Aim: Spinal wide-dynamic-range (WDR) neuron has been generally accepted to mediate the transmission of nociceptive information derived from peripheral tissues. The firing frequency of WDR neuron has long been used as a reliable index in measuring the intensity of nociceptive stimulation, while the nociceptive information generated by different sources of pain stimuli may be contained in the distinct firing pattern of WDR neuron with different ISI series. The temporal encoding features have not been revealed so far due to the lack of Aim: Spinal wide-dynamic-range (WDR) neuron has been generally accepted to mediate the transmission of nociceptive information derived from peripheral tissues. The firing frequency of WDR neuron has long been used as a reliable index in measuring the intensity of nociceptive stimulation, while the nociceptive information generated by different sources of pain stimuli may be contained in the distinct firing pattern of WDR neuron with different ISI series. The temporal encoding features have not been revealed so far due to the lack of of