Mb. Botchin et al., LOW VERSUS HIGH PROLACTIN RESPONDERS TO FENFLURAMINE CHALLENGE - MARKER OF BEHAVIORAL-DIFFERENCES IN ADULT MALE CYNOMOLGUS MACAQUES, Neuropsychopharmacology, 9(2), 1993, pp. 93-99
Prolactin response to acute administration of fenfluramine hydrochlori
de is considered an indirect assessment of ''net' central serotonergic
activity. This study compared behavioral characteristics of adult, ma
le cynomolgus macaques (Macaca fascicularis) having ''low'' or ''high'
' prolactin responses to fenfluramine challenge. The subjects were 75
animals housed in five-member social groups for 28 months. In month 23
, prolactin responses to fenfluramine challenge were evaluated. Observ
ations of specific behaviors (aggressive, submissive, affiliative, and
nonsocial) were made three times per week on animals in each social g
roup. The dominance status of each animal within a social group was as
sessed at weekly intervals. Low prolactin responders had a significant
ly higher index of ''overt'' aggression (ratio of fights involving phy
sical contact and chasing or lunging/all forms of aggressive behavior)
compared to high prolactin responders (p < .03). There were no differ
ences in the dominance status of low and high responders (p = .34). Fu
rthermore, low responders were more socially withdrawn than high respo
nders, as they spent significantly more time alone (passive or neutral
state; p < .03) and less time in passive body contact with other anim
als than high responders (p < .05). These data support the hypothesis
that reduced central serotonergic activity in nonhuman primates is ass
ociated with a high level of overt aggression and a low level of posit
ive social interaction.