Pulsed laser versus electrical energy for peripheral nerve stimulation

Abstract

Transient optical neural stimulation has previously been shown to elicit highly controlled, artifactfree potentials within the nervous system in a non-contact fashion without resulting in damage to tissue. This paper presents the physiologic validity of elicited nerve and muscle potentials from pulsed laser induced stimulation of the peripheral nerve in a comparative study with the standard method of electrically evoked potentials. Herein, the fundamental physical properties underlying the two techniques are contrasted. Key laser parameters for efficient optical stimulation of the peripheral nerve are detailed. Strength response curves are shown to be linear for each stimulation modality, although fewer axons can be recruited with optically evoked potentials. Results compare the relative transient energy requirements for stimulation using each technique and demonstrate that optical methods can selectively excite functional nerve stimulation. Adjacent stimulation and recording of compound nerve potentials in their entirety from optical and electrical stimulation are presented, with optical responses shown to be free of any stimulation artifact. Thus, use of a pulsed laser exhibits some advantages when compared to standard electrical means for excitation of muscle potentials in the peripheral nerve in the research domain and possibly for clinical diagnostics in the future.

Thermal Transients Excite Neurons through Universal Intramembrane Mechanoelectrical Effects

“…This study explored the effects of temperature changes on membrane capacitance and its associated currents in a joint attempt to clarify the experimental results of a key recent study [16] and to pave the way towards predictive modeling of INS [2][3][4][5][6][7][8][9][10][11][12][13][14][15] and other thermal neurostimulation techniques [18][19][20], which could potentially facilitate the development of more advanced and multimodal methods for neural circuit control. Another key motivation to pursue this problem came from our noting the very similar temperature-related capacitance rates of change observed in very different model systems [ Fig.…”

“…Both approaches also offer the long-term prospect of remotely affecting aberrant localized neural circuits that underlie many neurological diseases. A multitude of INS-related studies explored the ability of short-wave infrared (IR) pulses to stimulate neural structures including peripheral [3,4] and cranial nerves [5][6][7][8][9][10], retinal and cortical neurons [10][11][12], as well as cardiomyocytes [13,14]. It is stipulated that the INS phenomenon is mediated by temperature transients induced by IR absorption [15][16][17]; such transients can alternatively be induced using other forms of photoabsorption [18][19][20], or potentially by any other physical form of thermal neurostimulation that can be driven rapidly enough [21,22].…”

Synergistic combination of near-infrared irradiation and targeted gold nanoheaters for enhanced photothermal neural stimulation

“…Although it is an excellent tool for preclinical breakthroughs, optogenetics is still unavailable in clinical use owing to controversial issue of genetic manipulation in human. On the other hand, infrared neural stimulation (INS) enables us to control neural activities by delivering infrared light energy into the target neural cells without genetic modification [2,6,9,10]. While the underlying mechanism is not clear yet, it has been hypothesized that infrared light can excite or inhibit neural cells depending on the thermal gradient at the cell membrane [4,6,[11][12][13][14].…”

Spinal Cord Injury: Present and Future Therapeutic Devices and Prostheses

“…Photic stimulation of peripheral nerves has been demonstrated to be possible. 76,77 Photolytic uncaging of neurotransmitters 118 from the covalently bonded chromophore moieties that render them biologically inert is now possible at wavelengths that are of little risk. Uncaging is a tradeoff of energetics of light delivered, speed of uptake of uncaged neurotransmitter by neural and glial scavenging systems, diffusion delivery and excitotoxic or other effects at extrasynaptic receptors (FIG.…”

“…Light has been tested as a peripheral nerve stimulation device. 76,77 The packaging and clinical use remain unclear, but this method under development requires no special transfection or chromophore and channel insertions. Specificity of fascicle targeting within a nerve with such stimulation remains to be developed.…”