Learning and memory processes in mice:A behavioral, molecular and pharmacological study in wild-type and transgenic animals

Abstract

Aiming at species-specific tests for assessing cognitive functions in transgenic mice, several versions of the water maze task were established which showed that wild-type mice navigate by means of distal visual cues only when they provide geometric information (i.e., asymmetric disposition of landmarks or asymmetric shape of the environment). We then designed a new spatial learning task in which wild-type male mice learn in one trial the location of a female mouse by means of geometry. The hippocampus-dependency of this test was proven by molecular and pharmacological approaches. The newly established tests were used to evaluate cognitive abilities of mice deficient for two neural cell adhesion molecules, NCAM and L1. NCAM deficient mice showed cognitive deficits depending on the activation of the stress response and on the complexity of spatial information. No alterations were observed in L1-deficent mice. Finally, stereotactic pharmacological treatments were performed to test the role of L-type voltage dependent calcium channels in the impaired extinction of mice deficient for the extracellular matrix glycoprotein tenascin-C.