Monoamine changes in the brain of BALB/c mice following sub-lethal infection with Nocardia asteroides (GUH-2)

BALB/c mice injected intravenously with a single, sub-lethal dose of Nocard ia asteroides GUH-2 develop several levodopa responsive movement disorders. These included head-shake, stooped posture, bradykinesia, and hesitation t o forward movement (6). The changes in monoamine levels in the brain of the se mice were determined. There was a significant loss of dopamine with grea tly increased dopamine turnover in the neostriatum 7 to 29 days after infec tion. These effects were specific for dopaminergic neurons since minimal ch anges were found in neostriatal norepinephrine and serotonin even though se rotonin turnover was increased. Changes in monoamine metabolism were not li mited to the neostriatum. There were reduced levels of serotonin and norepi nephrine with increased serotonin turnover in the cerebellum. One year afte r infection, dopamine metabolism had returned to near normal levels, but ma ny of the movement disorders persisted. Specific changes in neurochemistry did not always appear to correspond with these impairments. Nevertheless, t hese data are similar to those reported in MPTP treated BALB/c mice.