Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease characterized by a substantial loss of motor neurons in the spinal cord, brainstem and motor cortex. Previous evidence has shown that in a mouse model of a familial form of ALS expressing high levels of the human mutated protein Cu,Zn superoxide dismutase (Gly93Ala, G93A), the firing properties of single motor neurons are altered to induce neuronal hyperexcitability. To determine whether the functionality of the macroscopic voltage-dependent Na⁺ currents is modified in G93A motor neurons, in the present work their physiological properties have been examined. The voltage-dependent sodium channels were studied in dissociated motor neurons in culture from non-transgenic mice (Control), from transgenic mice expressing high levels of the human wild-type protein (SOD1) and from G93A mice, using the whole cell configuration of the patch clamp recording technique. The voltage dependence of activation and of steady-state inactivation, the kinetics of fast inactivation and slow inactivation of the voltage-dependent Na⁺ channels were not modified in the mutated mice. Conversely, the recovery from fast inactivation was significantly faster in G93A motor neurons compared to Control and SOD1. The recovery from fast inactivation was still significantly faster in G93A motor neurons exposed for different times (3-48 hours) and concentrations (5-500 µM) to edaravone, a free radical scavenger. The clarification of the importance of these changes in membrane ion channel functionality may have diagnostic and therapeutic implications in the pathogenesis of ALS.