9310065 Scroggs The brain receives input about the environment from signals coming in through the sensory systems. The brain also has mechanisms that modulate those afferent input systems, and one example of such phenomena is the suppression of pain signals during emergencies that activate the "fight or flight" responses. Suppression of pain information may be achieved by nerve cells in the brain releasing neurotransmitters such as serotonin and norepinephrine to bathe cells down in the spinal cord where the nerves enter that carry pain information. It is not understood how these substances may selectively inhibit pain without also inhibiting other important sensory inputs that use the same transmitter molecules. This work uses anatomical tracing techniques to identify the source of input (skin, joints, muscles) and the central targets in the spinal cord of single neurons, and electrophysiology and pharmacology to determine how the important transmembrane channels in these identified individual nerve cells are affected by these transmitters. Discovery of how various types of sensory neurons have differential sensitivity to these two neurotransmitters will advance our understanding of how the brain controls its own input, and so will have an impact on all sensory neuroscience, in addition to providing a basis for potential applications toward developing medicines with selective effects on different sensory pathways. ***
