Combined molecular, structural and memory data unravel the destructive effect of tramadol on hippocampus.

Tramadol is a synthetic analogue of codeine and stimulates neurodegeneration in several parts of the brain that leads to various behavioral impairments. Despite the leading role of hippocampus in learning and memory as well as decreased function of them under influence of tramadol, there are few studies analyzing the effect of tramadol administration on gene expression profiling and structural consequences in hippocampus region. Thus, we sought to determine the effect of tramadol on both PC12 cell line and hippocampal tissue, from gene expression changes to structural alterations. In this respect, we investigated genome-wide mRNA expression using high throughput RNA-seq technology and confirmatory quantitative real-time PCR, accompanied by stereological analysis of hippocampus and behavioral assessment following tramadol exposure. At the cellular level, PC12 cells were exposed to 600 µM tramadol for 48 hrs, followed by the assessments of ROS amount and gene expression levels of neurotoxicity associated with neurodegenerative pathways such as apoptosis and autophagy. Moreover, the structural and functional alteration of the hippocampus under chronic exposure to tramadol was also evaluated. In this regard, rats were treated with tramadol at doses of 50 mg/kg for three consecutive weeks. In vitro data revealed that tramadol provoked ROS production and caused the increase in the expression of autophagic and apoptotic genes in PC12 cells. Furthermore, in-vivo results demonstrated that tramadol not only did induce hippocampal atrophy, but it also triggered microgliosis and microglial activation, causing upregulation of apoptotic and inflammatory markers as well as over-activation of neurodegeneration. Tramadol also interrupted spatial learning and memory function along with long-term potentiation (LTP). Taken all together, our data disclosed the neurotoxic effects of tramadol on both in vitro and in-vivo. Moreover, we proposed a potential correlation between disrupted biochemical cascades and memory deficit under tramadol administration.

Implantation of human olfactory ecto-mesenchymal stem cells restores locomotion in a rat model of Parkinson's disease.

One of the complex neurodegenerative disorders is Parkinson disease (PD). PD is mainly caused by dopaminergic (DAergic) neuron degeneration in the midbrain. The loss of DAergic neurons is considered as a key reason of motor functional defects in PD patients. Cell replacement strategies are considered as an alternative remedy to effectively address neurodegeneration in PD. In this report, we evaluated the restorative effect of human olfactory ecto-mesenchymal stem cells (OE-MSCs) in rat models of PD. Accordingly, human OE-MSCs were isolated and phenotypically characterized by flow cytometry and immunocytochemistry. Next, the undifferentiated OE-MSCs were unilaterally transplanted into the striatum of 6-hydroxydopamine (6-OHDA)-lesioned rat models, followed by molecular and histological analyzes as well as assessment of motor skills. Our results displayed that the grafting of OE-MSCs increased the expression of DAergic markers namely dopamine transporter (DAT), tyrosine hydroxylase (TH), nuclear receptor related-1 (Nurr1) in a 6-OHDA model compared with that of control, detected by immunohistochemical staining and western blot. Moreover, noticeable improvements in motor coordination, muscle activity and locomotor performance were observed in 6-OHDA model of PD following OE-MSCs transplantation. Taken together, our finding indicates that undifferentiated OE-MSCs might be counted as an appropriate source for cell replacement therapy particularly aimed at PD.

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 50 mg/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.

Chronic administration of methylphenidate did not affect memory and GDNF levels but increase astrogliosis in adult male rat's hippocampus.

BACKGROUND: ADHD is the most common developmental disorder affecting approximately three to seven percent of school-aged children and 2.5 percent of adults worldwide. The drug of choice for the pharmacotherapy of ADHD is Methylphenidate (MPH). However, there is growing concerns about side effects resulting from its potential interference with brain anatomical and behavioral development. AIM: This article focuses on the adverse effects of MPH on the rat's hippocampus. METHODS: The animals received an oral dose of 5 mg/kg MPH or normal saline, as the vehicle, on a daily basis for 30 days. Y-maze test, passive avoidance, Barnes maze and field potential recording were conducted. Western blot for detecting the neurotrophic factor of GDNF and immunohistochemistry of astrogliosis were performed. RESULTS: Our results revealed that MPH treatment suppressed the willingness of rats to explore new environments. Also, it had no effect on improving long-term potentiation, long-term memory and spatial memory in the MPH group as opposed to the control group. There was also a significant increase of astrogliosis in the treated rats' hippocampi. On the other hand, there was not a significant relationship between MPH administration and the decrement of the GDNF level. CONCLUSION: We encourage the need to conduct more research on the adverse effects of MPH on the brain.

Tramadol exposure upregulated apoptosis, inflammation and autophagy in PC12 cells and rat's striatum: An in vitro- in vivo approach.

AIM AND BACKGROUND: Tramadol is a synthetic analogue of codeine, mostly prescribed for the alleviation of mild to moderate pains. It bears several side effects including emotional instability and anxiety. In this study, we focused on the alteration in expression of autophagic and apoptotic genes in PC-12 cells for our in vitro and structural and functional changes of striatum for our in vivo under chronic exposure of tramadol. METHODS: For in vitro side of the study, PC12 cells were exposed to tramadol (50 µM) and expression of apoptosis and autophagy genes were determined. In parallel, rats were daily treated with tramadol at doses of 50 mg/kg for three weeks for the in vivo side. Motor coordination, EMG, histopathology and gene expression were done. RESULTS: Our in vitro findings revealed that tramadol increased expression of apoptosis and autophagy genes in PC12 cells. Moreover, our in vivo results disclosed that tramadol not only provoked atrophy of rats' striatum, but also triggered microgliosis along with neuronal death in the striatum. Tramadol also reduced motor coordination and muscular activity. CONCLUSION: Altogether, our data indicated that tramadol induced neurotoxicity in the PC12 cells via apoptosis and autophagy and in striatum chiefly through activation of neuroinflammatory and apoptotic responses.

The effect of 3-nitropropionic acid on behavioral dysfunction, neuron loss and gliosis in the brain of adult male rats: The case of prefrontal cortex, hippocampus and the cerebellum.

3-nitropropionic acid (3-NP) is a mycotoxin widely used to produce a rat model of Huntington's disease. While there are numerous studies on the effect of this neurotoxin, still further investigation is required to understand the influence of this toxin on different regions of the brain. In the present study, there are two groups of rats of which one is treated with 3-NP. Behavioral, stereological and immunohistochemical analyses were conducted. The results show that locomotor activity is largely affected and anxiety is induced up to a certain level, but there is no gross manifestation of deficit in memory. Microscopic observations illustrate damages in the hippocampus and other parts of the brain. Astrogliosis and glial scars were another finding of this study. In conclusion, although 3-NP can be used as a model of Huntington's disease, it exerts a disseminated effect on different regions of the brain.

Tramadol: a Potential Neurotoxic Agent Affecting Prefrontal Cortices in Adult Male Rats and PC-12 Cell Line.

Tramadol is a synthetic analogue of codeine that is often prescribed for the treatment of mild to moderate pains. It has a number of side effects including emotional instability and anxiety. In this study, we focus on the structural and functional changes of prefrontal cortex under chronic exposure to tramadol. At the cellular level, the amounts of ROS and annexin V in PC12 cells were evidently increased upon exposure to tramadol (at a concentration of 600 µM for 48 h). To this end, the rats were daily treated with tramadol at doses of 50 mg/kg for 3 weeks. Our findings reveal that tramadol provokes atrophy and apoptosis by the induction of apoptotic markers such as Caspase 3 and 8, pro-inflammatory markers, and downregulation of GDNF. Moreover, it triggers microgliosis and astrogliosis along with neuronal death in the prefrontal cortex. Behavioral disturbance and cognitive impairment are other side effects of tramadol. Overall, our results indicate tramadol-induced neurodegeneration in the prefrontal cortex mainly through activation of neuroinflammatory response.

Effect of Sertoli Cell Transplantation on Reducing Neuroinflammation-Induced Necroptosis and Improving Motor Coordination in the Rat Model of Cerebellar Ataxia Induced by 3-Acetylpyridine.

To date, no certain cure has been found for patients with degenerative cerebellar disease. In this trial, we examined the in vivo and in vitro neuroprotective effects of Sertoli cells (SCs) on alleviating the symptoms of cerebellar ataxia. Testicular cells from an immature male rat were isolated and characterized by immunocytochemical analysis for somatic cell markers (anti-Mullerian hormone, vimentin). The protein assessment had already confirmed the expression of neurotrophic factors of glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial factor (VEGF). In vitro neuroprotective impact of SCs was determined after exposing PC12 cells to Sertoli cell-conditioned media (SC-CM) and H2O2, simultaneously. Afterwards, ataxia rat models were induced by a single dose of 3-AP (3-acetylpyridin), and 3 days later, SCs were bilaterally implanted. Motor and neuromuscular activity test were conducted following SC transplantation. Finally, immunohistochemistry against RIPK3 and Iba-1 was done in our generation. The in vivo results revealed substantial improvement in neuromuscular response, while ataxia group exhibited aggravated condition over a 28-day period. Our results suggested enhanced motor function and behavioral characteristics due to the ability of SCs to suppress necroptosis and consequently extend cell survival. Nevertheless, more studies are required to affirm the therapeutic impacts of SC transplantation in human cerebellar ataxia. In vitro data indicated cell viability was increased as a result of SC-CM with a significant reduction in ROS.