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Large neurons in the neostriatum of patients with Alzheimer's disease (AD) and progressive supranuclear palsy (PSP) were investigated topographically, histologically and ultrastructurally. The number of large neurons whose nuclear area is greater than 101 microns2 was uniformly decreased in the neostriatum in PSP, but the decrease of these neurons in AD appeared to be more marked in the nucleus accumbens. Most of the remaining large neurons in both diseases contained neurofibrillary tangles (NFTs). In addition, some of the small neurons in PSP were positive for tau-immunostaining. Curly fibers were frequently observed in AD, but were absent in PSP. Ultrastructurally, NFTs in AD were composed mainly of paired helical filaments, whereas those in PSP contained straight tubules.

The morphology and degree of maturation of intrafissural colony-forming ectopic granule cells (EGCs) were investigated in the cerebella of normal adult rats. These EGCs exhibit a notable degree of morphological maturity, with 2-5 short dendrites radiating from a globular soma, typical dendritic claw-like terminals and descending axons. The EGCs receive the afferent input of mossy fiber terminals and their axons also establish homologous synapses with the postsynaptic dendritic spines of the Purkinje cells. Although these EGCs exhibit the typical morphology of mature granule cells, the morphometric analysis shows, however, a significant reduction in the number of dendrites (mean 3.30 +/- 0.60) and 'claws' (mean 3.66 +/- 0.12) in the EGCs with respect to the controls (mean 3.85 +/- 0.73 and 4.53 +/- 0.13, respectively). These differences may be indicative of a slight numerical mismatching between EGCs and afferent mossy fibers, which limit the input that the ectopic neurons receive. The karyometric study also showed that the average nuclear area in EGCs was significantly smaller (mean 19.38 +/- 0.24 micron2) than in controls (mean 21.88 +/- 0.24 micron2), suggesting a positive correlation between nuclear size and the number of postsynaptic dendritic terminals available in the granule cells. The influence of some morphogenetic factors on the degree of maturity attained by these ectopic neurons is discussed, particularly the interactions of mossy fibers and astrocytes with maturing EGCs.

To elucidate the mechanism of the Reilly syndrome (irritation syndrome), direct current (DC) potential changes in the medulla oblongata were investigated. Ipsilateral and contralateral trigeminal stimulation induced a DC potential shift above the vagal nuclear area in the medulla. Maxillary and mandibular nerve stimulation showed a summation effect. Continuous stimulation of the tooth pulp cavity by croton oil induced a progressively developed DC shift. DC potential change by trigeminal stimulation was accompanied by the same process of elevation of extracellular potassium concentration. These findings suggest that trigeminal stimulation increases the excitability of vagal nuclear neurons and consequently provokes the Reilly syndrome.

In order to evaluate the quantitative changes in the neostriatum of Alzheimer's disease (AD) and senile dementia of Alzheimer type (SDAT), sections of the caudate head (CN) and putamen (PT) from 4 AD/SDAT and 6 age-matched control cases were stained with Kluver-Barrera, and the cell body and nuclear areas of the neurons were measured by a digitizer. This study revealed a significant decrease in the number of large neurons (nuclear area; greater than 101 μm2) and good preservation of the number of small neurons (nuclear area; less than 100 μm2) in CN and PT of AD/SDAT.

In order to evaluate the quantitative changes in the neostriatum in progressive supranuclear palsy (PSP), sections of the caudate head (CN) and putamen (PT) from 4 PSP patients were stained with Klüver-Barrera, and the cell body and nuclear area of the neurons were measured by a digitizer. Obtained results were compared to those of 6 age-matched control and 4 Alzheimer's disease and senile dementia of Alzheimer type (AD/SDAT) subjects which were previously reported. The number of large neurons (nuclear area greater than 101 microns 2) in PSP was about 40% (P less than 0.01) and 30% (P less than 0.01) of that of the controls in CN and PT, respectively. In contrast, the number of small neurons in PSP (nuclear area less than 100 microns 2) was well preserved. The values were quite similar to those in AD/SDAT. The implications and possible significance are discussed.

Age- and diabetes-associated changes in the neuronal density and area of the ventromedial (VMH) and arcuate (ARC) nuclei of the Chinese hamster hypothalamus were analyzed morphometrically. Neuronal density peaked much sooner in diabetic animals than in matched controls, and subsequently declined at a faster rate than did aging, control animals. Nuclear area measurements were depressed in diabetic animals as compared with controls. These findings indicate that diabetes has severe effects on nuclear maturation and dynamics in the Chinese hamster, which may be causally associated with impaired hypothalamus-pituitary function.

The morphological types of isolated ectopic granule cells (EGCs) were examined with Golgi-Rio Hortega staining in the cerebellar molecular layer of adult normal rats. The EGCs showed a significant reduction in the number of dendrites (mean 2.42 +/- 0.07) with respect to the controls (mean 3.97 +/- 0.09), and they usually exhibited poorly developed dendritic terminals. The karyometric analysis on semithin sections indicated that the average nuclear area in EGCs was significantly smaller (16.62 +/- 0.20 micron 2) than in normally positioned granule cells (21.08 +/- 0.24 micron 2).