[CURRENT HISTOCHEMICAL METHODS OF TISSUE IRON DEMONSTRATION BASED ON PERLS' REACTION].

The article presents the information on the modern modifications of Perls' reaction including diaminobenzidine enhancement according to R. Meguro (for various tissues). M.A. Smith (for nervous tissue), S.M. Levine (for detection of iron in oligodendrocytes and myelinated nervous fibers), and our own modification for visualization of the nucleolar iron. The analysis is performed of the advantages and disadvantages of these modifications of histochemical demonstration of iron. It is shown that the use of new methodological approaches significantly increases the sensitivity of Perls' reaction. Control procedures allow to to eliminate the possibility of artifacts.

[THE DISTRIBUTION OF CHOLINERGIC AND NITROXIDERGIC NEURONS IN THE SPINAL CORD OF NEWBORN AND ADULT RATS].

The aim of this study was to examine the distribution of cholinergic and nitroxidergic neurons in the spinal cord (SC) of adult and newborn rats. Using immunohistochemical demonstration of choline acetyltransferase (ChAT) and nitric oxide synthase (NOS), cervical portions of SC were studied in newborn (n=5) and adult (n=5) Wistar rats. It was found that ChAT-positive neurons were localized in the anterior horns of the SC, while individual cells were located in of SC posterior horns, in the central gray matter and at the boundary of VI-VII Rexed laminae. Nitroxidergic neurons were located in the superficial layers of SC posterior horns of grey matter, in the central gray matter and in the area of VI-VII Rexed laminae. It is found that SC of newborn and adult rats contained cholinergic neurons expressing NOS. Detection of cells containing both enzymes already at postnatal Day 1, suggests that they were formed in rat SC during prenatal ontogenesis

[A synaptic marker synaptophysin].

The review summarizes the current data on synaptophysin (SYP), its functional role in the cell and the use of SYP immunocytochemistry for labeling the synaptic contacts. SYP is a transmembrane glycoprotein found in small presynaptic vesicles of the nerve cells and in microvesicles of the neuroendocrine cells. Literature data and the authors' own experience suggest that currently SYP is an important synaptic marker, which allows, with the use of light and confocal laser microscopy, to obtain the reliable data on the morphological organization of the synaptic structures in the central nervous system. It is also indispensable in the study of the efferent innervation of the internal organs. Applicatioin of the quantitative analysis of SYP-immunopositive structures using light and confocal laser microscopy allows to solve some problems that previously could be solved only by using electron microscopy.

[CYTOPLASMIC LOCALIZATION OF NEUN/Fox-3 NUCLEAR PROTEIN IN THE PANCREATIC CELLS].

The study of the sections of Wistar rat pancreas (n=4) using the methods of immunocytochemistry and confocal laser microscopy has demonstrated previously unknown fact of the presence of NeuN protein in the secretory epithelial cells of the exocrine part of this organ. The protein was located in the apical part of the cytoplasm slightly below the zone of zymogen granules. Until now the nuclear protein NeuN was considered to be the panneuronal differentiation marker and was used in the studies of neurogenesis.

[Vimentin and S100 protein in the developing rat dorsal root ganglion cells].

The aim of this research was to study the expression of vimentin, one of the intermediate filament proteins, and S100 protein in the cells of developing dorsal root ganglion in prenatal ontogenesis in Wistar rat embryos (n=22) on 12-19 days of development and in newborn rats (n=6). Immunohistochemical staining methods were used to study the formation of rat dorsal root ganglion glial cells. Vimentin-immunopositive neural and glial progenitor cells were present in dorsal root ganglion primordia in rat embryos at 12-17 prenatal days. At the later stages (day 19 of prenatal life and day 1 of postnatal life) vimentin was found to be synthesized only by the differentiating glial cells. It was shown that at the same time, S100 protein was first detected in the glial cells of rat dorsal root ganglion. On postnatal day 1, the tendency was noted for the accumulation of S100 protein in the larger neurons, that was characteristic to mature dorsal root ganglia.

[The nucleolus of the cell is the site of iron accumulation in the substantia nigra neurons of the human brain].

Distribution of iron in the substantia nigra of the human brain (10 men and women aged 27-78 years) was studied using Perls' histochemical method. Iron ions were demonstrated in the nigral neuropil and melanin-containing neurons. For the first time the nuclei of some neurons were found to contain iron accumulations. The intranuclear iron inclusions correspond to the nucleolus according to their sharp outline and sizes. Detection of iron in the neuronal nucleolus may contribute to the understanding of mechanisms of iron neurotoxicity for nigral dopaminergic neurons.