Correlated Sensory and Sympathetic Innervation Between the Acupoint BL23 and Kidney in the Rat

Abstract

Objective: To investigate the sensory and sympathetic innervations associated with both acupoint “Shenshu” (BL23) and kidney in the rat for insight into the neuronal correlation between the Back-Shu Point and its corresponding visceral organ.Methods: The BL23 and kidney were selected as the representative acupoint and visceral organ in this study, in which their local nerve fibers were examined by using double fluorescent immunohistochemistry with calcitonin gene-related peptide (CGRP) and tyrosine hydroxylase (TH). Meanwhile, their neuronal correlation in the dorsal root ganglia (DRGs), spinal cord, and sympathetic (paravertebral) chain were investigated using a double fluorescent neural tracing technique with Alexa Fluor 488 and 594 conjugates with cholera toxin subunit B (AF488/594-CTB).Results: The local tissue of acupoint BL23 and the fibrous capsule of kidney distributed abundantly with CGRP- and TH-positive nerve fibers, corresponding to their sensory and sympathetic innervation. On the other hand, the sensory neurons associated with acupoint BL23 and kidney were labeled with AF488/594-CTB and distributed from thoracic (T) 11 to lumbar (L) 3 DRGs and from T10 to L2 DRGs, respectively, in which some of them in T12-T13 DRGs were simultaneously labeled with both AF488/594-CTB. Also, postganglionic neurons associated with both acupoint BL23 and kidney were found in the sympathetic chain at the same spinal segments but separately labeled with AF488-CTB and AF594-CTB.Conclusion: Our study demonstrates the neural characteristics of the acupoint BL23 and kidney in the rat from the perspective of neurochemistry and neural pathways, providing an example for understanding the neuronal correlation between the Back-Shu Points and their corresponding visceral organs. These results suggest that the stimulation of the Back-Shu Points may regulate the activities of the target-organs via the periphery sensory and sympathetic pathways.

Modulation of colonic function in irritable bowel syndrome rats by electroacupuncture at ST25 and the neurobiological links between ST25 and the colon

“…Then a double fluorescent neural tracing technique with Alexa Fluor 488 and 594 conjugates of cholera toxin subunit B (AF488/594-CTB) was used for figuring out the neuronal correlation between ST25 and the colon. Tao et al (1981) was a pioneer in applying nerve tracing techniques to acupuncture, and retrograde nerve tracing has been successfully used to study the neuroanatomical connections of acupoints–target organs ( Cui et al, 2015 , 2019 ; Xu et al, 2021 ; Zhang et al, 2021 ). By injecting different nerve tracers, sensory, sympathetic, and motor neurons associated with ST25 and the colon can be observed.…”

Comparison of Sensory and Motor Innervation Between the Acupoints LR3 and LR8 in the Rat With Regional Anatomy and Neural Tract Tracing

“…However, it is absent until now of structural basis to support this discussed interconnection. In our previous study, we have demonstrated the correlated sensory and sympathetic innervations between acupoint BL 23 and kidney in the rat (Zhang et al, 2021). In this study, we focused our observation on the differential innervation between the different acupoints.…”

“…Herein, regional anatomy was used to show the peripheral nerves under the regions of LR3 and LR8, and neural tract tracing was applied to trace the origin and termination of the sensory and motor innervation from both acupoints to the CNS. According to our previous studies, single cholera toxin subunit B (CTB) and dual Alexa Fluor 594/488 conjugated with CTB (AF594/488-CTB) were selected for neural tract tracing in this study ( Wang et al, 2018 ; Cui et al, 2019 ; Wang H. et al, 2019 ; Zhang et al, 2021 ). With the peripheral application, the single CTB is capable of retrogradely and transganglionically labeling the sensory and motor neurons and the sensory axon terminals ( Cui et al, 2013a , 2019 ; Wang et al, 2018 ).…”

“…With the peripheral application, the single CTB is capable of retrogradely and transganglionically labeling the sensory and motor neurons and the sensory axon terminals ( Cui et al, 2013a , 2019 ; Wang et al, 2018 ). Additionally, dual AF594/488-CTB are preferentially used in pair to retrogradely trace the sensory and motor neurons for identifying the neuronal correlation between the different acupoints or between the acupoint and its corresponding visceral organ ( Cui et al, 2013b ; Wang H. et al, 2019 ; Zhang et al, 2021 ).…”

The Impact of Acupuncture and Moxibustion on the Microenvironment

“…The presence of neuropeptide Y-positive nerve fibers and calcitonin gene-related peptide around the cells suggests that the therapeutic effect of acupuncture at Guanyuan point is related to the activation of sensory, sympathetic, and mast cells in the small intestine. Zhang and coworkers used fluorescent labeling tracing technology to reveal the regular distribution of Shenshu acupoint and adrenal-related innervation in rats from sympathetic nerve, sensory nerve, and motor nerve perspectives, as well as the neuroanatomical link between the two (9). It demonstrates that the Shenshu point and the adrenal gland are linked to the first-level nerves.…”