Before the animals were euthanized for morphological and biochemical analyses, the animals were subjected to ERG analyses to evaluate the changes in the electrical activity of the retina as we have done previously [2 (link),6 (link)]. Briefly, mice were dark-adapted overnight. ERG responses were recorded from both eyes together using platinum wire corneal electrodes, a forehead reference electrode, and a ground electrode in the tail. Pupils were fully dilated using 1% tropicamide solution (Alcon, Ft Worth, TX). Methylcellulose (Celluvise; Allergan, Irvine, CA) drops were applied as well to maintain a good electrical connection, and body temperature was maintained at 37 °C with a water-based heating pad. All ERG experiments were approved by the University of Tennessee Institutional Animal Care and Use Committee on Protocol #1992. ERG waveforms were recorded with a bandwidth of 0.3–500 Hz and samples at 2 kHz by a digital acquisition system and were analyzed a custom-built program (MatLab software, Mathworks, Natick, MA). Statistics was done on the mean ± standard deviation (SD) amplitudes of the a- and b-waves of each treatment group. Comparisons were made of ERG amplitudes, but implicit times were not measured.