title: Mass spectrometric imaging of peptide release from neuronal cells within microfluidic devices.
abstract: Microfluidic devices are well suited for manipulating and measuring mass limited samples. Here we adapt a microfluidic device containing functionalized surfaces to chemically stimulate a small number of neurons (down to a single neuron), collect the release of neuropeptides, and characterize them using mass spectrometry. As only a small fraction of the peptides present in a neuron are released with physiologically relevant stimulations, the amount of material available for measurement is small, thereby requiring minimal sample loss and high-sensitivity detection. Although a number of detection schemes are used with microfluidic devices, mass spectrometric detection is used here because of its high information content, allowing the characterization of the released peptide complement. Rather than using an on-line approach, off-line analysis is used; after collection of the peptides onto a surface, mass spectrometric imaging interrogates that surface to determine the peptides released from the cell. The overall utility of this scheme is demonstrated using several device formats with measurement of neuropeptides released from Aplysia californica bag cell neurons.
authors.affiliation: Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, 405 N. Mathew Avenue, Urbana, Illinois 61801, USA.
authors.forename: Kyubong
authors.initials: K
authors.lastname: Jo
authors.forename: Michael L
authors.initials: ML
authors.lastname: Heien
authors.forename: Lucas B
authors.initials: LB
authors.lastname: Thompson
authors.forename: Ming
authors.initials: M
authors.lastname: Zhong
authors.forename: Ralph G
authors.initials: RG
authors.lastname: Nuzzo
authors.forename: Jonathan V
authors.initials: JV
authors.lastname: Sweedler
mesh_terms: D000818:Animals; D001048:Aplysia; D013058:Mass Spectrometry / Q000379:methods*; D044085:Microfluidics / Q000295:instrumentation*; D009474:Neurons / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*
chemical_list: D010455:Peptides