Animal experiments on thiamine avitaminosis and cerebral function.

Before industrial production of thiamine becam possible, among many beriberi patients some showed symptoms of encephalopathy, the cerebral form of the disease. In this animal experiment, thiamine-deficient rats showed failure or blocking of the operant behavior in the maze box, pole climbing box and shuttle box, indicating orientation disturbance and defective memory. This Wernicke's syndrome-like sign dramatically disappeared by treatment with thiamine. Potentiated narcosis with thiopental or alcohol induced in thiamine-deficient rats and mice was readily reversible by thiamine administration. These phenomena are associated with thiamine content of the brain and are found long before histopathological changes in the brain of deficient animals. It is easily surmised that thiamine deficiency in the brain may block the brain metabolism and subsequently cause changes in any chemical substances in the brain, refracting on biophysical phenomenon, such as EEG. However, in the present study, generally speaking, no meaningful results concerning these points were obtained.