ALTERATIONS IN FINE STRUCTURE OF NUCLEOLI IN SYMPATHETIC NEURONS FOLLOWING NGF-ANTISERUM TREATMENT

Antiserum to the nerve growth factor (NGF) produces a severe cytotoxic effect on sympathetic nerve cells when injected into newborn mice. The early cytological lesions were studied by electron microscopy in superior cervical ganglia of 1-day-old mice 12 and 24 h after antiserum treatment. In line with previous observations, early and marked ultrastructural changes were observed in the nuclear compartment. Alterations in the fine structure of nucleoli of the nerve cells are very prominent by 12 h after the As injection. The early alterations consist of condensation and disarrangement of the nucleolar components, which become progressively more severe in the following hours. Distinct dense bodies form from the separation and condensation of the nucleolar material and eventually the nuclear envelope breaks down and cytoplasmic and nuclear material mix. In later stages, marked disorganization of ribosomes and mitochondria is apparent in the cell cytoplasm. Incorporation experiments show that RNA synthesis is markedly reduced in the experimental ganglia already 12 h after the As injection. © 1969.