The antiallodynic action of pregabalin may depend on the suppression of spinal neuronal hyperexcitability in rats with spared nerve injury

BACKGROUND: Pregabalin (PGB) is a novel antiepileptic drug and is also used as a first-line medication for the treatment of neuropathic pain. However, the mechanisms of its analgesic effects remain largely unknown. OBJECTIVES: To elucidate the mechanisms underlying the antiallodynic action of PGB in rats with neuropathic pain. METHODS: In a rat model of neuropathic pain induced by spared nerve injury, mechanical allodynia, as a behavioural sign of neuropathic pain, was assessed by measuring 50% paw withdrawal threshold with von Frey filaments. Activities of dorsal horn wide dynamic range (WDR) neurons were examined by extracellular electrophysiological recording in vivo. RESULTS : Spinal administration of PGB exerted a significant antiallodynic effect and a prominent inhibitory effect on the hypersensitivity of dorsal horn WDR neurons in rats with spared nerve injury. CONCLUSION: The antiallodynic action of PGB is likely dependent on the suppression of WDR neuron hyperexcitability in rats with neuropathic pain.