title: Monitoring neurotransmitter release using surface-enhanced Raman spectroscopy.
abstract: Surface-enhanced Raman spectroscopy (SERS) is a promising tool to monitor neurotransmitter release at the single-cell level: it is a sensitive technique that provides structural information of the released compounds and spatial information about their release sites. In this study we demonstrate that depolarization-evoked catecholamine secretion by rat phaeochromocytoma (PC12) cells can be spatially resolved by SERS using silver colloids. A suitable SERS substrate was created by adding silver colloids to the cell culture medium. Nomarski-DIC microscopy combined with reflection confocal laser scanning microscopy showed that the colloids were primarily present on top of the cell membrane. The SERS spectra were successfully corrected for the contribution of cell constituents. Dopamine and noradrenaline were localized by examining the correlation coefficient between spectra and reference catecholamine spectra. Potential improvements of the temporal resolution of the technique are discussed.
authors.affiliation: Applied Molecular Physics, Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands.
authors.forename: Reyer J
authors.initials: RJ
authors.lastname: Dijkstra
authors.forename: Wim J J M
authors.initials: WJ
authors.lastname: Scheenen
authors.forename: Nico
authors.initials: N
authors.lastname: Dam
authors.forename: Eric W
authors.initials: EW
authors.lastname: Roubos
authors.forename: J J
authors.initials: JJ
authors.lastname: ter Meulen
mesh_terms: D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D003102:Colloids; D017979:Gold Colloid; D018613:Microscopy, Confocal; D018377:Neurotransmitter Agents / Q000378:metabolism*; D016716:PC12 Cells; D051381:Rats; D012015:Reference Standards; D016622:Silver Staining; D013059:Spectrum Analysis, Raman / Q000295:instrumentation / Q000379:methods*
chemical_list: D002395:Catecholamines; D003102:Colloids; D017979:Gold Colloid; D018377:Neurotransmitter Agents