Dietary Antioxidant Deficiency Facilitates Cortical Spreading Depression Induced by Photoactivated Riboflavin

Area of Science:

• Neuroscience
• Biochemistry

Background:

• Photoactivation of riboflavin generates superoxide radicals.
• Superoxide radicals are implicated in various physiological and pathological brain processes.

Purpose of the Study:

• To investigate if photoactivated riboflavin can elicit spreading depression (SD) in the rat cerebral cortex.
• To determine the effect of dietary deficiency in antioxidant vitamins C and E on the brain's susceptibility to SD induced by photoactivated riboflavin.

Main Methods:

• Spreading depression (SD) was elicited using topical KCl application as a baseline.
• Photoactivated riboflavin (1.0 mM) was applied to the frontal cortex and illuminated.
• EEG and DC-recordings monitored SD propagation in control and vitamin C/E deficient rats.

Main Results:

• Photoactivated riboflavin elicited SD in 29.7% of applications in control rats.
• In rats deficient in vitamins C and E, photoactivated riboflavin elicited SD in 62.8% of applications (P < 0.05).
• Neither illumination alone nor riboflavin without illumination induced SD.

Conclusions:

• Photoactivated riboflavin is capable of inducing spreading depression in the rat cerebral cortex.
• Dietary deficiency of antioxidant vitamins C and E significantly enhances brain susceptibility to spreading depression induced by photoactivated riboflavin.