title: Effects of Combined Electrical Stimulation of the Dorsal Column and Dorsal Roots on Wide-Dynamic-Range Neuronal Activity in Nerve-Injured Rats.
abstract: OBJECTIVE
  Electrical stimulation at the dorsal column (DC) and dorsal root (DR) may inhibit spinal wide-dynamic-range (WDR) neuronal activity in nerve-injured rats. The objective of this study was to determine if applying electrical conditioning stimulation (CS) at both sites provides additive or synergistic benefits.
  
  
  METHODS
  By conducting in vivo extracellular recordings of WDR neurons in rats that had undergone L5 spinal nerve ligation, we tested whether combining 50 Hz CS at the two sites in either a concurrent (2.5 min) or alternate (5 min) pattern inhibits WDR neuronal activity better than CS at DC alone (5 min). The intensities of CS were determined by recording antidromic compound action potentials to graded stimulation at the DC and DR. We measured the current thresholds that resulted in the first detectable Aα/β waveform (Ab0) and the peak Aα/β waveform (Ab1) to select CS intensity at each site. The same number of electrical pulses and amount of current were delivered in different patterns to allow comparison.
  
  
  RESULTS
  At a moderate intensity of 50% (Ab0 + Ab1), different patterns of CS all attenuated the C-component of WDR neurons in response to graded intracutaneous electrical stimuli (0.1-10 mA, 2 msec) and inhibited windup in response to repetitive noxious stimuli (0.5 Hz). However, the inhibitory effects did not differ significantly between different patterns. At the lower intensity (Ab0), no CS inhibited WDR neurons.
  
  
  CONCLUSIONS
  These findings suggest that combined stimulation of DC and DR may not be superior to DC stimulation alone for inhibition of WDR neurons.
authors: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Fei
authors: F
authors: Yang
authors: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.|Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors: Tong
authors: T
authors: Zhang
authors: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Vinod
authors: V
authors: Tiwari
authors: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Bin
authors: B
authors: Shu
authors: Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.
authors: Chen
authors: C
authors: Zhang
authors: Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.
authors: Yun
authors: Y
authors: Wang
authors: Neuromodulation Research, Medtronic Inc., Minneapolis, MN, USA.
authors: Louis P
authors: LP
authors: Vera-Portocarrero
authors: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Srinivasa N
authors: SN
authors: Raja
authors: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Yun
authors: Y
authors: Guan
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D001703:Biophysics; D004195:Disease Models, Animal; D004599:Electric Stimulation Therapy / Q000379:methods*; D008297:Male; D009474:Neurons / Q000502:physiology*; D059348:Peripheral Nerve Injuries / Q000628:therapy*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012121:Respiration, Artificial; D012584:Sciatic Nerve / Q000503:physiopathology; D013116:Spinal Cord / Q000502:physiology*; D013126:Spinal Nerve Roots / Q000502:physiology*
keywords: Dorsal column; dorsal root; nerve injury; neurostimulation; wide-dynamic-range neurons