This paper is the 29th consecutive installment of the annual review of research concerning
the endogenous opioid system, now spanning 30 years of research. It summarizes papers …

Widespread or ectopic sensitization is a hallmark symptom of chronic pain, characterized by
aberrantly enhanced pain sensitivity in multiple body regions remote from the site of original …

Pain is a complex biological phenomenon that encompasses intricate neurophysiological,
behavioural, psychosocial and affective components. Protracted or chronic pain alerts an …

Palmitoylethanolamide (PEA) is an endogenous cannabinoid-like compound in the central
nervous system, which can modulate several functions in different pathological states, such …

Objective Pain resulting from local tissue injury or inflammation typically resolves with time.
Frequently, however, this pain may unexpectedly persist, becoming a pathological chronic …

The role of the neuropeptide calcitonin gene‐related peptide (CGRP) is well established in
nociceptive behaviors. CGRP is highly expressed in the projection pathway from the …

The purpose of this study was to investigate whether 1%, 2% or 5% formalin injection
produce hypersensitivity with characteristics of the neuropathic pain induced by spinal nerve …

It has been recently proposed that a5-subunit containing GABAA receptors (a5-GABAA
receptors) that mediate tonic inhibition might be involved in pain. The purpose of this study …

The role of 5-hydroxytryptamine (5-HT) 4, 5-HT6, and 5-HT7 receptors in formalin-induced
secondary allodynia and hyperalgesia in rats was assessed. Formalin produced acute …

This investigation determined whether the activation of the kappa opioid receptor (KOR) in
the spinal cord produces estrogen-dependent, sex-specific modulation of acute and …