Conduction Velocity Distribution Reveals Fast-Fiber-Dominant Dysfunction in Acrylamide-Induced Peripheral...

Area of Science:

• Neuroscience
• Toxicology
• Peripheral Nervous System Research

Background:

• Acrylamide (ACR) is a known neurotoxicant.
• The specific impact of acute high-dose ACR on different peripheral nerve fiber types is not well understood.
• This study investigates whether ACR affects all myelinated fibers equally or targets specific subpopulations.

Purpose of the Study:

• To test the hypothesis that acute high-dose ACR exposure differentially affects nerve fibers with distinct conduction velocities.
• To elucidate the fiber population-specific pattern of ACR-induced peripheral neurotoxicity.
• To assess the utility of conduction velocity distribution (CVD) analysis in detecting selective fiber involvement.

Main Methods:

• Adult male Sprague-Dawley rats were administered daily intraperitoneal injections of ACR (50 mg/kg/day) or saline for 11 days.
• Sciatic nerves were analyzed using compound action potential (CAP) recordings and conduction velocity distribution (CVD) analysis.
• Nerve excitability, oxidative stress markers, and histomorphometric parameters were evaluated.

Main Results:

• ACR exposure led to significant body weight loss and reduced nerve excitability.
• CAP analysis revealed reduced amplitude, area, and conduction velocities, with a pronounced decrease in maximum upstroke velocity.
• CVD analysis demonstrated a significant reduction in fast-conducting fibers (>50 m/s), while slower fibers remained relatively preserved.
• Increased oxidative stress and histomorphometric evidence of myelin and axonal damage were observed.

Conclusions:

• Acute high-dose ACR preferentially impairs fast-conducting, large-diameter myelinated fibers in rats.
• CVD analysis is a sensitive method for detecting this selective fiber neurotoxicity.
• The findings highlight a fiber population-specific neurotoxic pattern under acute high-dose exposure conditions.