Keiichi Higuchi

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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)
No long-term exercise training regimen with high adherence and effectiveness in middle-aged and older people is broadly available in the field. We assessed the adherence to, and effects of, our long-term training program comprising an interval walking training (IWT) and an information technology network system and the factors affecting adherence.(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)
Amyloidosis refers to a group of protein folding diseases. Various innocuous and soluble proteins in physiological conditions polymerize to insoluble amyloid fibrils in several serious diseases, including Alzheimer's disease (AD) and prion diseases. In addition, senile amyloidosis is a form of amyloidosis in which the incidence and severity of amyloid(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)
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)
We previously reported that cerebral activation suppressed baroreflex control of heart rate (HR) at the onset of voluntary locomotion. In the present study, we examined whether vasopressin V1a receptors in the brain were involved in these responses by using free-moving V1a receptor knockout (KO, n = 8), wild-type mice locally infused with a V1a receptor(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)