Effects of the Ultra-low Frequencies TENS on the Arousal Circuits

Changes in pupil size are indicative of the activity of the noradrenergic system, with pupil dilation associated with a higher state of arousal. According to various studies, odontological ULFTENS, through trigeminal stimulation, can help rebalance this altered system with positive effects. Our goal is to harness the capabilities of ULFTENS by stimulating the dorsal lingual mucosa and evaluating its effects on pupil size in the dark. Healthy women aged between 20 and 30 will be recruited and divided into two groups: a control group and an experimental group. Participants in the control group will lie down on a bed with their eyes closed, and will then be asked to open their eyes without moving their eyelids. Pupil diameter will be measured using a pupillometer for 15 seconds. This procedure will be repeated twice. The experimental group will receive a tongue stimulator connected to the ULFTENS, which will be activated after the first measurement. The stimulation will last approximately 15 minutes, with a second measurement taken after 15 seconds. At the end of the stimulation, the final measurement will be taken. The goal is to measure the pupil diameter of both eyes at the three time points and compare the results between the two groups to assess the effect of the stimulator on arousal circuits.

Inclusion criteria

• good health status and physical fitness
• female sex
• age between 20 and 30 years
• non-smoker
• no more than 3 espresso coffees per day
• no intake of stimulant or psychotropic drugs in general
• body mass index between 18.5 and 24.9

Exclusion criteria

• presence of acute and/or chronic cardiocirculatory and respiratory disorders
• metabolic and autonomic system disorders
• intake of peripheral and central nervous system excitatory or inhibiting substances
• presence of generalized anxiety and/or panic attacks, or mood disorders.