Reduced number of satellite oligodendrocytes of pyramidal neurons in layer 5 of the prefrontal cortex in schizophrenia

European Archives of Psychiatry and Clinical Neuroscience - Neuroimaging, genetic and molecular biological studies have shown impaired intra-cortical myelination in patients with schizophrenia,...     

The effects of haloperidol on synaptic plasticity in rat's medial prefrontal cortex

Morphometric analysis of Medial prefrontal cortex (layer VI) of rats treated daily with haloperidol in a dose of 0.1 mg/kg during 3 weeks was performed on the electron microscopic level. The efficacy of the haloperidol dosage was tested on the amphetamine psychosis model. Synapses on dendritic shafts and dendritic spines were studied. The density of synapses on dendritic shafts increased on 51%, while on spine's neck it decreased on 19%. There were significant changes of some synaptic parameters only in axo-dendritic synapses: area of presynaptic terminal decreased on 13% (p less than 0.05), length of postsynaptic density decreased on 15% (p less than 0.05), but the density of synaptic vesicles near the active zone increased on 10% (p less than 0.05).     

Ultrastructure of B-cell tumors of the pancreas (insulinomas - insular carcinoid tumors)]

The subcellular organization of 6 B-cell tumours of the human pancreas was studied. The tumour parenchyma consisted of processed light, dark, and moderately electron dense cells containing insulin granules. The presence of villi in the cytoplasm of tumour cells and intranuclear fibrills was demonstrated. The participation of tumour cells in formation of amyloid-like thin-fiber substance filling the intercellular and perivascular spaces was established. The similarity between endothelial cells of tumour vessels and parenchymatous cells was shown. A hypothesis on neuroectodermal origin of the endocrine tissue of the pancreas is supported.     

Morphometric study of ultrastructural changes in oligodendroglial cells in the postmortem brain in endogenous psychoses

A qualitative and quantitative electron microscopic study of oligodendroglial cells was performed in autoptic (4-6.5 hours after death) prefrontal area 10 in 16 cases of schizophrenia, 6 cases of bipolar affective disorder and 16 normal controls, as well as in the caudate nucleus in same schizophrenic and control cases. The signs of reactive, regressive, and progressive changes of oligodendroglia were described in endogenous psychoses. ANOVA demonstrated a significant decrease in the area of the nucleus, in the volume density of euchromatin, in the volume density and count of mitochondria in oligodendroglial cells in the caudate nucleus and prefrontal area. In affective psychosis, there was a significant reduction in the area of the nucleus and in the volume density of euchromatin and slight changes in cellular organelles. No correlation between the changes and the postmortem interval, age, and neuroleptic therapy, as well as the most pronounced changes in oligodendroglial cells in subgroups of continuous schizophrenia and those with predominantly negative symptoms suggest the involvement of abnormal oligodendroglial cells in the pathogenesis of endogenous psychoses.     

Morphometric analysis of synaptic contacts in the anterior limbic cortex in the endogenous psychoses

Translated from Zhurnal Nevropatologii i Psikhiatrii imeni S. S. Korsakova, Vol. 90, No. 10, pp. 53–57, October, 1990.     

Impairments to Oligodendrocyte Clustering in the Supra- and Infragranular Layers of Field 10 of the Prefrontal Cortex in Schizophrenia

Neuroscience and Behavioral Physiology - Objectives. Intravital studies have shown that alterations to myelination in the gray matter of the cortex in schizophrenia are the most marked in the...     

Ultrastructural reorganizations of synaptic contacts in an organotypic culture of the brain cortex in the presence of ethanol

The effect of various ethanol concentrations (0.5 and 1%) on the ultrastructure of interneouronal contacts is studied in an organotypic culture of the brain cortex from newborn rats. It is shown that ethanol in the culture medium causes geometric complications in the synaptic contacts. Morphometric analysis of synapses reveals an increase of the area and perimeter of axon terminals and of the length of the active zone of the contact, as well as a decrease of the coefficient determined by the ratio of the number of synaptic vesicles to the length of the active zone of the contact. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120 N ^o 7, pp. 99–102, July, 1995 Presented by V. Ya. Semke, Member of the Russian Academy of Medical Sciences.     

The role of oligodendrocyte pathology in schizophrenia

Neuroimaging and microarray studies provide evidence for myelin and oligodendrocyte abnormalities in schizophrenia (SZ). Electron microscopy demonstrated dystrophy, necrosis and apoptosis of oligodendrocytes, the most severely affected cells in SZ. The proportion of myelinated fibres with atrophy of axon and swelling of periaxonal oligodendrocyte processes increased significantly in the prefrontal cortex (PFC), caudate nucleus and hippocampus in SZ compared to controls. Morphometry showed a deficit of oligodendrocytes in the PFC and in adjacent white matter, lower number of oligodendroglial satellites of pyramidal neurons and a loss of pericapillar oligodendrocytes in the PFC in SZ compared to normal controls. A lowered number of oligodendrocytes in the PFC was also found in mood disorders. These data provide evidence for altered oligodendrocyte-axon, oligodendrocyte-neuron and oligodendrocyte-capillar interactions in SZ brains suggesting a key role of damage and loss of oligodendrocytes in altered neuronal connectivity and in atrophy of neurons in SZ.