title: [Colorectal nociceptive signal input facilitates impact of acupoint stimulation of "Zusanli" (ST 36) on electrical activities of wide dynamic range neurons in lumbar spinal cord in rats].
abstract: OBJECTIVE
  To observe changes of electrical activities of wide dynamic neurons (WDR) in the lumbar spinal cord after electroacupuncture (EA) stimulation of "Zusanli" (ST 36) during colorectal distension in rats, so as to analyze alternations of acupoint's functions under pathological conditions.
  
  
  METHODS
  Experiments were performed in male Sprague-Dawley rats. Visceral nociceptive information input was generated by colorectal distension (CRD). Extracellular discharges of WDR neu- rons in the dorsal horns of L(1-3) spinal cord were recorded using glass micropipettes and a microelectrode amplifier. EA stimulation (15 Hz, 1, 4, 7, 10 mA) was applied to ipsilateral "Zusanli" (ST 36) area.
  
  
  RESULTS
  A total of 40 neurons were recorded in the present study. Under no CRD conditions, the firing rates of WDR neurons were significantly increased by (18.12 +/- 13.56)% (1 mA), (152.38 +/- 36.19)% (4 mA), (231.21 +/- 49.74)% (7 mA) and (331.54 +/- 61.89)% (10 mA) respectively after EA sti- mulation of ST 36. Under CRD conditions, the firing rates of these WDR neurons were increased by (226.78 +/- 39.59)% (1 mA), (282.80 +/- 47.54)% (4 mA), (343.06 +/- 58.35)% (7 mA), and (338.62 +/- 80.04)% (10 mA) respectively after EA stimulation. It showed a considerablely increased sensitivity of electrical activities of WDR neurons to EA stimulation during CRD nociceptive stimulation.
  
  
  CONCLUSIONS
  colorectal distension (visceral nociceptive stimulation) can strengthen the sensitivity of acupoint-EA stimulation-induced increase of firing rates of WDR neurons in the dorsal horns of the lumbar spinal cord in rats, suggesting a potentiation of the acupoint action under visceral nociceptive signal inputs.
authors.forename: Ling-ling
authors.initials: LL
authors.lastname: Yu
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.forename: Qing-guang
authors.initials: QG
authors.lastname: Qin
authors.forename: Hui
authors.initials: H
authors.lastname: Ben
authors.forename: Pei-jing
authors.initials: PJ
authors.lastname: Rong
authors.forename: Bing
authors.initials: B
authors.lastname: Zhu
mesh_terms: D015669:Acupuncture Points; D000818:Animals; D015671:Electroacupuncture; D004594:Electrophysiology; D008159:Lumbar Vertebrae / Q000737:chemistry / Q000502:physiology*; D008297:Male; D009619:Nociceptors / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000737:chemistry / Q000502:physiology*