Early regional cerebral blood volume (CBV) reductions in amyloid precursor protein transgenic mice

Abstract

Recent advance in NMR microimaging has enabled in vivo CBV mapping with high spatial resolution[1]. Using an intravascular susceptibility contrast agent(MION) and T2-weighted MRI on a 9.4 Tesla NMR microimager, the relative CBV maps were obtained for 4-mon old APP mice(N=6) and littermate controls(N=6) in the resting state. Fig.1 shows a typical axial CBV map and corresponding MRI anatomic image obtained. It has a spatial resolution of 100um, permitting more quantitative examination of various regions and subregions. Note that CBV is generally low in hippocampal regions except for the hippocampus fissure(HF). Regional analysis of the multislice CBV maps revealed statistically significant CBV reductions among APP mice in cerebral cortex(-14.7%, p<0.001) and hippocampus(-11.6%, p<0.01)(Fig.2). No significant difference was found in other regions. It has been shown recently by others that young APP mice exhibit impaired cerebrovascular autoregulation[1] and volume reduction of dentate gyrus[2]. The preliminary study here indicates early change of microvasculature. REFERECES: 1. Wu EX et al. MRM 49:765,2003. 2. R JM et al. PNAS 100:1381,2003. 3. N K et al. AJP Heart Circ Phy. 283:315,2002. Supported by CA85594,AG17490,AG16736,AG08702