D-Serine, an endogenous coagonist of the N-methyl-D-aspartate receptor (NMDAR), is widely distributed in the central nervous system and is synthesized from L-serine by serine racemase (SR). NMDAR plays an important role in pain processing including central sensitization that eventually causes hyperalgesia. To elucidate the roles of D-serine and SR in pain transmission, we evaluated the behavior...

Although non-steroidal anti-inflammatory drugs (NSAIDs) and opioid compounds are widely used in the releif of pain, they are not always useful due to their side effects. It seems necessary to search for newer analgesic compounds. Therefore, we decided to study the analgesic effects of this plant. For extraction, percolation method was used and different weights of dried extract were dissolved i...

Abstract Introduction: Chronic heterogeneous stress may be better for evaluation of the effect of chronic stress situations on the nociceptive behaviour. The present study investigated the effects of chronic heterogeneous sequential stress on thermal-induced nociception and formalin induced pain behavior in rats. Methods: In the present study, adult rats (220-300 g) were used. Animals were ...

Effect of four calcium channel blockers (CCBs) belonging to different chemical classes, alone and in combination with morphine was investigated on two models of pain sensitivity, i.e. formalin and tail flick tests in mice. All the studied CCBs, i.e. diltiazem, flunarizine, nimodipine and verapamil inhibited formalin-induced pain responses; however, with verapamil, though there was a trend towar...

This review describes therapeutically relevant mechanisms of action of botulinum toxin (BT). BT's molecular mode of action includes extracellular binding to glycoproteine structures on cholinergic nerve terminals and intracellular blockade of the acetylcholine secretion. BT affects the spinal stretch reflex by blockade of intrafusal muscle fibres with consecutive reduction of Ia/II afferent sig...

Objective(s): Oxytocin is involved in modulation of many brain-mediated functions. In the present study, we investigated the central effects of oxytocin and its receptor antagonist, atosiban on inflammatory pain. The contribution of opiate receptors was explored using non-selective and selective antagonists. Materials and Methods: The fourth ventricle of the brain of anesthetized rats was impla...

Background Several studies have shown that scorpion venom peptide BmK AGAP has an analgesic activity. Our previous study also demonstrated that intraplantar injection of BmK AGAP ameliorates formalin-induced spontaneous nociceptive behavior. However, the effect of intrathecal injection of BmK AGAP on nociceptive processing is poorly understood. Methods We investigated the effects of intrathecal...

Inflammation, peripheral nerve injury and chemical irritants can cause central sensitization in pain pathways. Prostaglandins produced in the CNS induce central sensitization during inflammation mainly by relieving nociceptive neurons from glycinergic inhibition. We have recently identified spinal prostaglandin E receptors of the EP2 subtype (EP2 receptors) and the glycine receptor a3 subunit (...

Naloxone has been reported to affect pain and locomotor activity differently depending on the dose. The objective of the present investigation was to study the effects of low and high (6 micrograms and 3 mg/kg, s.c.) doses of naloxone (Nx) on formalin-induced pain (tonic pain) and spontaneous motor activity and any correlation between them. The experiments were conducted on adult male Wistar ra...

BACKGROUND Persistently active PKMζ has been implicated in maintaining spinal nociceptive sensitization that underlies pain hypersensitivity. However, evidence for PKMζ in the maintenance of pain hypersensitivity comes exclusively from short-term studies in males using pharmacological agents of questionable selectivity. The present study examines the contribution of PKMζ to long-lasting allodyn...