Changes in choline acetyltranferase distribution in the cervical spinal cord after reversible cervical spinal cord injury

Reversible spinal cord injury (SCI) at C6 level in rats, produced by the weight-placed method, resulted in a severe motor functional deficit initially, followed by a gradual recovery. During the recovery, choline acetyltransferase (CAT) distribution in the cervical spinal cord was investigated at 2, 4, 7, 14 and 28 days after the injury by quantitative immunohistochemistry with a fluorescence microphotometry system. At C6 level, the flourescence intensity of the ventrolateral anterior horn (VLAH), which reflected the concentration of CAT, decreased to approximately 50% of that of the sham-operated group at 2 days. It then recovered to 60% at 4 days after the injury, and remained unchanged thereafter. Fluorescence intensities in VLAH at C4-5 and C7-8 levels decreased to approximately 60-70% at 2 days after the injury, but it recovered and increased to 110-130% thereafter.