title: Adult-age inflammatory pain experience enhances long-term pain vigilance in rats.
abstract: BACKGROUND
  Previous animal studies have illustrated a modulatory effect of neonatal pain experience on subsequent pain-related behaviors. However, the relationship between chronic pain status in adulthood and future pain perception remains unclear.
  
  
  RESULTS
  In the current study, we investigated the effects of inflammatory pain experience on subsequent formalin-evoked pain behaviors and fear conditioning induced by noxious stimulation in adult rats. Our results demonstrated an increase of the second but not the first phase of formalin-induced pain behaviors in animals with a history of inflammatory pain that have recovered. Similarly, rats with persistent pain experience displayed facilitated acquisition and prolonged retention of pain-related conditioning. These effects of prior pain experience on subsequent behavior were prevented by repeated morphine administration at an early stage of inflammatory pain.
  
  
  CONCLUSIONS
  These results suggest that chronic pain diseases, if not properly and promptly treated, may have a long-lasting impact on processing and perception of environmental threats. This may increase the susceptibility of patients to subsequent pain-related disorders, even when chronic pain develops in adulthood. These data highlight the importance of treatment of chronic pain at an early stage.
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Sheng-Guang
authors.initials: SG
authors.lastname: Li
authors.forename: Jin-Yan
authors.initials: JY
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Luo
mesh_terms: D000818:Animals; D059031:Anticipation, Psychological / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects; D002908:Chronic Disease / Q000523:psychology; D003213:Conditioning, Psychological / Q000187:drug effects; D003463:Cues; D005239:Fear / Q000523:psychology; D005557:Formaldehyde / Q000009:adverse effects; D006309:Hearing; D007249:Inflammation / Q000150:complications; D007834:Lasers / Q000009:adverse effects; D008297:Male; D010146:Pain / Q000139:chemically induced / Q000150:complications / Q000523:psychology*; D058748:Pain Perception / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D005557:Formaldehyde