Three classes of GABAergic interneurons in neocortex and neostriatum

We have compared the cellular organization of GABAergic interneurons between frontal cortex and neostriatum of rats by immunohistochemistry for calcium-binding proteins, somatostatin and nitric oxide synthase (NOS). GABAergic interneurons in both neocortex and neostriatum could be divided into three separate populations containing parvalbumin, somatostatin, or calretinin. NOS cells were considered to be GABAergic and belong to somatostatin cells in both structures. Distributions of calbindin D28k in three classes of interneurons were different among neocortical layers and neostriatum.