Antinociceptive Effect of Transauricular Electrical Vagal Nerve Stimulation

Antinociceptive Effect of Transauricular Electrical Vagal Nerve Stimulation and Its Underlying Mechanisms

This investigation is going to study whether electrical tVNS applied at the cymba of auricular conchae reduces central sensitization of experimentally induced pain in comparison with electrical sham stimulation applied at the earlobes and whether the hypoalgesic effects of tVNS disappear after pharmacological block of muscarinic receptors. Also, this investigation will examine whether tVNS is associated with activation in brain areas, involved in processing of thermal pain stimuli and emotional and vegetative modulation of thermal pain in subjects who will respond with antinociceptive reaction to tVNS.

Inclusion Criteria:

• healthy volunteers aged 18-45 years old, who have given informed consent
• at least two days free from consume of recreational drugs
• no local infection at the site of tVNS and pain stimulation

Exclusion Criteria:

• psychiatric disorders
• abnormal skin conditions (infection, scars, psoriasis, eczema) at the site of tVNS
• contra-indications for MRI (e.g. claustrophobia, pregnancy, tattoos, metallic implants)
• history of coronary heart disease, cardiac arrhythmia, glaucoma, allergy to sulphates