In a transgenic mouse model for early-onset Alzheimer's, severe atrophy in the corpus callosum and hippocampal formation was observed even before amyloid deposition.

“even before there was any amyloid deposition in that model that they had inserted they had it was a transgenic mouse model that they had taken away the native gene from the mouse and replaced that gene we wonder with Ag normal for on a patient with early onset Alzheimer's but even before the gene could store any any observable deposition of amyloid these brains by that very manipulation were abnormal they had severe atrophy in for example the corpus callosum and all that communicates to Hemisphere and the region of the hippocampal formation has lost one third of his volume”