An In Vitro Adult Mouse Muscle-nerve Preparation for Studying the Firing Properties of Muscle Afferents

• Type of Material: Article
• Authors: Joy A. Franco, San Jose State University; Heidi E. Kloefkorn, University of Florida; Shawn Hochman, Emory University; Katherine A. Wilkinson, San Jose State University
• Language: English
• Date: 2014-09-01
• Publisher: Journal of Visualized Experiments (JoVE)
• Publication Version: Final Published Version
• Copyright Statement: © 2014 Creative Commons Attribution-NonCommercial License
• License: Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.3791/51948
• Title of Journal or Parent Work: Journal of Visualized Experiments
• ISSN: 1940-087X
• Issue: 91
• Start Page: 51948
• End Page: 51948
• Grant/Funding Information: This work was supported by a California State University Program for Education and Research in Biotechnology (CSUPERB) New Investigator Grant (KAW), a grant from Pfizer (WS753098, SH), and an NIH MARC fellowship (#2T34GM008253-21, JAF).; The open access charges for this manuscript have been paid by Aurora Scientific, Inc., the company that makes the force and length controller and in vitro bath plate used in this manuscript.
• Keywords: muscle spindle; electrophysiology; Science & Technology - Other Topics; RAT; Science & Technology; MAMMALIAN MUSCLE; sensory neurons; extensor digitorum longus; SPINDLES; SKELETAL-MUSCLE; Neuroscience; Issue 91; Multidisciplinary Sciences; RECEPTORS; muscle afferent; AUGMENTED MECHANICAL RESPONSE; FORCE; MICE
• Research Categories: Engineering, Biomedical; Biology, Physiology

Abstract

Muscle sensory neurons innervating muscle spindles and Golgi tendon organs encode length and force changes essential to proprioception. Additional afferent fibers monitor other characteristics of the muscle environment, including metabolite buildup, temperature, and nociceptive stimuli. Overall, abnormal activation of sensory neurons can lead to movement disorders or chronic pain syndromes. We describe the isolation of the extensor digitorum longus (EDL) muscle and nerve for in vitro study of stretch-evoked afferent responses in the adult mouse. Sensory activity is recorded from the nerve with a suction electrode and individual afferents can be analyzed using spike sorting software. In vitro preparations allow for well controlled studies on sensory afferents without the potential confounds of anesthesia or altered muscle perfusion. Here we describe a protocol to identify and test the response of muscle spindle afferents to stretch. Importantly, this preparation also supports the study of other subtypes of muscle afferents, response properties following drug application and the incorporation of powerful genetic approaches and disease models in mice.