The questions of how the nervous system processes information about the sense of touch and various levels of unpleasant sensations elicited by applying stimuli to the skin are poorly understood. In this project the investigator will conduct a detailed study of how spinal cord neurons discriminate between such stimuli, an important part of the processing of the information. It is already known that it is possible to categorize spinal cord neurons on the basis of the type of stimulus that leads to their activation. For example, some respond when the skin is stimulated with light touch, others when it is stimulated with pressure, still others when the stimulus is heat, and so forth. It is not known to what extent the various subcategories of tactile and mechanical stimuli can be unambiguously identified by the responses of individual spinal cord nerve cells. This is the issue to be addressed in this project. The approach will be to record activity from many spinal cord neurons while subjecting the skin to precisely controlled mechanical stimuli. In addition, activity will be recorded simultaneously from spinal cord neurons and nerve fibers carrying the information from the skin to the spinal cord, allowing the investigator to discover how the neuronal signals are transformed during processing in the spinal part of the nervous system. This is very basic information with a number of implications in health related research engineering.
