Effects of neurotensin on the release of glutamic acid in the prefrontal cortex and striatum of the rat.

The effects of neurotensin (NT) on the extracellular concentrations of excitatory amino acids (EAA) glutamic acid (GLU) and aspartic acid (ASP) in the medial prefrontal cortex (MPC) and striatum (ST) of the conscious rat have been studied. NT was infused directly into these two structures for 10 min at doses of 10, 100 and 1000 nM. In the MPC, NT produced a dose-related increase of GLU. Also, NT produced a delayed increase of ASP at the highest dose. In ST, NT at doses of 10, 100 and 1000 nM produced no effect on GLU and ASP. It is suggested that the increase of GLU and ASP in the MPC could be due to a direct effect of NT on pyramidal cortical neurones. On the contrary, it is suggested that a direct interaction NT-GLU does not exist in the ST of the rat.