Membrane potential function as a battery, providing power to operate a variety of "molecular devices" embedded in the membrane. Second, in electrically excitable cells such as neurons and muscle cells, it is used for transmitting signals between different parts of a cell. Signals are generated by opening or closing of ion channels at one point in the membrane, producing a local change in the membrane potential. This change in the electric field can be quickly affected by either adjacent or more distant ion channels in the membrane. Those ion channels can then open or close as a result of the potential change,
Drug delivery to the brain Drug delivery to the brain Drug delivery to the brain is the process of passing therapeutically active molecules across the blood–brain barrier for the purpose of treating brain maladies. This is a complex process that must take into account the complex anatomy of the brain as well as the restrictions imposed by the special junctions of the blood–brain barrier. The blood–brain barrier is formed by special tight junctions between the epithelial cells that surround the brain tissue. All tissue is separated by this layer of epithelial cells, however only the brain epithelial cells have these tight junctions that do not