Mechanism of anoxic depolarization in the brain intracellular Na and Ca ions, and extracellular glutamate and aspartate. Glutamate and aspartate are normally present as the brain's primary excitatory neurotransmitters, but high concentrations activate a number of downstream apoptotic and necrotic pathways. This results in neuronal dysfunction and death. Neurons function in the central nervous system by generating signals from synapses, and this only works in the proper chemical environment. An electrical signal is mediated by the sodium channels and leaky potassium channels in which intracellular K ion concentration is higher than its corresponding extracellular concentration, whereas extracellular concentrations of Na, Ca, and Cl ions are higher than
Nanoparticles for drug delivery to the brain constituents bind to nanoparticles, and then this complex binds to a low-density lipoprotein receptor (LDLR) in the BBB and allows transport to occur. The mechanism for the transport of polymer-based nanoparticles across the BBB has been characterized as receptor-mediated endocytosis by the brain capillary endothelial cells. Transcytosis then occurs to transport the nanoparticles across the tight junction of endothelial cells and into the brain. Surface coating nanoparticles with surfactants such as polysorbate 80 or poloxamer 188 was shown to increase uptake of the drug into the brain also. This mechanism also relies on certain receptors located on the luminal surface