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Biomedical subjects

I S Bernstein

Publications and source records attributed to I S Bernstein.

At least 37 records · Page 2Linked to original sources
PubMed1978

Diurnal variation in plasma testosterone and cortisol in rhesus monkeys living in social groups.

Concentrations of cortisol and testosterone in the plasma of adult male rhesus monkeys living in social groups were determined during a 27-h period. Capture and venipuncture of experienced, conditioned animals did not lead to a fall in the concentration of testosterone in the plasma during the 90 min immediately after removal from the group. Both plasm cortisol and plasma testosterone concentrations showed a significant fall and rise in samples collected every 3 h during a 27-h period, even though there was considerable individual variation. During the autumn breeding season, animals showed higher concentrations of testosterone at both 10.00 and 22.00 h compared with those observed at the same times during the summer. Even though animals demonstrated significant diurnal changes, testosterone samples withdrawn at the same time of day (10.00 h) on consecutive days were significantly correlated with one another (r = 0.65, n = 27, P less than 0.01), suggesting the usefulness of sampling once a day to study potential environmental influences on plasma testosterone concentrations.

Animals↗
PubMed1977

Behavioural and hormonal responses of male rhesus monkeys introduced to females in the breeding and non-breeding seasons.

Six adult male rhesus monkeys were introduced individually to an all-female group for 10 days during the mating season. The initial aggressive responses of the females were rapidly replaced by positive social behaviour, and each male achieved alpha status and had access to social and sexual partners. A repetition of this paradigm in the non-breeding season produced significantly more female aggression, and no male attained high rank or engaged in sexual or other social behaviour. Male testosterone levels rose following introduction to the females in both seasons, but were significantly higher during the breeding season. Hormonal levels following removal from the females suggest a complex interplay between social, sexual and seasonal variables and recent social experiences. The differences in female social behaviour with newly introduced males, as a function of season, suggest an explanation for the seasonal limitation of male troop transfers.

Aggression↗
PubMed1977

Behavioral research in breeding colonies of Old World monkeys.

The existence of an active behavioral research program using animals in primate breeding colonies was considered to be not only a compatable multiple use of animals, but a way of materially improving the management and efficiency of the breeding colonies. In colonies of monkeys specifically established for behavioral research programs directed at the examination of social relationships, incidental breeding resulted in levels of reproductive success equivalent to or greater than that normally experienced in colonies devoted entirely to breeding. Behavioral research revealed patterns of seasonality, fostering, kidnapping, and infant care which would otherwise have escaped notice and which would significantly influence culling and management choices in a breeding colony. Many young males and certain low ranking adult males actively contributed to reproduction. Females born and reared in the colonies were the most productive, exceeding wild born or other introduced females in reproductive efficiency. Specific recommendations for establishing, expanding and culling of nonhuman primate breeding colonies were derived from the behavioral research.

Animals↗
PubMed1976

Activity patterns in a sooty mangabey group.

Diurnal, temperature and weather influences on the activity profiles of a sooty mangabey group were compared to similar data previously reported for geladas and pigtail monkeys. Distinct behavioral profiles for each group were obtained despite the near identity of living conditions. Mangabey patterns in captivity appeared very similar to those reported for mangabeys in the wild. Sexually dimorphic behavioral patterns were demonstrated as well as the independence of several social orders. Infant care by multiple females and by males was observed and the conservative nature of mangabey responses to novelty noted.

Agonistic Behavior↗
PubMed1976

Paternity and status in a rhesus monkey group.

In the blood from 63 rhesus monkeys (Macaca mulatta), transferrin, 6-phosphogluconate dehydrogenase, carbonic anhydrase II, phosphohexose isomerase, NADH diaphorase and leucocyte antigens were polymorphic. On the basis of these traits, paternity eliminations were determined for 29 offspring of 26 females from an established breeding group containing 8 sexually mature males. The dominance of the males was assessed by the directionality of the agonistic encounters. After examination of the results for two breeding seasons it was found that (1) the alpha male did not do all, or even most, of the successful mating and (2) there was evidence demonstrating increased reproductive success for males as a function of relative agonistic rank for the second but not the first of the 2 years.

Alleles↗
PubMed1975

Activity patterns in a gelada monkey group.

Diurnal, temperature and weather influence on the activity profiles of a gelada monkey group were compared to similar data previously reported for pigtail monkeys. Each of these variables influenced gelada behavior and many effects similar to those reported for pigtails were noted. Females were once again more active in agonistic, sexual and grooming patterns. The one male units of gelada groups influenced many activity patterns, and the special role of bachelor males as a focus for immature animal activities was demonstrated. Although 'aunt' behavior was present, it was superceded by patterns of 'paternal' care.

Aggression↗
PubMed1972

Plasma testosterone levels in the male rhesus: influences of sexual and social stimuli.

Four adult male rhesus monkeys were provided access individually to a group of receptive females. Each male assumed dominance and engaged in frequent copulations. Plasma testosterone levels increased two- to threefold during this period. Next, each male was subjected to sudden and decisive defeat by a large all-male group, and plasma testosterone fell following this experience. Two males were later reintroduced to the females, and plasma testosterone rose rapidly to the previous elevated levels.

Aggression↗