Rotational behavior produced by unilateral ventral noradrenergic bundle lesions: evidence for a noradrenergic-dopaminergic interaction in the brain.

In this study the effect of unilateral electrocoagulation of the ventral noradrenergic bundle (VB) on rotational behavior produced by dopaminergic agonists was investigated. Unilateral lesions to the VB produced a decrease in the concentration of noradrenaline but not dopamine, serotonin or 5-hydroxyindoleacetic acid (5-HIAA) in the ipsilateral part of the forebrain. These lesions produced also strong and dose-dependent preference for ipsilateral rotation after systemic injection of apomorphine or amphetamine. The results are discussed in terms of possible interaction between noradrenergic and dopaminergic systems and it is proposed that the VB plays a regulatory role in the function of brain nigro-striatal dopaminergic system.