Haloperidol increases DOPAC in the substantia nigra but not in the ventral tegmental area

Haloperidol (0.1 to 0.5 mg/kg) caused a dose related increase in DOPAC content both in the substantia nigra (pars compacta + pars reticulata) (by 27 to 134%) and in the caudate nucleus (by 127 to 252%). On the contrary even 5 mg/kg of haloperidol failed to modify DOPAC level in the ventral tegmental area. The results indicate that DA cells in ventral tegmental area differ from those in the substantia nigra not only on anatomical grounds but also on a functional point of view.