Comparative localization of neurotensin receptors on nigrostriatal and mesolimbic dopaminergic terminals.

Neurotensin (NT), a brain-gut peptide, possesses many biological actions similar to those reported for neuroleptics. Moreover, it has been shown that NT alters dopaminergic activity of both nigrostriatal and mesolimbic pathways. We now report that NT receptors are located on dopaminergic cell bodies in both systems. However, the proportion of NT receptors on presynaptic dopaminergic terminals appears to be different. NT receptor sites are mainly found on presynaptic dopaminergic terminals in the caudate-putamen while they are pre- and post-synaptically located in the nucleus accumbens and the olfactory tubercule. NT receptors differential localization in these two pathways could be used as a model to study the comparative physiology of various dopaminergic brain systems.