MICROGLIA AND ASTROCYTES OF THE HUMAN BRAIN SUBSTANTIA NIGRA

In recent years, attention of researches has focused on glial cells of different brain formations - astrocytes and microglial cells. This is due to active role of these cells in ensuring synaptic plasticity and regulation of neurogenesis. The study aimed at analyzing the structural organization of microglia and astrocytes of the human brain substantia nigra, which is the main dopaminergic nerve center. For the study, material from the archive of the Morphology Department (Institute of Experimental Medicine, Saint Petersburg, Russia) was used. Cells were detected using immunocytochemical markers (GFAP for astrocytes and Iba-1 for microglia). It has been established that microglial cells bodies in substantia nigra are located in neuropile singly. In pars compacta of substantia nigra these cells distributed relatively evenly, rarely being in close proximity to neurons. An unexpected fact was that the processes of microglia cells of the human brain substantia nigra have a sufficiently large thickness - 1.5-3 microns, which is not typical for a ramified microglia. Astrocytes of substantis nigra were characterized by the presence of very long processes (more than 100 microns) and the formation of the pericellular sheath around the nerve cells. These sheaths consisted of a dense interweaving of thin sparingly branched astrocyte processes. The processes of microglia were rarely present within such sheaths. The results obtained indicate moderate activation of microglia in substantia nigra and the special role of astrocytes in ensuring the compartmentalization of the pericellular zones in this nerve center.

microglia, astrocytes, substantia nigra, brain, human, immunohistochemistry, confocal laser microscopy