Activation of neurotensin receptors in the prefrontal cortex stimulates midbrain dopamine cell firing.

The effects of medial prefrontal cortex microinjections of 3 nmol/0.5 microl of neurotensin-(1-13), the inactive fragment neurotensin-(1-8), or vehicle on the firing rate of midbrain dopamine neurons were studied in anesthetized rats. Twelve of 19 cells tested with neurotensin-(1-13) showed an average 20-25% increase in firing rate between 10 and 20 min after the injection. This effect was not mimicked by neurotensin-(1-8) (9 cells), nor by a control injection (10 cells) suggesting that it is mediated by high-affinity neurotensin receptors. These results suggest that activation of neurotensin receptors in the medial prefrontal cortex can modulate neural activity of a subpopulation of midbrain dopamine neurons.