Effects of different anesthetic drugs on electroretinography in mice

Electrophysiology (ERG) is widely used for retinal function assessment, but the effects of different anesthetics on ERG recordings, particularly in degenerated retinas, remain unclear. This study investigated the effects of different anesthetic drugs on ERG in wild-type (WT), Kv8.2 knockout (KO), and rd10 mice. Anesthetic drugs, avertin (300 mg/kg) and pentobarbital sodium (50 mg/kg) were administered intraperitoneally, isoflurane was given at 5% for induction and 1.5% for maintenance. Full-field flash electroretinography (ff-ERG) was recorded, including scotopic and photopic responses. Specifically, the amplitudes of a-wave, b-wave, oscillatory potentials (OPs), photopic negative response (PhNR), and c-wave were analyzed, respectively. Additionally, fundus imaging and optical coherence tomography (OCT) were performed to analyze retinal morphology. The three anesthetics had no obvious effect on retinal morphology. Pentobarbital sodium decreased scotopic OPs, increased scotopic and photopic b-wave amplitudes and decreased photopic a-wave amplitude in all groups of mice. Isoflurane resulted in larger scotopic OPs and photopic a-wave amplitudes in all groups, with a larger scotopic a-wave amplitude in KO mice. The PhNR amplitude was greater in WT mice anesthetized with avertin. The ERG amplitudes in mice showed significant differences among the three anesthetic conditions. Pentobarbital sodium markedly suppressed retinal OPs, suggesting it may not be suitable for assessing inner retinal function, particularly amacrine cells. Isoflurane enabled excellent recordings of various types of ERG, making it suitable for nearly all ERG recordings. Avertin might serve as a suitable alternative in the absence of isoflurane.