Applications of the Morris water maze in the study of learning and memory

The Morris water maze (MWM) was described 20 years ago as a device to inves tigate spatial learning and memory in laboratory rats. In the meanwhile, it has become one of the most frequently used laboratory tools in behavioral neuroscience. Many methodological variations of the MWM task have been and are being used by research groups in many different applications. However, researchers have become increasingly aware that MWM performance is influenc ed by factors such as apparatus or training procedure as well as by the cha racteristics of the experimental animals (sex, species/strain, age, nutriti onal state, exposure to stress or infection). Lesions in distinct brain reg ions like hippocampus, striatum, basal forebrain, cerebellum and cerebral c ortex were shown to impair MWM performance, but disconnecting rather than d estroying brain regions relevant for spatial learning may impair MWM perfor mance as well. Spatial learning in general and MWM performance in particula r appear to depend upon the coordinated action of different brain regions a nd neurotransmitter systems constituting a functionally integrated neural n etwork. Finally, the MWM task has often been used in the validation of rode nt models for neurocognitive disorders and the evaluation of possible neuro cognitive treatments. Through its many applications, MWM testing gained a p osition at the very core of contemporary neuroscience research. (C) 2001 El sevier Science B V All rights reserved.