Disruption of myelin sheaths in mouse brain in vitro and in vivo by staphylococcal alpha-toxin.

In recent studies we have demonstrated that staphylococcal alpha-toxin can specifically bind to rabbit vagus nerves and cause disruption of myelin sheaths in this peripheral nerve in vitro. We report here that staphylococcal alpha-toxin, incubated in vitro with brain slices or injected intracerebrally into mice, can induce disruption of myelin sheaths in central nervous tissue. Intracerebral injection of alpha-toxin is followed by a characteristic and reproducible syndrome involving ataxia followed by a severe contraction of the limbs on the side contralateral to the injection and a maximal extension of the opposing limbs. At 1.1 micrograms of toxin injected, death occurs within 20 min. Histopathologic examination reveals extensive demyelination with minimal involvement of the axons. It is possible that staphylococcal alpha-toxin may play a role in the etiology of multiple sclerosis.