TY - JOUR
T1 - MALDI mass spectrometric imaging using the stretched sample method to reveal neuropeptide distributions in Aplysia nervous tissue
AU - Zimmerman, Tyler A.
AU - Rubakhin, Stanislav S.
AU - Romanova, Elena V.
AU - Tucker, Kevin R.
AU - Sweedler, Jonathan V.
PY - 2009
Y1 - 2009
N2 - Neuropeptides are a diverse set of complex cell-cell signaling molecules that modulate behavior, learning, and memory. Their spatially heterogeneous distributions, large number of post-translational modifications, and wide range of physiologically active concentrations make their characterization challenging. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometric imaging is well-suited to characterizing and mapping neuropeptides in the central nervous system. Because matrix application can cause peptide migration within tissue samples, application parameters for MALDI typically represent a compromise between attaining the highest signal quality and preserving native spatial distributions. The stretched sample approach minimizes this trade-off by fragmenting the tissue section into thousands of spatially isolated islands, each ∼40 μm in size. This inhibits analyte migration between the pieces and, at the same time, reduces analyte-salt adduct formation. Here, we present methodological improvements that enable the imaging of stretched tissues and reveal neuropeptide distributions in nervous tissue from Aplysia californica. The distributions of known neuropeptides are shown to correspond with previous immunohistochemical results, demonstrating that the stretched imaging method is well-suited for working with easily redistributed molecules and heterogeneous tissues and reduces adducts from physiological salts.
AB - Neuropeptides are a diverse set of complex cell-cell signaling molecules that modulate behavior, learning, and memory. Their spatially heterogeneous distributions, large number of post-translational modifications, and wide range of physiologically active concentrations make their characterization challenging. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometric imaging is well-suited to characterizing and mapping neuropeptides in the central nervous system. Because matrix application can cause peptide migration within tissue samples, application parameters for MALDI typically represent a compromise between attaining the highest signal quality and preserving native spatial distributions. The stretched sample approach minimizes this trade-off by fragmenting the tissue section into thousands of spatially isolated islands, each ∼40 μm in size. This inhibits analyte migration between the pieces and, at the same time, reduces analyte-salt adduct formation. Here, we present methodological improvements that enable the imaging of stretched tissues and reveal neuropeptide distributions in nervous tissue from Aplysia californica. The distributions of known neuropeptides are shown to correspond with previous immunohistochemical results, demonstrating that the stretched imaging method is well-suited for working with easily redistributed molecules and heterogeneous tissues and reduces adducts from physiological salts.
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U2 - 10.1021/ac901820v
DO - 10.1021/ac901820v
M3 - Article
C2 - 19835365
AN - SCOPUS:70649106980
SN - 0003-2700
VL - 81
SP - 9402
EP - 9409
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 22
ER -