ULTRASTRUCTURAL-CHANGES IN THE GANGLIA OF VIVIPARUS-ATER FOLLOWING EXPERIMENTAL LEAD-INTOXICATION

Ultrastructural damage in the ganglia of Viviparus ater specimens exposed to short-term staticpollution by lead (1,2,5, and 10 mgiliter for 24,48, and 96 hr) was studied. In polluted samples theneurons inside the ganglia are not regularly arranged in layers in the superficial zone of the gangliabut are irregularly scattered. Neuron structure appears particularly affected by lead exposure: thecell swells and the axon hillock is poorly distinguishable; the nucleus also frequently swells and thechromatin appears particularly dispersed; Nissl bodies appear disassembled and the ribosomes arenot generally linked to the vesicle membranes; the mitochondria are also swollen, cristae practicallydisappear, and the matrix becomes homogeneous and electron transparent; and a noticeableincrease in the number and size of secondary lysosomes was observed. 8 1990 Academic PXSS, I~IC.