Serotonin laterality in amygdala predicts performance in the elevated plusmaze in rats

BEHAVIOR in the elevated plus maze was correlated with hemispheric asymmetr ies in neurotransmitter content in limbic brain regions assayed with HPLC-E C in adult rats. A strong (r = 0.86, p < 0.003) correlation exists between increased anxiety (more time spent in the closed arm) and the lateralizatio n of serotonin in the amygdala. Greater serotonin in the right versus left amygdala relates to greater anxiety. In addition, increased dopamine in rig ht prefrontal cortex is strongly correlated with anxiety (r = 0.84, p < 0.0 1). No such correlations were observed for accumbens, hippocampus, or stria tum. These data support the hypothesis that the right hemisphere is involve d in emotional states: increased serotonin in the right amygdala is related to anxiety, while cortical dopamine may be associated with attention to th e environment. (C) 1999 Lippincott Williams & Wilkins.