We have reported that conditioning electrical stimulation of the amygdala has an inhibitory effect on responses of nociceptive neurons of the rat medullary dorsal horn to electrical stimulation of the receptive field. However, it is not clear if amygdala stimulation has influences on the non-noxious response. The purpose of the present study is to determine using natural stimulation whether amygdala stimulation induces inhibition of noxious and non-noxious responses of wide-dynamic range (WDR) neurons. Rats were anesthetized with N₂O-O₂ and 0.5% halothane and immobilized with pancuronium bromide. Peripheral natural stimulus was applied continuously to the facial area, and ipsilateral amygdala stimulations (trains of 33 pulses, 0.5msec in duration, 300μA) to the recording site were delivered at a stimulus interval of 5-6sec. In 7 WDR neurons, noxious responses were inhibited by amygdala (central, cortical basomedial or basolateral nuclei) stimulation. Effects of amygdala stimulation on the responses to 3 kinds of stimuli (brushing, pressure and pinching) was tested in 4 neurons. In 3 of those neurons, both noxious and non-noxious responses were inhibited and the mean inhibitory effect were nearly equivalent (58.7-38.7%) for those responses. Amygdala stimulation inhibited noxious responses without affecting non-noxious responses in the remaining neuron. These inhibitory effects lasted for 200-300msec. In addition, responses of low-threshold mechanoreceptive (LTM) neurons were not affected by amygdala stimulation of the same site at which stimulation inhibited responses of nociceptive neurons. These findings suggest that excitation of neurons in the amygdala induce postsynaptic inhibition on the most of nociceptive neurons but not on non-nociceptive neurons in the medullary dorsal horn.