The degeneration of sensory and motor neurons after axotomy in young adult rat and prevention by leukemia inhibitory factor

Abstract

Leukemia inhibitory factor, (LIF), a multifunction polypeptide cytokine, has been demonstrated to it prevent apoptosis of sensory and motor neurons in newborn rats. This study has investigated and compared the time course of sensory and motor neuron loss after axotomy only with axotomy with ligation. The study investigated whether LIF also supports the suvival of axotmized sensory and motor neurons in adult rat. It was found that the loss cells in the DRG of axotomy with ligation group at the C7 ,C8, and T1 levels were nearly the same as the loss cells in the DRG of axotomy only group. In motor neuron, there was no different between the axotomy only group and the axotomy with ligation group. The median and ulnar nerve of adult rats were unilateral transected and treated with either the phosphate buffer saline (PBS) or LIF. It was clear that the survival cell in LIF-treated group was higher than the PBS group at every levels. However , a significant differences were shown at the T1 level (1week), C7 and T1 (2 weeks), and C7 to T1 (4 weeks)of the DRG , and C7 (1week) of the motor neuron. The results demonstrated that the apotosis of the motor neuron was found only within the first week after nerve axotomy.