Department of Zoology, University of Toronto, Toronto, Ontario, Canada M5S 1A1
Abstract:
1. 1.|The mitochondrial population in hypothalamic and hypophysial brain tissue from warm (30°C) and cold (5°C) acclimated goldfish (Carassius auralus L.) was analyzed using sterological techniques.
2. 2.|It was revealed that there is a significantly larger volume density (Vv) in the cold acclimated tissue, with no significant difference in either of the surface densities (Svext and Svint) from either of the brain areas.
3. 3.|The hypothalamic brain tissue has a significantly lower specific surface (S/V) in the cold acclimated tissue but there is not a significant difference in this parameter for the hypophysial brain tissue.
4. 4.|The values for these three parameters (Vv, Svext and SVint, and S/V) indicate that mitochondria from acclimated brain tissue undergo shape changes in response to thermal stress.
5. 5.|We suggest that the shape changes may be related to the change in the phospholipid composition of the inner mitochondrial membrane with acclimation temperature.