Kir2.1, Kir5.1 and TREK1 channels was strongly upregulated in reactive astrocytes 1 month after ischemia. NG2 glia displayed a significant increase in the outwardly rectifying delayed and A-type K+ (KDR and KA) currents 2 hours and 3 days after ischemia, and a decrease in the inwardly rectifying K+ currents 3 days after ischemia, a typical current pattern of proliferating cells. Complex astrocytes in the spinal cord pre-incubated in a solution with high [K+] showed the largest changes in their membrane...