Related Experiment Video
Updated: Feb 13, 2026
Somatosensory Event-related Potentials from Orofacial Skin Stretch Stimulation
Published on: December 18, 2015
Laser evoked potential amplitude and laser-pain rating reduction during high-frequency non-noxious somatosensory
Massimiliano Valeriani1, Costanza Pazzaglia2, Vincenzo Rizzo3
1Neurology Unit, Ospedale Pediatrico Bambino Gesú, IRCCS, Piazza di Sant'Onofrio, 4, 00165 Rome, Italy; Center for Sensory-Motor Interaction, Aalborg University, Fredrik Bajers Vej 7D-3, 9220 Aalborg, Denmark.
Objective:
To investigate the mechanism subtending the analgesic effect of high frequency non-painful somatosensory stimulation.
Methods:
Laser evoked potentials (LEPs) and laser-pain rating were obtained from healthy subjects to stimulation of different parts of the body. LEPs were recorded at baseline and during non-painful electrical stimulation of the superficial branch of the right radial nerve (RRES).
Results:
RRES reduced N2/P2 LEP amplitude to right radial (F(8,10) = 82.4, p < 0.001), left radial (F(8,10) = 22.2, p < 0.001), and right ulnar (F(8,10) = 7.2, p = 0.008) stimulation, while the N2/P2 amplitude to left ulnar territory stimulation remained unchanged (F(8,10) = 3.6, p = 0.07). The laser-pain rating was reduced by RRES to bilateral radial territory stimulation (p < 0.05). In a control experiment, laser-pain rating and LEPs to left foot stimulation were not modified by RRES (p > 0.05).
Conclusions:
Our study confirms that the non-nociceptive afferents dampen the nociceptive input. The spatial pattern of this interaction suggests that, when conditioning higher frequency non-painful stimulation is used, the inhibition takes place at the spinal cord.
Significance:
Our experimental design reproduces what happens when non-painful somatosensory stimuli are used to reduce pain, such as rubbing a wound or during transcutaneous electrical nerve stimulation. Therefore, in these situations the analgesia is likely to occur at the spinal cord level.
More Related Videos
07:52Simultaneous Recordings of Cortical Local Field Potentials and Electrocorticograms in Response to Nociceptive Laser Stimuli from Freely Moving Rats
Published on: January 7, 2019
09:38Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies
Published on: December 18, 2015
Related Concept Videos
01:22Muscle Stimulation Frequency
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
01:28Action Potential: Phases of Stimulation
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...
01:08Matrix-Assisted Laser Desorption Ionization (MALDI)
01:17Pulse amplitude and quality
A weak or absent pulse may indicate reduced cardiac output or poor left ventricular contraction, which can be signs of cardiovascular dysfunction or...
02:55Temperature Dependence on Reaction Rate
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
03:02Standard Electrode Potentials