Vagal nerve stimulation (VNS) refers to any tech‑ nique that stimulates the vagal nerve, including man‑ ual or electrical stimulation. Approved by the FDA at the end of the 20th century, VNS was initially used as an add-on treatment for medically refractory epilep‑ sy. Today, VNS has also been studied as a treatment for mood and cognitive disorders, such as major depression, bipolar disorder, and Alzheimer’s disease. Although VNS requires an invasive surgical procedure, this technique is increasingly widespread in medical practice. Recent‑ ly, we have demonstrated that hippocampal (HPC) thetarhythm can be produced, depending on current inten‑ sity, directly during vagal nerve stimulation (VNS) or post-stimulation. This suggests that theta EEG pattern can be used as a bio-indicator of the efficiency of VNS. In the present study, we focused on three specific tech‑ nical issues related to the stimulation procedure of the vagal nerve: 1) Does the type of electrode used for VNS and the technique of its implantation affect the param‑ eters of the HPC theta rhythm? 2) Does the type of elec‑ trode used determine the current intensity threshold of VNS-induced HPC theta? 3) Is the repeatability of the VNS effect determined by the type of electrode used? In rats (male Wistar) with an implanted tungsten micro‑ electrode (0.1–0.9 MΩ) for recording the HPC field ac‑ tivity, VNS was applied using two types of stimulating electrodes: tungsten bipolar fork electrode and plati‑ num-iridium cuff electrode. The first type of stimulating electrode touched a vagal nerve surface only during the stimulation and the second type surrounded the nerve and has contact with it throughout the entire experi‑ ment. During experiments the following VNS intensi‑ ties were tested: 1, 2, 4, 6, 8, and 10 mA. The remaining parameters were constant: pulse duration (1 ms), train duration (10 s), and frequency (10 Hz). A direct (brief) effect of VNS on the HPC field potential was evaluated. We demonstrated that using the cuff electrode for VNS offers a lower current intensity threshold for inducing HPC theta than using a fork electrode. Furthermore, in contrast to a fork electrode, the cuff electrode offers re‑ peatability of the VNS effect on HPC theta activity. The final effect of VNS is determined by many factors in‑ cluding the stimulation protocol and type of stimulating electrode used. This work was supported by RPO grant (RPLD.01.02.02-10-0067/17-00)
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.