5-HT modulation of pain perception in humans

Abstract

IntroductionAlthough there is clear evidence for the serotonergic regulation of descending control of pain in animals, little direct evidence exists in humans. The majority of our knowledge comes from the use of serotonin (5-HT)-modulating antidepressants as analgesics in the clinical management of chronic pain.ObjectivesHere, we have used an acute tryptophan depletion (ATD) to manipulate 5-HT function and examine its effects of ATD on heat pain threshold and tolerance, attentional manipulation of nociceptive processing and mood in human volunteers.MethodsFifteen healthy participants received both ATD and balanced amino acid (BAL) drinks on two separate sessions in a double-blind cross-over design. Pain threshold and tolerance were determined 4 h post-drink via a heat thermode. Additional attention, distraction and temperature discrimination paradigms were completed using a laser-induced heat pain stimulus. Mood was assessed prior and throughout each session.ResultsOur investigation reported that the ATD lowered plasma TRP levels by 65.05 ± 7.29% and significantly reduced pain threshold and tolerance in response to the heat thermode. There was a direct correlation between the reduction in total plasma TRP levels and reduction in thermode temperature. In contrast, ATD showed no effect on laser-induced pain nor significant impact of the distraction-induced analgesia on pain perception but did reduce performance of the painful temperature discrimination task. Importantly, all findings were independent of any effects of ATD on mood.ConclusionAs far as we are aware, it is the first demonstration of 5-HT effects on pain perception which are not confounded by mood changes.

The Affirmation – Tapping on Pain Perception and Serotonin Serum Level of Post – Caesarian Section patients

“…Praying by focusing one's attention and thoughts on God followed by acupoint stimulation through affirmation-taping will increase the level of serotonin (Liu, Tan, Molassiotis, Suen, & Shi, 2015;Ménard, Pfau, Hodes, & Russo, 2017). This will modulate their pain perception (Martin et al, 2017). Affirmations using prayers that are uttered with sincerity and confidence can double the empowerment in the forebrain and amygdaloid, boosting performance so then the function of pain control becomes better and more effective (Beiranvand, Noparast, et al, 2014;Fajarudin, 2006;H.M.…”

Anti-Inflammatory and Anti-Nociceptive Effects of Cocoa: A Review on Future Perspectives in Treatment of Pain

“…These findings suggested a complex role of 5-HT in the modulation of pain [45]. Research by Martin et al [46] found that acute TRP depletion decreased both heat pain tolerance and threshold. Furthermore, acute TRP depletion was reported to decrease brain 5-HT levels, and to increase visceral perception and negative emotional bias in patients with irritable bowel syndrome [47].…”

“…At higher doses (approximately 15-45 mg/kg), caffeine augments antinociception by acetaminophen and others non-steroidal anti-inflammatory drugs (NSAIDs) and produces intrinsic antinociception in some preclinical models. At even higher doses polyphenols [23][24][25][26][27][28][29], methylxanthines [32,33], Nacylethanolamines [34][35][36], biogenic amines [36][37][38], alkaloids [39][40][41][42], and tryptophan [43][44][45][46][47][48] of the central adenosine receptors A2B and A2A, and of the microglial COX [32].…”

Оцінка Ефективності Антистресорного Захисту Хірургічних Стоматологічних Хворих Із Різним Рівнем Нейротизму

“…Впливає на патогенез депресивних станів та неврозів [37]. У фаховій літературі містяться дані про виражений антистресорний ефект L-триптофану, корегуючий вплив на больову перцепцію [36][37][38][39][40]. Крім того, для зменшення функціональної активності симпатичної нервової системи пацієнти упродовж 7 днів до операцій та за 30 хв до їх початку приймали ендоназально розчин даларгіну (синтетичний аналог лейцин-енкефаліну) -1 мг сухої речовини, розчиненої в 0,5 мл 0,9 % хлориду натрію.…”