Electrical stimulation of afferent fibers of the tibial nerve in anaesthetiz ed rats evokes somato sympathetic reflexes which are recorded from efferent sym p athetic fibers such as branches of the inferior cardiac ne...Electrical stimulation of afferent fibers of the tibial nerve in anaesthetiz ed rats evokes somato sympathetic reflexes which are recorded from efferent sym p athetic fibers such as branches of the inferior cardiac nerve or the renal nerve . The reflex sympathetic response consists of two components: A reflex, whi c h has a short latency (41±2 ms) and is elicited by stimulation of afferent myel inated fibers, and C reflex, which has a long latency (210±13 ms) and is a t tributed to unmyelinated afferent fibers. Generally speaking, the A and C ref lexes represent different somatic sensory inputs. Studies demonstrated that in anesthetized rats, the somato sympathetic A and C reflexes could be, respectively, modulated not only by several chemical agen ts involving neurotic transmission such as glutamate and nitric oxide, but al s o by sensory inputs from chemoreceptor or baroreceptor. Glutamate augmented, whi le nitric oxide inhibited the somato sympathetic A and C reflexes. Activatio n o f chemoreceptor augmented, while activation of baroreceptor inhibited the somato sympathetic A and C reflexes. In another study, an acupuncture needle (diam ete r 0.34 mm) was inserted into the hind limbs of the rat, dorsolaterally around th e area of acupoint: Huantiao (GB 30), at a depth of 4～5 mm and was twisted righ t and left ward twice every second during recording the somato sympathetic r efle xes. The study found that acupuncture inhibited both somato sympathetic A and C reflexes. These results suggest that the somato sympathetic reflexes may be an experimental model for study on acupuncture mechanism, because acupuncture, as a kind o f sensory input to the central nervous system, may has similar reflex pathways w hen it plays a therapeutic role in some target tissues and organs.展开更多
文摘Electrical stimulation of afferent fibers of the tibial nerve in anaesthetiz ed rats evokes somato sympathetic reflexes which are recorded from efferent sym p athetic fibers such as branches of the inferior cardiac nerve or the renal nerve . The reflex sympathetic response consists of two components: A reflex, whi c h has a short latency (41±2 ms) and is elicited by stimulation of afferent myel inated fibers, and C reflex, which has a long latency (210±13 ms) and is a t tributed to unmyelinated afferent fibers. Generally speaking, the A and C ref lexes represent different somatic sensory inputs. Studies demonstrated that in anesthetized rats, the somato sympathetic A and C reflexes could be, respectively, modulated not only by several chemical agen ts involving neurotic transmission such as glutamate and nitric oxide, but al s o by sensory inputs from chemoreceptor or baroreceptor. Glutamate augmented, whi le nitric oxide inhibited the somato sympathetic A and C reflexes. Activatio n o f chemoreceptor augmented, while activation of baroreceptor inhibited the somato sympathetic A and C reflexes. In another study, an acupuncture needle (diam ete r 0.34 mm) was inserted into the hind limbs of the rat, dorsolaterally around th e area of acupoint: Huantiao (GB 30), at a depth of 4～5 mm and was twisted righ t and left ward twice every second during recording the somato sympathetic r efle xes. The study found that acupuncture inhibited both somato sympathetic A and C reflexes. These results suggest that the somato sympathetic reflexes may be an experimental model for study on acupuncture mechanism, because acupuncture, as a kind o f sensory input to the central nervous system, may has similar reflex pathways w hen it plays a therapeutic role in some target tissues and organs.
