Levels and uptake of taurine in various brain regions after druginduced generalized convulsions

In a study of the role of taurine in the genesis of epilepsy the effects of metrazol-induced convulsions on the uptake and distribution of taurine in the brain were measured.In vivo we found no significant uptake of taurine in the mouse brain; in rabbit brain in most areas significant taurine uptake was found. The physiological levels of taurine were much higher in mouse brain than in rabbit brain.In vivo the regional levels and the uptake of taurine were not significantly changed after generalized convulsions. Uptakein vivo was lowered in slices obtained from mice treated with metrazol. The lack of effect of metrazol convulsions on cerebral taurinein vivo indicates that further studies are needed to clarify the relationship between taurine, a putative inhibitory transmitter, and epilepsy.Supported in part by a grant from the C.N.R., Rome, Italy     

Lifetime fitness consequences of early‐life ecological hardship in a wild mammal population

Early‐life ecological conditions have major effects on survival and reproduction. Numerous studies in wild systems show fitness benefits of good quality early‐life ecological conditions (“silver‐spoon” effects). Recently, however, some studies have reported that poor‐quality early‐life ecological conditions are associated with later‐life fitness advantages and that the effect of early‐life conditions can be sex‐specific. Furthermore, few studies have investigated the effect of the variability of early‐life ecological conditions on later‐life fitness. Here, we test how the mean and variability of early‐life ecological conditions affect the longevity and reproduction of males and females using 14 years of data on wild banded mongooses (Mungos mungo). Males that experienced highly variable ecological conditions during development lived longer and had greater lifetime fitness, while those that experienced poor early‐life conditions lived longer but at a cost of reduced fertility. In females, there were no such effects. Our study suggests that exposure to more variable environments in early life can result in lifetime fitness benefits, whereas differences in the mean early‐life conditions experienced mediate a life‐history trade‐off between survival and reproduction. It also demonstrates how early‐life ecological conditions can produce different selection pressures on males and females.