A Quantitative Study of the Metabolism of CNS Phrenic Neurons in the Adult Rat Following Axotomy in the PNS
Previous studies of the metabolism of CNS neurons have shown an apparent neuronal cell death in response to nerve injury. These studies have been ambiguous due to possible connective tissue and neuroglial cell infiltration into the lesion site. Cell death due to axotomy could not be conclusively established due to these extrinsic factors. This study demonstrated a decrease in the retrograde-uptake of Horseradish peroxidase in the CNS following double transection of the rat's phrenic nerve in the PNS. This experimental design provided an indirect way of measuring the CNS neuronal metabolism. An overall decrease in the metabolism of the CNS neurons with increasing post-phrenicotomy periods was noted. In addition, a possible feedback mechanism with respect to retrograde transport of axoplasm in response to axotomy was noted in this study.