Mutations in hereditary retinal degeneration genes identified in control subjects from various world populations.

<p>Mutations in hereditary retinal degeneration genes identified in control subjects from various world populations.</p

Measurement of Electroretinograms and Visually Evoked Potentials in Awake Moving Mice

<div><p>The development of new treatments for intractable retinal diseases requires reliable functional assessment tools for animal models. <i>In vivo</i> 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.</p></div

Stability of the ERG and VEP recording.

<p>A, B, Amplitude time courses of ERG and VEP waveforms recorded in anesthetized mice (<i>N</i> = 4 for each time point). The flashes (0 log cd/m²) were given in the scotopic condition. The bars indicate mean ± S.E.M.</p

Demographic data for this study.

<p>Demographic data for this study.</p

Comparison of OPs extracted from ERGs acquired under awake and anesthetized conditions.

<p>Representative ERG traces before and after the extraction of OPs from a scotopic ERG (0 log cd s/m²). Schematic illustration showing the amplitude (a_n) and implicit time (t_n) of each OP wavelet (OP_n). C, D. Amplitudes (C) and implicit times (D) of individual OP wavelets (OP₁–OP₄) recorded in the awake (black) and anesthetized (red) condition from the same mice. E, F. Summed amplitudes (C) and implicit times (D) of all OP wavelets (OP₁–OP₄) from ERGs recorded under awake (black) and anesthetized (red) conditions from the same mice. * <i>P</i> < 0.05. Data from seven mice. The bars indicate mean ± S.E.M. anes: anesthetized.</p

RD mutations identified by WES analyses.

<p>RD mutations identified by WES analyses.</p

Changes in visual cortex GMD in glaucoma.

<p>Bar chart showing visual cortex GMD in normal subjects and patients with OAG in BA 17 (A), BA 18 (B), and BA 19 (C).</p

Correlation between optic nerve CSA and visual cortex GMD.

<p>Scatter graph showing the relationship between optic nerve CSA and visual cortex GMD in BA 17 (A), BA 18 (B), and BA 19 (C).</p

Correlation between optic nerve CSA and glaucoma severity.

<p>Scatter graph showing the relationship between CSA and HFA MD (A) and cpRNFLT (B).</p

The potential of optic nerve cross-section area (CSA) in glaucoma management.

<p>(A) Coronal sections of the optic nerve region, showing the region of interest centered on the optic nerve between the optic disc and the chiasm, in a T2-weighted MRI image. (B) Higher magnification image of the white square in A. The circle indicates the optic nerve and the black circular area indicates the optic nerve. (C) Bar chart showing optic nerve CSA at different glaucoma stages. * indicates a significant difference (P<0.05). n.s.: not significant. (D) Receiver operating characteristic curve (ROC) analysis of optic nerve CSA for differentiating normal and glaucoma subjects.</p