Age- related structural changes in the cerebellar cortex of the albino rats and the possible protective role of melatonin

It was reported that the cerebellum undergoes extensive atrophic changes with advanced age. The free radicals derived species are considered to be highly responsible for the aging process. Recently, melatonin was found to be a potent free radical scavenger. The aim of the current work was to demonstrate the age- related alterations in the structure of the cerebellar cortex in rals and 10 study the possible beneficial role of long - term melatonin administration to ameliorate these changes. In this work, a total number of 40 male albino rats were used, They were equally divided into 4 groups. Group I [young adult rats], it included 3-month- old rats. Croup II [middle -aged rats], it included 12- month - old rats. Group III [control old rats], it included 22- month- old rats. Group IV [melatonin- treated old rats], the animals of this group were treated with melatonin in a dose equal to 1mg/kg/day subcutaneously for 10 months. Their treatment began when they were 12 months old [middle -aged] and continued until they became 22 months old. At the end of the experiment the animals were sacrificed, and their cerebella were processed for light and transmission electron microscopic studies. In addition, the thickness of the molecular layer and the number of thepurkinje cells and granule cells per area [1800 um[2]] in their corresponding layers were measured in all the studied groups and statistically analyzed. The organization of the cerebellar cortex in the middle- aged rat group appeared to he closely similar to that of the young adult rats. In the old control rat group, examination of the cerebellar cortex revealed the presence of degenerative changes affecting the purkinje and the granule cells. These changes were associated with extensive cell loss. Marked decrease in the extent and branching of the dendrites of the purkinje cells could also be observed. In addition, there 'was a significant reduction in the thickness of the molecular layer. The old rat group treated with melatonin showed that the majority of the purkinje and granule cells had normal appearance. Only few cells had darkly stained nuclei. Furthermore, melatonin administration to the old rats markedly reduced aging- induced cell loss in the cerebellar cortex. The purkinje cells appeared to have many dendritic branches but still their extent was not reaching to the I'ial surface. The presynaptic nerve fiber terminals making contact with the granule cells and their dendrites showed the presence of considerable amount of synaptic vesicles. This study suggested that melatonin might have a potential role for attenuation of the age -related changes in the structure of the cerebellar cortex. It would he considered as a promising prophylactic or therapeutic agent for age -related neurological disorders

Effect of chronic nicotine administration on the anterior cingulate cortex [area 24a] of adult albino rats: a histological and immunohistochemical study

Nicotine is the principal active component in cigarettes and cigars. It was reported that tobacco smoking enhances the performance of cognitive processing. The anterior cingulate cortex plays an important role in attention and working memory performance. This study was conducted to demonstrate the effects of chronic administration of various nicotine doses on the structure of the ventral anterior cingulate cortex [area 24a] in adult rats, as well as study the effect of withdrawal of high doses of nicotine. A total of 48 adult male albino rats were used. They were divided into four groups. Group I [N=1 2] was considered the control group. Group II [n=12] rats were treated with 1 mg/kg nicotine subcutaneously for 2 months. Group III rats [n=24] were treated with 6 mg/kg nicotine subcutaneously for 2 months. Thereafter, half of the animals were sacrificed. Group IV [the recovered group] consisted of the remaining I 2 rats of group III that were kept for another 2 months without treatment and then sacrificed. Brains were processed to be studied using Einarson's gallocyanin stain, the Golgi-Cox method, transmission electron microscopy, and immunohistochemical study for glial fibrillary acidic protein [GFAP]. Further, the number of cells in the second and fifth layers of the cingulate cortex [area 24a] was measured and statistically analyzed for all the studied groups. Examination of the cingulate cortex [area 24a] in low-dose nicotine-treated rats [group II] revealed an increase in the branching of the dendrites of the pyramidal cells together with a relative increase in the density of the spines. An ultrastructural study showed the presence of numerous synaptic contacts between the nerve processes. In high-dose nicotine-treated rats [group III] the cells showed degenerative changes, which were more evident in pyramidal cells. These changes were associated with a marked reduction in the extension and branching of the dendrites. Dense GFAP immunostained fibers and cells could be seen particularly in layer I. In the recovered rats [group IV] most of the cells restored their normal appearance. Mild GFAP expression could be observed. An insignificant difference in the number of cells was also found in comparison with controls. The effect of nicotine on the organization of the anterior cingulate cortex [area 24a] was found to vary according to dose. Withdrawal of high doses of nicotine will result in a marked reduction in the structural impairment of neurons

Postnatal development of the cat's epididymis [light microscopic study] [with 20 figures]

This study was carried out to follow up the postnatal development of the epididymis in cats. A total number of twenty cats was used at the ages of one week, one, three and six months as well as adult cats. Some specimens were prepared for routine histological examination and stained with haematoxylin and eosin while others were prepared for making semithin sections. The results showed that the epithelial cells of all regions of the epididymis were undifferentiated at the age of one week. At the age of one month differentiation occurred by the appearance of "halo" cells and 2 types of dark cells. While at the three month of age basal cells appeared. At the age of 6 month, expansion of the epididymal tubules occurred with the appearance of narrow cells, apical cells and clear cells and also the principal cells became differentiated. No sperms were observed at this age. In adult cat, sperms appeared in the epididymal lumen with more development of principal cells and disappearance of narrow cells from corpus and caudal regions. The results also revealed differences in the epithelial height of the epididymal tubules, diameter of the lumen, length of stereocilia and peritubular smooth muscle cells of the three regions of the epididymis

Experimental study on the effects of melatonin administration on the ovary and the oviduct in the adult mice [with 2 tables and 22 figures]

The aim of the present work is to demonstrate the effect of the melatonin administration for different periods of time on the ovarian follicles and the oviductal epithelium in the adult mice. Also the reversibility of melatonim effect is studied in a trial for assessment of its effect on the fertility in females. In this work, a high dose [8.0 mg/kg] and a low dose [4.0 mg/kg] of melatonin were used. Melatonin was injected to the animals subcutaneously once daily in the late afternoon. A total number of 40 young adult female mice were used. At the beginning of the experiments, they were two months old. Animals were divided into eight groups. Groups I and II composed of three and four months old control animals. Group III received the low dose of melatonin for one month and group IV received the same dose for two months. Group V received the high dose of melatonin for one month and group VI received the same dose for two months. At the end of the experiments, animals received the treatment for one month became three months old and those received the treatment for two months became four months old. Group VII composed of seven months old control animals. Group VIII composed of recovered animals [animals allowed to survive three months without treatment after receiving the high dose for two months]. At the end of the experiment, the recovered animals became seven months old. Animals were sacrificed, their ovaries and the oviducts were removed and processed for histological examination after staining with Haematoxylin and Eosin. Some specimens of the ampulla of the oviduct were processed for ultrastructural study with transmission electron microscope. The numerical density and the diameter of the primary follicles, growing follicles and corpora lutea in the ovaries of all groups of animals were measured and statistically analyzed. The results of the present work demonstrated apparent increase in the size of the ovary in the melatonin treated animals. The numerical density and the diameter of the growing follicles and corpora lutea in all melatonin treated groups showed significant increase in comparison with their corresponding control. The primary follicles showed significant reduction in their numerical density in melatonin treated animals as compared with the control. In the recovered animals, the size and the structure of the ovary appeared nearly similar to the control. Also the numerical density and the diameter of the primary follicles, growing follicles and corpora lutea showed non significant change in comparison with their corresponding control. The oviductal epithelium of the ampulla in the high dose melatonin treated animals showed predominance of the secretory cells. The ultrastructual study of these cells revealed that the apical surface had many microvilli and their cytoplasm contained a lot of secretory granules. This study revealed that nighttime melatonin administration had a stimulatory effect on the ovarian follicular growth. This effect was independent to the dose or the duration of its administration. The oviductal epithelium showed predominance of secretory cells. Its effect on the ovary was reversible. This may provide in the future new insights and directions for the study of its role in the physiology and pharmacology of fertility and contraception in animals and humans

Anatomical study on the correlation between lip prints and dermatoglyphic pattern on finger tips

Dermatoglyphics and Lip prints have been proved to be ectodermal in origin, completely developed by the end of the fourth month of foetal life and remained unchanged throughout the whole person's life. The correlation between finger and lip print patterns was studied, where it was carried out on six hundred Upper Egyptians [three hundred males and three hundred females,]. Fingerprints were taken by the inked method, whereas, lip prints were taken by two methods; smearing lips with lip-stick and photography by close up camera to focus on lips only. The present work showed that, the complex fingerprint patterns tend to occur in the individuals who have complex up print patterns and the simple fingerprints tend to occur in the individuals who have simple lip print patterns. Furthermore, the complex patterns in one hand are present in the individuals who have complex patterns in the other hand, and the simple patterns in one hand are present in the individuals who have simple patterns in the other hand. In conclusion, the results of the present work may participate in the fields of forensic medicine as a method of personal identification, anthropology and the studies of the genetic diseases

study on the effect of aging on the organization of the septal region in the brain ofmice

In this study, 40 male mice were used and divided into two groups: Group I included 20 young adult male mice [3 months old] considered as a control group and group II included 20 male aged mice [20-24 months old]. The animals were sacrificed and the septal region was dissected. In each group, five animals were processed for study by Golgi-Cox method and other ten animals were prepared for an ultrastructural study by transmission electron microscope. The total number of cells and the numerical density in the septal nuclei were measured in both young adult and aged mice. The study clearly demonstrated the presence of many morphological differences in neurons of the septal nuclei, which reflected the differences in the processing of information. This can explain the wide variety of functions of this region. It also demonstrated that neurons of the septal nuclei suffered from the occurrence of many degenerative changes with aging. These changes may account for the age-related decline in the cognitive functions

Histological effects of gentamicin intake during pregnancy on the liver and kidney of the fetus and mother of albino rat

Gentamicin is an aminoglycoside antibiotic which is widely used in the treatment of Gram-negative bacterial infections. The aim of this study is to demonstrate its effects not only on the liver and kidney of the pregnant female but also to show its effects on the developing liver and kidney of the fetus. In this work, a total of 40 albino rats were used. Twenty animals used as control groups for the mothers and fetuses. The other twenty were used as treated groups with gentamicin for the mothers and fetuses. Gentamicin in a dose of 100 mg / kg / day was given subcutaneously to the albino rats. The treatment was continuous for six days strating form 15-21 day of pregnancy. After that, the mothers and their fetuses were sacrified. Specimens of kidney and liver of some animals were processed and embedded in paraffin for routine histological examination after staining with Hematoxylin and Eosin. Liver and Kidney specimens of other animals were prepared for ultrastructural study. The mother kidney shows areas of focal hemorrhage with degeneration of the proximal convoluted tubules. The fetal kidney shows increase in the immature renal corpuscles. It also shows focal areas of tubular dilation with disruption of their lining epithelium. The mother liver shows distorted hepatic architecture. The blood sinusoids and bile ducts are dilated. There is also centrilobular inflammatory cellular infiltration. The fetal liver cells have vacuolated cytoplasm with a lot of lysosomes. From the findings observed in the present work, it xould be concluded that Gentamicin is the antibodies which had adverse reactions to the kidney and liver of both mother and fetus. It is thus recommended that it should be used with caution during pregnancy and only for strong clinical indications in the absence of suitable alternative