Mitochondrial plasticity and synaptic plasticity crosstalk; in health and Alzheimer's disease.

Synaptic plasticity is believed to underlie the cellular and molecular basis of memory formation. Mitochondria are one of the main organelles involved in metabolism and energy maintenance as plastic organelles that change morphologically and functionally in response to cellular needs and regulate synaptic function and plasticity through multiple mechanisms, including ATP generation, calcium homeostasis, and biogenesis. An increased neuronal activity enhances synaptic efficiency, during which mitochondria's spatial distribution and morphology change significantly. These organelles build up in the pre-and postsynaptic zones to produce ATP, which is necessary for several synaptic processes like neurotransmitter release and recycling. Mitochondria also regulate calcium homeostasis by buffering intracellular calcium, which ensures proper synaptic activity. Furthermore, mitochondria in the presynaptic terminal have distinct morphological properties compared to dendritic or postsynaptic mitochondria. This specialization enables precise control of synaptic activity and plasticity. Mitochondrial dysfunction has been linked to synaptic failure in many neurodegenerative disorders, like Alzheimer's disease (AD). In AD, malfunctioning mitochondria cause delays in synaptic vesicle release and recycling, ionic gradient imbalances, and mostly synaptic failure. This review emphasizes mitochondrial plasticity's contribution to synaptic function. It also explores the profound effect of mitochondrial malfunction on neurodegenerative disorders, focusing on AD, and provides an overview of how they sustain cellular health under normal conditions and how their malfunction contributes to neurodegenerative diseases, highlighting their potential as a therapeutic target for such conditions.

Permanent longitudinal strain damage of cardiotoxic drugs in childhood cancer: What is the safe level?

Objective: Anthracycline administration in children is associated with cardiac dysfunction. Speckle-tracking echocardiography (STE) can detect subclinical cardiac damage that may go undetected by conventional two-dimensional (2D) echocardiography. This study aims to investigate medium-term anthracycline cardiotoxicity using STE and determine a safer administrable level of anthracyclines (ACs). Methods: This observational case-control study enrolled 37 healthy controls and 78 pediatric cancer survivors who received chemotherapy. The patients were divided into two groups: cardiotoxic received (CR) and cardiotoxic free (CF). Data on segmental longitudinal strain (LS), global LS (GLS), and 2D echocardiographic parameters were collected after a drug-free period of at least one year. Results: A total of 115 children with a mean age of 108 ± 55 months, of whom 66% were males, were included in the study. Both the groups of cancer survivors exhibited significantly reduced GLS compared to healthy controls (CR vs. controls, P = 0.001; CF vs. controls, P = 0.013), but no significant difference in left ventricular ejection fraction (LVEF) was observed (P = 0.75). Overall, cancer survivors treated with ACs demonstrated a significant reduction in strain in 10 left ventricular segments, particularly in the basal segments (P < 0.05). Among CR patients, those with impaired GLS (n = 43, GLS worse than -21.9) had significantly higher mean age and cumulative anthracycline dose compared to CR patients with normal GLS (age, P = 0.024; anthracycline dosage, P = 0.036). Using an anthracycline cutoff of 223 mg/m2 resulted in a higher detection rate (49% vs. 25%) and fewer missed cases (51% vs. 74%) compared to the 360 mg/m2 anthracycline cutoff. Conclusion: Childhood cancer survivors demonstrate significantly reduced GLS while preserving a normal LVEF, which does not differ significantly from reference values of healthy children. The reduction in strain appears to be associated with higher anthracycline doses and older age. Lowering the anthracycline threshold to 223 mg/m2 may improve the predictability of a decline in cardiac function using strain imaging at medium-term follow-up.

A novel scoring system for early prediction of massive transfusion requirement in trauma patients.

Early resuscitation using blood products is critical for patients with severe hemorrhagic shock. We aimed to develop and validate a new scoring system, hemorrhagic shock transfusion prediction (HSTP) score, to predict the need for massive transfusion (MT) in these patients, compared to the widely used Assessment of Blood Consumption (ABC) score. Trauma patients admitted to Emtiaz Hospital in Iran from 2017 to 2021 were retrospectively included. Patients assigned a code 1 or 2 according to the Emergency severity index (ESI) triage system have been divided into MT and non-MT groups. MT was defined as receiving ≥ 10 units of packed cells (PCs) in 24 h. Demographic information, admission vital signs, and lab results available within 15 min were compared between the groups. A new predictive score was developed using logistic regression of statistically significant parameters. Out of 1029 patients, 651 (63.3%) required MT. An arrival, diastolic blood pressure < 79.5 mm Hg, absolute lymphocyte count > 1850/µL, base excess < - 4.25, and blood glucose > 156 mg/dL were independent predictors included in the HSTP score. The sensitivity and specificity were 74.36% and 53.87% for the HSTP score, compared to 31.03% and 76.16% for the ABC score. Moreover, the positive and negative predictive values were 77.88% and 49.03% for the HSTP score, versus 74.15% and 33.66% for ABC. The new scoring system demonstrated higher sensitivity and improved positive and negative predictive values compared to the ABC score. This score can assist physicians in making accurate transfusion decisions quickly, but further prospective studies are warranted to validate its clinical utility.

Does red blood cell transfusion affect clinical outcomes in critically ill patients? A report from a large teaching hospital in south Iran.

BACKGROUND: Despite the beneficial effects, RBC transfusion can be associated with infectious and non-infectious complications in critically ill patients. OBJECTIVES: Investigate current RBC transfusion practices and their effect on the clinical outcomes of patients in intensive care units (ICUs). DESIGN: Retrospective observational study. SETTING: Three mixed medical-surgical adult ICUs of a large academic tertiary hospital. PATIENTS AND METHODS: From March 2018 to February 2020, all adult patients admitted to medical or surgical ICU. Patients who received one or more RBC transfusions during the first month of ICU admission were included in the "transfusion" group, while the remaining patients were assigned to the "non-transfusion" group. MAIN OUTCOME MEASURES: Mortality and length of ICU and hospital stay. SAMPLE SIZE: 2159 patients. RESULTS: Of 594 patients who recieved transfusions, 27% of patients received red blood cell (RBC) products. The mean pre-transfusion hemoglobin (Hb) level was 8.05 (1.46) g/dL. There was a significant relationship between higher APACHE II scores and ICU mortality in patients with Hb levels of 7-9 g/dL (OR adjusted=1.05). Also, ICU mortality was associated with age (OR adjusted=1.03), APACHE II score (OR adjusted=1.08), and RBC transfusion (OR adjusted=2.01) in those whose Hb levels were >9 (g/dl). CONCLUSION: RBC transfusion was associated with an approximately doubled risk of ICU mortality in patients with Hb>9 g/dL. High APACHE II score and age increase the chance of death in the ICU by 8% and 3%, respectively. Hence, ICU physicians should consider a lower Hb threshold for RBC transfusion, and efforts must be made to optimize RBC transfusion practices. LIMITATIONS: Single-center and retrospective study.

Neuroprotective Effects of Ferrostatin and Necrostatin Against Entorhinal Amyloidopathy-Induced Electrophysiological Alterations Mediated by voltage-gated Ca2+ Channels in the Dentate Gyrus Granular Cells.

Alzheimer's disease (AD) is a progressive neurodegenerative disease that is the main form of dementia. Abnormal deposition of amyloid-beta (Aß) peptides in neurons and synapses cause neuronal loss and cognitive deficits. We have previously reported that ferroptosis and necroptosis were implicated in Aß25-35 neurotoxicity, and their specific inhibitors had attenuating effects on cognitive impairment induced by Aß25-35 neurotoxicity. Here, we aimed to examine the impact of ferroptosis and necroptosis inhibition following the Aß25-35 neurotoxicity on the neuronal excitability of dentate gyrus (DG) and the possible involvement of voltage-gated Ca2+ channels in their effects. After inducing Aß25-35 neurotoxicity, electrophysiological alterations in the intrinsic properties and excitability were recorded by the whole-cell patch-clamp under current-clamp condition. Voltage-clamp recordings were also performed to shed light on the involvement of calcium channel currents. Aß25-35 neurotoxicity induced a considerable reduction in input resistance (Rin), accompanied by a profoundly decreased excitability and a reduction in the amplitude of voltage-gated calcium channel currents in the DG granule cells. However, three days of administration of either ferrostatin-1 (Fer-1), a ferroptosis inhibitor, or Necrostatin-1 (Nec-1), a necroptosis inhibitor, in the entorhinal cortex could almost preserve the normal excitability and the Ca2+ currents. In conclusion, these findings suggest that ferroptosis and necroptosis involvement in EC amyloidopathy could be a potential candidate to prevent the suppressive effect of Aß on the Ca2+ channel current and neuronal function, which might take place in neurons during the development of AD.

The Analgesic and Anti-inflammatory Effects of Partially Purified Polysaccharide Fractions of Cell-free Medium and Biomass of Spirulina platensis PCST5.

Background: Spirulina is a cyanobacteria species containing various bioactive compounds. Spirulina is a known source of nutrients in some traditional diets. Different activities have been reported for various extracts of S. platensis. Objectives: In this study, the polysaccharide content of culture media and biomass extract of one species of Spirulina was partially purified, and its analgesic and anti-inflammatory effects were evaluated. Methods: Spirulina platensis PCST5 was cultured in a sterile Zarouk medium at 27°C and 16/8h of light/ dark exposure cycle for 25 days. Then, the polysaccharide content of biomass and cell-free culture medium samples (BPSs and CFPSs, respectively) was partially purified. The analgesic and anti-inflammatory effects were evaluated using animal models. Results: 16S rRNA gene analysis confirmed that the organism was genetically similar to Spirulina platensis. The CFPSs (30 and 100 mg/kg) and BPSs (30 mg/kg) significantly reduced pain-related behaviors in rats. Similarly, all samples could significantly reduce carrageenan-induced paw inflammation volume compared with the control group. Our results suggest Spirulina's polysaccharide fractions (CFPSs and BPSs) had significant analgesic and anti-inflammatory effects. Conclusions: Since Spirulina is a readily available source of bioactive compounds, finding such potent anti-inflammatory and anti-nociceptive compounds can provide promising leads for novel drug development.

Simultaneous adrenal and retroperitoneal myelolipoma resected by laparoscopic surgery: a challenging case.

BACKGROUND: Myelolipoma is a benign neoplasm of the adrenal cortex, composed of fat and hematopoietic cells. Although myelolipoma is benign, differentiation from adrenocortical cancer may be difficult. The presence of adrenal and extra-adrenal myelolipomas simultaneously is sporadic, making it a challenging case, especially when the preoperative diagnosis is ambiguous. CASE PRESENTATION: A 65-year-old man was referred to our clinic due to a mass in the adrenal fossa. In the abdominopelvic computed tomography (CT), a well-circumscribed fat-containing 78 × 61 × 65 mm bi-lobulated mass was reported in the left adrenal fossa. The first differential diagnosis was myelolipoma. The patient was then referred to our clinic for a mass excision. He was asymptomatic and was scheduled to undergo laparoscopic-assisted adrenalectomy. After adrenalectomy and mass dissection, surprisingly, another mass was detected in the retroperitoneal area. The second mass was also dissected. The final diagnosis was myelolipoma for both masses. The patient has been symptom-free for nine months after the operation. CONCLUSION: Simultaneous adrenal and extra-adrenal myelolipoma should be considered as one of the differential diagnoses. However, because this situation is extremely rare, the probability of malignancy should be highly regarded, and we suggest an obsessive approach when approaching this condition. It is essential to manage these cases on a case-by-case basis and tailor the management concerning intraoperative biopsy, the intraoperative appearance of tumors, and the location of extra-adrenal masses.

Development of Dual Inhibitors of Soluble Epoxide Hydrolase/Fatty Acid Amide Hydrolase with Tetrazole Core.

INTRODUCTION: The attractive biological actions of the eicosatrienoic acids (EETs) and endocannabinoids (eCBs) are terminated by means of enzymatic hydrolysis via soluble epoxide hydrolase (sEH) and fatty acid amide hydrolase (FAAH) enzymes. Simultaneous inhibition of both enzymes is considered a novel approach in the treatment of inflammatory and neuropathic pain. METHODS: In this study, a novel series of tetrazole derivatives as dual sEH/FAAH inhibitors were designed, synthesized, and biologically evaluated. Compounds 6c, 7d, and 8a, the most potent inhibitors against FAAH and sEH enzymes with acceptable IC50 values, significantly decreased carrageenan- induced paw edema 5h after carrageenan injection compared to the control group compound. In addition, compound 7d exhibited a significant reduction in pain scores compared to the control group. RESULTS: Docking studies showed that the presented dual inhibitors could bind to the essential residues in the catalytic sites of both enzymes. In silico prediction of several pharmacokinetic properties suggests that these dual inhibitors could potentially be orally active agents. CONCLUSION: These structures will be a valuable scaffold to develop soluble epoxide hydrolase inhibitors with dual potency towards fatty acid amide hydrolase.

Thigh Length as the Most Consistent Anthropometric Parameter in Predicting the Size of Hamstring Tendon Autografts in Patients Undergoing Anterior Cruciate Ligament Reconstruction: A Cross-Sectional Study.

Background: Individual variability in the length and thickness of hamstring tendon autografts is a serious drawback in using these tendons for anterior cruciate ligament reconstruction (ACLR). In this study, we aimed to determine the correlation between the anthropometric parameters and the size of hamstring tendon autografts. Methods: In a cross-sectional study, 52 male ACLR candidates were included. The length of semitendinosus and gracilis tendons and the diameter of single, doubled, and quadrupled tendons were measured. A graft sizing block device with an incremental size change of 0.5 mm (range 4.5-12) was used to measure the tendon graft diameter. The evaluated anthropometric parameters included age, gender, height, weight, BMI, thigh length and diameter, calf length, thigh-to-calf ratio, wrist diameter, and ankle diameter. A Pearson's or Spearman's correlation coefficient test was used for evaluating the correlation of anthropometric factors with graft characteristics. Results: The mean age of the patients was 27.1 ± 6.4 years. The semitendinosus length was significantly correlated with the patient's height (r = 0.373, P = 0.007), thigh length (r = 0.364, P = 0.009), and calf length (r = 0.340, P = 0.015). The gracilis length was significantly correlated with thigh length (r = 0.278, P = 0.049). The mean quadruple diameter was 8.56 ± 1.15 mm (range 6.5-11). The quadruple diameter was significantly correlated with the thigh length (r = 0.283, P = 0.044). No other significant correlation was found between the tendons' size and evaluated anthropometric parameters. Conclusion: Thigh length was correlated with the semitendinosus length, gracilis length, and quadruple diameter. Therefore, it could be regarded as the most consistent and promising anthropometric factor in the prediction of hamstring autograft size.

Functional outcomes and quality of life after surgically treated tibial plateau fractures.

BACKGROUND: Tibial plateau fractures (TPF) are uncommon and challenging for orthopedic surgeons with controversial reported outcomes. In this study, we aimed to evaluate the functional outcomes and quality of life (QOL) of patients with surgically treated TPF. METHODS: A total of 80 consecutive patients and 82 controls participated in this case control study. The patients were all surgically treated in our tertiary center from April 2012 to April 2020. The functional outcome was evaluated using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) scale. Moreover, we used the Short Form 36 health survey (SF-36) health survey to evaluate the QOL. RESULTS: No significant difference was observed in the overall mean SF-36 score in the two groups. We found a significant positive correlation between the scores of the SF-36 and WOMAC questionnaires (r = 0.642, p < 0.001) and between the ROM and the WOMAC questionnaire score (r = 0.478, p < 0.001). Further, ROM and SF-36 showed a weak positive correlation (r = 0.248, p = 0.026). Age had a weak negative correlation with the pain subscale of SF-36 (r = - 0.255, p = 0.22), even though it was not correlated with the total score or other subscales (p > 0.05). CONCLUSION: QoL after TPF is not significantly different from that of a matched control group. Also, neither age nor BMI correlates with the QoL and functional outcome.

Hybrid Analogues of Hydrazone and Phthalimide: Design, Synthesis, In vivo, In vitro, and In silico Evaluation as Analgesic Agents.

BACKGROUND: Based on the anti-inflammatory and analgesic activity of hydrazone and phthalimide, a new series of hybrid hydrazone and phthalimide pharmacophores was prepared and evaluated as analgesic agents. METHODS: The designed ligands were synthesized by reaction of the appropriate aldehydes and 2- aminophthalimide. Analgesic, cyclooxygenase inhibitory, and cytostatic activity of prepared compounds were measured. RESULTS: All the tested ligands demonstrated significant analgesic activity. Moreover, compounds 3i and 3h were the most potent ligands in the formalin and writhing tests, respectively. Compounds 3g, 3j, and 3l were the most COX-2 selective ligands and ligand 3e was the most potent COX inhibitor with a 0.79 of COX-2 selectivity ratio. The presence of electron-withdrawing moieties with hydrogen bonding ability at the meta position was found to affect the selectivity efficiently, in which compounds 3g, 3l, and 3k showed high COX-2 selectivity, and compound 3k was the most potent one. The cytostatic activity of selected ligands demonstrated that compounds 3e, 3f, 3h, 3k, and 3m showed good analgesic and COX inhibitory activity and were less toxic than the reference drug. CONCLUSION: High therapeutic index of these ligands is one of the valuable advantages of these compounds.

Design, synthesis, and biological evaluation of new 2-(4-(methylsulfonyl)phenyl)-N-phenylimidazo[1,2-a]pyridin-3-amine as selective COX-2 inhibitors.

Cyclooxygenase (COX), which plays a role in converting arachidonic acid to inflammatory mediators, could be inhibited by non-steroidal anti-inflammatory drugs (NSAIDs). Although potent NSAIDs are available for the treatment of pain, fever, and inflammation, some side effects, such as gastrointestinal ulcers, limit the use of these medications. In recent years, selective COX-2 inhibitors with a lower incidence of adverse effects attained an important position in medicinal chemistry. In order to introduce some new potent COX-2 inhibitors, a new series of 2-(4-(methylsulfonyl)phenyl)-N-phenylimidazo[1,2-a]pyridin-3-amines was designed, synthesized, and evaluated. The docking studies performed by AutoDock Vina demonstrated that docked molecules were positioned as well as a crystallographic ligand in the COX-2 active site, and SO2Me pharmacophore was inserted into the secondary pocket of COX-2 and formed hydrogen bonds with the active site. The designed compounds were synthesized through two-step reactions. In the first step, different 1-(4-(methylsulfonyl)phenyl)-2-(phenylamino)ethan-1-one derivatives were obtained by the reaction of aniline derivatives and α-bromo-4-(methylsulfonyl)acetophenone. Then, condensation of intermediates with different 2-aminopyridines gave final compounds. Enzyme inhibition assay and formalin test were performed to evaluate the activity of these compounds. Among these compounds, 8-methyl-2-(4-(methylsulfonyl)phenyl)-N-(p-tolyl)imidazo[1,2-a]pyridin-3-amine (5n) exhibited the highest potency (IC50 = 0.07 µM) and selectivity (selectivity index = 508.6) against COX-2 enzyme (selectivity index: COX-1 IC50/COX-2 IC50). The antinociceptive activity assessment via the formalin test showed that nine derivatives (5a, 5d, 5h, 5i, 5k, 5q, 5r, 5s, and 5t) possessed significant activity compared with the control group with a p value less than 0.05.

Role of amyloid beta (25-35) neurotoxicity in the ferroptosis and necroptosis as modalities of regulated cell death in Alzheimer's disease.

Neuronal cell death as a prominent pathological feature contributes to cognitive decline and memory loss in Alzheimer's disease. We investigated the role of two forms of cell death pathways, ferroptosis and necroptosis, and their interactions following entorhinal cortex (EC) amyloidopathy. The Aß25-35 was bilaterally injected into the rat's EC, and Morris Water Maze was applied to determine spatial performance one week after Aß injection. For evaluation of ferroptosis and necroptosis involvement in Aß induced pathology, ferroptosis inhibitor, Ferrostatin (Fer-1), and necroptosis inhibitor, Necrostatin (Nec-1), were injected into the EC during training days of behavioral test. Our behavioral and histological assessment showed spatial learning and memory impairment, along with neuropathology changes such as cell survival and intracellular Aß deposits in response to EC amyloidopathy, which were ameliorated by treatment with Fer-1 or Nec-1. The expression of ferroptosis key factors GPX4 and SLC7A11 were decreased and the level of TfR was increased following Aß toxicity. Also, Necroptosis pathway related factors RIP1, RIP3, and MLKL were modulated by Aß neurotoxicity. However, application of Fer-1 or Nec-1 could inhibit the hippocampal ferroptosis and necroptosis pathways due to EC amyloidopathy. Our data also demonstrated that Aß-induced necroptosis suppressed by Fer-1, although Nec-1 had no effect on ferroptosis, indicating that ferroptosis pathway is upstream of necroptosis process in the Aß neurotoxicity. Moreover, Aß induced hippocampal mGLUR5 overexpression and reduced level of STIM1/2 recovered by Fer-1 or Nec-1. According to our findings ferroptosis and necroptosis pathways are involved in Aß neurotoxicity through modulation of mGLUR5 and STIM1/2 signaling.

Feeding Byproduct-Based Concentrates Instead of Human-Edible Feed Ingredients Increases Net Food Production and Improves Performance of High-Producing Holstein Cows.

The effect of feeding greater amounts of byproducts (BP) as a replacement for human-edible (HE) feed ingredients on nutrient intake, chewing activity, rumen fermentation, production performance, human-edible feed conversion efficiency (HeFCE) and net food production (NFP) of high-producing Holstein cows was evaluated. Twelve multiparous Holstein cows (BW = 673 ± 44, DIM = 112 ± 8 d; 48 ± 2.25 kg/d of milk; mean ± SE) were used in a replicated 3 × 3 Latin square design with 28-d periods. Each period consisted of 21 d of adaptation followed by 7 d of data collection. Treatments diets were (DM basis): (1) concentrate containing 26% byproducts (BP26; control); (2) concentrate containing 60% byproducts (BP60); and (3) concentrate containing 95% byproducts (BP95). Alfalfa hay (20% dietary DM) and corn silage (20% dietary DM) were included in all diets. Dietary concentrations of neutral detergent fiber (NDF), non-fiber carbohydrates (NFC), starch and ether extract (EE) were 32.1, 41.0, 26.14 and 3.4% (BP 26); 35.3, 36.0, 22.05 and 4.7% (BP60); and 38.2, 32.0, 17.96 and 6.1% (BP95), respectively (DM basis). Dry matter (22.07 kg/d) and NEL (35.16 Mcal/d) intakes did not differ among treatments. However, ether extract and NDF intakes increased, whereas starch intake decreased linearly as BP ingredients increasingly replaced HE feed ingredients. Eating time was not affected by dietary treatment, but ruminating and total chewing time tended to increase with increasing amounts of BP. Replacing HE with BP ingredients did not affect rumen pH. An increased proportion of BP ingredients in the diet linearly decreased propionate, isobutyrate, isovalerate and valerate concentrations in the rumen and increased acetate concentration and the acetate to propionate ratio. Replacing HE with BP ingredients did not affect milk yield. The yield of 3.5% FCM (39.12, 40.14 and 41.33 kg/d for BP26, BP60 and BP95, respectively) and fat content (2.95, 2.99 and 3.13 % for BP26, BP60 and BP95, respectively) linearly increased. Substituting BP ingredients for HE feed ingredients increased unsaturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, stearic acid, oleic acid and preformed fatty acids but decreased saturated fatty acids, palmitic acid, de novo and mixed fatty acids. Replacing HE with BP feed ingredients increased human-edible efficiency (HeFCE) for crude protein (1.06, 1.66 and 4.14 kg/kg edible for BP26, BP60 and BP95, respectively) and for energy (2.27, 3.62 and 9.22 MJ/MJ edible for BP26, BP60 and BP95, respectively) and also net food production (NFP) for crude protein (0.064, 0.52, and 1.00 kg/d for BP26, BP60, and BP95, respectively) and energy (62.8, 83.0 and 104.7 MJ/d for BP26, BP60 and BP95, respectively). Feeding byproduct-based concentrates instead of human-edible feed ingredients increase human-edible feed conversion efficiency (HeFCE), net food production (NFP) and improved the performance of high-producing Holstein cows.

Phosphonate analog of 2-oxoglutarate regulates glutamate-glutamine homeostasis and counteracts amyloid beta induced learning and memory deficits in rats.

BACKGROUND: Metabolic alteration is a mainstream concept underlying the cognitive decline in neurodegenerative disorders including Alzheimer's disease (AD). Mitochondrial enzyme α-ketoglutarate dehydrogenase complex (α-KGDHC) seems to play a dual-edged sword role in cytotoxic insult. Here, using succinyl phosphonate (SP), a specific α-KGDHC inhibitor, we aimed to examine its potential action on AD progression. METHODS: Male Wistar rats were assigned to two separate experiments. First, they were bilaterally microinjected into the dorsal CA1 area by amyloid-beta (Aß)25-35 for four consecutive days. Seven days after the last injection, they were trained to acquire Morris Water Maze (MWM) task for three successive days when they were treated with SP after each training session. In the second experiment, SP was administered 30 min after the first Aß microinjection and behavioral tests were performed one week after the last Aß administration. The activity of glutamate dehydrogenase (GDH), and glutamine synthetase (GS), as key enzymes involved in glutamate-glutamine homeostasis and histological assays were evaluated in the hippocampi. RESULTS: Our behavioral results indicated that post-training SP treatment enhanced task acquisition but did not change memory performance in Aß-treated rats. However, administration of SP at the time of Aß injection precludes the deteriorative effect of Aß and neuronal injury on both spatial learning and memory performances indicating its preventive action against Aß pathology at its early stages. Measurement of enzymes activity shows that α-KGDHC activity was reduced in the Aß treated group, and SP administration restored its activity; also, GDH and GS activities were increased and decreased respectively due to Aß, and SP reversed the action of Aß on these enzymes. CONCLUSIONS: This study proposes that SP possibly a promising therapeutic approach to improve memory impairment in AD, especially in the early phases of this disease.

The Role of the Possible Receptors and Intracellular Pathways in Protective Effect of Exogenous Anandamide in Kindling Model of Epilepsy.

In this research, the involvement of CB1 and TRPV1 receptors in the possible protective effects of anandamide were investigated in the kindling model of epilepsy. The basolateral amygdala of the rat brain was chosen to put stimulating electrodes. Semi-rapid kindling was induced by a repetitive sub-threshold stimulation for 5-9 consecutive days. There were seven groups, six of which were kindled and used for drug testing by intracerebroventricular (i.c.v.) microinjection. (i) Sham, (ii) control group received vehicles, (iii) anandamide (AEA; 100 ng/rat), (iv) capsazepine (TRPV1 antagonist; 100 ng/rat), (v) AM251 (CB1 antagonist; 100 ng/rat), (vi) AM251 + anandamide, and (vii) capsazepine + anandamide. The after-discharge duration, seizure duration, and stage five duration were measured in rats. Moreover, the expressions of the extracellular signal-regulated kinase (ERK) and the cAMP responsive element binding (CREB) proteins in the hippocampus were also studied. The anandamide-treated group showed a significant decrease in seizure scores, while no change was shown in seizure scores in the capsazepine- and AM251-treated groups compared with the control group. Co-administrations of either capsazepine + AEA or AM251 + AEA attenuated the protective effect of AEA against seizure. Furthermore, the group received AEA showed a decrease in the expressions of CREB and p-CREB possibly through the activation of the CB1 and TRPV1 receptors. Activation of CB1 and TRPV1 receptors might be involved in AEA anticonvulsant effect in kindling model of epilepsy. This effect could be due to suppression of CREB phosphorylation in hippocampal neurons.

Lentiviral Expression of Rabies Virus Glycoprotein in the Rat Hippocampus Strengthens Synaptic Plasticity.

Rabies virus (RABV) is a neurotropic virus exclusively infecting neurons in the central nervous system. RABV encodes five proteins. Among them, the viral glycoprotein (RVG) plays a key role in viral entry into neurons and rabies pathogenesis. It was shown that the nature of the C-terminus of the RABV G protein, which possesses a PDZ-binding motif (PBM), modulates the virulence of the RABV strain. The neuronal protein partners recruited by this PBM may alter host cell function. This study was conducted to investigate the effect of RVG on synaptic function in the hippocampal dentate gyrus (DG) of rat. Two µl (108 T.U./ml) of the lentiviral vector containing RVG gene was injected into the DG of rat hippocampus. After 2 weeks, the rat's brain was cross-sectioned and RVG-expressing cells were detected by fluorescent microscopy. Hippocampal synaptic activity of the infected rats was then examined by recording the local field potentials from DG after stimulation of the perforant pathway. Short-term synaptic plasticity was also assessed by double pulse stimulation. Expression of RVG in DG increased long-term potentiation population spikes (LTP-PS), whereas no facilitation of LTP-PS was found in neurons expressing δRVG (deleted PBM). Furthermore, RVG and δRVG strengthened paired-pulse facilitation. Heterosynaptic long-term depression (LTD) in the DG was significantly blocked in RVG-expressing group compared to the control group. This blockade was dependent to PBM motif as rats expressing δRVG in the DG-expressed LTD comparable to the RVG group. Our data demonstrate that RVG expression facilitates both short- and long-term synaptic plasticity in the DG indicating that it may involve both pre- and postsynaptic mechanisms to alter synaptic function. Further studies are needed to elucidate the underlying mechanisms.

Group I metabotropic glutamate receptors contribute to the antiepileptic effect of electrical stimulation in hippocampal CA1 pyramidal neurons.

Low-frequency deep brain stimulation (LFS) inhibits neuronal hyperexcitability during epilepsy. Accordingly, the use of LFS as a treatment method for patients with drug-resistant epilepsy has been proposed. However, the LFS antiepileptic mechanisms are not fully understood. Here, the role of metabotropic glutamate receptors group I (mGluR I) in LFS inhibitory action on epileptiform activity (EA) was investigated. EA was induced by increasing the K+ concentration in artificial cerebrospinal fluid (ACSF) up to 12 mM in hippocampal slices of male Wistar rats. LFS (1 Hz, 900 pulses) was delivered to the bundles of Schaffer collaterals at the beginning of EA. The excitability of CA1 pyramidal neurons was assayed by intracellular whole-cell recording. Applying LFS reduced the firing frequency during EA and substantially moved the membrane potential toward repolarization after a high-K+ ACSF washout. In addition, LFS attenuated the EA-generated neuronal hyperexcitability. A blockade of both mGluR 1 and mGluR 5 prevented the inhibitory action of LFS on EA-generated neuronal hyperexcitability. Activation of mGluR I mimicked the LFS effects and had similar inhibitory action on excitability of CA1 pyramidal neurons following EA. However, mGluR I agonist's antiepileptic action was not as strong as LFS. The observed LFS effects were significantly attenuated in the presence of a PKC inhibitor. Altogether, the LFS' inhibitory action on neuronal hyperexcitability following EA relies, in part, on the activity of mGluR I and a PKC-related signaling pathway.

High-performance thin-layer chromatography fingerprinting and anti-inflammatory and antinociceptive activities of Pyracantha coccinea M.Roem.: A laboratory-based study.

This study aimed to investigate the high-performance thin-layer chromatography (HPTLC) fingerprinting and in-vivo anti-inflammatory and antinociceptive activities of different leaf extracts (ethanolic extract, n-hexane, chloroform, and ethyl acetate) of Pyracantha coccinea M.Roem. plant. A total of one hundred and twenty-four Wistar rats for anti-inflammatory and antinociceptive tests (carrageenan and formalin tests, respectively) were treated with two doses of the ethanolic extract (100 and 300 mg/kg), two doses of other plant fractions (30 and 100 mg/kg), Diclofenac (25 mg/kg) as the positive control, and normal saline as the negative control group, by oral gavage route. HPTLC fingerprinting is used for assay of terpenoids, flavonoids, alkaloids, and antioxidant activity. Treatment of the animal with the ethanolic extract at doses of 100 and 300 mg/kg, both ethyl acetate and chloroform fractions at the dose of 30 mg/kg and 100 mg/kg decreased the pain score in the formalin test and paw edema caused by carrageenan relative to control group significantly. Moreover, these extracts reported the highest amounts of flavonoid contents. In conclusion, phytochemicals present in Pyracantha coccinea M.Roem. leaves have anti-inflammatory and antinociceptive activities. Future studies are needed to identify the compounds with the anti-inflammatory and antinociceptive potential present in the plant.