Following electrical stimulation, all neurotransmitters are released into a gap between nerve cells known as the synaptic cleft. Once the neurotransmitter diffuses across the cleft, biological action is produced by interaction of the neurotransmitter with a signaling molecule known as a receptor. After the receptor has been activated, the neurotransmitter must be eliminated so that the cleft is clear, and the process can be repeated if necessary. Read the rest of this entry »