These morphological abnormalities in microglia of SAMP10 mice preceded the onset of neuronal degeneration and may lead to making brain tissue less protective to neurons. We propose that preceding abnormalities in microglia may contribute to the vulnerability to age-related neuronal degeneration in SAMP10 mice. “
“Y. Yamamoto, L. Craggs, M. Baumann, H. Kalimo and

R. N. Kalaria (2011) Neuropathology and Applied Neurobiology37, 94–113 Molecular genetics and pathology of hereditary small vessel diseases of the brain Advances in molecular genetics have enabled identification of several monogenic conditions involving small vessels predisposing to ischaemic and haemorrhagic strokes and diffuse white matter disease. With emphasis on cerebral autosomal dominant arteriopathy with PD0325901 supplier subcortical infarcts and leukoencephalopathy (CADASIL), we review the molecular pathogenesis of

recently characterized disorders including cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL), retinal vasculopathy with cerebral leukodystrophy (RVCL) and the Collagen type IV, alpha 1 (COL4A1)-related disorders. CADASIL remains the most common hereditary small vessel disease (SVD) caused by >190 different mutations in STA-9090 purchase the NOTCH3 gene, which encodes a cell-signalling receptor. Mutant NOTCH3 instigates degeneration of vascular smooth muscle cells in small arteries and arterioles leading to recurrent lacunar infarcts. Mutations in the serine protease HTRA1 gene are associated with CARASIL. Aberrant HTRA1 activity results in increased transforming growth factor-β signalling provoking multiple actions including vascular fibrosis and extracellular matrix synthesis. The RVCL disorders characterized by profound retinopathy are associated with mutations in TREX1, which encodes an abundant 3′–5′ DNA-specific exonuclease. TREX1 mutations lead to detrimental gain-of-function or insufficient quantities

of enzyme. The COL4A1-related disorders are highly variable comprising four major phenotypes with overlapping systemic and central nervous system features including SVD with cerebral haemorrhages in children and adults. Mutant COL4A1 likely disrupts the extracellular matrix resulting in fragile vessel walls. The hereditary SVDs albeit with Interleukin-3 receptor variable phenotypes demonstrate how effects of different defective genes converge to produce the characteristic arteriopathy and microvascular disintegration leading to vascular cognitive impairment. “
“N. Rogers, S. Paine, L. Bedford and R. Layfield (2010) Neuropathology and Applied Neurobiology36, 113–124 The ubiquitin-proteasome system: contributions to cell death or survival in neurodegeneration The significance of the accumulation of ubiquitin-positive intraneuronal inclusions in the brains of those affected with different neurodegenerative diseases is currently unclear.