title: [Segmental and regional innervation of acupoint "Taixi" (KI 3) area in the rat: a horseradish peroxidase method study].
abstract: OBJECTIVE
  To study the peripheral and central neural involvements of acupoint "Taixi" (KI 3) by using Horseradish Peroxidase (HRP).
  
  
  METHODS
  Ten male SD rats were used in the present study. 5 pL of 1% HRP was injected into the excavate site between the apex of medial malleolus and the Achilles tendon of the left hind foot, a corresponding site of acupoint "Taixi" (KI 3) in the human body. After 36 surviving hours, the rat's brain, spinal cord and dorsal root ganglia (DRG) of the lumbar segments (L) were dissected from the perfused experimental animals, and their tissue sections were examined with 3, 3', 5, 5' -tetramethyl-benzidine histochemistry for revealing HRP-labeling.
  
  
  RESULTS
  All the HRP-labeling appeared ipsilaterally to the injection side. Numerous HRP-labeled neurons were detected in the DRGs of L4 - L6 segments with their number being L5> L4 >L6. A longitudinal column of HRP-labeled motoneurons was found in the dorsolateral and mediolateral portions of the spinal cord, distributing in the lamina IX from the caudal L4 to the rostral L6. Additionally, the transganglionic HRP-labeled central prolection axonal terminals were found to be dense in the central part of laminae I-II from L4 to the rostral L6, and to scatter in the central part of gracile nucleus.
  
  
  CONCLUSIONS
  HRP-labeled primary afferent and efferent innervating acupoint "Taixi" (KI 3) are DRGs of L4-L6, the dorsolateral and mediolateral motoneuron columns of L4-L6, and the centrally projecting axonal terminals of laminae I-II of the spinal cord and the gracile nucleus.
authors.affiliation: Institute of Acu-moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Jiang
authors.forename: Wan-zhu
authors.initials: WZ
authors.lastname: Bai
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.forename: Xiang-hong
authors.initials: XH
authors.lastname: Jing
authors.forename: Zhi-gao
authors.initials: ZG
authors.lastname: Jin
mesh_terms: D015669:Acupuncture Points; D000818:Animals; D005727:Ganglia, Spinal / Q000737:chemistry* / Q000201:enzymology; D006735:Horseradish Peroxidase / Q000032:analysis*; D006801:Humans; D008297:Male; D023421:Models, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000737:chemistry* / Q000201:enzymology
chemical_list: D006735:Horseradish Peroxidase