IMPAIRED SPATIAL NAVIGATION LEARNING IN TRANSGENIC MICE OVER-EXPRESSING HEME OXYGENASE-L

Transgenic mice expressing heme oxygenase-1 (HO-1) using the neuron-sp ecific enolase promoter were impaired in learning the Morris water maz e compared to nontransgenic littermates. The memory of the HO-1 mice f or the location of the platform was similarly impaired when tested usi ng a probe trial after 7 training blocks, but performance on visible p latform trials was similar for both groups of mice. Importantly, both HO-1 and nontransgenic mice had normal sensorimotor function, and perf ormed the same on a Y-maze alternation task, highlighting the specific ity of memory deficit in the spatial navigation task. These results su ggest that carbon monoxide, one product of HO-1 activity, interferes i n the development of spatial navigation memory, and may play a role in normal memory function. (C) 1998 Published by Elsevier Science B.V. A ll rights reserved.