Ultrastructure of γ-motoneurons after temporary or permanent interruption of peripheral target contact

The paradigm of nerve crush, vs. nerve transection and ligation, was used to examine the effects of temporary or permanent interruption of peripheral target contact on the ultrastructure of cat thoracic γ-motoneurons. The normal, highly ordered ultrastructure of Nissl bodies was lost 8 days after axotomy. Nissl bodies remained disorganised up to 305 days after nerve transection and ligation. In contrast, normal ultrastructural orderliness was restored for many of the Nissl bodies of γ-motoneurons 64 days following nerve crush. A decrease in the area of the Golgi apparatus was found 64 days following both nerve crush and nerve transection with ligation. Other organelles were unaltered.