Stereological analysis of sciatic nerve in chickens following neonatal pinealectomy: an experimental study

<p>Abstract</p> <p>Background</p> <p>Although the injury to the peripheral nervous system is a common clinical problem, understanding of the role of melatonin in nerve degeneration and regeneration is incomplete.</p> <p>Methods</p> <p>The current study investigated the effects of neonatal pinealectomy on the sciatic nerve microarchitecture in the chicken. The chickens were divided into two equal groups: unpinealectomized controls and pinealectomized chickens. At the end of the study, biochemical examination of 10 sciatic nerve samples from both groups was performed and a quantitative stereological evaluation of 10 animals in each group was performed. The results were compared using Mann-Whitney test.</p> <p>Results</p> <p>In this study, the results of axon number and thickness of the myelin sheath of a nerve fiber in newly hatched pinealectomy group were higher than those in control group. Similarly, surgical pinealectomy group had significantly larger axonal cross-sectional area than the control group (p < 0.05). In addition, the average hydroxyproline content of the nerve tissue in neonatal pinealectomy group was higher than those found in control group. Our results suggest that melatonin may play a role on the morphologic features of the peripheral nerve tissue and that melatonin deficiency might be a pathophysiological mechanism in some degenerative diseases of peripheral nerves. The changes demonstrated by quantitative morphometric methods and biochemical analysis has been interpreted as a reflection of the effects of melatonin upon nerve tissue.</p> <p>Conclusion</p> <p>In the light of these results from present animal study, changes in sciatic nerve morphometry may be indicative of neuroprotective feature of melatonin, but this suggestion need to be validated in the human setting.</p

Rattus albinuslarda subdiaphragmatic Truncal bilateral vagotomy'den sonra midenin değişik bölümlerindeki myelinli halkaların dağılımı

SUMMARY Our research was made on a Rattus albinus group of 8 controls and 34 vagotomy cases. The sections were stained with Waigert - Landau myeline paint and examined under light microscope. Acalitative and quantitative examination was made on the nerves which innervated the gastrum and on the nerves which were left after the vagus was out. According to the result : The myelinated fibers vagus conxains are 0,5 - 5 m in diameter and 0,25 - 1,5** in thichness. Truncus sympha- ticus was found to be 0,5 - 1,5 ai in diameter, 0,25 - 0,5.ai in thickness and N.phrenicus was 4- - 6 m in diameter and 1 m in thickness. In vagotomy cases which were 2 Morless in diameter stayed intact. Neurits 1,5 - 3 >u in diameter, 0,5 m in thickness were found on the dorsal outer muscular layer of the oesophagus. Firstly, nerve sections covered by neurits which are 1 - 2 /a in diameter and 0,25 - 0,5 M in thickness and secondly, nerve sections which condained less number of neurits 0,5 - 1,5 M in diameter and 0,25 - 0,5 Ai thick were determined on the serosa of the gastrum. The number37 - of nerve sections, in the first group decreosed in the vagotomy cases, Fibers which are 0,5 or less in diameter were deter mined on gostrum's tunica muscularis and fibers 1 m, 0,5 M and less in diameter were found on the mucosa. Generally the neurits were seen collapsed on vago tomy cases.ÖZET Çalışmamız Rattus Albinuslarda 8 kontrol 34- VAGOTO- MÎLÎ vak' a üzerinde gerçekleştirildi. Kesitler Weigert Landau myelin boyası ile boyanıp bulgular ışık mikrosko- bi düzeyinde incelendi. Midenin innervasyonuna katılan sinirlerde ve vagusun dev re dışı bırakılması ile kalan sinirlere ait myelinli ipliklerin kalitatif ve kantitatif incelenmesi yapıldı. Alınan sonuçlara göre : Yagus yapısındaki myelinli lifler 0,5 - 5 M çapta ve 0,25 - l»5>u kalınlıktadır. Truncus sympathicusda. 0,5 - 1»5ju çap 0,25 - 0,5 ai kalınlık N.phrenicusda ise 4-6/ı çap ve 1 m kalınlıkta bulundu. Vagotomili vak' alarda 2 ai ve dana az çapta olanlar intakt kaldı. Oesophagus dorsal dış musculer tabakada lı5 - 3 M çap 0,5/ı kalınlıkta neuritler bulundu. Mide serozasmda 1 - 2 ju. çap ve 0,25 - 0,5 ai kalınlıkta neuritlerle kaplı sinir kesitleri, ikinci olarak da 0,5. l,5/ı çap ve 0,25 - 0,5 m kalınlığa sahip neuritleri az sayıda bulunduran sinir kesitleri tesbit edildi. I.gurup- takiler vagotomili vak1 alarda azaldı. Mide tunica musculariste 0,5 ai ve daha az çaplı mucozada 1 Ai 0,5-*ı ve daha az çaplı fibriller tesbit edildi. Genel olarak vagotomili vak' alarda neuritlerin kol- labe olduğu izlend

Melatonin Attenuates Histopathological Changes in the Hippocampus of Infantile Rats with Kaolin-Induced Hydrocephalus

WOS: 000435963700003PubMed ID: 29791910Objective/Aim: Hydrocephalus is defined as an incapacitating neurological disorder characterized by ventricular enlargement in children, but the effects of melatonin on this hydrocephalus have not yet been fully elucidated. In the present experiment, we attempted to investigate the effects of exogenous melatonin administration on hydrocephalus-induced hippocampal changes in infantile rats. Methods: In this study, we randomly divided 45 Swiss albino rats aged 2 weeks into 3 groups: group I, the control group received a sham injection with needle insertion only; groups II and III were given kaolin injections before treatment - group II, the hydrocephalus group, was treated with an isotonic NaCl solution, and group III, the hydrocephalus plus melatonin group, was treated with 0.5 mg/100 g body weight of exogenous melatonin. Both immunohistochemical and histological analyses were performed after hydrocephalus induction and melatonin administration. Immunohistochemical staining consisted antiglial fibrillary acidic protein staining. The TUNEL technique was used for defining quantitate apoptosis. Results: Melatonin administration significantly attenuated chronic hydrocephalus-induced histopathological changes in the hippocampal subregions of infantile rats. Compared to hydrocephalic rats treated with saline solution, melatonin significantly decreased the number of apoptotic cells and pyknotic index values of each hippocampal subregion after the kaolin-induced hydrocephalus (p < 0.001). Conclusion: The present results demonstrate that the chronic hydrocephalus-induced histopathological changes in the hippocampus were partially reversible with melatonin treatment, suggesting its neuroprotective effects in infantile rats. However, these findings need to be confirmed by further experimental studies and clinical trials. (C) 2018 S. Karger AG, Base

Effects of Melatonin on the Cerebellum of Infant Rat Following Kaolin-Induced Hydrocephalus: a Histochemical and Immunohistochemical Study

WOS: 000393586100016PubMed ID: 27113349Hydrocephalus is a developmental disorder causing abnormally collected cerebrospinal fluid within the cerebral ventricles. It leads to bigger skulls and many dysfunctions related to the nervous system. Here, we addressed whether exogenous melatonin administration could reverse the clinical features of kaolin-induced hydrocephalus in infantile rats. A controlled double-blinded study was conducted in 2-week-old 45 Wistar albino rats, which were divided into three groups: Group A, the control group, received intracisternal sham injection with solely the needle insertion; group B, the hydrocephalus group, was treated with isotonic NaCl after kaolin injection; and group C, the hydrocephalus + melatonin group, was given i.p. exogenous melatonin at a dose of 0.5 mg/100 g body weight after kaolin injection. Histological and immunohistochemical analyses were performed after the induction of hydrocephalus and melatonin administration. Glial fibrillary acidic protein was stained by immunohistochemical method. TUNEL method was used to define and quantitate apoptosis in the cerebellar tissues. Statistical analysis was performed by nonparametric Kruskal-Wallis H test, and once significance was determined among means, post hoc pairwise comparisons were carried out using Mann-Whitney U test. We found that melatonin administration significantly ameliorated ratio of substantia grisea area/substantia alba area in the cerebellum of infantile rats. Histologically, there was a significant reduction in the number of cerebellar apoptotic cells after the hydrocephalus induced by kaolin (P < 0.05). Our results clearly revealed that the histopathological changes in the cerebellum were reversed by systemic melatonin administration in infantile rats with kaolin-induced hydrocephalus. Nevertheless, further studies are needed to suggest melatonin as a candidate protective drug in children with hydrocephalus

Investigation of maternal melatonin effect on the hippocampal formation of newborn rat model of intrauterine cortical dysplasia

WOS: 000284470700019PubMed ID: 20461523Objectives Cortical dysplasia is a cortical malformation resulting from any developmental defects during different periods of development. This study aims to investigate the hippocampal histopathological alterations in the neonates with cortical dysplasia due to the prenatal exposure to carmustine (1,3-bis (2-chloroethyl)-1-nitrosoure; BCNU) and the possible effects of prophylaxis with melatonin, a neuroprotective agent. Methods Wistar albino female rats were randomly divided into four experimental groups; control, melatonin-treated, BCNU-exposed and BCNU-exposed+melatonin-treated. Light microscopy and immunohistochemistry were carried out on the newborn hippocampus. Results Histopathology of hippocampus from the control and melatonin-treated groups showed continuity of migration and maturation as patognomonic signs of the normal newborn hippocampus. Hippocampal cortex from the newborns exposed in utero to BCNU showed the histology of early embryonic hippocampal formation with immuno-histochemical increase in the number of nestin positive cells and decreases in the immunoreactivity of glial fibrillary acidic protein (GFAP) and synaptophysin. These findings indicate a significant delay in hippocampal maturation, migration, and synaptogenesis. Intrauterine treatment of BCNU-exposed rats with melatonin resulted in histopathological features almost similar to control group. Conclusion It has been concluded that cortical dysplasia induced by intrauterine BCNU administration results in delayed hippocampal maturation, which is successfully restored by intrauterine melatonin treatment

Melatonin Production and Bioavailability

WOS: 00035413460000