Objective To study the analgesic mechanism of gabapentin, an anticonvulsant, during antinociceptive clinical treatment.Methods Whole-cell voltage-clamp recordings were taken from adult rat spinal cord slices to invest...Objective To study the analgesic mechanism of gabapentin, an anticonvulsant, during antinociceptive clinical treatment.Methods Whole-cell voltage-clamp recordings were taken from adult rat spinal cord slices to investigate the effect of gabapentin on primary afferent A8-fiber evoked excitatory postsynaptic currents (EPSCs) to substantia gelatinosa (SG) neurons in normal and inflamed (established by plantar injection of carrageenan) rats.Results Gabapentin (5 -20 μmol/L for 5 min) depressed dorsal root A8 fiber evoked polysynaptic, but not monosynaptic EPSCs to SG experiencing inflammation by about 25% (n = 10, P <0. 01). However, gabapentin did not depress the evoked polysynaptic or monosynaptic EPSCs in normal rats. Gabapentin failed to block a glutamate receptor subtype, N-methyl-D-aspartate (NMDA), -induced slow excitatory currents on SG neurons.Conclusions Inflammation, at least in pan', unmasks the gabapentin depression on nociception transmission in the dorsal horn, and this depression is not due to the blockade of postsynaptic NMDA receptor.展开更多
文摘Objective To study the analgesic mechanism of gabapentin, an anticonvulsant, during antinociceptive clinical treatment.Methods Whole-cell voltage-clamp recordings were taken from adult rat spinal cord slices to investigate the effect of gabapentin on primary afferent A8-fiber evoked excitatory postsynaptic currents (EPSCs) to substantia gelatinosa (SG) neurons in normal and inflamed (established by plantar injection of carrageenan) rats.Results Gabapentin (5 -20 μmol/L for 5 min) depressed dorsal root A8 fiber evoked polysynaptic, but not monosynaptic EPSCs to SG experiencing inflammation by about 25% (n = 10, P <0. 01). However, gabapentin did not depress the evoked polysynaptic or monosynaptic EPSCs in normal rats. Gabapentin failed to block a glutamate receptor subtype, N-methyl-D-aspartate (NMDA), -induced slow excitatory currents on SG neurons.Conclusions Inflammation, at least in pan', unmasks the gabapentin depression on nociception transmission in the dorsal horn, and this depression is not due to the blockade of postsynaptic NMDA receptor.
