Chromogranin A, a soluble synaptic vesicle protein, is found in cortical neurons other than previously defined peptidergic neurons in the human neocortex.

Neuropeptides in the cerebral cortex have previously been identified in non-pyramidal neurons only. By comparing the location of chromogranin A (CgA), a soluble protein of large dense-core synaptic vesicles, with that of SMI-32, neuropeptide Y (NPY), parvalbumin (PV) and calbindin (CaBP) using double label immunohistochemistry, we demonstrate that CgA is present in pyramidal neurons as well as in several subtypes of non-pyramidal neurons.