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Biomedical subjects

A J Stynes

Publications and source records attributed to A J Stynes.

5 recordsLinked to original sources

Depression can be induced in a bonnet macaque infant.

Depression is a well-known reaction to separation in all species of macaques studied except the bonnet (M. radiata), in whom this reaction has never before been observed. We have produced the depressive response of postural collapse and social withdrawal in a bonnet infant by altering the social structure of the group in which it lived in a way calculated to interfere whith the species-typical system of social support.

Animals

Heart rate and body temperature in separated monkey infants.

Heart rate (HR) and body temperature (BT) were recorded from ten unrestrained group-living M. nemestrina (pigtail) monkey infants, using totally implantable multichannel biotelemetry systems, during a 4-day base line (preseparation) period, during the agitation-depression reaction accompanying 4 days of maternal separation, and for several days following reunion with the mother. Quantified behavioral data were collected in nine of the ten infants. Mean daytime (1000 to 1600 hr) and nightime (2200 to 0400 hr) HR and BT values were computed for each infant, and for the group as a whole. The behavioral agitation reaction immediately following separation was accompanied by increases in both HR and BT. Beginning with the first night of separation, both HR and BT showed marked decreases from base line. Whereas group mean HR and BT changes were maximal early in the separation, behavioral indices of depression tended to be maximal later in the separation period. Reunion with the mother tended to normalize HR and BT in most infants. Two infants exhibited sudden transient reversible drops in nocturnal BT well into the separation period, suggesting an impairment in thermoregulatory mechanisms during the period of depressive behavior. One infant had a prolonged separation-induced decrease in HR that persisted throughout reunion, indicating that the stress of maternal separation may induce physiological changes that considerably exceed the duration of the effective stress.

Animals

Monkey motor stimulation and altered social behavior during chronic methadone administration.

To assess the effects of chronic methadone administration on locomotor, social, and eating behavior od drug-native individuals under circumstances approximating those of methadone "maintenance" clinics, we gave single, daily oral doses of methadone to 5 Macaca radiata monkeys living in a social group. We obtained motor activity counts automatically during 6 weeks of baseline, 10 weeks of drug administration, and 3 weeks of post-drug abstinence. Social behaviors of association, dominance, submission, and sexuality were counted 5 days per week, and animal weights, food eaten and food-reinforced work were recorded. Plasma methadone levels were near those achieved in mechadone clincs. Methadone produced mixed stimulation and sedation in the daytime, with stimulation predominating for 4 hrs following administration. At night the subjects moved less while taking the drug. Associative behaviors were reduced by methadone, but dominance, submission, and sexual behaviors were not altered. The monkeys ate less while taking the drug, losing weight and working less for food. In these primates methadone had significant stimulant properties, impaired important social behaviors, and reduced the potency of food as a reinforcer of work. The results are compared with methadone's effects upon humans.

Animals