Deficit of satellite oligodendrocytes of neurons in the rostral part of the head of the caudate nucleus in schizophrenia.

Increasing evidence implicates compromised myelin integrity and oligodendrocyte abnormalities in the dysfunction of neuronal networks in schizophrenia. We previously reported a deficiency of myelinating oligodendrocytes (OL), oligodendrocyte progenitors (OP) and satellite oligodendrocytes of neurons (Sat-OL) in the prefrontal cortex and the inferior parietal cortex - cortical hubs of the frontoparietal cognitive network and default mode network (DMN) altered in schizophrenia. Deficiency of OL and OP was also detected in the head of the caudate nucleus (HCN), which accumulates cortical projections from the associative cortex and is the central node of these networks.

[Reduced numerical density of oligodendrocytes and oligodendrocyte clusters in the head of the caudate nucleus in schizophrenia].

Objective: Morphometric estimation of the numerical density of oligodendrocytes (NcOl) and numerical density of oligodendrocyte clusters (NvOlC) in the rostral part of the caudate head nucleus associated with the cortical regions of the default network in the norm and in schizophrenia.

Material And Methods: NcOl and NvOlC were determined in the gray matter of the rostral part of the head of the caudate nucleus in Nissl-stained sections using optical dissector in postmortem brains in 18 schizophrenia and 18 healthy control cases.

Results: The NvOl (-20%, 0.

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

Neuroimaging, genetic and molecular biological studies have shown impaired intra-cortical myelination in patients with schizophrenia, particularly in the prefrontal cortex. Previously we reported a significant deficit of oligodendrocytes and oligodendrocyte clusters in layers 3 and 5 of the prefrontal cortex, Brodmann area 10 (BA10) in schizophrenia. In this current study, we investigate the number of oligodendrocyte satellites (Sat-Ol) per pyramidal neuron in layer 5 of BA10 in schizophrenia (n = 17) as compared to healthy controls (n = 20) in the same section collection as previously used to study the numerical density (Nv) of oligodendrocytes and oligodendrocyte clusters.

Numerical density of oligodendrocytes and oligodendrocyte clusters in the anterior putamen in major psychiatric disorders.

There is increasing evidence to support the notion that oligodendrocyte and myelin abnormalities may contribute to the functional dysconnectivity found in the major psychiatric disorders. The putamen, which is an important hub in the cortico-striato-thalamo-cortical loop, has been implicated in a broad spectrum of psychiatric illnesses and is a central target of their treatments. Previously we reported a reduction in the numerical density of oligodendrocytes and oligodendrocyte clusters in the prefrontal and parietal cortex in schizophrenia.

[Abnormalities of oligodendrocyte clusters in supra- and infragranular layers of the prefrontal cortex in schizophrenia].

Aim: A deficit of cortical gray matter myelination in the frontal lobes has been reported in schizophrenia in neuroimaging studies. Previously the decrease in the numerical density (Nv) of oligodendrocytes (NvOl) in layers 3 and 5 in area 10 of the prefrontal cortex (PFC) has been reported in schizophrenia. Oligodendrocyte progenitors proliferate in the adult human brain and form oligodendrocyte clusters for functional-dependent adaptive myelination.

Reduced oligodendrocyte density in layer 5 of the prefrontal cortex in schizophrenia.

Neuroimaging and post-mortem studies have implicated altered myelin integrity and oligodendrocyte abnormalities in the dysfunction of neuronal network in schizophrenia, including the prefrontal cortex, Brodmann area (BA) 10. Pyramidal neurons in layer 5 of BA10 are the important link of reciprocal frontal cortical-basal ganglia-thalamic circuits altered in schizophrenia. Previously, we found ultrastructural dystrophic and degenerative alterations of oligodendrocytes in layer 5 of BA10 in schizophrenia.

[Disturbance of oligodendrocyte differentiation in schizophrenia in relation to main hypothesis of the disease].

Increasing evidence coming from neuroimaging, molecular genetic and post-mortem studies have implicated oligodendrocyte abnormalities and compromised myelin integrity in schizophrenia. Activity-dependent myelination in adult brain is considered to be an important mechanism of neural circuit's plasticity due to the presence of a large population of oligodendrocyte progenitor cells (OPC) in the adult CNS. Growing evidence for impairment of oligodendrocyte differentiation has been reported in the brain of schizophrenia subjects.

[Ultrastructural changes of myelinated fibers in the brain in continuous and attack-like paranoid schizophrenia].

Aim: Previously the authors have reported the ultrastructural pathology of myelinated fibers (MF) in the brain in schizophrenia. The aim of the present study was to compare the effect of disease course on ultrastructural changes of MF.

Material And Methods: Postmortem electron microscopic morphometric study of MF was performed in the prefrontal cortex, caudate nucleus and hippocampus in 19 cases of paranoid schizophrenia.

[The effects of blood serum from schizophrenia patients under olanzapine monotherapy on the ultrastructure of astrocytes in human fetal brain organotypic culture].

Objective: To study effects of blood serum (BS) from schizophrenia patients under olanzapine monotherapy on astrocytes in the human fetal brain organotypic culture.

Material And Methods: Authors studied the human fetal brain organotypic culture after the application of BS from 20 normals and 33 patients (ICD-10 schizophrenia, paranoid type, F20.02; F20.

[Effects of schizophrenic blood serum on astrocytes in human fetal brain organotypic culture: a morphometric study].

Aim: To detect cytotoxic effects of blood serum (BS) from schizophrenia patients on astrocytes and neurons in the human fetal brain organotypic culture.

Material And Methods: Authors studied the human fetal brain organotypic culture after the application of BS from 20 healthy donors and 33 untreated patients with attack-like progressive schizophrenia (ICD-10: schizophrenia, paranoid type, F20.02; F20.

[Role of astrocytes in alterations of glutamatergic neurotransmission in schizophrenia].

The glutamatergic hypothesis of schizophrenia based on the hypofunction of the N-methyl-D-aspartate-type glutamate receptors (NMDA-R) is one of the most widely implicated hypothesis that explains the origin of positive and negative symptoms of illness as well as cognitive deficits. The author considered a neuromorphological aspect of this hypothesis related to the glial astrocytes function. The literature on the astrocyte ability to regulate glutamate neurotransmission is reviewed.

[Current conceptions about astrocyte reactivity in schizophrenia].

Literature data of the last two decades are summarized. Based on the classic conceptions about structure and functions of astrocytes, the authors review further development of research concerning the role of astroglia in schizophrenia in the following aspects: astrocyte reactivity, ultrastructural astrocyte pathology, markers of gliosis and astrocyte activation in schizophrenia, effect of neuroleptics on astrocytes. In conclusion, the authors emphasize that current studies confirm the absence of astrogliosis in the brain of schizophrenic patients.

[Models of fetal ECG recorded on the pregnant woman's abdomen].

The article presents a literature review devoted to a description of electrical potentials of the fetus heart on the pregnant woman's abdomen using the model dipole generator. The main results of the model evaluation of the influence of extracardiac factors on the fetal ECG during pregnancy and of a choice of a preferable location of electrodes on the maternal abdomen are given. The fetal ECG models for evaluating signal filtering algorithms are described.

[Ultrastructural pathology of myelinated fibers in schizophrenia].

An electron microscopic morphometric study of myelinated fibers and proportions of pathological myelinated fibers in postmortem prefrontal cortex, caudate nucleus and hippocampus was performed in 25 cases with schizophrenia and 25 normal controls. Pathology of myelinated fibers was similar in all brain structures in schizophrenia and included focal destruction of myelin sheaths and atrophy of axons. These changes were not correlated with age, postmortem delay or neuroleptic exposure but they were significantly positively correlated with the age at onset of disease.

Ultrastructural abnormalities of astrocytes in the hippocampus in schizophrenia and duration of illness: a postortem morphometric study.

There is a lot of evidence of astrocytic dysfunction in schizophrenia. We performed an electron microscopic morphometric study of astrocytes in the CA3 hippocampal region in 19 cases of schizophrenia and 16 normal controls. No significant group differences were found in cell size, volume fraction (Vv) and area density (Na) of mitochondria and lipofuscin granules.

[Pathology of oligodendroglia and myelinated fibers of the hippocampus in schizophrenia (an ultrastructural and morphometric study)].

The authors studied the ultrastructure of oligodendroglia and myelinated fibers and assessed quantitatively their density and proportion of pathologically changed myelinated fibers in the CA3 region of the hippocampus in 25 cases with schizophrenia and 25 control cases without mental pathology. Dystrophic changes of oligodendrocytes structure and an atrophy of part of myelinated fibers were found in schizophrenia. The severity of pathology was significantly associated with the age at disease onset.

[Astroglia of the hippocampus in schizophrenia].

An electron microscopic morphometric study of volume fraction, areal numerical density and size of astrocytes in the pyramidal layer of CA3 hippocampal region has been carried out in 25 cases of schizophrenia and 25 normal controls. Both the volume fraction and areal density of astrocytes were increased significantly (20% and 28%) in schizophrenic cases. This local astrogliosis likely represents the compensatory mechanism in the context of glutamate hypothesis of schizophrenia.

Decreased numerical density of CA3 hippocampal mossy fiber synapses in schizophrenia.

The CA3 region of the hippocampus is unique in its connectivity, its role in cognitive maintenance, and its great vulnerability in schizophrenia. The down regulation of the expression and binding activity of glutamate receptors was revealed in the CA3 hippocampal region and may be attributed to cognitive disturbances in schizophrenia. Our previous study demonstrated that only schizophrenics with predominantly positive (but not predominantly negative) symptoms had smaller-sized branched spines (thorny excrescences) of CA3 pyramidal neurons and fewer synaptic contacts formed by dentate mossy fiber terminals (MFT-synapses).

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.

Ultrastructural alterations in hippocampal mossy fiber synapses in schizophrenia: a postmortem morphometric study.

Synapses formed between mossy fibers, the axons of hippocampal dentate granular cells, and the dendrites of CA3 pyramidal neurons are important links within the trisynaptic circuitry. Abnormalities in this circuitry are associated with the failure of schizophrenics to integrate affective experience with higher cognitive function, and with disturbances in memory and spatial learning processes. The abnormalities include reduced size and altered dendritic arborization of CA3 pyramidal neurons.

Organotypic cultures of free-floating slices of human embryo medulla oblongata.

The aim of the present work was to produce organotypic cultures of human embryo brain tissues, as needed for investigation of the effects of serum factors on mental diseases and their pharmacological treatment. Cultures were made using slices of medulla oblongata from human embryos aged 9-10 weeks, obtained from medical abortions. Free-floating slices were cultured using a modified roller method for four weeks.

[Organotypic cultures of free-floating sections of human embryonic medulla oblongata].

The aim of the present study was the development of organotypic culture of embryonic nerve tissue of human brain, which is necessary for the study of the effect of blood serum factors in mental diseases and their medicinal treatment. For the cultivation the sections of medulla oblongata were taken from human 9-10 week embryos obtained at legal medical abortion. Free-floating sections were cultured using a modified roller method for 4 weeks.

Electron microscopy of oligodendroglia in severe mental illness.

Qualitative electron microscopy was performed to verify whether brain pathology in schizophrenia and bipolar disorder is associated with alterations of oligodendroglial cells and myelinated fibers. Ultrastructural signs of apoptosis and necrosis of oligodendroglial cells were found in the prefrontal area 10 and the caudate nucleus in both schizophrenia and bipolar disorder. Damage of myelin sheath lamellae, with the formation of concentric lamellar bodies, were detected in both brain structures in schizophrenia.