Hippocampal anatomy and water maze performance ave affected by neonatal cryoanesthesia in rats of both sexes

There is recent evidence that cryoanesthesia, commonly used during neonatal hormone manipulations (e.g., gonadectomy), has deleterious effects on the morphology of the splenium of the corpus callosum and primary visual cortex in adult vats of both sexes. (Nunez and Juraska, 1998; Nunez, Kim, and Jur aska, 1998). In the present study, the effect of neonatal cryoanesthesia on the morphology of the hippocampus and dentate gyrus and on performance in the Morris water maze was investigated. Cold exposure for as brief as 30 mi n (5 degrees C) on Postnatal Day 1 resulted in a significant decrease in th e volume of the hippocampus and in brain weight of adults. Performance on t he water maze was also impaired in cold-exposed animals. This study indicat es that not only morphology but also behavioral performance in adulthood ar e affected by neonatal cryoanesthesia. (C) 2000 Academic Press.