The effect of the "segment" of spinal cord injury on the activity of the nucleotide-binding domain-like receptor protein 3 inflammasome and response to hormonal therapy.

Spinal cord injury (SCI) is a common devastating condition that causes neuronal loss and dysfunction. Neuroinflammation takes cardinal roles in the pathogenesis of SCI, and nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome is a mediator of inflammatory reactions occurring in SCI patients. The present study was designed to survey possible relation between thoracic segments whereby injury occurs with the activity of NLRP3 inflammasome complex, and to find the influence of hormonal therapy on the outcomes. Adult male Wistar rats underwent contusion SCI model at three different thoracic segments T1, T6 and T12, then receiving subcutaneous injection of either 10 mg/kg melatonin or 25 µg/kg 17-ß estradiol (E2) every 12 hours until 72 hours post-SCI. Inflammasome activity was assessed before and at the end of hormonal therapy. SCI rats showed decreased locomotor activity and myelination, and increased activity of the NLRP3, apoptosis-associated speck-like protein (ASC) and caspase-1 at gene and protein levels. Release of interleukins (ILs) 18 and 1ß was also augmented after SCI (P < 0.0.5). Hormonal therapy was most effective for targeting mRNA activity at T6 segment. Treatment with either melatonin or E2 caused a decrease in the protein activity of NLRP3 inflammasome at all segments (P < 0.0.5), except for T6 that NLRP3 protein had no response to melatonin. IL-1ß showed decreased activity in response to hormonal therapy at all segments, whilst IL-18 protein had no change at T1 segment. It is understood that although no alteration in the activity of NLRP3 was found for SCI at different segments, the response to hormonal therapy was influenced by segment. SIGNIFICANCE OF THE STUDY: From our results, the NLRP3 inflammasome activity is not influenced by segment, but there are differences in the effect of hormonal therapy on inflammasome activity at different segments in response to melatonin or E2. These findings also provide the beneficial effects of melatonin or E2 on inflammation caused by spinal cord injury in different thoracic segments. Finally, these data can have therapeutic importance for hormone therapy of spinal cord injury.

The Conference of the Birds: An Old Artistic Concept Making Sense in Modern Sciences.

In this article, we will discuss scientific aspects of an old Persian story, Simorgh, in the book of The Conference of the Birds. The story is fulfilled with artistic and philosophical metaphors that make sense in two hot topics of the contemporary modern sciences i.e. cognitive science and complexity science. The poet addresses some humanity's bygone concerns and fundamental questions about self, the quality that shapes a person's uniqueness, and essential existence. The sophisticated language used in the poem contains allusions, symbols, and implications that are interpreted in five main topics. We think that the story deserves to be the touchstone for questions on the nature of the mind, including the profound question of humanity's search for self and meaning of life.

Blockade of p75 Neurotrophin Receptor Reverses Irritability and Anxiety-Related Behaviors in a Rat Model of Status Epilepticus

Background: Many recent epidemiological studies have shown that epileptic patients are more likely suffer from depression, anxiety, and irritability. However, the cellular mechanisms of epilepsy-induced psychotic behaviors are not fully elucidated. Neurotrophin receptors have been suggested to be involved in epilepsy and also in psychiatric disorders. Up-regulation of p75NTR expression and activation of p75NTR signalling cascades after the seizure have been shown, but the role of the p75 receptor in epilepsy-induced psychotic behaviors has not been documented so far. Therefore, the present work aimed to investigate the effect of p75 receptor blockade on seizure activity, irritability, and anxiety-like behaviors in a rat model of status epilepticus. Methods: Rats were injected with pilocarpine (350 mg/ kg, i.p.) to induce status epilepticus. Then various behavioral tests were performed after the blockade of p75NTR alone or in combination with p75 antagonist and phenobarbital. Molecular analysis by PCR was performed to investigate the expression of p75 and pro-NGF. Results: Molecular findings indicated a high level of mRNA expression for both p75 receptors and pro-NGF in the epileptic model group. Results also showed that the administration of p75 antagonist alone or in combination with phenobarbital was able to significantly influence the behavioral responses. Furthermore, 20-hours video monitoring showed a decrease in the frequency and duration of seizures in the rat group receiving p75 antagonist. Conclusion: Taken together, the present study suggests that the blockade of the p75 receptor may affect the irritability and anxiety-related behavior in a rat model of status epilepticus.

Toll-like receptors expression in follicular cells of patients with poor ovarian response.

BACKGROUND: Poor ovarian response (POR) to gonadotropin stimulation has led to a significant decline in success rate of fertility treatment. The immune system may play an important role in pathophysiology of POR by dysfunctions of cytokines and the growth factor network, and the presence of ovarian auto-antibodies. The aim of this study is to investigate the expression of toll-like receptors (TLR) 1, 2, 4, 5, 6 and cyclooxygenase (COX) 2 genes in follicular cells and concentration of interleukin (IL)-6, IL-8 and macrophage migration inhibitory factor (MIF), as major parts of innate immunity, in follicular fluid (FF) obtained from POR women in comparison with normal women. MATERIALS AND METHODS: In this case-control study, 20 infertile POR patients and 20 normal women took part in this study and underwent controlled ovarian stimulation. The FF was obtained from the largest follicle (>18 mm). The FF was centrifuged and cellular pellet was then used for evaluation of expression of TLRs and COX2 genes by real-time PCR. FF was used for quantitative analysis for IL-6, IL-8 and MIF by enzyme-linked immunosorbent assay (ELISA). RESULTS: TLR1, 2, 4, 5, 6 and COX2 gene expression were significantly higher in POR (p<0.05). Concentration of IL-6, IL-8 and MIF proteins was significantly increased in POR compared with normal women (p<0.05). CONCLUSION: These findings support the hypothesis that the immune system may be involved in pathophysiology of POR through TLRs.

Tissue engineered poly(caprolactone)-chitosan-poly(vinyl alcohol) nanofibrous scaffolds for burn and cutting wound healing.

Natural-synthetic blend nanofibres have recently attracted more interest because of the ability of achieving desirable properties. Poly(ε-caprolactone) (PCL)-chitosan (Cs)-poly(vinyl alcohol) (PVA) blend nanofibrous scaffolds were electrospun in 2:1:1.33 mass ratio of PCL:Cs:PVA. The presence of PCL in the blend leads to improvement in web hydrophobicity and helped the web to retain its integrity in aqueous media. The scaffolds were used in two forms of acellular and with mesenchymal stem cells. They were applied on burn (n = 12) and excisional cutting (n = 12) wounds on dorsum skin of rats. Macroscopic investigations were carried out to measure the wounds areas. It was found that the area of wounds that were treated with cell-seeded nanofibrous scaffolds were smaller compared to other samples. Pathological results showed much better healing performance for cell-seeded scaffolds followed by acellular scaffolds compared with control samples. All these results indicate that PCL:Cs:PVA nanofibrous web would be a proper material for burn and cutting wound healing.

Morphometric and volumetric study of caudate and putamen nuclei in normal individuals by MRI: Effect of normal aging, gender and hemispheric differences.

BACKGROUND: The aim of this study was to determine age, gender, and hemispheric differences in the volume of the human neostriatum (striatum) nucleus in healthy humans. MATERIAL/METHODS: This study was performed on 120 normal human subjects (60 males, 60 females, right-handed) 15-65 years old, divided into two groups: young (<40 yrs) and old (=≥40 yrs). Sectional brain images were obtained via magnetic resonance imaging (MRI), analyzed and processed using the Image-J software, and the striatum volume was calculated using the Cavalieri's principle, retrospectively. RESULTS: The analyses revealed bilateral age-related shrinkage of the putamen in both genders and the putamen and caudate nucleus were significantly smaller in older than in younger subjects (P-value <0.001). The age-related shrinkage of the caudate and putamen nucleus in men and women was about 5%, 5% and 4%, 4%, respectively, and there were statistically significant volume differences between males and females (P-value <0.05). In both genders, a significant rightward asymmetry was observed in the caudate and putamen nucleus (3.89%, 4.21% in men and 4.51%, 3.32% in women). CONCLUSIONS: Bilateral age-related shrinkage and rightward asymmetry of the striate nucleus was found in healthy adults and there were significant volume differences between men and women. Obtained results provide useful baseline data on age and gender-related changes of the volume of the striatum.

A metabonomics investigation of multiple sclerosis by nuclear magnetic resonance.

Multiple sclerosis (MS) is a nervous system disease that affects the fatty myelin sheaths around the axons of the brain and spinal cord, leading to demyelination and a broad range of signs and symptoms. MS can be difficult to diagnose because its signs and symptoms may be similar to other medical problems. To find out which metabolites in serum are effective for the diagnosis of MS, we utilized metabolic profiling using proton nuclear magnetic resonance spectroscopy ((1)H-NMR). Random forest (RF) was used to classify the MS patients and healthy subjects. Atomic absorption spectroscopy was used to measure the serum levels of selenium. The results showed that the levels of selenium were lower in the MS group, when compared with the control group. RF was used to identify the metabolites that caused selenium changes in people with MS by building a correlation model between these metabolites and serum levels of selenium. For the external test set, the obtained classification model showed a 93% correct classification of MS and healthy subjects. The regression model of levels of selenium and metabolites showed the correlation (R(2)) value of 0.88 for the external test set. The results indicate the suitability of NMR as a screen for identifying MS patients and healthy subjects. A novel model with good prediction outcomes was constructed between serum levels of selenium and NMR data.

Stromal cell-derived factor-1 alpha (SDF-1α) improves neural recovery after spinal cord contusion in rats.

Stromal cell-derived factor-1 alpha (SDF-1α) is an important cytokine, implicated in the control of stem cell trafficking and bone marrow-derived stem cell mobilization. Generally, SDF-1α regulates multiple physiological processes such as embryonic development and organ homeostasis. There is also good evidence that SDF-1α and its receptor CXCR4(1) are key regulators of neurorepair processes after brain ischemia and spinal cord injury. In this study, we investigated the influence of chronic intrathecal delivery of SDF-1α after spinal cord contusion. After contusion T9, male Wistar rats at the age of 12 weeks were intrathecally treated with SDF-1α in different doses (100, 500 and 1000 ng/ml) via an osmotic pump for 28 days. Thereafter, animals were subjected to an open field locomotor test. Behavioral scores were significantly higher in SDF-1α treated animals compared to placebo-treated groups. In addition, we evaluated histopathological changes in the spinal cord in the presence or absence of SDF-1α. Chronic delivery of SDF-1α decreased numbers of apoptotic cells, boosted astroglia and microglia response, induced angiogenesis, and potentiated the number of proliferating cells in a dose-dependent manner. These results clearly indicate an improved functional CNS long-term recovery after spinal cord injury. This behavioral restoration was paralleled by a reduction of apoptosis and changes in neuroinflammatory cells.

The effects of cyclosporin-A on functional outcome and axonal regrowth following spinal cord injury in adult rats.

It has been shown that the immunophilin ligands have the special advantage in spinal cord repair. In this study, the effects of cyclosporine A (CsA) on functional recovery and histological outcome were evaluated following spinal cord injury in rats. After spinal cord hemisection in thirty six adult female Sprague-Dawley rats (200- 250 g), treatment groups received CsA (2.5 mg/kg i.p.) at 15min and 24h after lesion (CsA 15min group and CsA 24h group) daily, for 8 weeks. Control and sham groups received normal saline and in sham operated animals the spinal cord was exposed in the same manner as treatment groups, but was not hemisected. Hindlimb motor function was assessed in 1, 3, 5 and 7 weeks after lesion, using locomotive rating scale developed by Basso, Bresnahan and Beattie (BBB). Motor neurons were counted within the lamina IX of ventral horn and lesion size was measured in 5 mm of spinal lumbar segment with the epicenter of the lesion site. The mean number of motor neurons and the mean BBB scale in 3, 5 and 7 weeks in CsA 15min groups significantly increased compared to the control group. Although, the lesion size reduced in rats with CsA treatment compared to the control group, no significant difference was observed. Thus, it can be concluded that CsA can improve locomotor function and histological outcome in the partial spinal cord injury.

Neuroprotective effect of exogenous melatonin on dopaminergic neurons of the substantia nigra in ovariectomized rats.

BACKGROUND: Melatonin has receptors in substantia nigra pars compacta (SNc) and regulates development of dopaminergic (DA) neurons. This study was undertaken to determine ability of melatonin to protect SNc dopaminergic neuron loss induced by estrogen deficiency in ovariectomized rats. METHODS: Female rats were randomized into four groups of seven each: control, ethanol sham, ovariectomy (ovx) and ovx with melatonin (ovx + m). In ovx, ovaries were removed. Ovx + m group was intraperitoneally injected with melatonin for 10 days, while the ethanol sham group received only ethanol. All rats were perfused with 4% paraformaldehyde, midbrains removed, fixed and paraffin embedded, then processed for Nissl and tyrosine hydroxylase staining (IHC). Ten sections of SNc in Nissl and IHC staining were analyzed in each animal, Nissl stained and tyrosine hydroxylase (TH) immunoreactive cells were counted in five experimental groups randomly. Data was analyzed using SPSS by ANOVA and t-test. Differences were considered significant for P<0.05. RESULTS: There was less cell number in ovx compared to control and ethanol sham groups significantly (P<0.001). The ovx + m group had more cells than the ovx group in the SNc significantly (P<0.001). Furthermore, there was significant decrease of TH positive cell number in the ovx group compared to control and ethanol sham groups (P<0.05). The number of TH immunoreactive cells was higher in ovx + m compared to the ovx group (P<0.05). CONCLUSION: These findings can be compared with human and used in clinical application for prevention of DA neuron death of SNc after ovariectomy.

Neuroprotective effects of carnosic Acid in an experimental model of Alzheimer's disease in rats.

OBJECTIVE: Alzheimer's disease is the most common type of neurodegenerative disorder. It has been suggested that oxidative stress can be one of the pathological mechanisms of this disease. Carnosic acid (CA) is an effective antioxidant substance and recent studies have shown that its electrophilic compounds play a role in reversing oxidative stress. Thus we tried to find out whether CA administration protects hippocampal neurons, preventing neurodegeneration in rats. MATERIALS AND METHODS: ANIMALS WERE DIVIDED INTO FOUR GROUPS: Sham-operated (sham), CA-pretreated sham-operated (sham+CA), untreated lesion (lesion) and CA-pretreated lesion (lesion+CA). Animals in all groups received vehicle or vehicle plus CA (CA: 10mg/ kg) intra-peritoneally one hour before surgery, again the same solution injected 3-4 hours after surgery (CA: 3 mg/kg) and repeated each afternoon for 12 days. A lesion was made by bilateral intra-hippocampal injection of 4 µl of beta amyloid protein (1.5 nmol/µl) or vehicle in each side. 14 days after surgery, the brains were extracted for histochemical studies. Data was expressed as mean ± SEM and analyzed using SPSS statistical software. RESULTS: Results showed that pretreatment with carnosic acid can reduce cellular death in the cornu ammonis 1 (CA1) region of the hippocampus in the lesion+CA group, as compared with the lesion group. CONCLUSION: Carnosic acid may be useful in protecting against beta amyloid-induced neurodegeneration in the hippocampus.

Transplantation of olfactory mucosa improve functional recovery and axonal regeneration following sciatic nerve repair in rats.

BACKGROUND: Olfactory ensheathing glia (OEG) has been shown to have a neuroprotective effect after being transplanted in rats with spinal cord injury. This study was conducted to determine the possible beneficial results of olfactory mucosa transplantation (OMT) which is a source of OEG on functional recovery and axonal regeneration after transection of the sciatic nerve. METHODS: In this study, 36 adult female Sprague-Dawley rats were used. The sciatic nerve was transected in 24 rats and immediately repaired by sciatic-sciatic anastomosis, and randomly divided equally into two groups. The experimental group received the OMT at the transected site and the control group received the respiratory mucosa transplant. In another twelve rats as sham-operated animals, the sciatic nerve was exposed but no transection was made. DiI retrograde tracing was injected in the gastrocnemius muscle two months after surgery to allow visualization of the extent of axonal regeneration. Functional recovery was also assessed at 15, 30, 45 and 60 days after surgery using walking track analysis and sciatic function index (SFI) calculations. RESULTS: The total number of DiI labeled motorneurones in the ventral horn (L4-L6) and the SFI scores were significantly higher in the group of rats that received olfactory mucosa rather than respiratory mucosa. CONCLUSIONS: The outcome indicates that olfactory mucosa is a useful treatment to improve nerve regeneration in mammals with peripheral nerve injury.

Dendritic spine changes in medial prefrontal cortex of male diabetic rats using Golgi-impregnation method.

BACKGROUND: Neuropathy is one of the major complications contributing to morbidity in patients with diabetes mellitus. The effect of diabetes on brain has not been studied so much and no gross abnormality has been found in the central nervous system of patients with diabetic neuropathy. This study was conducted to evaluate the time-dependent structural changes in medial prefrontal cortex of male diabetic rats using Golgi-impregnation method. METHODS: Male Wistar rats were randomly divided into the control and diabetic groups. For induction of diabetes, a single dose of streptozotocin (60 mg/kg) was injected intraperitoneally. At the end of the first and second months, the rats were transcardially perfused with a solution of phosphate buffer containing paraformaldehyde and Golgi-impregnated method was used to evaluate the changes of dendritic spines in medial prefrontal cortex. RESULTS: There was a significant reduction in the mean density of pyramidal neuron dendritic spines in the layers II and III of medial prefrontal cortex only after 2 months in the diabetic group compared to age-matched controls (P < 0.05). CONCLUSION: Diabetes induces a reduction in the spine density of apical dendrites of medial prefrontal cortex only in two-month diabetic rats.

The beneficial effect of (-)-epigallocatechin-3-gallate in an experimental model of Alzheimer's disease in rat: a behavioral analysis.

BACKGROUND: Progressive cognitive decline is one of the hallmark symptoms of Alzheimer's disease (AD) which can be modeled by beta-amyloid injection into specific regions of brain. Since epigallocatechin-3-gallate (EGCG) is a potent antioxidant agent which its role against oxidative stress and inflammation has been shown in prior studies, we tried to determine whether EGCG administration protects against beta-amyloid-induced memory and coordination impairment in rats. METHODS: Animals (male Wistar rats) were divided into four groups: sham operated, EGCG-pretreated sham operated (sham+EGCG), untreated lesion (lesion), and EGCG-pretreated lesion (lesion+EGCG). Animals in lesion, lesion+EGCG, and sham+EGCG groups received sterile saline or saline plus EGCG (10 mg/kg) intraperitoneally one day pre-surgery and every other day for three weeks. The lesion was induced one day after EGCG pretreatment by injection of 4 microl of sterile saline or water containing 2 nmol/microl beta-amyloid (1-40) into the hippocampal fissure. For behavioral analysis, psychomotor coordination (PMC) index and spontaneous alternation behavior were assessed using Rota-rod Treadmill and Y-maze, respectively at the third week post-lesion. RESULTS: We found that beta-amyloid (1-40) injection into hippocampus can decrease these behavioral indexes in lesion group in comparison with sham group which is similar to behavioral changes in AD. On the other hand, pretreatment with EGCG can improve the PMC index and spatial Y-maze alternation in the lesion+EGCG group in comparison with lesion group. CONCLUSION: We concluded that EGCG can be effective in restoring beta-amyloid-induced behavioral derangements in rats regarding coordination and memory abilities.

Association between the DRD2 A1 allele and opium addiction in the Iranian population.

Dysfunction of the central dopaminergic neurotransmission has been suggested to play an important role in the etiology of certain neuropsychiatric disorders such as drug abuse. It has been shown that the dopamine D2 receptor (DRD2) gene dysfunction is associated with multi-drug addiction. Addiction to opium is the most common form of drug abuse in Iran. We studied the allelic association between DRD2 Taq I A polymorphism in 100 opium-dependent Iranian patients and 130 unrelated controls. A 310 bp (base pair) region surrounding Taq I site at the DRD2 locus was amplified by polymerase chain reaction (PCR) and the PCR product was incubated with Taq I restriction enzyme. The A1 allele remained intact while the A2 allele was cut. Significant association was observed between A1 allele and addiction in the patients group (P < 0.0001). Moreover, the frequency of A1A1 genotype was significantly higher in opium users than controls (P < 0.0001). Our result indicates that DRD2 might be involved in the pathophysiology of opium addiction.

Protective effect of caffeine against neurodegeneration in a model of Parkinson's disease in rat: behavioral and histochemical evidence.

Epidemiological studies have consistently demonstrated an inverse association between coffee consumption and Parkinson's disease (PD). This study was designed to investigate the beneficial effect of caffeine at a dose comparable to that of human exposure in a model of PD. For this purpose, unilateral intrastriatal 6-hydroxydopamine (6-OHDA)-lesioned rats were pretreated with caffeine (20 mg/kg; i.p.) 1 h before surgery and treated twice a day (10 mg/kg) for 1 month. Apomorphine-induced rotations and number of Nissl-stained neurons of substantia nigra pars compacta (SNC) were counted. The results demonstrated that caffeine administration for 1 month could attenuate the rotational behavior in lesioned rats and protect the neurons of SNC against 6-OHDA toxicity.