title: The optimal distance between two electrode tips during recording of compound nerve action potentials in the rat median nerve.
abstract: The distance between the two electrode tips can greatly influence the parameters used for recording compound nerve action potentials. To investigate the optimal parameters for these recordings in the rat median nerve, we dissociated the nerve using different methods and compound nerve action potentials were orthodromically or antidromically recorded with different electrode spacings. Compound nerve action potentials could be consistently recorded using a method in which the middle part of the median nerve was intact, with both ends dissociated from the surrounding fascia and a ground wire inserted into the muscle close to the intact part. When the distance between two stimulating electrode tips was increased, the threshold and supramaximal stimulating intensity of compound nerve action potentials were gradually decreased, but the amplitude was not changed significantly. When the distance between two recording electrode tips was increased, the amplitude was gradually increased, but the threshold and supramaximal stimulating intensity exhibited no significant change. Different distances between recording and stimulating sites did not produce significant effects on the aforementioned parameters. A distance of 5 mm between recording and stimulating electrodes and a distance of 10 mm between recording and stimulating sites were found to be optimal for compound nerve action potential recording in the rat median nerve. In addition, the orthodromic compound action potential, with a biphasic waveform that was more stable and displayed less interference (however also required a higher threshold and higher supramaximal stimulus), was found to be superior to the antidromic compound action potential.
authors.affiliation: Department of Hand Surgery of HuaShan Hospital, Fudan University; Key Laboratory of Hand Reconstruction, Ministry of Healthy; Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China ; Department of Orthopedics, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, China.
authors.forename: Yongping
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Hand Surgery of HuaShan Hospital, Fudan University; Key Laboratory of Hand Reconstruction, Ministry of Healthy; Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Lao
authors.affiliation: Department of Hand Surgery of HuaShan Hospital, Fudan University; Key Laboratory of Hand Reconstruction, Ministry of Healthy; Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Hand Surgery of HuaShan Hospital, Fudan University; Key Laboratory of Hand Reconstruction, Ministry of Healthy; Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Tian
authors.affiliation: Department of Hand Surgery of HuaShan Hospital, Fudan University; Key Laboratory of Hand Reconstruction, Ministry of Healthy; Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Orthopedics, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, China.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Wei
keywords: amplitude; compound nerve action potential; electrodes; median nerve; nerve regeneration; neural regeneration; peripheral nerve injury; recording electrode; supramaximal stimulus intensity; the Project 211 in China