Neurotransmitter Current Not Flowing Through Ion Channels

In studying how neurotransmitters travel between cells, Cornell researchers have discovered that an electrical current thought to be present during that process does not, in fact, exist. The scientists explained that neurotransmitters and hormones are stored in neurons -- nerve cells -- in small packets, membrane-bound vesicles, typically 30 to 300 nanometers in diameter. When a cell is stimulated by electrical activity, calcium ions enter the cell and the vesicles release their contents by fusion with the plasma membrane surrounding the cell.