Impaired allocentric spatial working memory and intact retrograde memory after thalamic damage caused by thiamine deficiency in rats.
Rats were tested on an allocentric-spatial working-memory task--delayed matching-to-place (DMTP) in a water maze--before and after either pyrithiamine-induced thiamine deficiency (PTD) or electrolytic lesions of the lateral internal medullary laminae (IML), an area damaged by PTD. DMTP trials consisted 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 groups 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 allocentric spatial working memory and that damage outside the IML is probably responsible. Neither PTD-induced diencephalic damage nor restricted IML lesions appear to produce a global retrograde amnesia.
Mumby
D G
DG
Department of Psychology, Concordia University, Montreal, Quebec, Canada. mumby@vax2.concordia.ca
Cameli
L
L
Glenn
M J
MJ
D000818:Animals; D001925:Brain Damage, Chronic / Q000503:physiopathology*; D001931:Brain Mapping; D004924:Escape Reaction / Q000502:physiology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D011939:Mental Recall / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D012153:Retention, Psychology / Q000502:physiology; D013788:Thalamus / Q000503:physiopathology*; D013832:Thiamine Deficiency / Q000503:physiopathology*