The neuroprotective effect of Diosgenin in the rat Valproic acid model of autism.

BACKGROUND AND AIM: Autism spectrum disorder (ASD) is a neurodevelopmental disorder with two core behavioral symptoms restricted/repetitive behavior and social-communication deficit. The unknown etiology of ASD makes it difficult to identify potential treatments. Valproic acid (VPA) is an anticonvulsant drug with teratogenic effects during pregnancy in humans and rodents. Prenatal exposure to VPA induces autism-like behavior in both humans and rodents. This study aimed to investigate the protective effects of Diosgenin in prenatal Valproic acid-induced autism in rats. METHOD: pregnant Wister female rats were given a single intraperitoneal injection of VPA (600 mg/kg, i.p.) on gestational day 12.5. The male offspring were given oral Dios (40 mg/kg, p.o.) or Carboxymethyl cellulose (5 mg/kg, p.o.) for 30 days starting from postnatal day 23. On postnatal day 52, behavioral tests were done. Additionally, biochemical assessments for oxidative stress markers were carried out on postnatal day 60. Further, histological evaluations were performed on the prefrontal tissue by Nissl staining and Immunohistofluorescence. RESULTS: The VPA-exposed rats showed increased anxiety-like behavior in the elevated plus maze (EPM). They also demonstrated repetitive and grooming behaviors in the marble burying test (MBT) and self-grooming test. Social interaction was reduced, and they had difficulty detecting the novel object in the novel object recognition (NOR) test. Also, VPA-treated rats have shown higher levels of oxidative stress malondialdehyde (MDA) and lower GPX, TAC, and superoxide dismutase (SOD) levels. Furthermore, the number of neurons decreased and the ERK signaling pathway upregulated in the prefrontal cortex (PFC). On the other hand, treatment with Dios restored the behavioral consequences, lowered oxidative stress, and death of neurons, and rescued the overly activated ERK1/2 signaling in the prefrontal cortex. CONCLUSION: Chronic treatment with Dios restored the behavioral, biochemical, and histological abnormalities caused by prenatal VPA exposure.

Applications of magnetic resonance spectroscopy in diagnosis of neurodegenerative diseases: A systematic review.

Background: Magnetic resonance spectroscopy (MRS) is an imaging technique used to measure metabolic changes in the tissue. Due to the lack of evidence, MRS is not a priority in diagnosing neurodegenerative diseases because it is a relatively specialized technique that requires specialized equipment and expertise to perform and interpret. This systematic review aimed to present a comprehensive collection of MRS results in the most common neurodegenerative diseases. Methods: A systematic search of four electronic databases (PubMed, Scopus, Web of Science, and ScienceDirect) was conducted for studies published from 2017 to 2022. Articles that provided specific biomarker levels were selected, and studies that assessed the diseases via treatment, featured MRS applying nuclei other than 1H, or compared different animal models were excluded. Results: A total of 25 articles, plus 3 articles for extra information in the introduction, were included in this review. Six of the most common neurodegenerative diseases, i.e., Alzheimer's and Parkinson's disease, Huntington chorea, ataxia, multiple sclerosis (MS), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP) were examined via MRS. The changes and ratios of N-acetylaspartate (NAA) could be seen in all of these disorders, which could lead to early diagnosis. However, there are other biomarkers, such as Cr and Chon, which can give convincing results. Discussion: This observational study is the first synthesis of the latest evidence proving metabolic changes during neurodegenerative diseases using MRS as a diagnosis method. The findings indicate decreased N-acetylaspartate (NAA) and NAA/Cr ratios in Alzheimer's disease (AD), Parkinson's disease (PD), ataxias, and MS, reflecting neuronal loss or dysfunction. Increased choline and myo-inositol were noted in some studies, suggesting cell membrane turnover and neuroinflammation. Findings were less consistent for other metabolites like glutamate and gamma-aminobutyric acid. However, there were limitations due to the lack of studies on the same volumes of interest (VOIs) and the small number of participants.

Improving Accuracy of Intravoxel Incoherent Motion Reconstruction using Kalman Filter in Combination with Neural Networks: A Simulation Study.

Background: The intravoxel Incoherent Motion (IVIM) model extracts perfusion map and diffusion coefficient map using diffusion-weighted imaging. The main limitation of this model is inaccuracy in the presence of noise. Objective: This study aims to improve the accuracy of IVIM output parameters. Material and Methods: In this simulated and analytical study, the Kalman filter is applied to reject artifact and measurement noise. The proposed method purifies the diffusion coefficient from blood motion and noise, and then an artificial neural network is deployed in estimating perfusion parameters. Results: Based on the T-test results, however, the estimated parameters of the conventional method were significantly different from actual values, those of the proposed method were not substantially different from actual. The accuracy of f and D* also was improved by using Artificial Neural Network (ANN) and their bias was minimized to 4% and 12%, respectively. Conclusion: The proposed method outperforms the conventional method and is a promising technique, leading to reproducible and valid maps of D, f, and D*.

Static magnetic field enhances the bone remodelling capacity of human demineralized bone matrix in a rat animal model of cranial bone defects.

The regeneration of bone defects that exceed 2 cm is a challenge for the human body, necessitating interventional therapies. Demineralized bone matrices (DBM) derived from biological tissues have been employed for bone regeneration and possess notable osteoinductive and osteoconductive characteristics. Nevertheless, their efficiency in regenerating critically sized injuries is limited, and therefore additional signaling cues are required. Thanks to the piezoelectric properties of the bone, external physical stimulation is shown to accelerate tissue healing. We have implanted human DBM in critically sized cranial bone defects in rat animal models and exposed them to an external magnetic field (1 T) to enhance endogenous bone formation. Our in vitro experiments showed the superior cytocompatibility of DBM compared to cell culture plates. Furthermore, alkaline phosphatase activity after 14 days and Alizarin red staining at 28 days demonstrated differentiation of rat bone marrow mesenchymal stem cells into bone lineage on DBM. Computer tomography images together with histological analyses showed that implanting DBM in the injured rats significantly enhanced bone regeneration. Notably, combining DBM transplantation with a 2 h daily exposure to a 1 T magnetic field for 2 weeks (day 7 to 21 post-surgery) significantly improved bone regeneration compared to DBM transplantation alone. This research indicates that utilizing external magnetic stimulation significantly enhances the potential of bone allografts to regenerate critically sized bone defects.

Neurochemical Ameliorating of the Hippocampus in Dyslipidemic Alzheimer Patients Following Silymarin; a Double-Blind Placebo-Controlled Randomized Clinical Trial.

Background: Amyloid-beta (Aß) production is a normal physiological process, and an imbalance in Aß production/excretion rate is the basis of the plaque load increase in AD. LRP1 is involved in both central clearance of Aß from the CNS and transport of Aß toward peripheral organs. In this study, the effect of silymarin combination compared to rosuvastatin and placebo on neuro-metabolites and serum levels of LRP1 and Aß1-42 proteins and oxidative stress enzymes and lipid and cognitive tests of Iranian AD patients. Methods: In this double-blind placebo-controlled study, thirty-six mild AD patients were divided into groups (n=12) of silymarin 140mg, placebo, and rosuvastatin 10mg. Medications were administered 3 times a day for 6 months. Clinical tests, lipid profile (TG, HDL, TC, and LDL), Aß1-42, and LRP1 markers were measured at the beginning and end of the intervention. Magnetic resonance spectroscopy (MRS) was used to measure metabolites. Using SPSS software a one-way ANOVA test was used to compare the means of the quantitative variables and Pearson and Spearman's correlations to measure the correlation. GraphPad Prism software was used for drawing graphs. P < 0.05 was considered a significant. Results: The levels of LRP1 and Aß1-42 in the silymarin group were significantly increased compared to the other groups (P < 0.05). NAA/mI in the silymarin group had a significant increase compared to both placebo and rosuvastatin groups (P < 0.05). Right and left hippocampal mI/Cr directly correlated with TG (r = 0.603, P = 0.003 and r = 0.595, P = 0.004, respectively). NAA/Cr of the right and left hippocampus was inversely related to TG (r = -0.511, P = 0.0033, and r = -0.532, P = 0.0021, respectively). NAA/Cr and NAA/mI of bilateral hippocampi directly correlated with HDL (P < 0.05). An inverse correlation was observed between the Aß1-42 and mI/Cr of the right and left hippocampus (r = -0.661, P = 0.000 and r = -0.638, P = 0.000, respectively). Conclusion: Donepezil and silymarin improved lipid profile associated with increased NAA/Cr, and decreased mI/Cr, in AD patients. Biomarker NAA/mI can be clinically significant in examining AD pathology. Measurement of the lipid factors and neurometabolites can be a suitable method for monitoring this disease.

Intra-Accumbal D1- But not D2-Like Dopamine Receptor Antagonism Reverses the Inhibitory Effects of Cannabidiol on Extinction and Reinstatement of Methamphetamine Seeking Behavior in Rats.

Introduction: Methamphetamine (METH) is an addictive psychostimulant that facilitates dopamine transmission to the nucleus accumbens (NAc), resulting in alterations in the mesocorticolimbic brain regions. Cannabidiol (CBD) is considered the second most abundant component of cannabis and is believed to decrease the METH effects. Reversing psychostimulant-induced abnormalities in the mesolimbic dopamine system is the main mechanism for this effect. Various other mechanisms have been proposed: increasing endocannabinoid system activity and modulating gamma-aminobutyric acid (GABA) and glutamate neurons in NAc. However, the exact CBD action mechanisms in reducing drug addiction and relapse vulnerability remain unclear. Methods and Results: The present study aimed to investigate the effects of intracerebroventricular (ICV) administrating 5, 10, and 50 µg/5 µL CBD solutions on the extinction period and reinstatement phase of a METH-induced conditioned place preference. This research also aimed to examine the NAc D1-like dopamine receptor (D1R) and D2-like dopamine receptor (D2R) roles in the effects of CBD on these phases, as mentioned earlier, using SCH23390 and sulpiride microinjections as an antagonist of D1R and D2R. The obtained results showed that microinjection of CBD (10 and 50 µg/5 µL, ICV) suppressed the METH-induced reinstatement and significantly decreased mean extinction latency in treated groups compared to both vehicles and/or untreated control groups. In addition, the results demonstrated that administrating intra-accumbal SCH23390 (1 and 4 µg/0.5 µL saline) reversed the inhibitory effects of CBD on extinction and reinstatement phases while different doses of sulpiride (0.25, 1, and 4 µg/0.5 µL; dimethyl sulfoxide 12%) could not alter the CBD effects. Conclusions: In summary, this study showed that CBD made shorter extinction latencies and suppressed the METH reinstatement, in part, by interacting with D1R but not D2R in the NAc.

Silk fibroin and Nettle extract promote wound healing in a rat model: A histological and morphometrical study.

INTRODUCTION: Considering the anti-inflammatory, antimicrobial ability, and antioxidant effects besides stimulating ability of silk fibroin (SF) in cell migration and proliferation of Nettle, the current study aimed to investigate the effect of Nettle leaf extract (NLE) and SF on histology, morphometrical parameters and apoptosis on the wound in the rat model. MATERIALS AND METHODS: Wistar rats are divided into 5 groups, including 1-control (rats with healthy skin and no treatment); 2-wound (without any treatment); 3-SF (administration of silk fibroin solution for 14 consecutive days); 4- Nettle (administration of Nettle ointment for 14 consecutive days), and 5- Eucerin group (administration of Eucerin substance for 14 consecutive days) and then assessed wound area by photography, angiogenesis, inflammation, and thickness of epidermis using hematoxylin and eosin (H&E) staining, collagen deposition, and structure of dermis layers evaluated by Masson's trichrome staining and the apoptosis index determined by tunnel assay on days 7, 14 and 21. RESULTS: photographic illustrations showed that the wound surface environment on the seventh day in group 4 was significantly different from group 2 (p < 0.002). The rate of wound healing on the fourteenth day was higher in groups 3 and 4 than in group 2 (p < 0.001). Also, at this time, group 4 was significantly different from group 3 and group 5 (p = 0.003 and p = 0.000, respectively). There was a significant difference in epidermal thickness between the wound group and other experimental groups (p < 0.05). The number of apoptotic cells at the wound edges on the seventh day in both group 3 and group 4 had a significant decrease compared to other groups of wounds (p = 0.000), but there was a significant increase on the fourteenth day. Also, on the 21st day, a significant decrease in apoptotic cells was observed in both group 3 and group 4 compared to other wound groups (p = 0.000). DISCUSSION AND CONCLUSION: Nettle and SF maintain cell homeostasis and accelerate wound closure by reducing cell apoptosis and enhancing cell proliferation on the seventh day, but by increasing the apoptosis of fibroblast cells on the fourteenth day, they lead to remodeling and keratinocytes migration to epidermis formation. Increased apoptosis also seems to be one of the pathophysiological mechanisms to prevent the formation of keloid and hypertrophic scar tissue. SF and Nettle extract, by increasing cell proliferation and migration of different cell types to the site of injury, control the remodeling process by inducing and regulating apoptosis in the first two weeks of wound healing and accelerating the process of collagen deposition and epithelialization.

Biomimetic Organic-Inorganic Nanocomposite Scaffolds to Regenerate Cranial Bone Defects in a Rat Animal Model.

While bone regenerates itself after an injury, a critical bone defect requires external interventions. Engineering approaches to restore bone provide a temporary scaffold to support the damage and provide beneficial biological cues for bone repair. Biomimetically generated scaffolds replicate the naturally occurring phenomena in bone regeneration. In this study, a gelatin-calcium phosphate nanocomposite was synthesized by an efficient and cost-effective double-diffusion biomimetic approach. Calcium and phosphate ions are impregnated in the gelatin, mimicking the natural bone mineralization process. Glutaraldehyde from 0.5 to 2 w/v% was used for gelatin cross-linking and mechanical properties of the scaffold, and its biological support for rat bone marrow mesenchymal stromal cells was analyzed. Analysis of scanning electron microscopy images of the nanocomposite scaffolds and Fourier transform infrared (FTIR) and X-ray diffraction (XRD) characterizations of these scaffolds confirmed precipitation of calcium phosphates in the gelatin. Moreover, lysozyme degradation assay showed that scaffold degradation reversely correlates with the concentration of the cross-linking agent. Increased glutaraldehyde concentrations enhanced the mechanical properties of the scaffolds, bringing them closer to those of cancellous bone. Rat bone marrow mesenchymal stromal cells maintained their viability on these scaffolds compared to standard cell culture plates. In addition, these cells showed differentiation into bone lineage as evaluated from alkaline phosphatase activity up to 21 days and Alizarin red staining of the cells over 28 days. Eventually, scaffolds were implanted in a cranial defect in a rat animal model with a 5 mm diameter. Bone regeneration was studied over 90 days. Analysis of histological sections of the injury and computer tomography images revealed that nanocomposite scaffolds cross-linked with 1% w/v glutaraldehyde provide the maximum bone regeneration after 90 days. Collectively, our data show that nanocomposite scaffolds developed here provide effective regeneration for extensive bone defects in vivo.

The Roles of Serotonin in Neuropsychiatric Disorders.

The serotonergic system extends throughout the central nervous system (CNS) and the gastrointestinal (GI) tract. In the CNS, serotonin (5-HT, 5-hydroxytryptamine) modulates a broad spectrum of functions, including mood, cognition, anxiety, learning, memory, reward processing, and sleep. These processes are mediated through 5-HT binding to 5-HT receptors (5-HTRs), are classified into seven distinct groups. Deficits in the serotonergic system can result in various pathological conditions, particularly depression, schizophrenia, mood disorders, and autism. In this review, we outlined the complexity of serotonergic modulation of physiologic and pathologic processes. Moreover, we provided experimental and clinical evidence of 5-HT's involvement in neuropsychiatric disorders and discussed the molecular mechanisms that underlie these illnesses and contribute to the new therapies.

The Relationship Between Brain Metabolites Alterations and Neuropsychological Deficits in Patients with Methamphetamine Use Disorder: A Proton Magnetic Resonance Spectroscopy Study.

INTRODUCTION: Chronic use of methamphetamine induces neuropsychological deficits and neurochemical changes in frontostriatal regions. This study aimed to examine the relationship between brain metabolites alterations in frontostriatal regions and neuropsychological deficits in patients with methamphetamine use disorder. METHOD: A total of 30 methamphetamine users and 20 control participants were selected and a battery of standardized executive function, attention, and memory tasks, including the Wisconsin Card Sorting Test, Stroop Test, and Wechsler Memory Scale, was administered to them. Proton-Magnetic resonance spectroscopy (H-MRS) of N-Acetylaspartate/Creatine (NAA/Cr), Choline/Creatine (Cho/Cr), and glutamate + glutamine/creatine (Glx/Cr) in dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and basal ganglia (BG) were also undertaken. RESULTS: Current findings indicated that there were significant differences between two groups in metabolite ratios including NAA/Cr, Cho/Cr, and Glx/Cr in three areas, except for Glx/Cr in BG. Moreover, compared to healthy controls, methamphetamine users showed poorer performance in all neuropsychological tests. Finally, a significant relationship was found between regional metabolites alterations, particularly in the ACC, and neuropsychological deficits in methamphetamine users. CONCLUSIONS: In addition to neurochemical changes and neuropsychological deficits in patients with methamphetamine use disorder, current results highlighted the relationship between these changes in DLPFC, ACC, and BG with cognitive deficits in methamphetamine users.

Cannabidiol impairs the rewarding effects of methamphetamine: Involvement of dopaminergic receptors in the nucleus accumbens.

Cannabidiol, as component of cannabis, can potentially hinder the rewarding impact of drug abuse; however, its mechanism is ambiguous. Moreover, the nucleus accumbens (NAc), as a key area in the reward circuit, extensively receives dopaminergic projections from the ventral tegmentum area. To elucidate the role of accumbal D1 and D2 dopamine receptor families in Cannabidiol's inhibitory impact on the acquisition and expression phases of methamphetamine (MET), the conditioned place preference (CPP) procedure as a common method to assay reward characteristics of drugs was carried out. Six groups of rats were treated by various doses of SCH23390 or Sulpiride (0.25, 1, and 4 µg/0.5 µL) in the NAc as D1 or D2 dopamine receptor family antagonists, respectively, prior to infusion of Cannabidiol (10 µg/5 µL) in the lateral ventricle (LV) over conditioning phase in the acquisition experiments. In the second step of the study, animals received SCH23390 or Sulpiride in the NAc before Cannabidiol (50 µg/5 µL) infusion into the LV in the expression phase of MET to illuminate the influence of SCH23390 or Sulpiride on the inhibitory impact of Cannabidiol on the expression of MET-induced CPP. Intra-NAc administration of either SCH23390 or Sulpiride impaired Cannabidiol's suppressive impact on the expression phase, while just Sulpiride could suppress the Cannabidiol's impact on the acquisition phase of the MET-induced CPP. Also, the inhibitory impact of Sulpiride was stranger in both phases of MET reward. It seems that Cannabidiol prevents the expression and acquisition phases of MET-induced CPP partly through the dopaminergic system in the NAc.

Hippocampal D1-but not D2-like dopamine receptors modulate the phosphorylation of ERK in food deprivation-induced reinstatement of morphine in extinguished rats.

Reinstatement to drug abuse is the most challenging issue in the treatment of addiction. Thus, knowledge of the involved neurobiological mechanisms of reinstatement is a fundamental necessity. There is substantial and crucial evidence that dopamine is implicated in motivational processes such as relapse. Our behavioral results reported that the administration of dopamine receptor antagonists inhibited reinstatement of morphine in food-deprived rats. Previous studies have indicated that the ERK pathway plays a critical role in the cellular responses to stress and reward. Therefore, the purpose of the current study was to evaluate the effect of intra-dentate gyrus administration of dopamine receptor antagonists on the phosphorylation of hippocampal ERK in the reinstatement phase of morphine reward in food-deprived rats. All groups of animals passed conditioned place preference and were bilaterally given different doses of D1- or D2-like dopamine compounds (0.25, 1 and 4 µg/0.5 µl) into the dentate gyrus. Immediately after the reinstatement phase, each animal was euthanized, and the hippocampi were immediately dissected. Then, the p-ERK/ERK ratio was evaluated using Western blot analysis. The principal findings in this study demonstrated that intra-dentate gyrus administration of the highest dose of the D1-like receptor antagonist could enhance the hippocampal p-ERK/ERK ratio in food-deprived rats while the D2-Like receptor antagonist failed to change this ratio.

Time-Dependent Changes in the Serum Levels of Neurobiochemical Factors After Acute Methadone Overdose in Adolescent Male Rat.

Acute methadone toxicity is a major public health concern which has adverse effects on brain tissue and results in recurrent or delayed respiratory arrest. Our study aimed to investigate the time-dependent changes in several serum biochemical markers of brain damage, spatial working memory, and the brain tissue following acute methadone overdose. Adolescent male rats underwent an intraperitoneal (i.p.) injection of 15 mg/kg methadone. In case of apnea occurrence, resuscitation was performed by a ventilatory pump and administrating naloxone (2 mg/kg; i.p.). The animals were classified into groups of treated rats; methadone and naloxone-Apnea (M/N-Apnea), M/N-Sedate, Methadone, Naloxone, and control (saline) groups. The serum levels of S100B, neuron-specific enolase (NSE), myelin basic protein factors, and (Lactate/Pyruvate) L/P ratio were evaluated at the time-points of 6, 24, and 48 h (h). We found that the alterations of S100B and L/P ratio were considerable in the M/N-Apnea and Methadone groups from the early hours post-methadone overdose, while NSE serum levels elevation was observed only in M/N-Apnea group with a delay at 48 h. Further, we assessed the spatial working memory (Y-maze test), morphological changes, and neuronal loss. The impaired spontaneous alternation behavior was detected in the M/N-Apnea groups on days 5 and 10 post-methadone overdose. The morphological changes of neurons and the neuronal loss were detectable in the CA1, striatum, and cerebellum regions, which were pronounced in both M/N-Apnea and Methadone groups. Together, our findings suggest that alterations in the serum levels of S100B and NSE factors as well as L/P ratio could be induced by methadone overdose with the presence or absence of apnea before the memory impairment and tissue injury in adolescent male rats.

The epigenetic alterations of human sperm cells caused by heroin use disorder.

The molecular mechanisms of drug use on sexual health are largely unknown. We investigated, the relationship between heroin use disorder and epigenetic factors influencing histone acetylation in sperm cells. The volunteers included twenty-four 20- to 50-year-old men with a normal spermogram who did not consume any drugs and twenty-four age- to BMI-matched men who consume only the drug heroin for more than last four months. HDAC1 and HDAC11 mRNA expression levels in spermatozoa and miR-34c-5p and miR-125b-5p expression levels in seminal plasma were measured. The heroin-user group showed significantly increased white blood cell counts and decreased sperm motility and survival rates (8.61 ± 1.73, 21.50 ± 3.11, 69.90 ± 4.69 respectively) as compared to the control group (1.49 ± 0.32, 38.82 ± 3.05, 87.50 ± 0.99 respectively) (p ≤ .001). An increase in DNA fragmentation index (DFI) (heroin-user group: 41.93 ± 6.59% and control group: 10.14 ± 1.43%, p = .003), a change in frequency of HDAC1 (heroin-user group: 1.69 ± 0.55 and control group: 0.45 ± 0.14, p = .045) and HDAC11 (heroin-user group: 0.29 ± 0.13 and control group: 2.36 ± 0.76, p = .019) in spermatozoa and a significant decrease in seminal miR-125b-5p abundance (heroin-user group: 0.37 ± 0.11 and control group: 1.59 ± 0.47, p = .028) were reported in heroin consumers. Heroin use can lead to male infertility by causing leukocytospermia, asthenozoospermia, DFI elevation in sperm cells and alterations in seminal RNA profile.

The Interplay of Tau Protein and ß-Amyloid: While Tauopathy Spreads More Profoundly Than Amyloidopathy, Both Processes Are Almost Equally Pathogenic.

Alzheimer's disease (AD) is a neurodegenerative disorder, in which amyloid precursor protein (APP) misprocessing and tau protein hyperphosphorylation are well-established pathogenic cascades. Despite extensive considerations, the central mediator of neuronal cell death upon AD remains under debate. Therefore, we examined the direct interplay between tauopathy and amyloidopathy processes. We employed primary culture neurons and examined pathogenic P-tau and Aß oligomers upon hypoxia treatment by immunofluorescence and immunoblotting. We observed both tauopathy and amyloidopathy processes upon the hypoxia condition. We also applied Aß1-42 or P-tau onto primary cultured neurons. We overexpressed P-tau in SH-SY5Y cells and found Aß accumulation. Furthermore, adult male rats received Aß1-42 or pathogenic P-tau in the dorsal hippocampus and were examined for 8 weeks. Learning and memory performance, as well as anxiety behaviors, were assessed by Morris water maze and elevated plus-maze tests. Both Aß1-42 and pathogenic P-tau significantly induced learning and memory deficits and enhanced anxiety behavior after treatment 2 weeks. Aß administration induced robust tauopathy distribution in the cortex, striatum, and corpus callosum as well as CA1. On the other hand, P-tau treatment developed Aß oligomers in the cortex and CA1 only. Our findings indicate that Aß1-42 and pathogenic P-tau may induce each other and cause almost identical neurotoxicity in a time-dependent manner, while tauopathy seems to be more distributable than amyloidopathy.

The blockade of D1- and D2-like dopamine receptors within the dentate gyrus attenuates food deprivation stress-induced reinstatement of morphine-extinguished conditioned place preference in rats.

The high rate of relapse to drug abuse is one of the main problems in the treatment of addiction. Stress plays an essential role in relapsing to drug abuse. The present study investigates the role of D1- and D2-like dopamine receptors in the dentate gyrus (DG) of the hippocampus on the reinstatement of morphine (5 mg/kg)-induced conditioned place preference (CPP) both by food deprivation stress (FDS) and a sub-threshold dose of morphine (0.5 mg/kg, s.c.). All the animals in this study experienced pre-test, conditioning, post-test (expression), extinction, and reinstatement phases. The CPP scores of the pre-test and post-test were compared between the groups, and a significant difference between the CPP scores of the pre- and post-test was the criterion for the induction of CPP. Extinction continued for each animal until the calculated score for two consecutive days became the same as the pre-test score. The animals received different doses of SCH-23390 or Sulpiride (0.25, 1 and 4 µg/0.5 µl vehicle), as D1- and D2-like dopamine receptor antagonists, into the DG. After the administration of the antagonists, the animals were deprived of food for 24 h. Then, on the reinstatement day, they received a sub-threshold dose of morphine and afterwards, the conditioning scores were measured. The results demonstrated that the effective doses 50% of SCH-23390 and Sulpiride on the reinstatement induced by FDS and morphine was 1.37 and 2.28 (µg/0.5 µl vehicle per side), respectively. The results also showed that both antagonists can lead to a decrease in morphine reinstatement, and this effect was in a dose-dependent manner. In conclusion, these results indicate that D1- and D2-like dopamine receptors in the DG may be a potential target for preventing relapse to drugs in stressful life conditions.

Investigation of the Relationship Between Mandibular Morphology and Upper Airway Dimensions.

INTRODUCTION: In this study, the authors aimed to perform a novel and extensive analysis, based on the most applicable correlations between the mandibular and upper airway parameters, using cone beam computed tomography across all malocclusion classes. The authors also focused on gender-dependent differences in an Iranian population. MATERIALS AND METHODS: Images were acquired from adult patients using cone beam computed tomography. The patients were classified into three groups of malocclusion classes (class I: 13 males and 27 females, class II: 13 males and 27 females, and class III: 25 males and 15 females). For each patient, 10 parameters for the mandible and 23 parameters for the pharynx, pyriform aperture, and nasal cavity were evaluated in the images. RESULTS: Pearson's correlation coefficient showed significant correlations between the mandibular morphology and upper airway dimensions in each malocclusion class. In females, the menton angle had a significant correlation with pharyngeal dimensions in all malocclusion classes. In males, the bigonial width, bicondylar width, and symphyseal height of the mandible were correlated with pharyngeal dimensions in all classes. The greatest correlation between the mandible and upper airways was observed in class III malocclusions, and the lowest correlation was observed in class I malocclusions. In addition, the mandibular parameters had relationships with the nasal cavity and pyriform aperture. CONCLUSION: It is important to consider the knowledge of the relationship between some characteristics of the mandible and airways in various clinical approaches.

Hypoxia in solid tumors: a key promoter of cancer stem cell (CSC) resistance.

PURPOSE: Cancer stem cells (CSCs) are highly tumorigenic cell types that reside within specific areas of tumor microenvironment (TME), and are endowed with self-renewal and resistance properties. Here, we aimed to discuss mechanisms involved in hypoxia-derived CSC resistance and targeting for effective cancer therapy. RESULTS: Preferential localization within hypoxic niches would help CSCs develop adaptive mechanisms, mediated through the modification of responses to various stressors and, as a result, show a more aggressive behavior. CONCLUSION: Hypoxia, in fact, serves as a multi-tasking strategy to nurture CSCs with this adaptive capacity, complexing targeted therapies.