Quantitative studies of nuclear bodies in astrocytes of chicken spinal cord following axotomy

The present study was designed to reveal whether astrocytic activation following axotomy causes a numerical increase of nuclear bodies (NBs) in chicken astrocytes. Astrocytes in the spinal cord were activated by a unilateral spinal nerve transection. The frequency of NBs was calculated at the lateral motor columns of the normal group and at the ipsi- and contralateral sides of operated group. In the growing chickens, NBs of each astrocyte were a few and decreased steadily in number with age. In the operated chickens, the frequency of NBs elevated temporarily both in the ipsi- and contralateral sides, and reached its maximum value by 30 post-operative days. The frequency of NBs increased more prominently in the operated side than in the unoperated side. Thus, the present study provides the first evidence for a significant increase in the number of NBs in the hyperactive astrocytes caused by axotomy.