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Delayed dispersal and elevated monoaminergic activity in free‐ranging rhesus monkeys
Author(s) -
Kaplan Jay R.,
Fontenot M. Babette,
Berard John,
Manuck Stephen B.,
Mann J. John
Publication year - 1995
Publication title -
american journal of primatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.988
H-Index - 81
eISSN - 1098-2345
pISSN - 0275-2565
DOI - 10.1002/ajp.1350350305
Subject(s) - monoaminergic , metabolite , homovanillic acid , serotonergic , serotonin , medicine , dopamine , endocrinology , cerebrospinal fluid , monoamine neurotransmitter , neurotransmitter , physiology , biology , central nervous system , receptor
Male rhesus monkeys typically disperse from their groups of birth when they are between 3 and 5 years of age. Some males, however, delay dispersal from their natal groups until after they are 5 years old. The current study evaluated central monoaminergic neurotransmitter activity as a potential correlate of such “delayed” dispersal among 54 randomly selected adolescent and adult male rhesus monkeys ( Macaca mulatta ) captured on Cayo Santiago during an annual trapping season. Specifically, cerebrospinal fluid (CSF) concentrations of 5‐hydroxyindoleacetic acid (5‐HIAA, a serotonin metabolite), 3‐methoxy‐4‐hydroxyphenylglycol (MHPG, a norepinephrine metabolite), and homovanillic acid (HVA, a dopamine metabolite) were compared in monkeys 60 months of age or more that had either dispersed (n = 33) or were still in their natal groups (n = 5). The monkeys still in their natal groups had higher CSF concentrations of both 5‐HIAA and HVA (but not MHPG) than did the animals that had emigrated ( Ps < 0.05). Subsequent analysis indicated that only 5‐HIAA independently differentiated dispersing monkeys from delayed dispensers. Of monkeys less than 60 months of age (n = 16), only two had dispersed from their natal groups; in this age class, there were no significant differences between dispersing and natal individuals in any CSF monoaminergic metabolite (all Ps = NS). Finally, there was no difference in the CSF 5‐HIAA concentrations of the five delayed dispersers and those of younger animals ( P = NS), suggesting a failure to experience the frequently reported adolescent decline in serotonergic activity. In contrast, the CSF 5‐HIAA concentrations of the dispersing animals were lower than those of the younger animals ( P < 0.05), consistent with either an agerelated decline or an effect of dispersal per se. © 1995 Wiley‐Liss, Inc.