Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 43

Study aim: the Ebf gene family has been implicated in several developmental processes, ranging from B-cell development to neuronal differentiation. As the murine Ebf2 gene is expressed in numerous sites of nervous system, Ebf2-null mice develop hypogonadotropic hypogonadism, due to defective migration of gonadotropin releasing hormone-synthesizing neurons, and a peripheral neuropathy as well. Therefore, we aimed to study whether electrophysiological tests would be able to detect abnormalities of peripheral nerve function. Methods: 2 groups of mice were studied, which consisted of 8 Ebf2-/- mice and 9 age-matched controls. The sciatic nerve was stimulated at the ankle and at the ischiatic notch; the compound motor action potential (cMAP) was recorded from the paw muscles with a pair of needle electrodes to measure the motor conduction velocity (MCV). Results: MCV mean values were lower in Ebf2-/-(21.8 m/sec; SD 2.9) than in controls (35.2 m/sec; SD 2.6) and the difference was significant (p < 0.001). The mean cMAP amplitude was also decreased in Ebf2-/-(6.2 mV; SD 2.7) as compared to controls (9.3 mV; SD 2.6, p < 0.05). Conclusions: electrophysiological tests demonstrated a sharp decrease of sciatic MCV in Ebf2-/- mouse, as consequence of defective axon sorting, segmental dysmyelination and axonal damage revealed by pathological study.