Depletion in substance P- and neurokinin A-like immunoreactivity in substantia nigra after ibotenate-induced lesions of striatum.

Changes in substance P (SP)- and neurokinin A (NKA)-like immunoreactivity (LI) in the rat substantia nigra (SN) after striatal lesion produced by ibotenate were studied using immunohistochemical methods. Compared to the SN on the control side, both SP- and NKA-LI were dramatically depleted in the SN on the lesion side. These findings are consistent with the existence of SP- and/or NKA-containing neurons in the striatum projecting to the SN.