title: Electrophysiological Motor Unit Number Estimation (MUNE) Measuring Compound Muscle Action Potential (CMAP) in Mouse Hindlimb Muscles.
abstract: Compound muscle action potential (CMAP) and motor unit number estimation (MUNE) are electrophysiological techniques that can be used to monitor the functional status of a motor unit pool in vivo. These measures can provide insight into the normal development and degeneration of the neuromuscular system. These measures have clear translational potential because they are routinely applied in diagnostic and clinical human studies. We present electrophysiological techniques similar to those employed in humans to allow recordings of mouse sciatic nerve function. The CMAP response represents the electrophysiological output from a muscle or group of muscles following supramaximal stimulation of a peripheral nerve. MUNE is an electrophysiological technique that is based on modifications of the CMAP response. MUNE is a calculated value that represents the estimated number of motor neurons or axons (motor control input) supplying the muscle or group of muscles being tested. We present methods for recording CMAP responses from the proximal leg muscles using surface recording electrodes following the stimulation of the sciatic nerve in mice. An incremental MUNE technique is described using submaximal stimuli to determine the average single motor unit potential (SMUP) size. MUNE is calculated by dividing the CMAP amplitude (peak-to-peak) by the SMUP amplitude (peak-to-peak). These electrophysiological techniques allow repeated measures in both neonatal and adult mice in such a manner that facilitates rapid analysis and data collection while reducing the number of animals required for experimental testing. Furthermore, these measures are similar to those recorded in human studies allowing more direct comparisons.
authors.affiliation: Department of Neurology, The Ohio State University Wexner Medical Center; Department of Physical Medicine and Rehabilitation, The Ohio State University; Department of Neuroscience, The Ohio State University Wexner Medical Center; William.Arnold@osumc.edu.
authors.forename: W David
authors.initials: WD
authors.lastname: Arnold
authors.affiliation: Department of Neurology, The Ohio State University Wexner Medical Center.
authors.forename: Kajri A
authors.initials: KA
authors.lastname: Sheth
authors.affiliation: Department of Biochemistry and Pharmacology, The Ohio State University Wexner Medical Center.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Wier
authors.affiliation: Department of Neurology, The Ohio State University Wexner Medical Center; Department of Neuroscience, The Ohio State University Wexner Medical Center.
authors.forename: John T
authors.initials: JT
authors.lastname: Kissel
authors.affiliation: Department of Neurology, The Ohio State University Wexner Medical Center; Department of Neuroscience, The Ohio State University Wexner Medical Center; Department of Biochemistry and Pharmacology, The Ohio State University Wexner Medical Center.
authors.forename: Arthur H
authors.initials: AH
authors.lastname: Burghes
authors.affiliation: Department of Neurology, The Ohio State University Wexner Medical Center; Department of Neuroscience, The Ohio State University Wexner Medical Center; Department of Biochemistry and Pharmacology, The Ohio State University Wexner Medical Center.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Kolb
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001369:Axons / Q000502:physiology; D006614:Hindlimb / Q000294:innervation / Q000502:physiology; D051379:Mice; D009046:Motor Neurons / Q000502:physiology; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology*; D012584:Sciatic Nerve / Q000502:physiology