Intrathecal administration of an NMDA or a non-NMDA receptor antagonist reduces mechanical but not thermal allodynia in a rodent model of chronic central pain after spinal cord injury

Peripheral μ-, κ- and δ-opioid receptors mediate the hypoalgesic effect of celecoxib in a rat model of thermal hyperalgesia

“…We undertook these experiments to extend the results we had obtained in the same inflammatory pain model using mechanical stimuli, because there is considerable evidence that different painful stimuli (thermal vs. mechanical) can give rise to different effects in the same models (Schepers et al 2008;Bennet et al 2000;Mansikka et al 2000). Overall, the results we report here are similar to those obtained with mechanical stimuli (Francischi et al 2002;França et al 2006) but with some important differences.…”

Spinal cord ionotropic glutamate receptors function in formalin-induced nociception in preweaning rats

“…The attenuation of the early and the late phases of the 10-and 21-day-old rats is consistent with data in the adult showing that AMPA antagonists reduce the nociceptive response of the second phase of the formalin response (Meller et al 1993;Nishiyama et al 1999a,b;Bennett et al 2000), although the diminishment of the second phase could be secondary to the decreased initial response. As with the NMDA receptors, there are quantitative and qualitative changes in AMPA receptor expression in the spinal cord during early development.…”

“…Within the spinal cord, these fibers release glutamate among other neurotransmitters and neuropeptides (Woolf and Costigan 1999). N-methyl-D-aspartate (NMDA) receptors play an important role in sensitized pain states such as inflammation-induced hyperalgesia (Coderre and Melzack 1992;Mao et al 1992;Ren et al 1992a,b;Ren and Dubner 1993;Kim et al 1997;Simpson et al 1997;Bennett et al 2000) and the tonic phase (second phase) of the formalin test (Hunter and Singh 1994). Alphaamino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors are involved in acute pain responses to thermal and mechanical stimulation and the acute phase (first phase) of the formalin test (Hunskaar and Hole 1987;Tjolsen et al 1992;Hunter and Singh 1994;Lutfy et al 1997).…”

“…Some report that AMPA receptor antagonists do not alter the second phase of the formalin test or reduce inflammation-induced hyperalgesia, suggesting AMPA receptors are uninvolved in sensitized pain states (Coderre and Melzack 1992;Chapman and Dickenson 1995). However, others report the opposite: that AMPA antagonists reduce responding during the second phase of the formalin test and attenuate mechanical allodynia after injury-induced inflammation (Meller et al 1993;Nishiyama et al 1999a,b;Bennett et al 2000).…”

Early Changes of β-Catenins and Menins in Spinal Cord Dorsal Horn after Peripheral Nerve Injury

“…Moreover, it is well accepted that activation of NMDA receptors in the spinal dorsal horn plays crucial roles in the development and maintenance of neuropathic pain following nerve injury (Bennett et al 2000;Bleakman et al 2006;Chizh and Headley 2005). NMDA receptor antagonists have been shown to reduce allodynia and hyperalgesia in animal models of neuropathic pain (Fundytus 2001).…”