A pilot study: Infrared laser stimulation of the rat vagus nerves

The vagus nerve originating from the brainstem in the central nervous system is a long cranial nerve that reaches the neck, thorax, abdomen, and colon. It plays a role in autonomic nervous, cardiovascular, gastrointestinal, and immune systems. Electrical stimulation of the vagus nerve has become a standard method for the treatment of neuropathic pain and epileptic conditions over the years. Infrared laser nerve stimulation (ILNS) is an evolving technique that uses infrared laser energy to stimulate cells with electrochemical capacity without the need for external agents or physical contact. This pilot study explores infrared laser stimulation of the rat vagus nerve, in-vivo. An infrared pigtailed single-mode diode laser operating at 1505 nm in continuous-wave (CW) mode was used in this study for noncontact CW-ILNS. Successful CW-ILNS of the rat vagus nerve was observed after the CN reached a threshold temperature of similar to 44 degrees C with response times as short as 10 s. With more improvement in instrumentation, better optimization of stimulation parameters, and a higher sample size, CW-ILNS may show some potential in vagus nerve stimulation for preclinical