Oligodendrocytes in the periaqueductal gray matter and the corpus callosum in adult male and female domestic sheep.

There is little information about oligodendrocytes (OLGs) in the Periaqueductal Gray matter (PAG). The literature has not provided data on the number, morphology, or quantification of the expression of the OLG protein yet. Myelin Basic Protein (MBP) in this region of the Central Nervous system (CNS). The study aimed was to perform a comparative analysis: the location and morphology of OLGs, the cellular and regional distribution of iron, and the number of OLGs in PAG and corpus callosum (CC) of adult 16 male and 16 female sheep. To determine the location of the OLG of PAG and CC, the method of impregnation of the neuroglia with silver salts was applied. In turn, the Nissl method was used to determine the location of the brain structure and to analyse the number of OLG. The performed analysis showed that PAG, OLGs are located singly or in pairs in blood vessels and neurons, while in CC they are arranged in characteristic rows and accompany both nerve fibres and blood vessels. Immunofluorescent staining for the presence of MBP confirmed the location of OLGs in male and female sheep. Morphometric analysis showed the importance of these glial cells in OLG-myelin fibres, correlation in adults regardless of sex even after the creation of the completion of myelin. The results obtained indicate that the functions of OLGs are not only confined to myelination in young individuals, but also play a crucial role in the brain of adults. Our observations seem to be useful to better understanding OLGs biology.

Distribution and Morphological Characteristics of Oligodendrocytes in Selected Areas of the Brain of Male and Female Red Kangaroos (Macropus rufus).

This study was carried out on six adult red kangaroos of both sexes. To determine the location of the oligodendrocytes (OLGs) of the hippocampus (Hip) and corpus callosum (CC), the method of impregnation of the neuroglia with silver salts was applied. The iron distribution in the OLGs was determined by the histochemical method. The Nissl method was used to determine the location of the brain structure and to analyze the number of OLGs. In the Hip, these cells are located one beside another, mainly in blood vessels and neurons; in the neocortex (NC), they are located in layers I-VI; and in the CC, they are arranged in characteristic rows and accompany both nerve fibers and blood vessels. The analysis of the results obtained by the chosen methods in the Hip, NC, and CC in males and females did not show statistically significant differences in the distribution and location of the red kangaroo OLGs. The involvement of these cells is a physiological process that proceeds in a similar manner throughout the life of individuals and actively influences the metabolism of neurons and myelin.

Co-expression patterns of cocaine- and amphetamine-regulated transcript (CART) with neuropeptides in dorsal root ganglia of the pig.

In the present study the neuronal distribution of CART was evaluated immunohistochemically in porcine dorsal root ganglia (DRGs). In co-localization studies the co-expression patterns of CART with SP, CGRP, galanin, CALB and LENK were investigated by means of triple immunohistochemical stainings. In porcine DRGs, the expression of CART was found in approximately 5% of primary sensory neurons. The vast majority (ca. 95%) of CART-immunoreactive (IR) neurons were small and middle sized, and only 5% were categorized as large. CART-IR neurons additionally exhibiting the presence of SP/CGRP (ca. 12%), SP/CALB (ca. 12%), SP/LENK (ca. 5%) were found. The vast majority of CART-IR/CGRP-IR neurons did not display immunoreaction to SP (ca. 60%). Subclasses of CART-IR/LENK-IR/SP-negative (ca. 5%), as well as CART-IR/CALB-IR/SP-negative neurons (ca. 10%), were also visualized. In addition, CART-IR neurons with no immunoreactivities to any of the neuropeptides studied were also shown. In porcine DRGs none of the CART-IR neurons exhibited the presence of galanin. The results obtained in the study suggest that CART may functionally modulate the activity of the porcine primary sensory neurons. It is concluded that co-expression of CART with CGRP, SP, LENK and CALB in subsets of the pig L1-L6 DRGs neurons provide anatomical evidence for a CART role in pain processing.