Neurotransmission Research

A key feature of neurons is that they receive inputs, often conduct action potentials to another site, and then transmit to another cell. Neurotransmission involves the synthesis, storage and release of chemical messengers (transmitters) into extracellular space; the reception of information from the neurotransmitters at the target cell; and then transduction of that signal into another set of biochemical and voltage changes. A set of neurons working together is called a network. Experimental systems include whole animals, neurons and endocrine cells grown in tissue culture, transgenic mice, Drosophila, and other lower creatures.

Transmitters come in several types: conventional, such as acetylcholine and norepinephrine; neuropeptides, such as cholecystokinin and neuropeptide Y; and others, such as gases and ATP. Acetylcholine is the molecule that killed so many people during nerve gas attacks in World War I. The nerve gases blocked the normal inactivation of acetylcholine, and acetylcholine is the transmitter whose biological punch is messed up in muscular dystrophy and in the key neurons lost in early Alzheimer's disease. Norepinephrine stabilizes blood pressure when you stand up, and the precursor of norepinephrine (dopamine) is the molecule lacking in Parkinson's disease. Cholecystokinin is a major peptide transmitter in the brain, and cholecystokinin imbalances underlie panic disorder. Neuropeptide Y contracts your pupil and causes long-lasting contractions of blood vessels in the brain. The department has experts in many of these areas, focusing on the synthesis, storage, release and regulation of transmitters. The studies of regulation of neurotransmitter metabolism now have progressed to include molecular modeling as part of experimental design.

Transduction of nervous signals falls into a couple of broad categories: ionic signals (currents and voltage changes) and biochemical events. The target cells for transmitters can respond by changing their membrane potentials up or down, by changing the rate of production or levels of "second messengers," and by other means. The department has active research concerning a number of second messenger systems. In addition, intracellular signaling among the far-flung parts of neurons is also a hot area of much interest in the department. Networks are a unique attribute of the nervous system and to a lesser extent the endocrine system. Networks are studied by recording the properties and responses of many individual neurons simultaneously in order to discern how their synaptic properties may be modified such that, as a coordinated group, they are able to store and transmit information.