Interactions between neurotensin and dopamine in the brain: an overview.

Neurotensin (NT)-like immunoreactivity is found in high concentrations in many brain areas under important dopaminergic control, such as the nucleus accumbens and the substantia nigra and its receptors are also highly concentrated in the A-9 and A-10 regions. Neurotensin-induced behavioral actions after intracerebral injections bear many similarities with neuroleptics. Moreover, NT is able to modify dopamine metabolism in various brain regions. Finally, 6-hydroxydopamine (6-OHDA) lesions of A-9 and A-10 regions markedly decrease NT receptors in these areas and in the caudate-putamen. All together, these data strongly suggest that NT interacts with mesolimbic and nigrostriatal dopaminergic pathways in the brain.