[Ultrastructural changes of myelinated fibers in the brain in continuous and attack-like paranoid schizophrenia]. / Ul'trastrukturnye izmeneniya mielinovykh volokon v golovnom mozge pri nepreryvnotekushchei i pristupoobraznoi paranoidnoi shizofrenii.

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. Fourteen cases of continuous schizophrenia, 5 cases of attack-like schizophrenia and 25 normal matched control cases were studied. The proportion (percentage) of pathological MF was estimated in the prefrontal cortex, layer 5, CA3 area of hippocampus, pyramidal layer, and in the head of the caudate nucleus. RESULTS: The percentage of MF having axonal atrophy and swelling of periaxonal oligodendrocyte process was significantly higher in both continuous and attack-like schizophrenia in all brain structures studied as compared to the control group. In the hippocampus and caudate nucleus, this parameter was increased significantly in attack-like schizophrenia as compared to continuous schizophrenia. In the prefrontal cortex. The percentage of the pathological MF having signs of deformation and destruction of myelin sheaths increased significantly only in continuous schizophrenia as compared to the control group. CONCLUSION: MF pathology is similar in attack-like and continuous paranoid schizophrenia but differ by the degree of severity of pathological MF. Abnormalities in MF contribute to the disconnectivity between the prefrontal cortex, caudate nucleus and hippocampus.

[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. The proportion of myelinated fibers with axonal atrophy was the most prominent in the prefrontal cortex and significantly positively correlated with the proportion of these fibers in the caudate nucleus and hippocampus. The authors suggest that ultrastructural abnormalities of myelinated fibers in schizophrenia might contribute to functional disconnections of the prefrontal cortex with other brain structures.

[Abnormal patterns of cortical synaptic connectivity in schizophrenia].

Electron microscopic morphometric study of postmortem prefrontal cortex (area 10) and visual cortex (area 17) was performed to estimate the numeric density (Nv) of synapses in layers I and II, neurons in layer II and the number of synapses per neuron in layer II in 20 cases of chronic schizophrenia and 16 healthy controls using stereological physical dissector method. In the prefrontal cortex the Nv of axospinous synapses was significantly lower in layer I (-20%, p < 0.05) in schizophrenia group and in the subgroup with predominantly positive symptoms as compared to controls (p < 0.05). On the contrary, a significantly higher Nv of synapses (+24%, p < 0.05) and the number of synapses per neuron were found in layer II (+42%, p < 0.05) in schizophrenia group and in the subgroups of cases with predominantly negative symptoms and a continuous course of schizophrenia (p < 0.001) as compared to the control group. The subgroup of cases with predominantly negative symptoms displayed a significantly lower number of neurons in layer II of the prefrontal cortex compared to controls (p < 0.05) and the subgroup of cases with predominantly positive symptoms (p < 0.01). In the visual cortex the number of axodendritic synapses per neuron in layer II was significantly higher in schizophrenia, but the other parameters did not differ from those in the control group. These prominent abnormalities of synaptic connectivity might be the structural basis for altered cognitive functions associated with changes in intracortical, cortico-cortical, and cortico-subcortical pathways, and could contribute to the formation of positive and negative symptoms and altered neuronal plasticity in patients with schizophrenia.

[Morphometric study of ultrastructural changes in oligodendroglial cells in the postmortem brain in endogenous psychoses]. / Morfometricheskaia otsenka ul'trastrukturnykh plasticheskikh perestroek v mozge pri éndogennykh psikhozakh (reaktsii oligodendroglii).

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.

[Ultrastructure of neurohypophysis during autolysis]. / Ul'trastruktura neirogipofiza v protsesse autoliza.

Autolysis was studied in neurohypophyseal secretory cells by electron microscopy at 30 min, 1-h, 3-h and 6-h intervals. In the first 30 minutes after decapitation mitochondrial slougness phenomenon was observed. "Mosaic" autolytic changes in the ultrastructure of neurohypophyseal cells were found. Severe destructive processes were clearly observed in neurohypophyseal cells when autolysis was continued for 6 hours.

[Certain structural details of developing in vitro human embryonal brain explants studied with the aid of fluorescence and scanning electron microscopy]. / Nekotorye detali stroeniia razvivaiushchikhsia in vitro eksplantatov embrional'nogo golovnogo mozga cheloveka, izuchennye s pomoshch'iu prosvechivaiushchei i skaniruiushchei elektronnoi mikroskopii.

The bundles growing away from the explants were mainly formed by neuroblast processes. It has been shown that the degree of differentiation of neuroblasts depends on "the age" of embryonal brain. The bundles of neuroblasts are accompained by slightly differentiated cells, having their own processes descending to the surface of the lining. These processes attached to the surface of a bundle cover and have no connection with the inner structures of the bundle. The use of a scanning electron microscopy allows to detect some new details of the behaviour of nerve cells in vitro.

[Ultrastructural features of brain cells from the embryos of schizophrenic women]. / Nekotorye ul'trastrukturnye osobennosti kletok golovnogo mozga émbrionov ot bol'nykh shizofreniei zhenshchin

With the use of the electron microscope the authors studied the embryonic brain tissue obtained during medical abortion of 6 female schizophrenic patients. Ultrastructural peculiarities of the cell elements in the embryonic brain in theses cases were estimated in comparison with those found in the embryonic brain of 14 mentally healthy women. There is a description of damages of membranes, mitochondrias and accumulation of granular material in the cytoplasma.