Action potential potential, such as plant cells, muscle cells, and the specialized cells of the heart (in which occurs the cardiac action potential). However, the main excitable cell is the neuron, which also has the simplest mechanism for the action potential. Neurons are electrically excitable cells composed, in general, of one or more dendrites, a single soma, a single axon and one or more axon terminals. Dendrites are cellular projections whose primary function is to receive synaptic signals. Their protrusions, known as dendritic spines, are designed to capture the neurotransmitters released by the presynaptic neuron. They have a high concentration of ligand-gated
Nanoparticles for drug delivery to the brain that it can bind and undergo endocytosis. Another mechanism is "adsorption mediated transcytosis", where electrostatic interactions are involved in mediating nanoparticle crossing of the BBB. Cationic nanoparticles (including cationic liposomes) are of interest for this mechanism, because their positive charges assist binding on the brain's endothelial cells. Using TAT-peptides, a cell-penetrating peptide, to functionalize the surface of cationic nanoparticles can further improve drug transport into the brain. In contrast to the above mechanisms, a delivery with magnetic fields doesn't strongly depend on the biochemistry of the brain. In this case, nanoparticles are literally pulled across the BBB via application of