TOXIC EFFECT OF QUINOLINIC ACID ADMINISTERED DURING PREGNANCY ON THE CEREBRAL-CORTEX OF RATS OFFSPRING - AN ULTRASTRUCTURAL-STUDY

The cerebral cortex of rat's offspring was ultrastructurally examined after quinolinic acid administration to mothers during the gestation period. Quinolinic acid was administered intraperitoneally in a dose of 60 mmol, once daily, throughout the entire gestation period. Brain specimens were taken on day 5 after birth, from experimental and control animals. Ultrastructural analysis of the cortex tissue revealed maturing neuronal cell bodies and immaturelike cells. The distinguishing feature of altered maturing neuronal cell bodies was the presence of vacuoles and/or swollen cytoplasm. The vacuoles were present in the perikaryon as well as in the processes. As a rule, the organelles within swollen cytoplasm were scarce, and the cytoplasm itself had a distinctly lower electron density. In some cases a loss of chromatin grains was noted. The nuclear envelope was distended, forming perinuclearly situated channels and vacuoles. The most frequently observed change in the im mature-like cells was a marked swelling of the cytoplasm, hence only few organelles could be seen. Only few synaptic complexes were present and their contact was weakly marked. The axon endings contained sometimes few vesicles. The postsynaptic dendritic processes were frequently significantly swollen. Astrocytes were swollen.