Effect of Hydrogen Peroxide on Neuron Sensitivity to Acetylcholine

Abstract

The dose-dependent effect of hydrogen peroxide on snail neuromembrane chemosensitivity was studied by means of standard voltage-clamp method. Short-term exposure (7 min) of neurons to H₂O₂ (10⁻¹¹–10⁻⁴ M) caused dose-dependent depression of Acetylcholine (Ach)-induced ionic currents in the membrane. The H₂O₂-induced depression of Ach-sensitivity of membrane was more pronounced in K⁺-free solution than in normal physiological solution and it disappeared in cold medium (5°C). The H₂O₂ (10⁻¹¹–10⁻⁴ M) decreased membrane electrical conductivity and cell volume. The dose-dependent decrease in Ach-sensitivity of the snail neuromembrane by H₂O₂ may be due to a decrease in the number of functionally active membrane receptors caused by a decrease in membrane active surface. H₂O₂-induced decrease in Ach-sensitivity has a metabolic but Na⁺–K⁺ pump independent character, the nature of which is the subject for current investigation.

Keywords:

• Acetylcholine-sensitivity
• Cell volume
• H₂O₂
• Membrane
• Neuron