Maternal diabetes decreases the expression of α2-adrenergic and M2 muscarinic receptors in the visual cortex of male rat neonates.

AIMS: This study investigates the impact of maternal diabetes on the expression of α2-adrenergic and M2 muscarinic receptors in the primary visual cortex of male offspring born to diabetic rats. MAIN METHODS: In adult female rats, a single dose of intraperitoneal streptozotocin (STZ) was used to induce diabetes (Diabetic group). Diabetes was controlled with insulin in the Insulin-treated group. Female rats in the control group received normal saline instead of STZ. Male newborns were euthanized at P0, P7, and P14, and the expression of α2-adrenergic and M2 muscarinic receptors in the primary visual cortex was determined using immunohistochemistry (IHC). KEY FINDINGS: The study showed that α2-adrenergic and M2 muscarinic receptors were significantly suppressed in all layers of the primary visual cortex of male neonates born to diabetic rats at P0, P7, and P14 compared to the control group. The highest expression was for the Con group at P14 and the lowest one was in the Dia group at P0 for both receptors. The insulin treatment in diabetic mothers modulated the expression of these receptors to normal levels in their newborns. SIGNIFICANCE: The results demonstrate maternal diabetes decreases the expression of α2-adrenergic and M2 muscarinic receptors in the primary visual cortex of male offspring born to diabetic rats. Insulin treatment can offset these effects of diabetes.

Maternal diabetes decreases the expression of GABAAα1, GABAB1, and mGlu2 receptors in the visual cortex of male rat neonates.

AIMS: This study examines the impact of maternal diabetes on the expression of GABAB1, GABAAα1, and mGlu2 receptors in the primary visual cortex layers of male rat newborns. MAIN METHODS: In diabetic group (Dia), diabetes was induced in adult female rats using an intraperitoneal dose of Streptozotocin (STZ) 65 (mg/kg). Diabetes was managed by daily subcutaneous injection of NPH insulin in insulin-treated diabetic group (Ins). Control group (Con) received normal saline intraperitoneally rather than STZ. Male offspring born to each group of female rats were euthanized via CO2 inhalation at P0, P7, and P14 days after delivery and the expression of GABAB1, GABAAα1, and mGlu2 receptors in their primary visual cortex was determined using immunohistochemistry (IHC). KEY FINDINGS: The expression of GABAB1, GABAAα1, and mGlu2 receptors increased gradually with age in the male offspring born to Con group while the highest expression was detected in layer IV of the primary visual cortex. In Dia group newborns, the expression of these receptors was significantly reduced in all layers of the primary visual cortex at every three days. Insulin treatment in diabetic mothers restored the expression of these receptors to normal levels in their newborns. SIGNIFICANCE: The study indicates that diabetes reduces the expression of GABAB1, GABAAα1, and mGlu2 receptors in the primary visual cortex of male offspring born to diabetic rats at P0, P7, and P14. However, insulin treatment can counteract these effects.

Developmental regulation and lateralization of N-methyl-d-aspartate (NMDA) receptors in the rat hippocampus.

N-methyl-d-aspartate receptors (NMDARs) are expressed abundantly in the brain and play a crucial role in the regulation of central nervous system (CNS) development, learning, and memory. During early neuronal development, NMDARs modulate neurogenesis, neuronal differentiation and migration, and synaptogenesis. The present study aimed to examine the developmental expression of NMDARs subunits, NR1 and NR2B, in the developing hippocampus of neonatal rats during the first two postnatal weeks. Fifty-four male offspring were randomly divided into three age groups, postnatal days (P) 0, 7, and 14. Real-time-PCR, western blotting, and immunohistochemistry (IHC) analyses were employed to examine and compare the hippocampal expression of the NMDA receptor subunits. The highest mRNA expression of NR1 and NR2B subunits was observed at P7, regardless of its laterality. The mRNA expression of both subunits in the right hippocampus was significantly higher than that of the left one at P0 and P7. Similarly, the highest protein level expression of NR1 and NR2B subunits was also observed at P7 in both sides hippocampi. Although the protein expression of NR1 was significantly higher on the right side in all studied days, the NR2B was significantly higher in the right hippocampus only at P7. The analysis of optical density (OD) has shown a marked increase in the distribution pattern of the NR1 and NR2B subunits at P7 in all hippocampal subregions. In conclusion, there is a marked right-left asymmetry in the expression of NR1 and NR2B subunits in the developing rat hippocampus, which might be considered as a probable mechanism for the lateral differences in the structure and function of the hippocampus in rats.

Effect of Microscopic Third Ventriculostomy (Lamina Terminalis Fenestration) on Shunt-needed Hydrocephalus in Patients with Aneurysmal Subarachnoid Hemorrhage.

There are reports that in patients with aSAH (aneurysmal subarachnoid hemorrhage), LTF (lamina terminalis fenestration) reduces the rate of shunt-needed hydrocephalus via facilitation of CSF (cerebrospinal fluid) dynamic, diminished leptomeningeal inflammation, and decreased subarachnoid fibrosis. Regarding the conflicting results, this study was conducted to evaluate the effects of LTF on decreased shunt-needed hydrocephalus in patients with aSAH. A cross-sectional retrospective study was carried out to survey all patients with confirmed aSAH operated from March 2011 to September 2016 in an academic vascular center (Rasool Akram Hospital in Tehran, Iran). Of a total of 151 patients, 72 patients were male and 79 were female. The mean age of the participants was 51 years. A transiently CSF diversion (EVD - external ventricular drainage) was performed (the acute hydrocephalus rate) on 21 patients (13.9%). In 36 patients (23.8%), aneurysm occlusion with LTF and in 115 patients (76.2%) only aneurysm occlusion surgery was performed. In hydrocephalus follow-up after surgery, 13 (12%) patients needed shunt insertion (the rate of shunt-needed hydrocephalus). The statistical analysis demonstrated no significant relation between LTF and shunt-needed hydrocephalus. Confirmation of the hypothesis that LTF may decrease the rate of shunt-needed hydrocephalus can significantly decrease morbidity, mortality, and treatment costs of shunting (that is a simple, but a potentially dangerous procedure). So, it is advised to plan and perform an RCT (randomized controlled trial) that can remove the confounding factors, match the groups, and illustrate the exact effect of LTF on shunt-needed hydrocephalus.

PCL/gelatin scaffolds and beta-boswellic acid synergistically increase the efficiency of CGR8 stem cells differentiation into dopaminergic neuron: A new paradigm of Parkinson's disease cell therapy.

Parkinson's disease is a progressive degenerative disorder in the central nervous system, which is distinguished by the death of dopamine-producing nerve cells. Levodopa, a dopamine precursor drug, is the current standard of care of symptomatic treatment for Parkinson's disease. However, the long-term use of the drug is associated with the development of motor fluctuations and dyskinesias. Cellular therapies aim to deploy fetal dopaminergic neurons as a means to replace the missing dopamine-producing cells. The present study aims to study the impact of beta-boswellic acid (BBA) coupled with poly ε-caprolactone (PCL)/gelatin scaffolds on the dopaminergic differentiation course of CGR8 embryonic stem cells (ESCs). For this purpose, CGR8 ESCs were cultured on PCL/gelatin scaffolds and a five-step protocol was employed to be promoted the neural differentiation of CGR8 ESCs. Gene expression analysis by real-time qPCR demonstrated that PCL/gelatin scaffolds along with BBA treatment impose synergistic effects on the derivation of dopaminergic-like cells from CGR8 ESCs. Reverse-phase high-performance liquid chromatography confirmed the functionality of the derived neurons by demonstrating the efficient secretion of dopamine in response to stimuli. Our results suggested that the generation of functional dopaminergic-like cells from CGR8 ESCs was increased and supported by PCL/gelatin scaffolds and BBA treatment can heighten the efficiency. The result of this study may open insight into Parkinson's disease cell therapy and provide future directions for tissue engineering aimed at the treatment of Parkinson's disease.

Developmental regulation and lateralisation of the α7 and α4 subunits of nicotinic acetylcholine receptors in developing rat hippocampus.

The purpose of this study was to describe the distinct regional distribution patterns of expression of the α7 and α4 subunits of nicotinic acetylcholine receptors (nAChRs) and their left-right lateralisation in the rat hippocampus during the first 2 weeks of postnatal (P) development. Eighteen male pups were randomly divided into three groups: P0, P7, and P14. After removing the newborn brains, real-time polymerase chain reaction, western blot, and immunohistochemistry techniques were used to evaluate expression of the receptors. Results indicated that the expression profile of these receptors were time- and spatially dependent. A significant increase was observed in the distribution of α7 and α4 nAChR subunits in the developing rat hippocampus from P0 to P7 (p < .001); however, there was a significant decrease from P7 to P14 (p < .05). As a spatial effect, the highest optical density (OD) was observed in the CA3 and CA2 regions of the hippocampus, while the lowest OD was in the dentate gyrus. Moreover, the distribution of α7 and α4 nAChR subunits in the left hippocampus was significantly higher than their counterparts in the right (p < .05). From these data, the expression patterns of α7 and α4 nAChR subunits exhibited left-right asymmetry in the developing rat hippocampus.

Developmental regulation and lateralization of GABA receptors in the rat hippocampus.

GABA is the chief inhibitory neurotransmitter in the adult brain. However, in the developing brain it acts as an excitatory transmitter causing depolarization. Thereby, activates calcium-dependent processes that are crucial for brain development. Accordingly, GABA receptors have the great role in the brain development, especially in the area with persisting neurogenesis such as hippocampus. The present study investigated the development and lateralization of two important subunits of GABA receptors, GABAAα1 and GABAB1, in the developing rat hippocampus during the neurogenesis-active period, at the first two postnatal weeks. Real-time PCR, western blot and immunohistochemistry were used. We found that the mRNA and protein of these GABA receptor subunits have already been expressed at birth and significantly increased at postnatal day (P) 7, and also at P14. Also, regarding the optical densities of GABAAα1 and GABAB1 expressing hippocampal cells, we found a significant increase in the distribution pattern of these subunits in the all hippocampal subregions on day 14 after birth. The highest optical density of GABAAα1 was observed in the CA3, and GABAB1 in the CA2. Nevertheless, our results did not show a significant laterality differences in the expression of these subunits. Regarding the crucial role of GABA receptors in the hippocampus development; they probably have the same effects on development of the rat hippocampus on both sides.

Some of the experimental and clinical aspects of the effects of the maternal diabetes on developing hippocampus.

Diabetes mellitus during pregnancy is associated with an increased risk of multiple congenital anomalies in progeny. There are sufficient evidence suggesting that the children of diabetic women exhibit intellectual and behavioral abnormalities accompanied by modification of hippocampus structure and function. Although, the exact mechanism by which maternal diabetes affects the developing hippocampus remains to be defined. Multiple biological alterations, including hyperglycemia, hyperinsulinemia, oxidative stress, hypoxia, and iron deficiency occur in pregnancies with diabetes and affect the development of central nervous system (CNS) of the fetus. The conclusion from several studies is that disturbance in glucose and insulin homeostasis in mothers and infants are major teratogenic factor in the development of CNS. Insulin and Insulin-like growth factor-1 (IGF-1) are two key regulators of CNS function and development. Insulin and IGF-1 receptors (IR and IGF1R, respectively) are distributed in a highly specific pattern with the high density in some brain regions such as hippocampus. Recent researches have clearly established that maternal diabetes disrupts the regulation of both IR and IGF1R in the hippocampus of rat newborn. Dissecting out the mechanisms responsible for maternal diabetes-related changes in the development of hippocampus is helping to prevent from impaired cognitive and memory functions in offspring.

Sex differences and laterality of insulin receptor distribution in developing rat hippocampus: an immunohistochemical study.

This study aimed to compare the regional distribution of insulin receptor in various portions of newborn rat hippocampus on postnatal days 0 (P0), 7 (P7), and 14 (P14) between male/female and right/left hippocampi. We found that the number of insulin receptor (InsR)-immunoreactive-positive (InsR+) cells in CA1 continued to increase until P7 and remained unchanged thereafter. A marked increase in distribution of InsR+ cells in CA3 from P0 to P14 was observed, although there was a significant decline in the number of InsR+ cells in dentate gyrus (DG) at the same time. No differences between the right/left and male/female hippocampi were detected at P0 (P > 0.05). Seven-day-old female rats showed a higher number of labeled cells in the left than in the right hippocampus. Moreover, the differences between the number of InsR+ cells in area CA1 and CA3 were statistically significant between males and females (P < 0.05). At P14, the number of InsR+ cells was significantly higher in CA1 and DG of males, especially in the right one (P < 0.05). These results indicate the existence of a differential distribution pattern of InsR between the left/right and male/female hippocampi. Together with other mechanisms, these differences may underlie sexual dimorphism and left/right asymmetry in the hippocampus.

Gender differences and lateralization in the distribution pattern of insulin-like growth factor-1 receptor in developing rat hippocampus: an immunohistochemical study.

Numerous investigators have provided data supporting essential roles for insulin-like growth factor-I (IGF-I) in development of the brain. The aim of this study was to immunohistochemically determine the distinct regional distribution pattern of IGF-1 receptor (IGF-IR) expression in various portions of newborn rat hippocampus on postnatal days 0 (P0), 7 (P7), and 14 (P14), with comparison between male/female and right/left hippocampi. We found an overall significant increase in distribution of IGF-IR-positive (IGF-IR+) cells in CA1 from P0 until P14. Although, no marked changes in distribution of IGF-IR+ cells in areas CA2 and CA3 were observed; IGF-IR+ cells in DG decreased until P14. The smallest number of immunoreactive cells was present in CA2 and the highest number in DG at P0. Moreover, in CA1, CA3, and DG, the number of IGF-IR+ cells was markedly higher in both sides of the hippocampus in females. Our data also showed a higher mean number of IGF-IR+ cells in the left hippocampus of female at P7. By contrast, male pups showed a significantly higher number of IGF-IR+ cells in the DG of the right hippocampus. At P14, the mean number of immunoreactive cells in CA1, CA3, and DG areas found to be significantly increased in left side of hippocampus of males, compared to females. These results indicate the existence of a differential distribution pattern of IGF-IR between left-right and male-female hippocampi. Together with other mechanisms, these differences may underlie sexual dimorphism and left-right asymmetry in the hippocampus.

The effects of induced type-I diabetes on developmental regulation of insulin & insulin like growth factor-1 (IGF-1) receptors in the cerebellum of rat neonates.

Diabetes during pregnancy impairs brain development in offspring, leading to behavioral problems, motor dysfunction and learning deficits. Insulin and insulin-like growth factor-1 (IGF-1) are important regulators of developmental and cognitive functions in the central nervous system. Aim of the present study was to examine the effects of maternal diabetes on insulin receptor (InsR) and IGF-1 receptor (IGF-1R) expression in the developing rat cerebellum. Wistar female rats were maintained diabetic from a week before pregnancy through parturition and male offspring was killed at P0, P7, and P14, an active neurogenesis period in brain development equivalent to the third trimester in human. The expression of InsR and IGF-1R in cerebelli was evaluated using real-time PCR and western blot analysis. We found a significant upregulation of both IGF-1R and InsR transcripts in cerebellum of pups born to diabetic mothers at P0, compared to controls. However, at the same time point, the results of western blot analysis revealed only a slight change in their protein levels. In contrast to InsR, which does not show any difference, there was a markedly reduction in cerebellar expression of IGF-1R mRNA and protein level in the diabetic group of newborns at P7. Moreover, 2 weeks after birth, mRNA expression and protein levels of both InsR and IGF-1R in cerebellum of the diabetic group was significantly downregulated. Compared to controls, we did not find any difference in cerebellar InsR or IGF-1R mRNA and protein levels in the insulin treated group. The present study revealed that diabetes during pregnancy strongly influences the regulation of both InsR and IGF-1R in the developing cerebellum. Furthermore, optimal maternal glycaemia control by insulin administration normalized these effects.

Sexual dimorphism in expression of insulin and insulin-like growth factor-I receptors in developing rat cerebellum.

The insulin and insulin-like growth factor-1 (IGF-1) are considered to play important roles in brain development; and their cognate receptors -InsR and IGF-1R- localized within distinct brain regions including cerebellum. Using Real-Time PCR and western blot analysis, we compared the expression of InsR and IGF-1R in male and female developing rat cerebellum at P0, P7, and P14. At all time points studied, the cerebellar expression of IGF-1R, both at mRNA and protein levels was higher than that of InsR. The lowest InsR and IGF-1R mRNA and protein levels were measured in the neonate cerebellum, independent of gender. In males, the highest InsR and IGF-1R mRNA and protein expression were found at P7. InsR and IGF-1R expression increased significantly between P0 and P7, followed by a marked downregulation at P14. In contrast, in females, mRNA and protein levels of InsR and IGF-1R remain unchanged between P0 and P7, and are upregulated at P14. Therefore, peaked InsR and IGF-1R expression in female cerebelli occurred at P14. Interestingly, changes in mRNA expression and in protein levels followed the same developmental pattern, indicating that InsR and IGF-1R transcription is not subject to modulatory effects during the first 2 weeks of development. These findings indicate that there are prominent sexual differences in InsR and IGF-1R expression in the developing rat cerebellum, suggesting a probable mechanism for the control of gender differences in development and function of the cerebellum.

The role of adenosine receptor agonist and antagonist on Hippocampal MDMA detrimental effects; a structural and behavioral study.

There is abundant evidence showing that repeated use of MDMA (3, 4-Methylenedioxymethamphetamine, ecstasy) has been associated with depression, anxiety and deficits in learning and memory, suggesting detrimental effects on hippocampus. Adenosine is an endogenous purine nucleoside that has a neuromodulatory role in the central nervous system. In the present study, we investigated the role of A2a adenosine receptors agonist (CGS) and antagonist (SCH) on the body temperature, learning deficits, and hippocampal cell death induced by MDMA administration. In this study, 63 adult, male, Sprague - Dawley rats were subjected to MDMA (10 and 20 mg/kg) followed by intraperitoneal CGS (0.03 mg/kg) or SCH (0.03 mg/kg) injection. The animals were tested for spatial learning in the Morris water maze (MWM) task performance, accompanied by a recording of body temperature, electron microscopy and stereological study. Our results showed that MDMA treatment increased body temperature significantly, and impaired the ability of rats to locate the hidden platform(P < 0.05). The number of hippocampal dark neurons also increased especially in CA1. These impairments were aggravated by co-administration of A2a antagonist (SCH) with MDMA. Furthermore, the administration of the A2a receptor agonist (CGS) provided partial protection against MWM deficits and hippocampal cell death(P < 0.05). This study provides for the first time evidence that, in contrast to A2a antagonist (SCH) effects, co-administration of A2a agonist (CGS) with MDMA can protect against MDMA hippocampal neurotoxic effects; providing a potential value in the prevention of learning deficits observed in MDMA users. However, the exact mechanism of these interactions requires further studies.

Neuronal injury and cytogenesis after simple febrile seizures in the hippocampal dentate gyrus of juvenile rat.

PURPOSE: Although simple febrile seizures are frequently described as harmless, there is evidence which suggests that hippocampal damage may occur after simple febrile seizures. This study aimed to investigate possible neuronal damages as well as alterations in cytogenesis in the hippocampal dentate gyrus following simple febrile seizures. METHODS: Simple febrile seizure was modeled by hyperthermia-induced seizures in 22-day-old male rats. The brains were removed 2 or 15 days after hyperthermia in all rats with (n=20) and without (n=10) occurrence of seizures as well as in control animals (n=10). The sections were stained with hematoxylin and eosin to estimate the surface numerical density of dark neurons. Ki-67 immunohistochemistry was performed to evaluate changes of cytogenesis following simple febrile seizures. RESULTS: Hyperthermia induced behavioral seizure activities in 67 % of the rats. The numerical densities of dark neurons as well as the mean Ki-67 index (the fraction of Ki-67-positive cells) were significantly increased in dentate gyrus after induction of seizures by hyperthermia compared to both controls and rats without seizure after hyperthermia. Both the seizure duration and intensity were correlated significantly with numerical densities of dark neurons (but not with Ki-67 index). CONCLUSION: The data indicate that simple febrile seizures can cause neuronal damages and enhancement of cytogenesis in the hippocampal dentate gyrus, which were still visible for at least 2 weeks. These findings also suggest the correlation of febrile seizure intensity and duration with neuronal damage.