Hippocampus-dependent learning in SKAP-HOM deficient mice.

SKAP-HOM is an adapter protein which regulates the cross-talk between immunoreceptors and integrins and is involved in signal transduction. It is present in murine brain structures such as the hippocampus, frontal cortex, and cerebellum. In the present study we investigated types of hippocampus-dependent learning (fear conditioning, social memory, and the Morris Water Maze) and locomotor sensitization to amphetamine in transgenic SKAP-HOM deficient mice (-/-) in comparison with respective controls (+/+). Animals from both groups showed comparable fear conditioning, and the extinction of conditioned fear was accelerated in -/-. In terms of sociability, there were no differences between the animals, but in -/- mice social memory was impaired. There was no difference between the two groups of mice in spatial learning and memory measured in the Morris Water Maze. Wild-type and deficient animals exhibited similar sensitization to amphetamine. In reaction to amphetamine challenge, the response in +/+ was enhanced. It was hypothesized that SKAP-HOM deficiency does not affect hippocampus-dependent learning in general, but that its effects on cognitive tasks seem to be dependent on the nature of the cognitive task, i.e. spatial vs. non-spatial.