Differential sensitivity of neuropeptide Y, somatostatin and NADPH-diaphorase containing neurons in rat cortex and striatum to quinolinic acid.

The tryptophan metabolite quinolinic acid (QUIN) was injected unilaterally into rat cerebral cortex or striatum in order to determine whether the neurotoxin would destroy neuropeptide Y (NPY)- and somatostatin (SS)-immunoreactive, and NADPH-diaphorase (NADPH-D)-containing neurons. Following intrastriatal injections of QUIN, NPY and SS immunoreactivity and NADPH-D-activity was absent in the injection core area. In contrast, cortical NPY- and SS-immunoreactive cells and NADPH-D-containing neurons were resistant to QUIN's neurotoxicity. These results suggest that in contrast to striatal neurons, cortical SS- and NPY-containing neurons do not express N-methyl-D-aspartate receptors.