Murat Cetin Ragbetli

Effect of prenatal exposure to an anti-inflammatory drug on neuron number in cornu ammonis and dentate gyrus of the rat hippocampus: A stereological study

Prenatal exposed to an anti-inflammatory drug is a major problem for the developing central nervous system. It is not well known the effect of prenatal exposed to a non-steroidal anti-inflammatory drug on the hippocampus. Total neuron number in one side of the cornu ammonis (CA) and gyrus dentatus (GD) of the hippocampal formation in control and drug-treated (diclofenac sodium, DS) groups of male rats was estimated using the optical fractionator technique. Each main group has also two subgroups that are 4 weeks old (4W-old) and 20 weeks old (20W-old). In CA, no significant difference between 4W-old DS-treated and their control was found, but a significant difference was observed between 20W-old DS-treated and their controls. A decreasing of neuron number was 12% for 20W-old DS-treated group. In GD, a decreasing of the granule cell number in 4W-old of DS-treated group was seen but an increasing of granule cell number was found in the 20W-old drug-treated rats in comparison to its control group, 7% and 9%, respectively. Although an increasing of neuron number in CA at the control group was seen with age, from 4th week to 20th week (10%), age-dependent substantial granule cell decline (17%) was observed in GD. No age effect on the total cell numbers of CA and GD of the drug-treated groups was seen in comparison to 4W-old week and 20W-old. A pronounced neuron loss observed in the drug-treated group may be attributed to the neurotoxicity of diclofenac sodium (DS) on the developing hippocampal formation. Age-dependent neuron increase in the CA of 20W-old and neuron decline in GD of 20W-old control groups may be a result of a dual effect of saline injection during the fetal life, since these animals were exposed to a stress of 15-day-period of saline injection, prenatal stress. The reason of no age effect on CA and GD cell number in the drug-treated groups may be attributed to the depletion of the progenitor cells due to neurotoxicity of DS in the fetal life of these animals.

Effect of prenatal exposure to diclofenac sodium on Purkinje cell numbers in rat cerebellum: a stereological study.

Diclofenac sodium (DS) is commonly used as a non-steroidal anti-inflammatory drug. Although several adverse effects are clearly established, it is still unknown whether prenatal exposure to DS has an effect on the development of the cerebellum. In this study, we investigated the total number of Purkinje cells of the cerebellum in a control group and in a DS-treated group of male rats using a stereological method. The DS in a dose of 1 mg/kg daily was intraperitoneally injected to the drug-treated group of pregnant rats beginning from the 5th day after mating for a period of 15 days during pregnancy. Physiological serum at 1 ml dose was intraperitoneally injected to the control group of pregnant rats at the same period. After delivery, male offspring were obtained and each main group was divided into two subgroups that were 4-week-old (4W-old) and 20-week-old (20W-old). Our results showed that the total number of Purkinje cells in offspring of drug-treated rats was significantly lower than in the offspring of control animals. These results suggest that the Purkinje cells of a developing cerebellum may be affected by administration of DS during the prenatal period.

Prenatal exposure to a non-steroidal anti-inflammatory drug or saline solution impairs sciatic nerve morphology: a stereological and histological study

The toxic effect of non‐steroidal anti‐inflammatory drugs (NSAIDs) during development has been widely investigated. While it has been shown that these drugs impair central nervous development and compromise the neural activity, the effects of these substances on the development of peripheral nerves are still not clarified. In the present study, sciatic nerves withdrawn from three experimental groups of 4‐week‐old rats, prenatally exposed to either saline solution, or diclofenac sodium, and controls not exposed to any substance, were evaluated in terms of axon number, cross‐sectional area of axon and myelin sheet thickness as well as of the ultrastructure of nerve fibers. Comparisons of stereological estimations among these three groups showed that axon number and mean axon cross‐sectional area, but not average myelin sheet thickness, were significantly decreased in rats that were exposed to both diclofenac sodium and also to the saline solution, in comparison of the control group. Electron microscope analysis revealed, in both treated groups, deterioration of myelin sheaths that was more pronounced in rats that were exposed to diclofenac sodium. Altogether, these findings show that the prenatal administration of both diclofenac sodium and saline solution impairs peripheral nervous system development, thus suggesting that this potential teratogenic effect should be also taken into consideration in the clinical use of these substances in pregnant patients.

Prenatal diclofenac sodium administration increases the number of Purkinje cells in female rats: a stereological study.

Diclofenac sodium (DS) may affect the number of Purkinje cells in the developing cerebellum since DS can easily be transported from the maternal to the fetal physiological system during the pregnancy. In the present study, the effects of prenatal exposure to DS on the number of Purkinje cells in the cerebellum of 4‐week‐old (4W‐old) and 20‐week‐old (20W‐old) female rats were investigated. There were two main groups: the drug‐treated group (DTG) and the control group (CG). Beginning from the 5th day after mating for a period of 15 days, a daily dose of 1 mg/kg of DS (Voltaren, 75 mg/3 ml ampul, Novartis, Mefar Ilaç Sanayi A.S., Kartal, İstanbul, Turkey) was intraperitoneally injected in the DTG of pregnant rats. In contrast, a daily dose of 1 ml/kg of isotonic saline was intraperitoneally administered to the CG of pregnant rats during the same period. After spontaneous delivery, female offspring were obtained, and the main groups’ offspring were divided into two subgroups as a 4W‐old group and a 20W‐old group. Therefore, there were four groups at the end of the experiment: the 4W‐old DTG and the CG, and the 20W‐old DTG and the CG. At the end of 4W and 20W, offspring were perfused, their brains were dissected, and the number of cells estimated via the optical fractionator technique. Our results showed that while the total number of Purkinje cells in the cerebellum of offspring of DT 20W‐old female rats was significantly higher than that of the CG, there was no significant difference between the 4W‐old DTG and the control groups. Therefore, it could be suggested that DS administration during the prenatal period increases the number of Purkinje cells in the cerebellum of a developing female rat throughout postnatal 20W.

Brief Communication SEX DIFFERENCES AND RIGHT-LEFT ASYMMETRIES IN RAT HIPPOCAMPAL COMPONENTS

Previous reports have indicated morphologic hippocampal asymmetry in thickness in male and female rats. In the present study, the possible sex differences and right-left asymmetries in rat hippocampal components were investigated. Pyramidal cells in four hippocampal sectors on thionin-stained sections were counted and the thickness of the hippo campal components was measured on microslide-projected images. The present study showed significant sexual dimorphism in two hippocampi as well as asymmetry in male. These findings agree with those found in humans.

The effect of mobile phone on the number of Purkinje cells: A stereological study

Purpose: The World Health Organisation proposed an investigation concerning the exposure of animals to radiofrequency fields because of the possible risk factor for health. At power frequencies there is evidence to associate both childhood leukaemia and brain tumours with magnetic field exposures. There is also evidence of the effect of mobile phone exposure on both cognitive functions and the cerebellum. Purkinje cells of the cerebellum are also sensitive to high dose microwave exposure in rats. The present study investigated the effect of exposure to mobile phone on the number of Purkinje and granule neurons in the developing cerebellum. Material and methods: Male and female Swiss albino mice were housed as control and mobile phone-exposed groups. Pregnant animals in the experimental group were exposed to Global System for Mobile Communication (GSM) mobile phone radiation at 890–915 MHz at 0.95 W/Kg specific absorption rate (SAR). The cerebella were processed by frozen microtome. The sections obtained were stained with Haematoxylin-eosin and cresyl violet. For cell counting by the optical fractionator method, a pilot study was firstly performed. Cerebellar areas were analysed by using Axiovision software running on a personal computer. The optical dissectors were systematically spaced at random, and focused to the widest profile of the neuron cell nucleus. Results: A significant decrease in the number of Purkinje cells and a tendency for granule cells to increase in cerebellum was found. Conclusion: Further studies in this area are needed due to the popular use of mobile telephones and relatively high exposure on developing brain.

THE RELATIONSHIP OF CALLOSAL ANATOMY TO PAW PREFERENCE IN DOGS

Previous studies have described the paw preference and asymmetry in dog brains, based on experimental studies. The purpose of the present study is to investigate a possible association between callosal anatomy and paw preference in dogs. The midsagittal area of the dog corpus callosum was measured in its entirety and in six subdivisions in a sample of 21 brains obtained from 9 male and 12 female mongrel dogs which had paw preference testing. The present study showed significant paw differences in dog corpus callosum. A posterior segment of the callosum, the isthmus, was significantly larger in the right pawedness than the left.

Effect of Prenatal Exposure to Mobile Phone on Pyramidal Cell Numbers in the Mouse Hippocampus: A Stereological Study

Because of the possible risk factor for the health, World Health Organization (WHO) recommended the study with animals on the developing nervous system concerning the exposure to radiofrequency (RF) field. A few studies related to hippocampal exposure are available, which indicate the impact of RF field in some parameters. The present study investigated the effect of exposure to mobile phone on developing hippocampus. Male and female Swiss albino mice were housed as control and mobile phone exposed groups. The pregnant animals in tested group were exposed to the effects of mobile phone in a room possessing the exposure system. The left hemispheres of the brains were processed by frozen microtome. The sections obtained were stained with Hematoxylin & Eosin. For cell counting by the optical fractionator method, a pilot study was first performed. Hippocampal areas were analyzed using Axiovision software running on a personal computer. The optical dissector, systematically and randomly spaced, was focused to the widest profile of the pyramidal cell nucleus. No significant difference in pyramidal cell number of total Cornu Ammonis (CA) sectors of hippocampus was found between the control and the mobile phone exposed groups (p > .05). It was concluded that further study is needed in this field due to popular use of mobile telephones and relatively high exposure to the developing brain.

Prenatal exposure to diclofenac sodium changes the morphology of the male rat cervical spinal cord: a stereological and histopathological study.

Diclofenac sodium is one of the most commonly used non-steroidal anti-inflammatory drugs. It may cause alteration in the nervous system during neuronal development. However, there is no investigation concerning its role in the cervical spinal cord. Pregnant rats were divided into two groups, namely drug-treated and control (saline-injected) groups. To obtain the offspring of the drug-treated group, a dose of 1mg/kg daily diclofenac sodium (Voltaren, 75 mg/3 ml ampoule, Novartis) was injected into the pregnant rats beginning from the 5th day after mating to the 20th day of the pregnancy. To obtain the control group of offspring, serum physiological at a 1 ml/kg daily dose was injected into the pregnant control rats during the same period. Male offspring were obtained after delivery and each group was divided into two subgroups: 4-week-old and 20-week-old. The total neuron number in diclofenac sodium-treated rats was significantly lower than in the control group animals. The total volume of the cervical spinal cord segments (C1-C4) was also estimated. There was a significant difference between the volumes of the two groups, especially in the 20-week-old subgroup. This may suggest that development of neurons and volume of cervical spinal cord are affected in prenatal animals after administration of diclofenac sodium.

THE RELATIONSHIPS OF DOG HIPPOCAMPUS TO SEX AND PAW PREFERENCE

Previous studies have described paw preference and asymmetry in dog brains. Electrical activity of the dorsal hippocampus also indicated the existence of hippocampal asymmetry in dogs. In the present study, the possible paw and sex-related asymmetries and right-left differences in dog hippocampus were investigated. The hippocampus was dissected and weighed. Each hippocampus was cut into slices by the slicing apparatus placed horizontally on the tissues. The volumetric measurements were performed using the formula modified from the Cavalieri principle. The present study indicated the significant sex and paw differences and no right-left asymmetry in dog hippocampi. The morphological asymmetries in normal subjects might be related to functional hippocampal asymmetries in memory or in cognitive skills.