Preliminary Morphological and Histochemical Changes in Rat Spinal Cord Neurons Following Arsenic Ingestion

The differences noted between the cervical and lumbar motor neurons, viz. (i) the decrease in mean log nuclear area were observed only in cervical motor neurons of animals receiving 2.0 mg/kg bw whereas for the lumbar motor neurons this was true of all doses of arsenite; (ii) in general, CO expression was higher in the cervical than in lumbar spinal cord and (iii) reduction in SDH activity was more pronounced in the cervical spinal cord with doses of 1.5 and 2.0 mg/kg bw as compared to lumbar spinal cord. These observations may throw some light on the earlier observations [Jenkins RB. Inorganic arsenic and the nervous system. Brain 1996;89:479-98] reporting differences in the affliction to arsenic ingestion between the fore limb and hind limb musculature (in human subjects). Our observations ascertain that the neurons, which innervate these musculature, also differ in some characteristics.