title: A photosensitive surface capable of inducing electrophysiological changes in NG108-15 neurons.
abstract: Retinal prostheses promise to be a viable therapy for many forms of blindness. Direct stimulation of neurons using an organic light-sensitive, self-assembled monolayer surface offers a simple alternative to conventional semiconductor technology. For this purpose we have derivatized an indium tin oxide (ITO) substrate with the photosensitive dye, NK5962, using 3-(aminopropyl)trimethoxysilane (APTMS) as cross-linker. The surface was characterized through contact angle goniometry, electrochemical impedance spectroscopy, grazing angle infrared and ultraviolet-visible spectrophotometry. NG108-15 neurons were grown on the ITO-APTMS-NK5962 surface and neural responses from electrical stimulation vs. photostimulation through the ITO-APTMS-NK5962 surface were measured using patch clamp electrophysiology. Under these conditions, photostimulation of depolarized cells caused an approximate 2-fold increase in voltage-gated sodium (Na(+)) current amplitude at a membrane potential of -30mV. Our results demonstrate the feasibility of stimulating neurons, grown on light-sensitive surfaces, with light impulses, which ultimately may facilitate the fabrication of a simple, passive retinal prosthetic.
authors.affiliation: The Bioengineering Institute, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA; Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Huang
authors.affiliation: The Bioengineering Institute, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: John
authors.initials: J
authors.lastname: Bladon
authors.affiliation: The Bioengineering Institute, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA; Department of Biomedical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: Ross C
authors.initials: RC
authors.lastname: Lagoy
authors.affiliation: The Bioengineering Institute, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA; Department of Biomedical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Shorrock
authors.affiliation: The Bioengineering Institute, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA; Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: Marie
authors.initials: M
authors.lastname: Hronik-Tupaj
authors.affiliation: Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Zoto
authors.affiliation: Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Connors
authors.affiliation: Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA.
authors.forename: W
authors.initials: W
authors.lastname: Grant McGimpsey
authors.affiliation: Institute of Biology, Faculty of Natural Sciences, University of West Hungary, Szombathely H-9700, Hungary.
authors.forename: Peter
authors.initials: P
authors.lastname: Molnar
authors.affiliation: Department of Medical Education, University of Central Florida, College of Medicine, 6850 Lake Nona Blvd., Orlando, FL 32827, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Lambert
authors.affiliation: Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA. Electronic address: Ann.Rittenhouse@umassmed.edu.
authors.forename: Ann R
authors.initials: AR
authors.lastname: Rittenhouse
authors.affiliation: The Bioengineering Institute, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA; Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA. Electronic address: clambert@wpi.edu.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Lambert
mesh_terms: D002460:Cell Line; D006801:Humans; D009474:Neurons / Q000502:physiology*; D013057:Spectrum Analysis / Q000379:methods*; D013499:Surface Properties
keywords: Current clamp; Neuronal stimulation; Retinal prosthetic; Self-assembled monolayer (SAM); Voltage clamp