Figure 2.

Quantitation of endogenous substance P 1–11 (SP) concentration in a mouse brain sagittal tissue section. (a) Digital photograph of the mouse brain tissue section indicating different brain tissue structures. (b) SP was quantified in the nucleus accumbens, caudoputamen, globus pallidus external segment, substantia nigra, substantia innominata. The matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) imaging analysis shows that endogenous SP is detected at high concentrations in substantia innominata, globus pallidus external segment, and substantia nigra. (c) Mass spectrum from the substantia innominata structure showing the monoisotopic mass of SP (inset). Reproduced with permission (Kallback et al, 2012).