Federal State Institution "Scientific Research Institute of Experimental Medicine", North-West Branch of the Russian Academy of Medical Sciences, St. Petersburg, Russia; St.Petersburg, Russia; email@example.com
Astrocytes perform many important functions in the central nervous system and this is the reason for their learning. However, the most of researchers prefer to study the functional characteristics of these cells. At the same time, in the literature, although in a small volume, there are the data about morphological features of cortical astrocytes, while the data about astroglial organization of the human substantia nigra are absent. The aim of this study was to examine the astrocytes structural organization in human substantia nigra. The material for this study were fragments of the human brain stem (n=14, age 27-78 years). Astrocytes were detected immunocytochemically using mouse monoclonal antibodies (clone SPM507) to glial fibrillary acidic protein. The preparations were analyzed by conventional light microscopy and confocal laser microscopy. Immunocytochemical visualization and three-dimensional reconstruction of substantia nigra astrocytes made possible to establish that there are two morphological types of astrocytes in the human substantia nigra, which are subtypes of fibrous astrocytes. The first types of astrocytes lie directly between the bodies of nigral neurons, have a typical star-shaped and radiating processes. The second types of astrocytes have flattened, longitudinally elongated body with spikes, coming mainly from the poles of the cell, and are located on the periphery of the substantia nigra. Both types of these astrocytes have very long (about 100 microns) thin (0.8-1 mm) slightly twisted little branching processes, some of which ends in the vessels, forming a perivascular glial border membrane. Another important feature of these cells is the formation a complex (basket-like) astrocyte network from predominantly longitudinally oriented processes around nigral neurons. These features of astrocytes structural organization showed originality of glial microenvironment of human dopaminergic neurons.
This work was supported by grant of RFBR (project No 12-04-31857).