Transcranial Direct Current Stimulation of the Dorsolateral Prefrontal Cortex Alters Emotional Modulation of Spinal Nociception.

Emotion has a strong modulatory effect on pain perception and spinal nociception. Pleasure inhibits pain and nociception, whereas displeasure facilitates pain and nociception. Dysregulation of this system has been implicated in development and maintenance of chronic pain.

Pain Acceptance Partially Mediates the Relationship Between Perceived Injustice and Pain Outcomes Over 3 Months.

Objectives: Perceived injustice is a maladaptive cognitive appraisal of pain or injury, characterized by attributions of blame, unfairness, severity of loss, and irreparability of loss. Research suggests that perceived injustice may negatively affect pain outcomes by inhibiting the development of pain-related acceptance. The current study aimed to extend cross-sectional research by testing whether pain acceptance mediates the effects of perceived injustice on pain-related outcomes longitudinally.

The nicotinic α6 subunit gene determines variability in chronic pain sensitivity via cross-inhibition of P2X2/3 receptors.

Chronic pain is a highly prevalent and poorly managed human health problem. We used microarray-based expression genomics in 25 inbred mouse strains to identify dorsal root ganglion (DRG)-expressed genetic contributors to mechanical allodynia, a prominent symptom of chronic pain. We identified expression levels of Chrna6, which encodes the α6 subunit of the nicotinic acetylcholine receptor (nAChR), as highly associated with allodynia.

Reducing social stress elicits emotional contagion of pain in mouse and human strangers.

Empathy for another's physical pain has been demonstrated in humans [1] and mice [2]; in both species, empathy is stronger between familiars. Stress levels in stranger dyads are higher than in cagemate dyads or isolated mice [2, 3], suggesting that stress might be responsible for the absence of empathy for the pain of strangers. We show here that blockade of glucocorticoid synthesis or receptors for adrenal stress hormones elicits the expression of emotional contagion (a form of empathy) in strangers of both species.