I recommend this paper
"This paper presents a fascinating, two-part hypothesis. It suggests that presenilin-1 is necessary for neurogenesis in the dentate gyrus of mice that have been stimulated by exposure to an enriched environment. It goes on to propose that a biological function of dentate gyrus neurogenesis may be to clear outdated memory traces from the hippocampus so that the hippocampus can remain continually available for newly formed memories once older ones have been consolidated in the cortex.
Clearly, this idea intrigues those interested in the memory deficits of Alzheimer's, (though note that the PS-1 mutations underlying FAD cause a gain, not loss, of function.) However, a careful reading of the paper raises concern in this writer's mind that the idea postulated here appears to go beyond the presented data.
For one, it is not clear that the conditional knockout mice used here have a PS-1 deletion in neural stem or progenitor cells. The paper states that PS-1 is deleted in excitatory neurons of adult mouse forebrain. This raises the question how accumulating APP-CTFs in...