Pyrithiamine-induced
thiamine deficiency (PTD), which has been used as a model of
Wernicke-Korsakoff syndrome (WKS), produces a range of neuropathological and behavioral abnormalities in rodents. The extent of the diencephalic damage produced by this treatment varies from moderate to extreme cell loss. The magnitude of working memory impairment tends to correlate with the degree of neuropathology. In this study a PTD protocol that produces moderate thalamic pathology was used to gain further insight into the neurobehavioral consequences of
thiamine deficiency. Towards this end, two distinct manipulations were conducted. First, the differential outcomes procedure (DOP), which correlates specific reinforcers with specific to-be-remembered events, was applied to an operant version of matching-to-position (MTP). This
behavioral manipulation was conducted to determine if the DOP would improve memory performance in PTD-treated rats, demonstrating some intact cognitive functions. Additionally, to assess the functional integrity of the
cholinergic and glutamatergic systems, normal and PTD-treated rats were administered i.p.
injections of
scopolamine and
MK-801. It was found that the DOP enhanced memory, but not acquisition performance, in both normal and PTD-treated rats. Furthermore, when administered
scopolamine, but not
MK-801, rats trained with the DOP continued to outperform rats trained with a non-differential outcomes procedure (NOP). However, PTD-treated rats, regardless of training procedure (DOP, NOP), were more disrupted by the 'amnestic' effects of both
scopolamine and
MK-801. The differential sensitivity of treatment groups to the amnestic effects of
scopolamine and
MK-801 reveals insights into the neurochemical correlates of memory processes and WKS.