Morphological and morphometric changes in the Purkinje cells of patients with essential tremor.

Essential tremor (ET) is a progressive neurological syndrome characterised by involuntary tremors of the hands or arms, head, jaw and voice. The pathophysiology of ET is not clearly understood yet. However, previous studies have reported several changes in the brain of patients with ET. One of the brain areas extensively investigated is the cerebellum. In the present study, a morphometric analysis of Purkinje cells in patients with ET and ET-plus was performed, and subsequently compared with normal controls using the Golgi silver staining method and 3D neuronal reconstruction. Substantial morphological changes were uncovered in the Purkinje cells of patients with ET compared with normal controls, including a decreased dendritic length and field density, an overall loss of terminal branches and a decreased density of dendritic spines.

Purkinje Cells Pathology in Alzheimer's Disease.

Alzheimer's disease (AD) is one of the main causes of dementia in senium and presenium. It is clinically characterized by memory impairment, deterioration of intellectual faculties, and loss of professional skills. The cerebellum is a critical part in the distributed neural circuits participating not only in motor function but also in autonomic, limbic, and cognitive behaviors. In present study, we aim to investigate the morphological changes in the Purkinje cells in different cerebellar regions in AD and to correlate them with the underlying AD pathology. Purkinje cells exhibit significant morphometric alterations in AD and prominently in the anterior lobe which is related to higher cognitive functions. The present study gives new insights into the cerebellar pathology in AD and confirms that Purkinje cells pathology is a key finding in AD brains and that AD is characterized by regional-specific atrophy picked in the anterior cerebellar lobe.

Age-related dendritic and spinal alterations of pyramidal cells of the human visual cortex.

INTRODUCTION: Normal aging is characterized by deterioration of visual abilities, affecting mainly visual acuity, contrast and wavelength sensitivity. In the present study we attempted to describe the morphological and morphometric alterations of the dendrites and the dendritic spines of the pyramidal cells of the visual cortex during normal aging, in order to approach the visual impairment of aged individuals from a neuropathological point of view. MATERIAL AND METHODS: We studied the visual cortex in 20 brains using the Golgi technique. RESULTS: In pyramidal cells, which represent the majority of cortical neurons, age-related pathology can be observed in cell somata as well as, most importantly, in dendrite number and morphology. The apical dendrites of some pyramidal cells are distorted and tortuous. Horizontal dendritic arborization is also severely decreased. These alterations were more prominent in the corticocortical pyramidal neurons of the 5th layer. CONCLUSIONS: The morphological and morphometric assessment of the dendrites and the dendritic spines in the visual cortex in normal aging revealed substantial alterations of the dendritic arborization and marked loss of the dendritic spines, which may be related to visual impairment even in normal aging.

Dendritic and spinal alterations of neurons from Edinger-Westphal nucleus in Alzheimer's disease.

Alzheimer's disease (AD) is a heterogeneous neurodegenerative disorder, causing a progressive decline of intellectual faculties, impairment of behavior and social performance, and impairment of speech eloquence, associated with various neurological manifestations based on a variable neuropathological background. Edinger-Westphal nucleus is a selective target of Alzheimer pathology early in the course of the disease. We attempted to determine the morphological alterations of the dendrites and the dendritic spines in Edinger-Westphal nucleus of 7 cases that fulfilled the diagnostic criteria for Alzheimer's disease. For the histological study, we applied (a) routine neuropathological techniques and (b) rapid Golgi method. We proceeded to 3D neuronal reconstruction for the estimation of dendritic and spinal changes in Alzheimer's disease. The morphological and morphometric analysis revealed a substantial neuronal loss and synaptic alterations in Edinger-Westphal nucleus in all the cases of Alzheimer's disease. Distal dendritic branches are prominently affected. The neuronal loss and alteration of the spines in Edinger-Westphal nucleus in Alzheimer's disease may be related to the exaggerated pupillary reaction to cholinergic antagonists. Furthermore, the vulnerability of distal branches to Alzheimer's disease might be related to neuroplasticity impairment.

Glutamate receptors in human caudate nucleus in normal aging and Alzheimer's disease.

Neostriatum is one of the brain areas that are not primarily affected in Alzheimer's disease, according to classic regard of the disease. However, recent data emphasize the involvement of neostriatum, especially the head of the caudate nucleus, in the emergence of characteristic symptoms of the disease. Glutamatergic neurotransmission is a key component of striatal pathways. The present study is focused on glutamate receptors of striatal neurons on human caudate nucleus in normal aging and Alzheimer's disease. Immunohistochemical studies were carried out for N-methyl-D-aspartate receptor subunit 1 (NMDAR1), α -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit 2 (GluR2) and metabotropic glutamate receptor 5 (mGluR5). Ionotropic receptors (NMDAR1 and GluR2) were found to be expressed by 82% - 93% of striatal neurons with no significant alterations in aging and Alzheimer's disease. On the other hand, metabotropic receptor mGluR5 was found to be expressed by just 40% of striatal neurons in young individuals, with significant intensity variations among the neurons. This percent was increased in elderly individuals and Alzheimer's disease patients to 80% and 92% of striatal neurons, respectively. The up-regulation of mGluR5 both in normal aging and Alzheimer's disease is possibly associated with reorganization of neuronal connections, indicates the complexity of this receptor function and renders quite unpredictable the intervention and treatment of dementia with mGluR5 inhibitors or modulators.

The issue of euthanasia in Greece from a legal viewpoint.

Modern Greek society appears to be split regarding the legalization of euthanasia. The Greek Orthodox Church maintains a negative attitude. Research shows that some forms of euthanasia are carried out "behind closed doors". There is no specific legal provision. The government avoids bearing the political cost of regulating this marginal issue. According to the dominant view of Criminal Law jurists, some forms of euthanasia are considered permissible de lege lata, under certain conditions. The safety of the concurrence of these conditions, safeguarding of the acceptability of forms that are considered permissible and - mostly - the need to regulate the prohibited forms in exceptional cases, all force the legislators to promptly fill any legal vacuums.

Neuropathological findings in Dandy Walker variant.

OBJECTIVE: Dandy-Walker malformation is a congenital malformation that is characterized by hypoplasia of the cerebellar vermis, cystic dilatation of the fourth ventricle and enlargement of the posterior fossa. The aim of the study is to describe the morphological and morphometric alterations of neurons (in various regions of the brain) in a case of Dandy-Walker Variant. METHODS: By Golgi method and routine techniques, the alterations in the brain of a 23 years old case of Dandy-Walker Variant who died accidentally were studied. Furthermore, a detailed morphometric analysis of neuronal parameters and a statistical comparison with an age-matched control were applied. RESULTS: In the cerebellum the morphological study, apart from gliosis, revealed reduction of the size of cell body and poverty of dendritic arborization with loss of dendritic branches and spines. In the cerebral cortex and the hippocampus the most prominent findings were the tortuous configuration of the apical dendrites of the pyramidal neurons, the focal swellings of the axons and the dendrites and significant gliosis. CONCLUSION: Although the gross anatomical examination of the brain demonstrated only mild neurodevelopmental anomalies (except the key features of the syndrome), the microscopic examination revealed significant morphological alterations of neurons and dendrites.

The clockwise rotation of myocardial fiber orientation from epicardial to endocardial surface in left ventricular free wall in a post-mortem human heart.

Following fixation and MRI imaging a post-mortem human heart was sliced at the sagittal plane. Each anatomical section was then cut into smaller segments and each one was objected to classical histology process. The resulting microscopy slides were digitalized with a scanner. The histological section reconstruction was achieved using Adobe Photoshop CS2(R). Using specific software, called FiberCad, the user can define and draw (with the assistance of optical microscope) those fibers that are parallel and those fibers that are vertical to the slides plane. To better align the histological 3D reconstruction, the software is equipped with an option that allows the user to make best possible fit between histological and MRI slices. We present the consequent sagittal sections of LV free wall (from epicardial to endocardial surface), whereby the clockwise rotation of the mean orientation of the fibers that are on the plane of sectioning is clearly evident. We present a post mortem analysis of the complete LV free wall of a human heart.