A NONHUMAN PRIMATE MODEL OF TYPE-II ALCOHOLISM .2. DIMINISHED SOCIAL COMPETENCE AND EXCESSIVE AGGRESSION CORRELATES WITH LOW CEREBROSPINAL-FLUID 5-HYDROXYINDOLEACETIC ACID CONCENTRATIONS
Jd. Higley et al., A NONHUMAN PRIMATE MODEL OF TYPE-II ALCOHOLISM .2. DIMINISHED SOCIAL COMPETENCE AND EXCESSIVE AGGRESSION CORRELATES WITH LOW CEREBROSPINAL-FLUID 5-HYDROXYINDOLEACETIC ACID CONCENTRATIONS, Alcoholism, clinical and experimental research, 20(4), 1996, pp. 643-650
The purpose of this study was to develop an animal model for behaviora
l features of type II, early-onset alcohol abuse. To perform this rese
arch, cerebrospinal fluid (CSF) monoamine metabolite concentrations an
d home-cage social behaviors of 29 rhesus macaque subjects were examin
ed in a 4-year longitudinal study. Half of the monkeys were reared for
their first 6 months with their mothers, and the other half were rear
ed without adults, instead with access only to monkeys of similar age.
When the subjects were 6 months old, and again when they were 50 mont
hs old, they underwent a series of four, 4-day social separations. We
obtained cisternal CSF before and during the first and last separation
of each series to quantify 5-hydroxy-indoleacetic acid (5-HIAA), 3-me
thoxy-4-hydroxyphenylgycol (MHPG), and homovanillic acid concentration
s. After the 6-month separations, subjects were placed into social gro
ups, and social dominance rankings were assessed. Before and after the
50-month separations, social dominance rankings were evaluated again,
and home-cage aggression and social behavior data were collected. Ove
r the 3 1/2 years between CSF samplings, records were maintained of su
bjects' removal from their social groups for excessive aggression or t
reatment for wounding. Our results showed that among infants, reduced
CSF 5-HIAA was correlated with low social dominance, As young adults,
subjects from both rearing groups with low CSF 5-HIAA and MHPG concent
rations exhibited reduced rates of social interaction and low social d
ominance rankings. In addition, peer-reared subjects with low CSF 5-HI
AA concentrations exhibited inept social behaviors, and were frequentl
y removed from their social groups for excessive aggression and devian
t social behaviors. From these results, we conclude that the peer-rear
ing paradigm aggravates the untoward social consequences associated wi
th low OSF 5-HIAA concentrations over and beyond reducing CSF 5-HIAA c
oncentrations, suggesting that early experiences may contribute to CNS
serotonin changes that increase the disposition to type II-related be
haviors.