Adulthood alterations in pain behavior, stress neuroendocrinology, and brain cFos expression resulting from neonatal noxious stimuli

Haverford College, Haverford PA

Investigators

Abstract

This project investigates the long-term consequences of high-intensity sensory stimulation during the neonatal period in the mouse. The role of early sensory input in guiding the development of sensory pathways is well known for some sensory modalities (i.e., vision), but not as well understood for the various submodalities of somatosensation (the body senses: touch, itch, vibration, tickle, pain). This project uses the newborn mouse as a model organism, since it is born in a highly immature state (the equivalent of a 15 week gestational human). Applying sensory stimulation to such an immature system will illuminate the processes by which external stimuli affect the developing nervous system. It is expected that since the developing nervous system is highly malleable, then sensory input during this stage will have long-term, maybe even permanent effects. Subjects will be exposed to a noxious stimulus during the neonatal period (within hours to days following birth). In adulthood, these same animals will be tested on a variety of measures to determine how sensory pathways form in response to the neonatal stimulus. Following re-exposure to a noxious stimulus, brain tissue will be examined for presence of cFos-a marker of neural activity. Blood levels of hormones involved in the stress response will be assessed, and behavioral responses to re-exposure to the stimulus will also be measured. This project also aims to identify the underlying genetic mediators of sensory-induced alterations. Thus, the undergraduate students who are involved in all portions of the project will be exposed to a wide range of neuroscientific techniques, from genes to cells to behavior. The findings of this research will contribute to an understanding of how the nervous system develops in response to sensory stimulation early in life.