Apr 25, 2020

Anxiety enhances pain in a model of osteoarthritis and is associated with altered endogenous opioid function and reduced opioid analgesia

BioRxiv : the Preprint Server for Biology
A. LillywhiteVictoria Chapman


Chronic pain states such as osteoarthritis (OA) are often associated with negative affect, including anxiety and depression. This is, in turn, associated with greater opioid analgesic use, potentially contributing to current and future opioid crises. We utilise an animal model to investigate the neurobiological mechanisms underlying increased opioid use associated with high anxiety and chronic pain. Combining a genetic model of negative affect, the Wistar Kyoto (WKY) rat, and intra-articular injection of monosodium iodoacetate (MIA; 1mg), our model of high anxiety and augmented OA-like pain behaviour mirrors the clinical problem. Effects of morphine (0.5-6mg.kg-1) on pain behaviour and spinal nociceptive neuronal activity were determined in WKY rats, and normo-anxiety Wistar rats, 3 weeks after MIA injection. WKY rats developed augmented OA-like pain, and had blunted inhibitory responses to morphine, when compared to Wistar rats. Potential alterations in endogenous opioid function were probed via systemic blockade of opioid receptors with naloxone (0.1-1mg.kg-1), quantification of circulating levels of {beta}-endorphin, and determination of spinal expression of the mu-opioid receptor (MOR). These studies revealed increased opio...Continue Reading

  • References
  • Citations


  • We're still populating references for this paper, please check back later.
  • References
  • Citations


  • This paper may not have been cited yet.

Mentioned in this Paper

Whole Blood
Sequence Determinations, RNA
Bipolar Disorder
Amyotrophic Lateral Sclerosis
Archaeal Proteins
Whole Blood Specimen

Related Feeds

BioRxiv & MedRxiv Preprints

BioRxiv and MedRxiv are the preprint servers for biology and health sciences respectively, operated by Cold Spring Harbor Laboratory. Here are the latest preprint articles (which are not peer-reviewed) from BioRxiv and MedRxiv.


Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease, is associated with the death of neurons that control voluntary muscles. Discover the latest research on ALS here.

Bipolar Disorder

Bipolar disorder is characterized by manic and/or depressive episodes and associated with uncommon shifts in mood, activity levels, and energy. Discover the latest research this illness here.