Genetically modified mice and cognition.

Cognition in transgenic and knockout mice is preferentially assessed by spatial learning in the Morris water maze. Awareness is growing, however, that the putative cognitive deficits observed using such a paradigm may be biased by the genetic background and behavioral peculiarities of the specific animals used. Recent progress in cognitive research includes new behavioral tests and refined analysis of performance impairments. Advances in our understanding of memory and learning are being made possible through use of transgenic rescue of disrupted genes, inducible and reversible gene targeting in selected brain regions, and single-cell recordings of hippocampal place cells in mutant mice.