Rat Cerebellum Research Articles

Vitamin A supplementation ameliorates motor incoordination via modulating RORα in the cerebellum in a valproic acid-treated rat autism model with vitamin A deficiency

Motor dysfunctions are common comorbidities among autism spectrum disorder (ASD) patients. Abnormal cerebellar development throughout critical periods may have an effect on motor functions and result in motor impairments. Vitamin A (VA) plays a crucial role in the developing process of the nervous system. The correlation of VA deficiency (VAD) and ASD with motor dysfunctions, however, is not clear. Therefore, we built rat models with different VA levels based on the valproic acid (VPA)-treated autism model. ASD rats with VAD showed aggravated motor coordination abnormalities, Purkinje cell loss and impaired dendritic arborization of Purkinje cells compared to ASD rats with normal VA levels (VA normal, VAN). Additionally, the expression levels of retinoid-related orphan receptor α (RORα) and retinoic acid receptor α (RARα) were lower in the cerebellum of ASD rats with VAD than in those of ASD rats with VAN. VA supplementation (VAS) effectively improved motor coordination and cerebellar Purkinje cell abnormalities in ASD rats with VAD. Furthermore, the results of chromatin immunoprecipitation (ChIP) assays confirmed that the enrichment of RARα was detected on the RORα promoter in the cerebellum and that VAS could upregulate the binding capacity of RARα for RORα promoters. These results showed that VAD in autism might result in cerebellar impairments and be a factor aggravating a subtype of ASD with motor comorbidities. The therapeutic effect of VAS on motor deficits and Purkinje neuron impairments in autism might be due to the regulation of RORα by RARα.

Gadolinium Clearance in the First 5 Weeks After Repeated Intravenous Administration of Gadoteridol, Gadoterate Meglumine, and Gadobutrol to rats.

BackgroundStudies of gadolinium (Gd) clearance from animals in the first weeks after administration of gadolinium‐based contrast agents (GBCAs) have previously looked at solitary timepoints only. However, this does not give information on differences between GBCAs and between organs in terms of Gd elimination kinetics.PurposeTo compare Gd levels in rat cerebellum, cerebrum, skin, and blood at 1, 2, 3, and 5 weeks after repeated administration of macrocyclic GBCAs.Study TypeProspective.Animal ModelOne hundred eighty male Sprague–Dawley rats randomized to three groups (n = 60/group), received intravenous administrations of gadoteridol, gadoterate meglumine, or gadobutrol (0.6 mmol/kg for each) four times/week for 5 consecutive weeks. Rats were sacrificed after washout periods of 1, 2, 3, or 5 weeks.Field Strength/SequenceNot applicable.AssessmentCerebellum, cerebrum, skin, and blood were harvested for Gd determination by inductively coupled plasma‐mass spectrometry (15 animals/group/all timepoints).Statistical TestsAnova and Dunnett's test (data with homogeneous variances and normal distribution). Kruskal–Wallis and Wilcoxon's rank sum tests (data showing nonhomogeneous variances or a non‐normal distribution, significance levels: P < 0.05, P < 0.01, and P < 0.001).ResultsGd levels in cerebellum, cerebrum, and skin were significantly lower after gadoteridol than after gadoterate and gadobutrol at all timepoints. Mean cerebellum Gd concentrations after gadoteridol, gadoterate, and gadobutrol decreased from 0.693, 0.878, and 1.011 nmol Gd/g at 1 week to 0.144, 0.282, and 0.297 nmol Gd/g at 5 weeks after injection. Similar findings were noted for cerebrum and skin. Conversely, significantly higher Gd levels were noted in blood after gadoteridol compared to gadobutrol at 1, 2, and 3 weeks and compared to gadoterate at all timepoints.Data ConclusionGadoteridol is eliminated more rapidly from rat cerebellum, cerebrum, and skin compared to gadoterate and gadobutrol in the first 5 weeks after administration, resulting in lower levels of retained Gd in these tissues.Evidence Level1Technical EfficacyStage 5

Effect of dental malocclusion on cerebellar neuron activation via the dorsomedial part of the principal sensory trigeminal nucleus

Occlusion has been proposed to play a role for body posture and balance, both of which are mediated mainly by the cerebellum. The dorsomedial part of the principal sensory trigeminal nucleus (Vpdm) has direct projection to the cerebellum. The experimental unilateral anterior crossbite (UAC) has an impact on the motor nuclei in the brain stem via trigeminal mesencephalic nucleus (Vme). The current aim was to explore whether UAC has an impact on Vpdm‐cerebellum circuit. The inferior alveolar nerve was injected into cholera toxin B subunit (CTb), the cerebellum was injected into fluoro‐gold (FG), and the Vpdm was injected into biotinylated dextran amine (BDA) to identify the activation of Vpdm‐cerebellum circuit by UAC. Data indicated that there were more neuronal nuclei (NeuN)/CTb/FG triple‐labelled neurons and NeuN/CTb/vesicular glutamate transporter 1(VGLUT1) triple‐labelled neurons in the Vpdm, and more NeuN/BDA/ VGLUT1 triple‐labelled neurons in the cerebellum of rats with UAC than in control rats. The VGLUT1 expression in the Vpdm and cerebellum in the UAC group was higher than that in control rats. These findings indicate an excitatory impact of UAC on the Vpdm‐cerebellum pathway and support the role of occlusion for body posture and balance.

A Study of 4G Radiofrequency Radiation effects on Juvenile Wistar Rats Cerebellum and Potential Attenuative Properties of Fish Oil Omega-3 Fat

Introduction: Technological devices have become a very important part of our everyday life. These electronic devices create an artificial electromagnetic field (EMF) and emit radiofrequency radiations (RFR) which have been reported to have deleterious effects on various tissues in living organisms. Fish oil is a rich source of the n-3 (also known as omega-3) fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The cerebellum plays an important role in motor control and the coordination, precision and timing of movements, as well as in motor learning. This study investigated the effect of radiofrequency radiation on the structures of the cerebellum of adolescent Wistar rats, its effect on pre-pubertal development and the potential attenuative properties of fish oil omega-3 fat.&#x0D; Materials and Methods: Forty (n=40) adolescent Wistar rats of approximately 35 days old were divided into five groups labelled A-E. A 4G RFR-emitting WI-FI device served as the RFR source. The 4G radiofrequency transmitter was installed at a distance of 0.5 meters from the base of the cage housing the experimental animals in each group. The fish oil was administered orally to the animals. Rats were sacrificed after 28 days of treatment and their brains harvested. The cerebellar tissues were excised and processed for histological, immunohistochemical and biochemical observations. Neurobehavioural studies including Barnes Maze and beam walk were carried out before sacrifice.&#x0D; Results: 4G radiofrequency radiation caused distortions in the morphology and spatial arrangement of Purkinje cells in the cerebellar tissues. It also induced neuroinflammation as marked by enhanced astrocyte reactions. Also, behavioural aberrations including negative changes in key memory parameters such as increased latency and error poke in Barnes maze assays, and increased movement parameter errors were attributable to FRR effects. Also, aberrations in neurotransmitters activities levels and vital neurochemistry enzymes were observed. The administered Omega-3 fat had an attenuative effect on the affected cortical structures, neurochemistry and selected neurobehavioural parameters.

Ethylmalonic acid impairs bioenergetics by disturbing succinate and glutamate oxidation and induces mitochondrial permeability transition pore opening in rat cerebellum.

Tissue accumulationand high urinary excretion of ethylmalonic acid (EMA) are found in ethylmalonic encephalopathy (EE), an inherited disorder associated with cerebral and cerebellar atrophy whose pathogenesis is poorly established. The in vitro and in vivo effects of EMA on bioenergetics and redox homeostasis were investigated in rat cerebellum. For the in vitro studies, cerebellum preparations were exposed to EMA, whereas intracerebellar injection of EMA was used for the in vivo evaluation. EMA reduced state 3 and uncoupled respiration in vitro in succinate-, glutamate-, and malate-supported mitochondria, whereas decreased state 4 respiration was observed using glutamate and malate. Furthermore, mitochondria permeabilization and succinate supplementation diminished the decrease in state 3 with succinate. EMA also inhibited the activity of KGDH, an enzyme necessary for glutamate oxidation, in a mixed manner and augmented mitochondrial efflux of α-ketoglutarate. ATP levels were markedly reduced by EMA, reflecting a severe bioenergetic disruption. Docking simulations also indicated interactions between EMA and KGDH and a competition with glutamate and succinate for their mitochondrial transporters. In vitro findings also showed that EMA decreased mitochondrial membrane potential and Ca2+ retention capacity, and induced swelling in the presence of Ca2+ , which were prevented by cyclosporine A and ADP and ruthenium red, indicating mitochondrial permeability transition (MPT). Moreover, EMA, at high concentrations, mildly increased ROS levels and altered antioxidant defenses in vitro and in vivo. Our data indicate that EMA-induced impairment of glutamate and succinate oxidation and MPT may contribute to the pathogenesis of the cerebellum abnormalities in EE.

Neurobehavioral, neurochemical and synaptic plasticity perturbations during postnatal life of rats exposed to chloroquine in-utero

Despite reports that quinoline antimalarials including chloroquine (Chq) exhibit idiosyncratic neuropsychiatric effects even at low doses, the drug continues to be in widespread use during pregnancy. Surprisingly, very few studies have examined the potential neurotoxic action of Chq exposure at different points of gestation or how this phenomenon may affect neurophysiological well-being in later life. We therefore studied behavior, and the expression of specific genes and neurochemicals modulating crucial neural processes in offspring of rats exposed to prophylactic dose of Chq during different stages of gestation. Pregnant rats were injected 5 mg/kg/day (3 times) of Chq either during early- (first week), mid- (second week), late- (third week), or throughout- (all weeks) gestation, while controls received PBS injection. Behavioral characterization of offspring between postnatal days 15–20 in the open field, Y-maze, elevated plus and elevated zero mazes revealed that Chq evoked anxiogenic responses and perturbed spatial memory in rats, although locomotor activity was generally unaltered. In the prefrontal cortex (PFC), hippocampus and cerebellum of rats prenatally exposed to Chq, RT-qPCR analysis revealed decreased mRNA expression of presynaptic marker synaptophysin, which was accompanied by downregulation of postsynaptic marker PSD95. Synaptic marker PICK1 expression was also downregulated in the hippocampus but was unperturbed in the PFC and cerebellum. In addition to recorded SOD downregulation in cortical and hippocampal lysates, induction of oxidative stress in rats prenatally exposed to Chq was corroborated by lipid peroxidation as evinced by increased MDA levels. Offspring of rats infused with Chq at mid-gestation and weekly treatment throughout gestation were particularly susceptible to neurotoxic changes, especially in the hippocampus. Interestingly, Chq did not cause histopathological changes in any of the brain areas. Taken together, our findings causally link intrauterine exposure to Chq with postnatal behavioral impairment and neurotoxic changes in rats.

Chronic Exposure to Tramadol Induces Neurodegeneration in the Cerebellum of Adult Male Rats.

Tramadol is a centrally acting synthetic opioid analgesic and SNRI (serotonin/norepinephrine reuptake-inhibitor) that structurally resembles codeine and morphine. Given the tramadol neurotoxic effect and the body of studies on the effect of tramadol on the cerebellum, this study aims to provide deeper insights into molecular and histological alterations in the cerebellar cortex related to tramadol administration. In this study, twenty-four adult male albino rats were randomly and equally divided into two groups: control and tramadol groups. The tramadol group received 50mg/kg of tramadol daily for 3 weeks via oral gavage. The functional and structural change of the cerebellum under chronic exposure of tramadol were measured. Our data revealed that treating rats with tramadol not only lead to cerebellum atrophy but also resulted in the actuation of microgliosis, neuroinflammatoin, and apoptotic biomarkers. Our results illustrated a significant drop in VEGF (vascular endothelial growth factor) level in the tramadol group. Additionally, tramadol impaired motor coordination and neuromuscular activity. We also identified several signaling cascades chiefly related to neurodegenerative disease and energy metabolism that considerably deregulated in the cerebellum of tramadol-treated rats. Overall, the outcomes of this study suggest that tramadol administration has a neurodegeneration effect on the cerebellar cortex via several pathways consisting of microgliosis, apoptosis, necroptosis, and neuroinflammatoin.

Hyperhomocysteinemia alters cytokine gene expression, cytochrome c oxidase activity and oxidative stress in striatum and cerebellum of rodents

AimsHomocysteine has been linked to neurodegeneration and motor function impairments. In the present study, we evaluate the effect of chronic mild hyperhomocysteinemia on the motor behavior (motor coordination, functional performance, and muscular force) and biochemical parameters (oxidative stress, energy metabolism, gene expression and/or protein abundance of cytokine related to the inflammatory pathways and acetylcholinesterase) in the striatum and cerebellum of Wistar male rats. Main methodsRodents were submitted to one injection of homocysteine (0.03 μmol Hcy/g of body weight) between 30th and 60th postnatal days twice a day. After hyperhomocysteinemia induction, rats were submitted to horizontal ladder walking, beam balance, suspension, and vertical pole tests and/or euthanized to brain dissection for biochemical and molecular assays. Key findingsChronic mild hyperhomocysteinemia did not alter motor function, but induced oxidative stress and impaired mitochondrial complex IV activity in both structures. In the striatum, hyperhomocysteinemia decreased TNF-α gene expression and increased IL-1β gene expression and acetylcholinesterase activity. In the cerebellum, hyperhomocysteinemia increased gene expression of TNF-α, IL-1β, IL-10, and TGF-β, while the acetylcholinesterase activity was decreased. In both structures, hyperhomocysteinemia decreased acetylcholinesterase protein abundance without altering total p-NF-κB, NF-κB, Nrf-2, and cleaved caspase-3. SignificanceChronic mild hyperhomocysteinemia compromises several biochemical/molecular parameters, signaling pathways, oxidative stress, and chronic inflammation in the striatum and cerebellum of rats without impairing motor function. These alterations may be related to the mechanisms in which hyperhomocysteinemia has been linked to movement disorders later in life and neurodegeneration.

On P2X receptors in the brain: microvessels. Dedicated to the memory of the late Professor Geoffrey Burnstock (1929-2020).

This tribute article presents selected immunocytochemical and transmission electron microscope data on the location of ATP-gated P2X receptor in the rat brain, as studied in the 1990s in Prof G. Burnstock's laboratory at University College London. There are examples of immuno-ultrastructural findings and introductory information about pre- and post-synaptic location of P2X receptors in the rat cerebellum and endocrine hypothalamus to support the concept of purinergic transmission in the central nervous system. Then findings of diverse immunoreactivity for P2X1, P2X2, P2X4, and P2X6 receptors associated with brain microvessels are shown, including vascular endothelium and pericytes as well as perivascular astrocytes and neuronal components. These findings imply the involvement of P2X receptors and hence purinergic signalling in the neurovascular unit, at least in microvessels in the rat cerebellum and hypothalamic paraventricular and supraoptic nuclei examined here. Various aspects of P2X receptors in brain microvessels are discussed.

Effect of Prenatal Topiramate Administration on Early Postnatal Expression of GFAP in Radial Glial Cells in Albino Rat Cerebellum and Spinal Cord

Background: Topiramate is known as a modern drug approved for the treatment of patients with partial seizures. Radial glial cells are bipolar-shaped cells in the developing central nervous system of vertebrates. It can differentiate into other neurons and astrocytes. GFAP, Glial fibrillary acidic protein, is a glial intermediate filament protein that is known as the most comprehensive marker for astroglial cells including the radial glia Aim of the work: There are few reports on topiramate administration during pregnancy. Therefore, this drug was chosen to investigate its effects, if any, especially the expression of GFAP in radial glia in the pups’ cerebellum and spinal cord. Material and Methods: Male and female rats were coupled in one cage for mating. On the next morning, mating was approved by the presence of sperms in the female vaginal swab, it was considered as Gestation Day zero:0. Twelve female pregnant rats were divided equally into two groups; control and topiramate treated. Topiramate drug was given to the treated group via orogastric tube from GD zero (0) till the time of delivery in a dose of 100mg/kg the control rats were administered tap water by orogastric tube. At the end of the experiment, the newly born pups (PN1) were weighed, anesthetized with Ketamine (60 mg/kg i.p.). The cerebellum and spinal cord were dissected and weighted. The specimens were fixed in Bouin’s solution then processed for preparation of H& E and GFAP immunostained sections. Results:In H& E-stained sections, the cerebellum in the control group was formed of subsequent layers, purkinje cells were arranged in one row, rounded or fusiform shape. GFAP positive Immunostained radial fibers (Bregman glia) were detected in granular and purkinje cell layers. The treated group showed that cells were disorganized and degenerated with focal areas of neuronal loss. Weak GFAP reaction was observed in Bregman glia in granular, purkinje and white matter cell layers. The lumbosacral segment of the spinal cord ventral horn showed large multipolar motor neurons with vesicular nucleus (“owl-eye” appearance), dendrites and axons were obvious. Glial cells with deeply stained nuclei were noticed. In the treated group, neurons appeared degenerated, vacuolated cytoplasm and pyknotic nuclei with focal areas of cellular loss. GFAP immunostained section in the control group showed an intense reaction in the radial fibers of the glia of the ventral funiculus, in contrast to the treated group which showed a faint reaction in both ventral funiculus and horn. Conclusion: it could be concluded that daily regular administration of topiramate during a childbearing period in females may result in a neurotoxic effect in the cerebellum and spinal cord. So, the administration of this drug should be under strict medical observation.

Comparative study of the possible protective effects of omega-3 and saffron extract on the cerebellum of adult male albino rats exposed to cell phone electromagnetic radiations: Histological and Immunohistochemical study

Background: Quickly changing technologies and dramatic world-wide increase in the uses of radiofrequency electromagnetic radiations (RF-EMRs) emitting cell phones represents a challenge to public health. So, the interest of studying its hazards that could affect human health has been increased. Recently, omega-3 and saffron had attracted a great attention as an antioxidant.Aim of work: This study focused on estimation of the neuroprotective effects of omega-3 and saffron against the histological and immunohistochemical changes within the cerebellum of adult male albino rats exposed to the cell phone electromagnetic radiations. Materials and Methods: Sixty adults male albino rats were used. They were divided into six groups, group I (control group), group II (omega-3 group), group III (saffron group), group IV (cell phone-exposed group), group V (cell phone and omega-3 group) and group VI (cell phone and saffron group). The cerebellum from each animal was cut off and processed for biochemical, histological studies by Hematoxylin and Eosin (Hx. & E.), Toluidine blue (T.B) and electron microscope examination, immunohistochemical studies by Glial fibrillary acidic protein (GFAP), caspase-3, myelin basic protein (MBP) and morphometric studies were also, done.Results: Cell phone exposed group revealed disturbed cerebellar architecture. The molecular layer displayed pyknotic nuclei, perineuronal vacuolation and disruption of myelin sheath around nerve fibers. The Purkenje cells appeared with irregular heterochromatic nuclei, shrunken, and surrounded with empty neuropil. The granular layer appeared with some small, degenerated granule cells. Significant increase in GFAP, Caspase-3 and significant decrease in MBP immunoreactivity were also observed. Omega-3 and saffron administrations decreased these adverse effects. Saffron showed higher protection against the histological alterations on the cerebellar cortex exposed to cell phone electromagnetic radiations (EMRs).Conclusion: Cell phone emitted EMRs induces histological and immunohistochemical changes within the cerebellar tissues and saffron has a better neuroprotective effect than omega 3.

Acute hypermethioninemia impairs redox homeostasis and acetylcholinesterase activity in the hippocampus, striatum, and cerebellum of young rats

Hypermethioninemia is characterized by high plasma concentrations of methionine (Met) and its metabolites, such as methionine sulfoxide (MetO), and neurological changes, such as cerebral edema and cognitive deficits. The aim of this study was to analyze the redox status and acetylcholinesterase (AChE) activity in the hippocampus, striatum, and cerebellum of young Wistar rats subjected to an acute hypermethioninemia protocol. The animals received, by subcutaneous injection, a single dose of Met (0.4g/kg), MetO (0.1g/kg), and Met+MetO, and 1 or 3hr after administration, the animals were euthanatized for brain structure obtaining. In the hippocampus, an increase in lipid peroxidation and glutathione peroxidase (GPx) activity was observed at 1hr in the MetO and Met+MetO groups, and a reduction in the superoxide dismutase activity was found in the Met+MetO group. Met and/or MetO induced a decrease in the thiol content and GPx activity and enhanced the lipid peroxidation at 3hr. In the striatum, a reduction in the thiol content and GPx activity, an increase in lipid peroxidation, and AChE activity were induced by Met and/or MetO at 1 or 3hr. Additionally, in the cerebellum, an increase in the AChE in the MetO and Met+MetO groups 1hr after administration was observed. These data help to better understand the pathophysiological mechanisms that underlie the neurological changes found in hypermethioninemia patients.

Disabling VEGF-Response of Purkinje Cells by Downregulation of KDR via miRNA-204-5p.

The vascular endothelial growth factor (VEGF) is well known for its wide-ranging functions, not only in the vascular system, but also in the central (CNS) and peripheral nervous system (PNS). To study the role of VEGF in neuronal protection, growth and maturation processes have recently attracted much interest. These effects are mainly mediated by VEGF receptor 2 (VEGFR-2). Current studies have shown the age-dependent expression of VEGFR-2 in Purkinje cells (PC), promoting dendritogenesis in neonatal, but not in mature stages. We hypothesize that microRNAs (miRNA/miR) might be involved in the regulation of VEGFR-2 expression during the development of PC. In preliminary studies, we performed a miRNA profiling and identified miR204-5p as a potential regulator of VEGFR-2 expression. In the recent study, organotypic slice cultures of rat cerebella (postnatal day (p) 1 and 9) were cultivated and VEGFR-2 expression in PC was verified via immunohistochemistry. Additionally, PC at age p9 and p30 were isolated from cryosections by laser microdissection (LMD) to analyse VEGFR-2 expression by quantitative RT-PCR. To investigate the influence of miR204-5p on VEGFR-2 levels in PC, synthetic constructs including short hairpin (sh)-miR204-5p cassettes (miRNA-mimics), were microinjected into PC. The effects were analysed by confocal laser scanning microscopy (CLSM) and morphometric analysis. For the first time, we could show that miR204-5p has a negative effect on VEGF sensitivity in juvenile PC, resulting in a significant decrease of dendritic growth compared to untreated juvenile PC. In mature PC, the overexpression of miR204-5p leads to a shrinkage of dendrites despite VEGF treatment. The results of this study illustrate, for the first time, which miR204-5p expression has the potential to play a key role in cerebellar development by inhibiting VEGFR-2 expression in PC.

Proteome profiling of different rat brain regions reveals the modulatory effect of prolonged maternal separation on proteins involved in cell death-related processes

BackgroundEarly-life stress in the form of maternal separation can be associated with alterations in offspring neurodevelopment and brain functioning. Here, we aimed to investigate the potential impact of prolonged maternal separation on proteomic profiling of prefrontal cortex, hippocampus and cerebellum of juvenile and young adult rats. A special attention was devoted to proteins involved in the process of cell death and redox state maintenance.MethodsLong-Evans pups were separated from their mothers for 3 h daily over the first 3 weeks of life (during days 2–21 of age). Brain tissue samples collected from juvenile (22-day-old) and young adult (90-day-old) rats were used for label-free quantitative (LFQ) proteomic analysis. In parallel, selected oxidative stress markers and apoptosis-related proteins were assessed biochemically and by Western blot, respectively.ResultsIn total, 5526 proteins were detected in our proteomic analysis of rat brain tissue. Approximately one tenth of them (586 proteins) represented those involved in cell death processes or regulation of oxidative stress balance. Prolonged maternal separation caused changes in less than half of these proteins (271). The observed alterations in protein expression levels were age-, sex- and brain region-dependent. Interestingly, the proteins detected by mass spectrometry that are known to be involved in the maintenance of redox state were not markedly altered. Accordingly, we did not observe any significant differences between selected oxidative stress markers, such as the levels of hydrogen peroxide, reduced glutathione, protein carbonylation and lipid peroxidation in brain samples from rats that underwent maternal separation and from the corresponding controls. On the other hand, a number of changes were found in cell death-associated proteins, mainly in those involved in the apoptotic and autophagic pathways. However, there were no detectable alterations in the levels of cleaved products of caspases or Bcl-2 family members. Taken together, these data indicate that the apoptotic and autophagic cell death pathways were not activated by maternal separation either in adolescent or young adult rats.ConclusionProlonged maternal separation can distinctly modulate expression profiles of proteins associated with cell death pathways in prefrontal cortex, hippocampus and cerebellum of juvenile rats and the consequences of early-life stress may last into adulthood and likely participate in variations in stress reactivity.

Intergenerational thyroid hormone homeostasis imbalance in cerebellum of rats perinatally exposed to glyphosate-based herbicide.

Agrochemicals became a public health concern due to increased human exposure and possible endocrine disruption effects in several organs, including the brain. Thyroid hormones controls neurodevelopment, which turn them sensitive to endocrine disruptors (EDs). In this work, we evaluated the effect of glyphosate-based herbicides (GBH) as an intergenerational endocrine disrupter on thyroid homeostasis in cerebellar cells. Female pregnant Wistar rats were exposed to Roundup Transorb® solution at 5 and 50 mg/kg/day, from gestation day 18 to post-natal day 5 (P5). Cerebellum of male offspring was used to evaluate gene expression. The mRNA levels of thyroid hormone receptors, hormonal conversion enzymes, hormone transporters, as well as, de novo epigenetic regulators were altered, with some of these genes presenting a non-monotonic dose response. Furthermore, metabolomic profile correlation with tested dose demonstrated altered metabolic profile, in agreement with cerebellar gene alterations. Moreover, cerebellar primary cultures exposed to non-toxic GBH concentration presented a decrease level in glial fibrillary acidic protein, a protein regulated by endocrine signals. In conclusion, our results indicate that animals exposed to non-toxic GBH doses during perinatal phase carry intergenerational alterations in key regulators of cellular thyroid hormone homeostasis and epigenetic controllers in adulthood, indicating the possible ED effect of GBH based on epigenetic alterations.

Thymoquinone Protects Neurons in the Cerebellum of Rats through Mitigating Oxidative Stress and Inflammation Following High-Fat Diet Supplementation.

High-fat diet (HFD) is a major problem causing neuronal damage. Thymoquinone (TQ) could regulate oxidative stress and the inflammatory process. Hence, the present study elucidated the significant role of TQ on oxidative stress, inflammation, as well as morphological changes in the cerebellum of rats with HFD. Rats were divided into three groups as (1) control, (2) saturated HFD for eight weeks and (3) HFD supplementation (four weeks) followed by TQ 300 mg/kg/day treated (four weeks). After treatment, blood samples were collected to measure oxidative stress markers glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), and inflammatory cytokines. Furthermore, neuronal morphological changes were also observed in the cerebellum of the rats. HFD rats show higher body weight (286.5 ± 7.4 g) as compared with the control group (224.67 ± 1.78 g). TQ treatment significantly (p < 0.05) lowered the body weight (225.83 ± 13.15 g). TQ produced a significant (p < 0.05) reduction in cholesterol, triglycerides, high-density lipoprotein (HDL), and low-density lipoprotein (LDL). The antioxidative enzymes significantly reduced in HFD rats (GSH, 1.46 ± 0.36 mol/L and SOD, 99.13 ± 5.41 µmol/mL) as compared with the control group (GSH, 6.25 ± 0.36 mol/L and SOD, 159.67 ± 10.67 µmol/mL). MDA was increased significantly in HFD rats (2.05 ± 0.25 nmol/L) compared to the control group (0.695 ± 0.11 nmol/L). Surprisingly, treatment with TQ could improve the level of GSH, MDA, and SOD. TQ treatment significantly (p < 0.05) reduced the inflammatory markers as compared with HFD alone. TQ treatment minimizes neuronal damage as well as reduces inflammation and improves antioxidant enzymes. TQ can be considered as a promising agent in preventing the neuronal morphological changes in the cerebellum of obese populations.

Impact of three-month morphine withdrawal on rat brain cortex, hippocampus, striatum and cerebellum: proteomic and phosphoproteomic studies

Opioid addiction is characterized by compulsive drug seeking and taking behavior, which is thought to result from persistent neuroadaptations. However, there is a lack of information about the changes at both the cellular and molecular levels occurring after cessation of drug administration. The aim of our study was to determine alterations of both phosphoproteome and proteome in selected brain regions of the rats (brain cortex, hippocampus, striatum, and cerebellum) 3 months after cessation of 10-day morphine treatment. Phosphoproteome profiling was performed by Pro-Q® Diamond staining. The gel-based proteomic approach accompanied by label-free quantification (MaxLFQ) was used for characterization of proteome changes.The phosphoproteomic analysis revealed the largest change in the hippocampus (14); only few altered proteins were detected in the forebrain cortex (5), striatum (4), and cerebellum (3). The change of total protein composition, determined by 2D electrophoresis followed by LFQ analysis, identified 22 proteins with significantly altered expression levels in the forebrain cortex, 19 proteins in the hippocampus, 12 in the striatum and 10 in the cerebellum. The majority of altered proteins were functionally related to energy metabolism and cytoskeleton reorganization. As the most important change we regard down-regulation of 14-3-3 proteins in rat cortex and hippocampus.Our findings indicate that i) different parts of the brain respond in a distinct manner to the protracted morphine withdrawal, ii) characterize changes of protein composition in these brain parts, and iii) enlarge the scope of evidence for adaptability and distinct neuroplasticity proceeding in the brain of drug-addicted organism.

Evaluation of the effect of methotrexate on the hippocampus, cerebellum, liver, and kidneys of adult male albino rat: Histopathological, immunohistochemical and biochemical studies

Methotrexate (MTX) has been used for treatment of autoimmune diseases, inflammatory disorders as rheumatic arthritis, and different types of cancers. However, it has shown adverse effects on vital organs. The current study was conducted to investigate the toxic effect of MTX on the hippocampus, cerebellum, liver and kidneys of adult male albino rats. MTX was injected weekly at 5 mg/kg body weight via I/P injection for 6 weeks. At the end of the experiment, histopathological, immunohistochemical and biochemical evaluation were performed on the hippocampus, cerebellum, liver, and kidney tissues of the sacrificed rats. We observed that methotrexate induced neural tissue damage in the hippocampus and cerebellum, degeneration of hepatocytes, congestion of the central vein and blood sinusoids of the liver, distortion in the renal corpuscles and necrosis of the renal tubule. Immunohistochemical findings revealed strong positive expression of Caspase-3, PCNA and GFAP. Biochemical studies revealed significant elevation in the serum levels of AST and ALT, in addition to high serum concentrations of creatinine and urea. Also, MTX injection increased MDA, while it decreased GSH, SOD and AChE levels. We conclude the ability of MTX to induce oxidative stress that results into apoptosis and tissue injury, leading to neurotoxicity, hepatotoxicity, and nephrotoxicity.

Immune-tolerance to human iPS-derived neural progenitors xenografted into the immature cerebellum is overridden by species-specific differences in differentiation timing

We xeno-transplanted human neural precursor cells derived from induced pluripotent stem cells into the cerebellum and brainstem of mice and rats during prenatal development or the first postnatal week. The transplants survived and started to differentiate up to 1 month after birth when they were rejected by both species. Extended survival and differentiation of the same cells were obtained only when they were transplanted in NOD-SCID mice. Transplants of human neural precursor cells mixed with the same cells after partial in vitro differentiation or with a cellular extract obtained from adult rat cerebellum increased survival of the xeno-graft beyond one month. These findings are consistent with the hypothesis that the slower pace of differentiation of human neural precursors compared to that of rodents restricts induction of immune-tolerance to human antigens expressed before completion of maturation of the immune system. With further maturation the transplanted neural precursors expressed more mature antigens before the graft were rejected. Supplementation of the immature cells suspensions with more mature antigens may help to induce immune-tolerance for those antigens expressed only later by the engrafted cells.

Subchronic exposure to acrylamide caused behaviour disorders and related pathological and molecular changes in rat cerebellum

Acrylamide (ACR) is a neurotoxin with moderate acute toxicity. Significant level of ACR exists in diet and drinking water. Occupational exposure causes motor function impairment, but the underlying mechanisms remain poorly defined. This study aims to explore whether microtubule-associated protein tau phosphorylation, excessive activation of protein kinase RNA-like endoplasmic reticulum kinase (PERK) signaling pathway and BDNF decline are involved in cerebellar neuron lesions and motor dysfunction after subchronic ACR exposure. The present results displayed that ACR caused gait abnormality and hind foot splay in rats. The HE and Nissl staining results revealed that ACR exposure aggravated cerebellar neuron lesions especially in purkinje cell layer. ACR markedly increased tau phosphorylation at Ser262 and Ser396/404 and inhibited the level of phosphorylation of glycogen synthase kinase 3β (P-GSK3β) at Ser9. The PERK-eukaryotic initiation factor-2α (eIF2α)-activating transcription factor 4 (ATF4) pathway was activated to promote CHOP expression and then to accelerate neuron lesions. Furthermore, ACR significantly decreased P-CREB at Ser133 and BDNF expression, which might be related to the inhibition of upstream signals from extracellular signal-related kinase (ERK) and protein kinase B (Akt). This work helps to elucidate the underlying mechanisms of ACR-induced neurotoxicity and present a potential target for prevention against the neurotoxicity.