Growth of neural transplants in rats: effects of initial volume, growth potential, and fresh vs frozen tissues

Interactions between growth potential (as related to the age of donor embryos and type of tissue), initial volume, and fresh vs frozen conditions of neural transplants were studied in rats. Neural tissues with high growth potential (16-day gestation neocortical tissue) when used fresh yielded the best growth of the transplants, which was positively related to the initial volume of the tissue. At the other extreme, neural tissues with very low growth potential when used following their freezing and thawing yielded the poorest results. Changes in the initial volume of transplants did not seem to improve the final growth. Combination of these variables in between these two extremes yielded transplants of variable sizes.