A rat model manifesting methanol-induced visual dysfunction suitable for both acute and long-term exposure studies

Area of Science:

• Toxicology
• Neuroscience
• Ophthalmology

Background:

• Methanol toxicity in humans causes visual dysfunction and metabolic acidosis.
• The precise dose-response and mechanisms of methanol-induced visual impairment remain unclear.
• Nonprimate animal models do not accurately replicate human methanol toxicity.

Purpose of the Study:

• To investigate methanol-induced visual dysfunction in a folate-reduced (FR) rat model.
• To determine if this model can replicate human methanol toxicity.
• To explore the utility of the FR rat as a surrogate for studying methanol's effects on the visual system.

Main Methods:

• Methanol was administered orally and via inhalation to folate-reduced rats.
• Flash-evoked potentials (FEPs) were used to assess the retinogeniculocortical visual pathway.
• Electroretinograms (ERGs) were employed to evaluate retinal function.

Main Results:

• Methanol administration significantly increased FEP latencies in FR rats, indicating visual pathway impairment.
• A dose-related reduction in ERG b-wave amplitude was observed after oral methanol exposure.
• Methanol vapors also reduced ERG b-wave amplitude in FR rats, mirroring human toxicity.

Conclusions:

• The folate-reduced rat model effectively replicates methanol-induced visual dysfunction observed in humans.
• This model serves as a valuable surrogate for investigating the mechanisms of methanol toxicity.
• The FR rat model can provide reliable toxicity data for the visual system across different exposure scenarios.