Dg. Mumby et al., Impaired allocentric spatial working memory and intact retrograde memory after thalamic damage caused by thiamine deficiency in rats, BEHAV NEURO, 113(1), 1999, pp. 42-50
Rats were tested on an allocentric-spatial working-memory task-delayed matc
hing-to-place (DMTP) in a water maze-before and after either pyrithiamine-i
nduced thiamine deficiency (PTD) or electrolytic lesions of the lateral int
ernal medullary laminae (IML), an area damaged by PTD. DMTP trials consiste
d of paired swims, with the escape platform in a new location on each trial
. PTD rats were impaired at retention delays of 300 s, but not at delays of
4 or 60 s. Rats with IML lesions performed normally at all delays. Both gr
oups displayed normal retention of object-discrimination problems that they
had learned at different intervals before treatment (5 weeks, 3 weeks, and
1 week). The results suggest that PTD causes delay-dependent deficits of a
llocentric spatial working memory and that damage outside the IML is probab
ly responsible. Neither PTD-induced diencephalic damage nor restricted IML
lesions appear to produce a global retrograde amnesia.