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Dentate Nucleus (dentate + nucleus)

Distribution by Scientific Domains

Medical Sciences	87%

Selected Abstracts

Pick's disease with Pick bodies: An unusual autopsy case showing degeneration of the pontine nucleus, dentate nucleus, Clarke's column, and lower motor neuron

NEUROPATHOLOGY, Issue 1 2007
Tatsuro Oda
We report a 51-year-old female with Pick's disease with Pick bodies (PDPB) showing a brainweight of 530 g. This case was considered to be a very rare case of PDPB, in which the lesion developed in the temporal and frontal lobes and later spread to the parietal lobe, occipital lobe, brainstem, cerebellum and spinal cord. This case showed very atypical clinicopathological findings. Clinically, bulging eyes and myoclonus were observed. Neuropathologically, Pick bodies were widely distributed beyond the usual distribution areas to the parietal cortices, occipital cortices, dentate nuclei, motor neuron nuclei in the brain stem, and spinal cord. The atypical clinical symptoms and the widespread neuropathological abnormalities observed in this case seem to represent an extremely extended form of PDPB. [source]

Decreased GAD65 mRNA levels in select subpopulations of neurons in the cerebellar dentate nuclei in autism: an in situ hybridization study

AUTISM RESEARCH, Issue 1 2009
Jane Yip
Abstract The laterally positioned dentate nuclei lie in a key position in the cerebellum to receive input from Purkinje cells in the lateral cerebellar hemisphere participating in both motor and cognitive functions. Although neuropathology of the four cerebellar nuclei using Nissl staining has been qualitatively reported in children and adults with autism, surprisingly the dentate nuclei appeared less affected despite reported reductions in Purkinje cells in the posterolateral cerebellar hemisphere. To determine any underlying abnormalities in the critically important GABAergic system, the rate-limiting GABA synthesizing enzyme, glutamic acid decarboxylase (GAD) type 65 was measured via in situ hybridization histochemistry in dentate somata. GAD65 mRNA labeling revealed two distinct subpopulations of neurons in adult control and autism postmortem brains: small-sized cells (about 10,12,µm in diameter, presumed interneurons) and larger-sized neurons (about 18,20,µm in diameter, likely feedback to inferior olivary neurons). A mean 51% reduction in GAD65 mRNA levels was found in the larger labeled cells in the autistic group compared with the control group (P=0.009; independent t -test) but not in the smaller cell subpopulation. This suggests a disturbance in the intrinsic cerebellar circuitry in the autism group potentially interfering with the synchronous firing of inferior olivary neurons, and the timing of Purkinje cell firing and inputs to the dentate nuclei. Disturbances in critical neural substrates within these key circuits could disrupt afferents to motor and/or cognitive cerebral association areas in the autistic brain likely contributing to the marked behavioral consequences characteristic of autism. [source]

Variable-field relaxometry of iron-containing human tissues: a preliminary study

CONTRAST MEDIA & MOLECULAR IMAGING, Issue 4 2009
Aline Hocq
Abstract Excess iron is found in brain nuclei from neurodegenerative patients (with Parkinson's, Alzheimer's and Huntington's diseases) and also in the liver and spleen of cirrhosis, hemochromatosis and thalassaemia patients. Ferritin, the iron-storing protein of mammals, is known to darken T2 -weighted MR images. Understanding NMR tissue behavior may make it possible to detect those diseases, to follow their evolution and finally to establish a protocol for non-invasive measurement of an organ's iron content using MRI methods. In this preliminary work, the MR relaxation properties of embalmed iron-containing tissues were studied as well as their potential correlation with the iron content of these tissues. Relaxometric measurements (T1 and T2) of embalmed samples of brain nuclei (caudate nucleus, dentate nucleus, globus pallidus, putamen, red nucleus and substantia nigra), liver and spleen from six donors were made at different magnetic fields (0.00023,14 T). The influence of the inter-echo time on transverse relaxation was also studied. Moreover, iron content of tissues was determined by inductively coupled plasma atomic emission spectroscopy. In brain nuclei, 1/T2 increases quadratically with the field and depends on the inter-echo time in CPMG sequences at high fields, both features compatible with an outer sphere relaxation theory. In liver and spleen, 1/T2 increases linearly with the field and depends on the inter-echo time at all fields. In our study, a correlation between 1/T2 and iron concentration is observed. Explaining the relaxation mechanism for these tissues is likely to require a combination of several models. The value of 1/T2 at high field could be used to evaluate iron accumulation in vivo. In the future, confirmation of those features is expected to be achieved from measurements of fresh (not embalmed) human tissues. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Pick's disease with Pick bodies: An unusual autopsy case showing degeneration of the pontine nucleus, dentate nucleus, Clarke's column, and lower motor neuron

Pick's disease with Pick bodies combined with progressive supranuclear palsy without tuft-shaped astrocytes: A clinical, neuroradiologic and pathological study of an autopsied case

NEUROPATHOLOGY, Issue 3 2006
Lu-Ning Wang
We report clinical, neuroradiologic features, and neuropathologic findings of a 76-year-old man with coexistent Pick's disease and progressive supranuclear palsy. The patient presented with loss of recent memory, abnormal behavior and change in personality at the age of 60. The symptoms were progressive. Three years later, repetitive or compulsive behavior became prominent. About 9 years after onset, he had difficulty moving and became bed-ridden because of a fracture of his left leg. His condition gradually deteriorated and he developed mutism and became vegetative. The patient died from pneumonia 16 years after the onset of symptoms. Serial MRI scans showed progressive cortex atrophy, especially in the bilateral frontal and temporal lobes. Macroscopic inspection showed severe atrophy of the whole brain, including cerebrum, brainstem and cerebellum. Microscopic observations showed extensive superficial spongiosis and severe neuronal loss with gliosis in the second and third cortical layers in the frontal, temporal and parietal cortex. There were Pick cells and argyrophilic Pick bodies, which were tau- and ubiquitin-positive in neurons of layers II,III of the above-mentioned cortex. Numerous argyrophilic Pick bodies were observed in the hippocampus, especially in the dentate fascia. In addition, moderate to severe loss of neurons was found with gliosis and a lot of Gallyas/tau-positive globus neurofibrillary tangles in the caudate nucleus, globus pallidus, thalamus, substantia nigra, locus coeruleus and dentate nucleus. Numerous thorned-astrocytes and coiled bodies but no-tuft shaped astrocytes were noted in the basal ganglion, brainstem and cerebellar white matter. In conclusion, these histopathological features were compatible with classical Pick's disease and coexistence with progressive supranuclear palsy without tuft-shaped astrocytes. [source]

Immunohistochemical studies of the PrPCJD deposition in Creutzfeldt-Jakob disease

NEUROPATHOLOGY, Issue 2 2000
Shinichiro Tanaka
The PrPCJD deposition in eight brains of sporadic Creutzfeldt-Jakob disease (CJD) was examined immunohistochemically using both hydrolytic autoclaving and formic acid pretreatment in order to understand the pathogenesis of CJD. Synaptic-type PrP immunoreactivity was revealed in the gray matter in all cases and had a tendency to be weaker in devastated areas in cases with a longer duration of illness. However, in one particular case with numerous prion plaques, the degeneration was relatively mild while PrPCJD immunoreactivity was intense despite the longest duration of illness among the examined cases. Deep layer accentuation of PrPCJD immunoreactivity was observed in the cerebral cortices in most cases. This staining pattern, however, disappeared in a burnt-out lesion exhibiting status spongiosus. The granular layer was damaged mostly in the cerebellum of the advanced cases. PrPCJD and synaptophysin immunoreactivities decreased as the tissue degeneration progressed. Interestingly, the Purkinje cells had no positivity for PrPCJD in all cases, although the neurons in relatively preserved cerebellum showed apparent positivity for synaptophysin. In the Ammon's horn and subiculum the neurons were well preserved despite the marked immunoreactivity for PrPCJD in all cases, although some cases demonstrated severe spongiform change. Approximately half of the cases showed intracytoplasmic inclusion body-like immunoreactivity for PrPCJD in neurons of the dentate nucleus. These findings suggest that PrPCJD deposition may be an event that precedes neuronal degeneration evolving from deeper layers of the cerebral cortex. Although the Ammon's horn and subiculum showed striking PrPCJD deposition and spongiform change, neuronal loss did not take place, suggesting that deposited PrPCJD itself seems not to be directly harmful to the neurons. Some investigators have assumed that microglia activated by PrPCJD plays an important role in neuronal degeneration. Considering this, we speculate that microglia in the Ammon's horn and subiculum may have a unique characteristic of not responding to PrPCJD. [source]

Morphological Analysis of the Lung of Neonatal Yak

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2010
B. Yang
Summary With 20 figures and 5 tables Although yaks play an important role as companion or pack and draught animals on Chinese plateaus in alpine and sub-alpine regions, morphological studies and anatomical data on the lung of yak are sparse. To provide anatomical descriptions and morphometric data, 10 one-day-old yaks were examined by means of dissection, light and electron microscopy. The measurements of lung were made on dissected specimens and histological sections. Unequal dichotomous branching was demonstrated in the dissected tracheobronchial tree. The diameters of bronchial airways and height of epithelium were measured, and showed that the variation of diameters in airways was always greater than that of height of epithelium. In addition, the thickness of muscularis, cartilage and adventitia was examined, as well as the number of goblet and Clara cells in airways. Ultrastructural studies showed that the surface epithelium was mainly composed of goblet, ciliated, Clara and basal cells, similar to that in other domestic animals. Under electron microscope, two distinctive types of ciliated cells could be seen in the tracheobronchial epithelium. The first type contained some mitochondria, distended smooth endoplasmic reticulum (SER), little rough endoplasmic reticulum (RER) and numerous vacuoles in electron-lucent cytoplasm. The second type had dense cytoplasm with abundant mitochondria, RER and no vacuoles. Both types were rich of glycogen granules. The goblet cells in neonatal yak lung had the following characteristic features: dentate nucleus in dense cytoplasm, with stacks of RER and numerous dense membrane-bounded mucous droplets, which were round or oval, often with an electron-lucent core. The droplets were not confluent. Glycogen granules were numerous, and Golgi complex was occasionally present. Clara cells were dome-shaped and usually protruded into the airway lumen. Large amounts of SER and many secretory droplets were found within the cytoplasm. Several typical ,clefts' were also found in the cytoplasm. [source]