Thiamine deficiency decreases glutamate uptake in the prefrontal cortex and impairs spatial memory performance in a water maze test.

Using an animal model of Wernicke-Korsakoff syndrome, in which rats were submitted to a chronic ethanol treatment with or without a thiamine deficiency episode, the glutamate uptake in the prefrontal cortex and spatial memory aspects were studied. It was found that (i) thiamine deficiency, but not chronic ethanol consumption, induced a significant decrease of glutamate uptake; (ii) thiamine-deficient subjects showed an impaired performance in the water maze spatial memory test though these animals were able to learn the task during the acquisition. In spite of the fact that thiamine deficiency affects both glutamate uptake and spatial reference memory, there was no significant correlation between these two data. The present results show that, although prefrontal cortex is considered by some authors a not vulnerable area to lesions caused by thiamine deficiency, this vitamin deficiency does cause a neurochemistry dysfunction in that region.