1 November 2009 Combined optical and electrical stimulation of neural tissue in vivo
Author Affiliations +
J. of Biomedical Optics, 14(6), 060501 (2009). doi:10.1117/1.3257230
Low-intensity, pulsed infrared light provides a novel nerve stimulation modality that avoids the limitations of traditional electrical methods such as necessity of contact, presence of a stimulation artifact, and relatively poor spatial precision. Infrared neural stimulation (INS) is, however, limited by a 2:1 ratio of threshold radiant exposures for damage to that for stimulation. We have shown that this ratio is increased to nearly 6:1 by combining the infrared pulse with a subthreshold electrical stimulus. Our results indicate a nonlinear relationship between the subthreshold depolarizing electrical stimulus and additional optical energy required to reach stimulation threshold. The change in optical threshold decreases linearly as the delay between the electrical and optical pulses is increased. We have shown that the high spatial precision of INS is maintained for this combined stimulation modality. Results of this study will facilitate the development of applications for infrared neural stimulation, as well as target the efforts to uncover the mechanism by which infrared light activates neural tissue.
Austin R. Duke, Jonathan M. Cayce, Jonathan D. Malphrus, Peter Konrad, Anita Mahadevan-Jansen, E. Duco Jansen, "Combined optical and electrical stimulation of neural tissue in vivo," Journal of Biomedical Optics 14(6), 060501 (1 November 2009). http://dx.doi.org/10.1117/1.3257230
Submission: Received ; Accepted

Tissue optics

Infrared radiation


Ocean optics


Laser damage threshold

Laser induced damage

Back to Top