title: Measurement of Electroretinograms and Visually Evoked Potentials in Awake Moving Mice.
abstract: The development of new treatments for intractable retinal diseases requires reliable functional assessment tools for animal models. In vivo measurements of neural activity within visual pathways, including electroretinogram (ERG) and visually evoked potential (VEP) recordings, are commonly used for such purposes. In mice, the ERG and VEPs are usually recorded under general anesthesia, a state that may alter sensory transduction and neurotransmission, but seldom in awake freely moving mice. Therefore, it remains unknown whether the electrophysiological assessment of anesthetized mice accurately reflects the physiological function of the visual pathway. Herein, we describe a novel method to record the ERG and VEPs simultaneously in freely moving mice by immobilizing the head using a custom-built restraining device and placing a rotatable cylinder underneath to allow free running or walking during recording. Injection of the commonly used anesthetic mixture xylazine plus ketamine increased and delayed ERG oscillatory potentials by an average of 67.5% and 36.3%, respectively, compared to unanesthetized mice, while having minimal effects on the a-wave and b-wave. Similarly, components of the VEP were enhanced and delayed by up to 300.2% and 39.3%, respectively, in anesthetized mice. Our method for electrophysiological recording in conscious mice is a sensitive and robust means to assess visual function. It uses a conventional electrophysiological recording system and a simple platform that can be built in any laboratory at low cost. Measurements using this method provide objective indices of mouse visual function with high precision and stability, unaffected by anesthetics.
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Tomiyama
authors.affiliation: Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Fujita
authors.affiliation: Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Koji M
authors.initials: KM
authors.lastname: Nishiguchi
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Tokashiki
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Daigaku
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Faculty of Engineering, Graduate School of Engineering, Iwate University, Morioka, Japan.
authors.forename: Kitako
authors.initials: K
authors.lastname: Tabata
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Faculty of Engineering, Graduate School of Engineering, Iwate University, Morioka, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Sugano
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Faculty of Engineering, Graduate School of Engineering, Iwate University, Morioka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tomita
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan.|Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Japan.|Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Nakazawa
mesh_terms: D000777:Anesthetics; D000818:Animals; D004596:Electroretinography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009068:Movement / Q000502:physiology*; D015203:Reproducibility of Results; D014851:Wakefulness / Q000502:physiology*
chemical_list: D000777:Anesthetics