Distribution of brain monoamines in left- and right-handed mice injected with bacillus Calmette-Guerin.

Concentrations of brain monoamines from various cerebral structures were determined in right and left sides of the brain from female mice selected for paw preference and injected or not with BCG 8 weeks before. BCG-induced changes in brain monoamine distribution in prefrontal cortex, medial hypothalamus and brain stem were only observed in right-handers. In the posterior hypothalamus, even though there was no BCG effect, norepinephrine asymmetry observed in right-handed controls was suppressed after BCG-injection. Moreover, BCG-induced brain monoamine changes in right-handers mainly involved the right hemisphere except the NE decrease in brain stem which was left-sided. This work demonstrates that the injection of BCG leads to long lasting asymmetrical changes in brain monoamine distribution that furthermore depend on behavioral lateralization of mice.