IN a previous paper (Shapiro and Zwarenstein, 1933) it was shown that castration in Xenopus laevis results after 6 months in a persistent fall in serum calcium in males and females. During the course of the investigation it was observed that the serum calcium of the females used as controls, i.e. animals maintained in captivity, was significantly lower than that of animals brought in fresh from...

Captive breeding programs are widely used for the conservation and restoration of threatened and endangered species. Nevertheless, captive-born individuals frequently have reduced fitness when reintroduced into the wild. The mechanism for these fitness declines has remained elusive, but hypotheses include environmental effects of captive rearing, inbreeding among close relatives, relaxed natura...

Long-term maintenance of captive populations followed by release of captive animals into the wild is one of many approaches to endangered species conservation. To assess captivity’s effects on behavior, a simulated predator was presented and response behaviors measured in oldfield mice, Peromyscus polionotus subgriseus. The animals tested were from four populations collected from Ocala National...

Experiments conducted on captive animals allow scientists to control many variables; however, these settings are highly unnatural. Previous research has documented a large difference in microbial communities between wild animals and captive-bred individuals. However, wild-caught animals brought into captivity might retain their natural microbiota and thus provide a better study system in which ...

Evidence points to heightened physiological arousal in response to acute stress exposure as both a prospective indicator and a core characteristic of posttraumatic stress disorder (PTSD). Because females may be at higher risk for PTSD development, it is important to evaluate sex differences in acute stress reactions. This study characterized sex differences in cardiovascular and subjective stre...

Two adaptationist hypotheses have been proposed to explain why stress, particularly elevation of stress hormones (i.e. glucocorticoids), tends to suppress immune functions. One is that immune suppression represents efforts to minimize autoimmune responses to self-antigens released as organisms cope with stressors (i.e. the autoimmune-avoidance hypothesis). The other is that immune suppression o...

The complexity of an animal's physical environment is known to affect the hippocampus. Captivity may affect hippocampal anatomy and this may be attributable to the limited opportunities for memory-based experiences. This has tangential support, in that differential demands on memory can mediate changes in the hippocampus. What remains unclear is whether captivity directly affects hippocampal ar...

the present survey covers a number of 91 iranian repatriated war prisoners who, six months after their freedom, approached three psychiatric clinics in tehran during 1989 and spring 1990. of these, 34 persons (37.4%) who showed higher symptoms of disorders were hospitalized and 57 (62.6%) who showed milder signs of disorders were carefully diagnosed mentally and psychologically as outpatients. ...