Specific influence of striatal target neurons on the in vitro outgrowth of mesencephalic dopaminergic neurites: a morphological quantitative study.

In previous studies, we have shown that dissociated dopaminergic neurons from embryonic mouse in co-culture with striatal target neurons take up and synthesize dopamine to a greater extent. We now report that striatal target cells influence the morphology of dopaminergic neurons as well. In co-culture, the total length of neuritic arborization visualized by autoradiography is reduced when compared to cultures of mesencephalic neurons alone or to co-cultures with cerebellar cells. Experiments performed in the presence of striatal glial cells at the same density as striatal neurons or with media conditioned with striatal glia or neurons suggest that striatal neurons regulate dopaminergic afferent growth in vitro through specific neuro-neuronal interactions.