Near-infrared stimulation on globus pallidus and subthalamus

Abstract

Abstract. Near-infrared stimulation (NIS) is an emerging technique used to evoke action potentials in nervous systems. Its efficacy of evoking action potentials has been demonstrated in different nerve tissues. However, few studies have been performed using NIS to stimulate the deep brain structures, such as globus pallidus (GP) and subthalamic nucleus (STN). Male Sprague-Dawley rats were randomly divided into GP stimulation group (n ¼ 11) and STN stimulation group (n ¼ 6). After introducing optrodes stereotaxically into the GP or STN, we stimulated neural tissue for 2 min with continuous near-infrared light of 808 nm while varying the radiant exposure from 40 to 10 mW. The effects were investigated with extracellular recordings and the temperature rises at the stimulation site were also measured. NIS was found to elicit excitatory responses in eight out of 11 cases (73%) and inhibitory responses in three cases in the GP stimulation group, whereas it predominantly evoked inhibitory responses in seven out of eight cases (87.5%) and an excitatory response in one case in STN stimulation group. Only radiation above 20 mW, accompanying temperature increases of more than 2°C, elicited a statistically significant neural response (p < 0.05). The responsiveness to NIS was linearly dependent on the power of radiation exposure. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Infrared neural stimulation of human spinal nerve rootsin vivo

“…Further, other studies investigating INS have demonstrated that the technique must be optimized for each new application due to different tissue geometries and function. [5][6][7]15,17,22,25,30 Optimization of INS for human applications will be required, but as this study demonstrates, preclinical results will likely translate to clinical application, indicating most optimization can be achieved in preclinical models.…”

“…[23][24][25] Several studies have demonstrated the ability of pulsed infrared light to modulate neural activity in cortical neurons, highlighting the clinical applicability for central nervous system applications, such as deep brain stimulation and cortical neural prosthetics for brain machine interfaces. 7,[26][27][28][29][30]44 These example applications of INS given here represent only a small percentage of the possible applications where INS may improve the standard clinical care. The high spatial selectivity of INS will allow clinicians to stimulate subfascicular for peripheral nerve reconstruction, such as brachial nerve plexus or otolaryngology applications, where surgeons have a need to identify small groups of fibers to determine function and connectivity.…”

“…3 The initial results from our group's efforts have led to the development of INS for clinically relevant diagnostic and therapeutic applications, including neural monitoring, 5,[15][16][17][18] cochlear and vestibular stimulation, [19][20][21][22] cardiac pacing, [23][24][25] and applications in the central nervous system. 7,[26][27][28][29][30] Each of these studies demonstrates that INS is capable of producing high levels of spatial precision in stimulating excitable tissue.…”

The “curved lead pathway” method to enable a single lead to reach any two intracranial targets

“…Further work is required to determine how safe and accurate this method is for different combinations of targets, evaluate potential side effects, and establish a more complete procedure for “curved lead pathway” design. Third, in this study, we used adult male Sprague-Dawley rats weighing 280–300 g, but the Paxinos and Watson atlas is developed from study of adult male Wistar rats with weights ranging from 270 to 310 g. Althought the Paxinos and Watson atlas is also suitable for the male Sprague Dawley rats with the same weight38394041, there might be a few of anatomic differences between the Sprague-Dawley rat brain and the Paxinos and Watson atlas.…”

“…The coordinates of the targets in rat brain were determined with The Rat Brain in Stereotaxic Coordinates of Paxinos and Watson (Sixth edition, 2007 )38. The Paxinos and Watson atlas was suitable for male Sprague-Dawledy rats with an average weight of 290 g used in this study38394041. Since there are several radii available for the “curved lead pathway”, and the bilateral STN occupy certain volume, there are more than one “curved lead pathways” that could pass the bilateral STN simultaneously.…”