A quantitative histological study of the effects of acute triethyl lead poisoning on the adult mouse brain.

The effects of a single injection of triethyl lead chloride on the mouse brain was studied 1, 3, 5, 7 and 30 days postinjection using quantitative histological techniques. The total number of glia in the anterior commissure was significantly reduced following injection but by 30 days postinjection had returned to normal. The number of neurons and the number of glia in the indusium griseum did not change significantly. The number of mitotic cells in the subependymal layer fell slightly from 1 to 3 days postinjection then returned to normal 5 days postinjection. The number of pyknotic cells in the subependymal layer did not appear to change following injection. In the anterior commissure the number of mitotic cells fell significantly from 1 to 3 days postinjection and then increased significantly at 5 days postinjection. A similar increase in mitosis was found at 5 days postinjection in the indusium griseum. At 7 days postinjection a significant decrease occurred in pyknotic cells in the anterior commissure and indusium griseum. Changes in the percentage of each type of glial cell present were found 30 days postinjection. This suggests that although the total number of glia may return to normal the number of each type of glial cell present changes following injection of triethyl lead. There was no evidence of cerebral oedema following triethyl lead injection either at the light or electron microscopic level.