P.I.:John T. Hackett IBN-9634400 Neurons (nerve cells) in our brains communicate between each other at contact points (synapses) which excite the following neurons by means of chemicals known as transmitters. When things go right, this process of signaling continues repeatedly in an organized way that results in integration of information coming into and leaving the brain. This process also is the basis of memory and learning. The proposed research has as its long range goal to clarify the process by which neurotransmitter substances are released from neurons. At an early stage, the neurotransmitter are packaged in a stored form from which they must be mobilized to dock at the membrane of the release site. To help explain the mobilization process, mathematical calculations will test various possible outcomes that will be compared with experimentally obtain results. Of particular interest is the finding that following repetitive stimulation more and more neurotransmitter substance is release by a process known as facilitation. Understanding how facilitation comes about will be key to our understanding of more complicated forms of memory and learning.