Although placebos have long been considered a nuisance in clinical research, today they
represent an active and productive field of research and, because of the involvement of …

Animal studies suggest that fear inhibits pain whereas anxiety enhances it; however it is
unclear whether these effects generalize to humans. The present study examined the effects …

Opioid drugs play important roles in the clinical management of pain, as well as in the
development and treatment of drug abuse. The mu opioid receptor is the primary site of …

Despite the fact that many research articles have been written about stress and stress-
related diseases, no scientifically accepted definition of stress exists. Selye introduced and …

Agonists for the μ-opioid receptor are powerful analgesics and are highly addictive;
however, the contribution of the δ-and κ-opioid and opioid receptor-like receptors to …

Cognitive self-regulation can strongly modulate pain and emotion. However, it is unclear
whether self-regulation primarily influences primary nociceptive and affective processes or …

Highlights•Descending pathways play a critical role in the central modulation of pain.•A
particular descending PAG–RVM pathway mediates the phenomenon of stress-induced …

Although laughter forms an important part of human non-verbal communication, it has
received rather less attention than it deserves in both the experimental and the …

Background: Exercise is an effective treatment for various chronic pain disorders, including
fibromyalgia, chronic neck pain, osteoarthritis, rheumatoid arthritis, and chronic low back …

The major functions of the midbrain periaqueductal gray (PAG), including pain and
analgesia, fear and anxiety, vocalization, lordosis and cardiovascular control are considered …