Sensorimotor Reflexes in Adult Rats Following a Neonatal Spinal Cord Transection
Faculty Mentor Information
Dr. Michele Brumley (Mentor), Idaho State University
Abstract
Approximately 18,000 Americans sustain spinal cord injuries (SCI) each year, resulting in impairments in autonomic processes and sensorimotor behaviors, such as reflexes. To better understand the long-term effects of neonatal SCI in adulthood, postnatal day 1 (P1) rats received a low thoracic spinal cord transection or a sham (control) operation. On P50, testing was performed for three reflexes: surface righting, placing, and crossed-extensor. For righting, rats are placed supine and then released. The reflex is complete when the rat has returned to a prone position with its weight centered. For placing, a stimulus is applied to the top of a hind paw. The reflex is displayed when the rat lifts the paw and places it onto the spatula. For the crossed extensor reflex, a hind paw is lightly pinched. This reflex is displayed by withdrawal of the pinched paw and extension of the contralateral hindlimb. We found no effect of surgical condition on any of the reflexes. Overall, the P50 rats tested here did not show consistent reflex responses. Findings suggest that, unlike in younger rats, spinal-mediated reflexes degrade over time.
Sensorimotor Reflexes in Adult Rats Following a Neonatal Spinal Cord Transection
Approximately 18,000 Americans sustain spinal cord injuries (SCI) each year, resulting in impairments in autonomic processes and sensorimotor behaviors, such as reflexes. To better understand the long-term effects of neonatal SCI in adulthood, postnatal day 1 (P1) rats received a low thoracic spinal cord transection or a sham (control) operation. On P50, testing was performed for three reflexes: surface righting, placing, and crossed-extensor. For righting, rats are placed supine and then released. The reflex is complete when the rat has returned to a prone position with its weight centered. For placing, a stimulus is applied to the top of a hind paw. The reflex is displayed when the rat lifts the paw and places it onto the spatula. For the crossed extensor reflex, a hind paw is lightly pinched. This reflex is displayed by withdrawal of the pinched paw and extension of the contralateral hindlimb. We found no effect of surgical condition on any of the reflexes. Overall, the P50 rats tested here did not show consistent reflex responses. Findings suggest that, unlike in younger rats, spinal-mediated reflexes degrade over time.