DIETARY GLUTEN AND LEARNING TO ATTEND TO REDUNDANT STIMULI IN RATS

The purpose of the present study was to assess the effect of a high-gl uten diet against a gluten-free diet on learning stimulus-response rel ationships in rats. In the first phase of training rats learned to ass ociate a stimulus light with responding on a particular response lever . In the second phase, the same rats were exposed to new, but redundan t, stimuli to guide responding (a tone and houselight). Probe trials, involving only new stimuli, revealed that rats fed a gluten-free diet displayed a ''blocking'' effect. That is, gluten-free rats did not lea rn to associate these new stimuli with particular responses. In contra st, high-gluten rats very quickly learned to use these redundant stimu li to guide responding. Subsequent phases of training demonstrated how ever, that this group difference could be removed. The present finding s are discussed in the context of the possible links between dietary g luten and schizophrenia. (C) 1997 Society of Biological Psychiatry.