Cholecystokinin- and dexfenfluramine-induced anorexia compared using devazepide and c-fos expression in the rat brain

It has been proposed that there might be a link between the anorectic actions of cholecystokinin (CCK) and serotonin (5HT). The present study compared the patterns of c-fos protein-like immunoreactivity (FLI) induced in rat brain by CCK and the indirect 5HT agonist dexfenfluramine (DFEN), as well as the ability for devazepide, a CCK-A receptor antagonist, to antagonize both anorexia and FLI induced by these agents. Devazepide reversed the anorectic effect of CCK but not that of DFEN in food deprived rats. The FLI induced by CCK and DFEN occurred in similar brain regions, but in different subdivisions. Such regions included the bed nucleus of the stria terminalis (BST), the lateral central nucleus of the amygdala (CeL), and the lateral parabrachial nucleus (LPB). Devazepide abolished the FLI induced by CCK most of these brain regions, but had no effect on FLI induced by DFEN. These results suggest that the LPB-CeL/BST pathway might be responsible for the anorectic effects of both CCK and DFEN, but different parts or neuronal populations in these structures might be differentially engaged by CCK and DFEN. The putative interaction between CCK and 5HT might happen along this pathway, rather than in the periphery.     

Temporal patterns of parturition in mammals in captivity

Previous research indicates that many primate species are more likely to give birth at night than during the day. This study attempted to determine whether temporal patterns of birth are discernible in a number of non-primate mammals. In addition, it sought to relate time of birth to the sleep/wake cycle and to the level of predation on the species. Data were collected and analyzed on birth hours in 26 mammalian species from two Chicago area zoos . Although temporal patterns of parturition were discernible for many species, the hypothesis that most birth would occur during the restive phase was not supported. However, a significant positive correlation between level of predation and the likelihood that birth would occur during the restive phase was found (n = 0.40). These findings are discussed in terms of predator/prey interaction and the protection (or lack of protection) that restive birthing might afford the mother and offspring at this vulnerable time.