Effects of electrical stimulation on WGA-HRP transport in pubococcygeus motoneurons of male rats

Introduction: The retrograde axonal transport from dendrites and the axon terminal to the soma is very important mechanism for transferring contents among the different regions of the neuron. However, the correlation between tracers labeling on motoneurons with neural electrical activity is somewhat debatable. Objetives: Therefore, we used horseradish peroxidase conjugated to wheat germ agglutinin (WGA-HRP) to analyze spinal motoneurons of the Pubococcygeus (Pc) muscle in male rats that received electrical stimulation on the left somatomotor branch of the pelvic nerve. Materials and Methods: Three groups were made according to the timing of stimulation: A) after injection of WGA-HRP, B) before perfusion of the rat, and C) both conditions, A+B. Results: The results indicated that motoneurons located on the ipsilateral side of stimulation applied twice (group C) obtained the lower values of morphological labeling. Conclusions: We suggested that the electrical activity of a motoneuron results in an increase of dendritic movement to concentrate substances in the soma, which indeed regulates WGA-HRP labeling. It is suggested that the state of electrical activity of a motoneuron increases the centripetal movement of cytoplasmic contents, as represented by the stain. The mechanism could serve to maintain the integrity of the different regions of the motoneuron by allowing recycling, degradation or transferring of components into the soma.