[The expression of connexin 36 and some neuroglial antigens in human brain astrocytic tumors of different grades].

OBJECTIVE: To reveal the expression of neuronal connexin 36 (Cx36) in gliomas and then to analyze the ratio of expression of Cx36 to that of neuroglial antigens (synaptophysin, neurofilaments, and glial fibrillary acidic protein). MATERIAL AND METHODS: Varying grade human glioma samples and tumor-adjacent tissue fragments were used for immunohistochemical examination. RESULTS: A procedure for immunohistochemical detection of Cx36 in brain tissue was tried out. It was shown that the decreased level of the examined neuronal proteins was accompanied by the impaired coexpression of synaptophysin/neurofilaments and Cx36 in the series of astrocytomas--anaplastic astrocytomas--glioblastomas. The immunohistochemical heterogeneity of glioblastomas was found. CONCLUSION: The findings suggest that it is promising to include anti-Cx36 antibodies in immunohistochemical panels when examining brain tumors. Data on the lower levels of the examined neuronal proteins, on the specific features of their distribution and impaired coexpression expand their idea on the pathogenesis of a brain tumor process and determine an area for further investigations.

[Neuronal and glial antigen distribution in the columns of somatosensory cortex of rat brain (an immunohistochemical study)].

The aim of the study was to detect the neocortical columns in the S1 field on frontal sections of brain of albino rats using the method of immunohistochemistry and the antibodies against neuronal (synaptophysin, neurofilament) and gliocyte (glial fibrillary acidic protein--GFAP, myelin basic protein) proteins. The examination of the expression of the major neurospecific antigens revealed that on thin sections (4 micromin) a column could be identified due to accumulations of the astrocytes and neuronal processes--axons and dendrites. GFAP expression study also showed that cortical layer I usually contained multiple large astrocytes with branching processes, as well as numerous smaller processes with high intensity of expression. Synaptophysin content was high in all the layers of the cortex, but the most intense reaction was detected in the molecular layer, similarly with the intensity of GFAP reaction. The expression of myelin basic protein was detected in accordance with the radially extending myelinated processes of the neurons in the cortex.