Iron prevents demyelination of frog sciatic nerves

Metal ions are of particular importance in nervous system function, notably iron. However, very little has been done to investigate its physiological role in frog peripheral nervous system. The present research aim to evaluate i) the time-effect of sciatic nerve ligation and/or ii) iron sulphate (1.50 mg/kg, in lymphatic sac) on frog myelin sheaths. Histological sections following ligation shows degeneration of some fibres with axonal and myelin breakdown associated to a decrease of Schwann cells number following 2 h (45.00 +/- 0.30, p < 0.0001), 24 h (28.00 +/- 0.020, p < 0.0001). Interestingly, iron administration reduces the degeneration of myelin sheaths classically observed in frog ligated sciatic nerve associated with an increase of Schwann cells number (139.00 +/- 0.50, p < 0.0001). Thus, iron could prevent degeneration or promote regeneration induced by ligation in frog sciatic nerve.