Acupuncture inhibition on neuronal activity of spinal dorsal horn induced by noxious colorectal distention in rat

Figure 3 Effect of acupuncture and noxious stimuli on the responses of convergent neuron to CRD. Whole recording time covers 60 s, of which first 5 s (0-5 s) is the duration for recording spontaneous background (bg) activity; from 5^th to 55^th s the CRD was consecutively administered, during 15^th to 45^th s the stimulations of acupuncture, pinch or hotwater was given (CRD + testing); from 55^th to 60^th s was for recording only the post-stimuli bg activity. Inhibitory effects induced by the stimuli of pinch in hind paw (A), 48 °C-hotwater on tail (B) and acupuncture at contralateral St-36 acupoint (C) in non-receptive fields (NRFs), and facilitated effect produced by acupuncture at ipsilateral St-36 acupoint (D) in receptive field (RF). The top traces in each section are original computer-captured spike records, and the bottom traces are the corresponding peri-stimulus time histograms of the discharges.