Keiichi Higuchi

Learn More
This study examined age-dependent deficits in the learning and memory of inferential tasks, using an established senescence-accelerated mouse model in age-related brain dysfunction (SAMP8) and its genetically related inbred strain (SAMR1). The mice learned two sets of nonspatial odor-odor pairs by association learning successively (i.e., A-->B, X-->Y, then(More)
The SAMP1 strain is a mouse model for accelerated senescence and severe senile amyloidosis. We determined whether supplementation with coenzyme Q10 (CoQ10) could decelerate aging in SAMP1 mice and its potential role in aging. Plasma concentrations of CoQ10 and CoQ9 decreased with age in SAMP1 but not in SAMR1 mice. Supplementation with reduced CoQ10 (CoQH2,(More)
β-Amyloid (Aβ) is deposited in neurons and vascular cells of the brain and is characterized as a pathologic feature of Alzheimer's disease (AD). Recently studies have reported that there is an association between cardiovascular risk factors and AD, however the mechanism of this association is still uncertain. In this study we observed Aβ had an effect on(More)
Senescence-accelerated mice (SAM) are a series of mouse strains originally derived from unexpected crosses between AKR/J and unknown mice, from which phenotypically distinct senescence-prone (SAMP) and -resistant (SAMR) inbred strains were subsequently established. Although SAMP strains have been widely used for aging research focusing on their short life(More)
Amyloidosis describes a group of protein folding diseases in which amyloid proteins are abnormally deposited in organs and/or tissues as fine fibrils. Mouse senile amyloidosis is a disorder in which apolipoprotein A-II (apoA-II) deposits as amyloid fibrils (AApoAII) and can be transmitted from one animal to another both by the feces and milk excreted by(More)
Common neurodegenerative diseases, including Alzheimer's disease (AD) and Parkinson's disease (PD), are now considered as "protein misfolding diseases," because the misfolding of a small number of proteins is a key event in the pathogenesis and progression of these diseases. Proteins that are prone to misfolding and thereby associated with neurodegenerative(More)
Senescence accelerated mice P8 (SAMP8) show significant age-related deteriorations in memory and learning ability in accordance with early onset and rapid advancement of senescence. Brains of SAMP8 mice reveal an age-associated increase of PAS-positive granular structures in the hippocampal formation and astrogliosis in the brain stem and hippocampus. A(More)
In mouse senile amyloidosis, apolipoprotein (Apo) A-II is deposited extracellularly in many organs in the form of amyloid fibrils (AApoAII). Reduction of caloric intake, known as caloric restriction (CR), slows the progress of senescence and age-related disorders in mice. In this study, we intravenously injected 1 μg of isolated AApoAII fibrils into(More)