Effects of electroacupuncture (EAP) and intravenous injection of morphine (5 mg/kg) on evoked potentials (EP) elicited in the second somatosensory (S2) and orbitofrontal areas of the brain cortex by nociceptive (the pulp of the upper canine) and non-nociceptive (the upper lip) stimulation were studied in acute experiments on cats. After EAP the EP elicited by nociceptive stimulation of the S2 and orbital gyrus were inhibited 75 and 58%, respectively, with reference to the control level, whereas the EP elicited by non-nociceptive stimulation of the S2 and orbital gyrus rose by 30 and 45%, respectively. Morphine injection produced the same effect on the EP: an increase in the EP during non-nociceptive stimulation and inhibition during nociceptive stimulation. It is suggested that by stimulating the release of endogenous opiates and other neurotransmitters EAP remodels the function of the CNS afferent systems, facilitating the transmission of the non-nociceptive signal through the rapid-conducting lemniscal system, thereby blocking the transmission of the nociceptive signals in the multi-synaptic extralemniscal system.

Download full-text PDF

Source

Publication Analysis

Top Keywords

nociceptive stimulation
8
stimulation orbital
8
orbital gyrus
8
non-nociceptive stimulation
8
stimulation
5
[changes bioelectric
4
bioelectric activity
4
activity orbitofrontal
4
orbitofrontal somatosensory
4
somatosensory areas
4

Similar Publications

Radiofrequency evoked potentials: A new window into the nociceptive system.

Clin Neurophysiol

January 2025

Institute for Research and Development on Bioengineering and Bioinformatics (IBB), CONICET-UNER, Oro Verde, Argentina; Center for Rehabilitation Engineering and Neuromuscular and Sensory Research (CIRINS), National University of Entre Ríos (UNER), Oro Verde, Argentina. Electronic address:

Objective: To describe the cortical evoked potentials in response to radiofrequency stimulation (RFEPs) in human volunteers.

Methods: Seventeen healthy volunteers participated in an experimental session in which radiofrequency (RF) and electrical (ES) stimulation were applied to the dorsum of the hands and feet. EEG was recorded to evaluate evoked responses for each stimulus modality and stimulation site.

View Article and Find Full Text PDF

Dimethyl Fumarate attenuates synovial inflammation, reduces nociception, and inhibits the development of post-traumatic osteoarthritis.

Biomed Pharmacother

January 2025

Joseph Maxwell Cleland Atlanta VA Medical Center, Decatur, GA 30033, USA; Department of Orthopaedics, Emory Musculoskeletal Institute, Emory University, Atlanta, GA 30329, USA. Electronic address:

There is currently no cure or disease-modifying treatment for post-traumatic osteoarthritis (PTOA). This study aims to assess the efficacy of dimethyl fumarate (DMF), a US-FDA approved drug for multiple sclerosis, as a treatment for PTOA. PTOA was induced in male Lewis rats by medial meniscal transection (MMT) surgery, and DMF was intra-articularly administered once, one week following surgery.

View Article and Find Full Text PDF

Background: The Qnox index is a novel monitor to quantify intraoperative nociception based on an electroencephalographic algorithm. We evaluated the ability of the Qnox index to discriminate noxious from non-noxious stimuli, respond to stimuli, and discriminate different levels of analgesia in patients under propofol anaesthesia with neuromuscular block.

Methods: Qnox was compared with heart rate and mean arterial pressure with five designated stimuli: tetanic stimulations without (tetanic 1) and with sufentanil (tetanic 2), skin incision, tracheal intubation, and a non-noxious period.

View Article and Find Full Text PDF

Background: Healthy individuals demonstrate considerable heterogeneity upon dynamic quantitative sensory testing assessment of endogenous pain modulatory mechanisms. For those who stratify into a 'pro-nociceptive profile' cohort, consisting of inefficient conditioned pain modulation (CPM) and elevated temporal summation of pain (TSP), the optimal approach for balancing the net output of pain modulatory processes towards anti-nociception remains unresolved. In this translational healthy human and rat study, we examined whether descending modulation countered spinal amplification during concurrent application of a CPM and TSP paradigm alongside pupillometry since pontine activity was previously linked to functionality of endogenous pain modulatory mechanisms and pupil dilation.

View Article and Find Full Text PDF

In healthy intervertebral discs (IVDs), nerves and blood vessels are present only in the outer annulus fibrosus, while in degenerative IVDs, a large amount of nerve and blood vessel tissue grows inward. Evidence supports that neurogenic inflammation produced by neuropeptides such as substance P and calcitonin gene related peptide released by the nociceptive nerve fibers innervating the IVDs plays a crucial role in the process of IVD degeneration. Recently, non-neuronal cells, including IVD cells and infiltrating immune cells, have emerged as important players in neurogenic inflammation.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!