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The effects of a non-competitive NMDA receptor antagonist, MK-801, on behavioral hyperalgesia and dorsal horn neuronal activity in rats with unilateral inflammation
| Content Provider | Semantic Scholar |
|---|---|
| Author | Hylden, Janice L. K. Williams, Gene M. Ruda, Mary Ann Dubner, Ronald |
| Copyright Year | 1992 |
| Abstract | The involvement of NMDA receptors in rats with peripheral inflammation and hyperalgesia was evaluated by administration of the non-competitive NMDA receptor antagonist, MK-801. Inflammation and hyperalgesia was induced by intradermal injection of complete Freund's adjuvant (CFA) or carrageenan into the left hind paw. The latency of paw withdrawal from a thermal stimulus was used as a measure of hyperalgesia in awake rats. MK-801 (1.6 mg/kg, i.p., or 31.5 micrograms, intrathecal) significantly attenuated thermal hyperalgesia and reduced its duration in comparison to saline-injected rats (P less than 0.05). The receptive field size of nociceptive-specific and wide-dynamic-range neurons in the superficial and deep spinal dorsal horn recorded 24 h after injection of CFA was significantly reduced to 73 +/- 6% (P less than 0.05, n = 8) and 74 +/- 4% (P less than 0.05, n = 8) of control values, respectively, by a cumulative dose of 3 mg/kg of MK-801 (i.v.). MK-801 (2 mg/kg) prevented the expansion of the receptive fields of dorsal horn neurons recorded 5 +/- 0.4 h (n = 5) after intradermal injection of CFA as compared to saline-injected rats (P less than 0.05). MK-801 had no significant effect on receptive field size of dorsal horn neurons in rats without CFA-induced inflammation but blocked a transient expansion of the receptive fields induced by 1 Hz, C-fiber intensity electrical stimulation of the sciatic nerve. The background activity and noxious heat-evoked response of dorsal horn neurons in rats with CFA-induced inflammation were primarily inhibited and noxious pinch-evoked activity was both facilitated and inhibited by the administration of MK-801. These results support the hypothesis that NMDA receptors are involved in the dorsal horn neuronal plasticity and behavioral hyperalgesia that follows peripheral tissue inflammation. |
| Starting Page | 331 |
| Ending Page | 344 |
| Page Count | 14 |
| File Format | PDF HTM / HTML |
| DOI | 10.1016/0304-3959(92)90039-E |
| Alternate Webpage(s) | https://api.elsevier.com/content/article/pii/030439599290039E |
| Alternate Webpage(s) | https://www.sciencedirect.com/science/article/pii/030439599290039E?dgcid=api_sd_search-api-endpoint |
| PubMed reference number | 1454389 |
| Alternate Webpage(s) | https://doi.org/10.1016/0304-3959%2892%2990039-E |
| Journal | Medline |
| Volume Number | 50 |
| Journal | PAIN |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
