Background: Aspartame is considered the most widely used nocaloric artificial sweetener. It is used in a variety of food products and beverages. However, the consumption of aspartame has been controversial as several studies have reported an association between its use and many serious diseases. Aim of the work: The aim of the present study was to evaluate
the potential neurotoxic effect of long duration aspartame consumption on the sciatic nerve of the adult male albino rats and the possibility of spontaneous recovery following cessation of its administration. Material and methods: Thirty adult male albino rats were used in this study, aged from 6-8 months, weighting 180 -200 gm. Rats were randomly divided into three groups: Group I: ten rats that received nothing except food and water, Group II: ten rats that received aspartame (250 mg/kg/d) for 12 weeks and Group III: ten rats that received aspartame as in group II then left for four weeks to recover. Results: The present work revealed that aspartame induced histological changes of rats' sciatic nerves in the form of irregular nerve structure with wide separation of myelinated nerve fibers and dark elongated Schwann cells. Ultrastructural examination of group II showed separated myelin lamellae and excessive in folding with myelin loops formation. The recovery group showed histological improvement when compared to group II, yet it didn't reach completely to the histological picture of the control group. Conclusion: The results supported the neurotoxic effect of aspartame on rats' sciatic nerves when consumed regularly for a long period and proved that the spontaneous recovery wasn't complete.