Long-lasting delayed hyperalgesia after subchronic swim stress.
Journal Article
Rats subjected to an inescapable subchronic stress, consisting of 10-20 min of forced swimming for 3 days, showed a thermal hyperalgesia and an enhanced nociceptive behavior to the subcutaneous administration of formalin 24 and 48 h, respectively, after the last swim session. Hyperalgesia to thermal and chemical stimulants was still present 8 and 9 days after the last swim session, respectively. Chemical, but not thermal, nociception was negatively correlated with the swim effort or struggle times during the last swim session. The serotonin-selective reuptake inhibitors clomipramine (2.5 mg/kg/day, i.p., started 3 or 7 days before stress) and fluoxetine (0.25 mg/kg/day, i.p., started 7 days before stress), or serotonin precursor tryptophan (3 mg/kg/day, i.p., 24 h before each swim stress) blocked the development of both the thermal and the chemical hyperalgesia and increased swim effort times compared to vehicle-treated rats. These treatments did not affect nociceptive responses in control rats subjected to sham swimming. These findings suggest that repeated stress can produce a long-lasting increase in pain sensitivity to both phasic or tonic noxious stimuli by diminishing central serotonin activity. This model may help elucidate the underlying neural mechanisms that mediate the effects of repeated stress on pain sensitivity and affective states.
Full Text
Duke Authors
Cited Authors
- Quintero, L; Moreno, M; Avila, C; Arcaya, J; Maixner, W; Suarez-Roca, H
Published Date
- November 2000
Published In
Volume / Issue
- 67 / 3
Start / End Page
- 449 - 458
PubMed ID
- 11164071
Pubmed Central ID
- 11164071
Electronic International Standard Serial Number (EISSN)
- 1873-5177
International Standard Serial Number (ISSN)
- 0091-3057
Digital Object Identifier (DOI)
- 10.1016/s0091-3057(00)00374-9
Language
- eng