TY - JOUR
T1 - Isoflurane is an effective alternative to ketamine/xylazine/acepromazine as an anesthetic agent for the mouse electroretinogram
AU - Woodward, William R.
AU - Choi, Dongseok
AU - Grose, Jared
AU - Malmin, Bojan
AU - Hurst, Sawan
AU - Pang, Jiaqing
AU - Weleber, Richard G.
AU - Pillers, De Ann M.
N1 - Funding Information:
Acknowledgments This work was supported by the Arlene Silfberg Trust, The Foundation Fighting Blindness, an unrestricted grant from Research to Prevent Blindness, the NIH Core Grant EY01572 (DC), and NIH R01EY10084 (DP). We thank Dr. Joseph Robertson, President of OHSU, who while he was Chair of Ophthalmology, provided financial and moral support for the establishment of a rodent ERG facility. We also thank Dr. F. Leonard Johnson, who while he was Chair of Pediatrics, financially supported the relocation and remodeling of the rodent ERG facility.
PY - 2007/11
Y1 - 2007/11
N2 - The electroretinogram (ERG) is an essential measure of retinal function for studying mouse models of retinal disease. Ketamine, in combination with xylazine and/or acepromazine, is the most commonly used anesthetic agent. Although it works well in most situations, some fragile mouse strains have high mortality rates with this ketamine cocktail. We compared isoflurane with the ketamine cocktail in a longitudinal study of light-adapted and dark-adapted ERGs in C57BL/6J mice. Waveforms were averaged, oscillatory potentials (OPs) were extracted by digital filtration, and key ERG parameters were analyzed. The ERG waveforms were qualitatively similar with both anesthetics, and the male and female ERG parameters did not show significant differences. For light-adapted ERGs, b-wave amplitude and implicit time, and wavelet index were decreased under isoflurane anesthesia, whereas for dark-adapted ERGs, a- and b-wave implicit times were decreased and wavelet index was increased. The dark-adapted b-wave amplitude showed a significant inverse correlation with animal weight and age. Rod phototransduction gain and the Naka-Rushton n and Rmax parameters were the same for both anesthetics, and only the Naka-Rushton log k parameter was significantly elevated for isoflurane anesthesia. We propose that isoflurane is a satisfactory alternative to the ketamine cocktail for anesthesia in the mouse ERG. Precise quantitative comparisons, however, should only employ study designs using isoflurane versus isoflurane, or ketamine versus ketamine. Moreover, in light of the effects of both isoflurane and the ketamine cocktail on blood glucose levels, it would be prudent to control the fasting state of the animals in quantitative ERG studies.
AB - The electroretinogram (ERG) is an essential measure of retinal function for studying mouse models of retinal disease. Ketamine, in combination with xylazine and/or acepromazine, is the most commonly used anesthetic agent. Although it works well in most situations, some fragile mouse strains have high mortality rates with this ketamine cocktail. We compared isoflurane with the ketamine cocktail in a longitudinal study of light-adapted and dark-adapted ERGs in C57BL/6J mice. Waveforms were averaged, oscillatory potentials (OPs) were extracted by digital filtration, and key ERG parameters were analyzed. The ERG waveforms were qualitatively similar with both anesthetics, and the male and female ERG parameters did not show significant differences. For light-adapted ERGs, b-wave amplitude and implicit time, and wavelet index were decreased under isoflurane anesthesia, whereas for dark-adapted ERGs, a- and b-wave implicit times were decreased and wavelet index was increased. The dark-adapted b-wave amplitude showed a significant inverse correlation with animal weight and age. Rod phototransduction gain and the Naka-Rushton n and Rmax parameters were the same for both anesthetics, and only the Naka-Rushton log k parameter was significantly elevated for isoflurane anesthesia. We propose that isoflurane is a satisfactory alternative to the ketamine cocktail for anesthesia in the mouse ERG. Precise quantitative comparisons, however, should only employ study designs using isoflurane versus isoflurane, or ketamine versus ketamine. Moreover, in light of the effects of both isoflurane and the ketamine cocktail on blood glucose levels, it would be prudent to control the fasting state of the animals in quantitative ERG studies.
KW - Dark-adapted
KW - Electroretinogram
KW - Isoflurane
KW - Ketamine
KW - Light-adapted
KW - Mouse
KW - Xylazine
UR - http://www.scopus.com/inward/record.url?scp=35748931754&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=35748931754&partnerID=8YFLogxK
U2 - 10.1007/s10633-007-9079-4
DO - 10.1007/s10633-007-9079-4
M3 - Article
C2 - 17885776
AN - SCOPUS:35748931754
SN - 0012-4486
VL - 115
SP - 187
EP - 201
JO - Documenta Ophthalmologica
JF - Documenta Ophthalmologica
IS - 3
ER -