Objectives and experimental design Cerebella of young adults, elderly adults, and patients with Alzheimer's disease (AD) (with and without cerebellar amyloid deposits) were studied by Golgi staining and glial fibrillary acid protein (GFAP) immunocytochemical methods. Observations Three subtypes of Golgi epithelial cells and nine subtypes of stellate neuroglia (both normal and hypertrophic) were defined by their morphology, their GFAP‐reactivity, their specific location in the cortical layers, and their responses in senility and AD. The GFAP immunoreaction was subtype specific. In aged and AD cerebella, different morphological and GFAP‐immunoreactive subtype‐specific changes were observed: in the white matter, the subtypes were always GFAP‐immunopositive, but in the grey matter some astroglial subtypes showed a variable or no increase in GFAP staining. The astrocytes at the limits of the granule cell layer showed more and longer processes. Variations were seen in one or more folia, involving one or more subtypes and affecting different numbers of cells of each subtype. No clear differences were seen in glial reactivity between beta‐amyloid positive and β‐amyloid (Aβ) negative AD cerebella. No important relationships were found between Aβ deposits. In aged and AD cerebella, different subtypes expressed new proteins (APP, calretinin). Conclusions The existence of different glial subtypes in different locations suggests they have different functions. General and local variations in these subtypes suggest that both general and local induction factors must also exist. The responses of glial cells to as‐yet undefined stimuli might lead to general or local neuronal changes important in senility and the pathogenic course of AD. GLIA 2015;63:287–312
In this study we have determined whether Raman and infrared spectroscopy of blood plasma differentiates Alzheimer's disease (AD) from normal aging of healthy controls. Spectroscopic analysis was conducted on blood plasma samples from 8 mild AD, 16 moderate AD, 11 severe AD, and 12 normal elderly control persons using Fourier transform spectrometers and a near-infrared laser beam as excitation source for Raman spectroscopy. Spectra were processed employing discriminant analysis to determine whether band areas and frequency-intensity relationships might reveal biochemical differences associated with AD. Seven spectral biomarkers were identified in the Raman regions of 1700-1600 cm-1 (protein secondary structure), 980-910 cm-1 (protein α-helices), 790-730 cm-1 (protein tertiary structure), and 440-390 cm-1 (protein backbone) and in the infrared regions of 1700-1600 cm-1 (protein secondary structure) and 1150-1000 cm-1 (oxidative stress). This discriminant analysis model differentiated AD from normal aging of elderly control persons with a sensitivity of 89% and specificity of 92%. Moreover, specificity increases to 100% for the detection of mild AD. In summary, our results open the possibility of using this spectroscopic approach as a non-invasive, rapid, and relatively inexpensive procedure for early accurate diagnosis of AD.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.