Social hierarchy differentially influences the anxiety-like behaviors and dendritic spine density in prefrontal cortex and limbic areas in male rats.

Social hierarchy is a fundamental feature of social organization that can influence brain and emotional processing regarding social ranks. Several areas, including the medial prefrontal cortex (mPFC), the hippocampus, and the basolateral nucleus of the amygdala (BLA), are recognized to be involved in the regulation of emotional processing. However, its delicate structural correlates in brain regions are poorly understood. To address this issue, social hierarchy in home-caged sibling Wistar rats (three male rats/cage) was determined by employing a social confrontation tube test (postnatal weeks 9-12). Then, locomotor activity and anxiety-like behaviors were evaluated using an open-field test (OFT) and elevated plus-maze (EPM) at 13 weeks of age. The rapid Golgi impregnation method was conducted to quantify the spine density of the first secondary branch of the primary dendrite in 20 µm length. The results indicated that dominant rats had significantly higher anxiety-like behaviors compared to subordinates, as was evident by lower open-arm entries and time spent in the EPM and lower entries and time spent in the center of OFT. The spine density analysis revealed a significantly higher number of spines in subordinates compared to the dominant rats in dmPFC pyramidal neurons and the apical and basal dendrites of hippocampal CA1 pyramidal neurons. However, the spine density of pyramidal-like neurons in the BLA was higher in dominant rats. Our findings suggest that dominant social rank is associated with higher anxiety and differential density of the dendritic spine in the prefrontal cortex and limbic regions of the brain in male rats.

Comparative effects of the alcoholic extract of Terminalia chebula and crocin on stress­induced anxiety­like behavior and memory impairment in male rats.

Crocin and Terminalia chebula (T. chebula) were proven to have neuroprotective effects. In this study, we evaluated the preventive effects of crocin and alcoholic extract of the T. chebula alone and in combination to examine their efficacy against chronic restraint stress (CRS)­induced cognitive impairment, anxiety­like behaviors, hippocampal synaptic plasticity deficit as well as neuronal arborization damage in the hippocampal CA1 neurons. Over 14 consecutive days, animals received crocin, T. chebula, or their combination (5 min before CRS). The elevated plus­maze results showed that crocin and T. chebula alone and in combination treatment significantly increased the time spent in open arms, percentage of open arm entries, and head dipping as compared with the CRS group. Barnes maze results showed that administration of crocin and T. chebula alone and their combination significantly improves spatial memory indicators such as distance traveled, latency time to achieving the target hole, and the number of errors when compared to the CRS group. These learning deficits in CRS animals correlated with a reduction of long-term potentiation (LTP) in hippocampal CA1 synapses, which both T. chebula and crocin treatment improved field excitatory postsynaptic potentials (fEPSP) amplitude and fEPSP slope reduction induced by CRS. Golgi­Cox staining showed that T. chebula and crocin treatment increased the number of dendrites and soma arbors in the CA1 neurons compared with the CRS group. Our results suggest that both T. chebula and crocin attenuated CRS­induced anxiety­like behaviors, memory impairment, and synaptic plasticity loss in hippocampal CA1 neurons. We found no significant difference between single treatments of T. chebula or crocin and their combination in protecting CRS­induced anxiety­like behaviors, memory impairment, and synaptic plasticity loss in hippocampal CA1 neurons.

Alteration in social interaction and tactile discrimination of juvenile autistic-like rats following tactile stimulation and whisker deprivation.

INTRODUCTION: Autism spectrum disorder is a developmental disorder that can affect sensory-motor behaviors in the valproic acid (Val) rodent model of autism. Although whisker deprivation (WD) induces plastic changes in the cortical neurons, tactile stimulation (TS) during the neonatal period may reverse it. Here, we investigate the interaction effects of TS and WD on behavioral and histologic features of barrel cortex neurons in juvenile Val-treated. METHODS: Control (CTL, CTL-TS, CTL-WD, and CTL-TS-WD groups) and Val-treated (Val, Val-TS, Val-WD, and Val-TS-WD groups) rats of both sexes were subjected to behavioral tests of social interaction, and novel texture recognition, and Nissl staining. The TS groups were exposed to sensory stimulation for 15 min, three times/day; moreover, all whiskers in the WD groups were trimmed every other day from postnatal days 1 to 21. RESULTS: Both prenatal valproic acid administration and postnatal WD decreased the rats' performance percentage of the Val and CTL-WD groups of both sexes compared with the CTL groups in the social interaction and texture discrimination tests. Following TS, the performance of the Val-TS-WD group increased significantly compared to the Val group (p < .05), whereas the performance of the CTL-TS-WD group rescued to the CTL group. Nissl staining results also revealed the neuron degeneration percentage in the barrel field area of the Val and CTL-WD groups was increased significantly (p < .05) compared with the CTL group. In this regard, TS decreased the neuron degeneration percentage of the Val-TS-WD and the CTL-TS-WD groups, compared with the CTL group, significantly (p < .05). CONCLUSION: TS in juvenile male and female rats can act as a modulator and compensate for the behavioral and histological consequences of WD and prenatal valproic acid exposure.

L-carnitine attenuates acoustic startle reflex dysfunction in adult male rats exposed to mancozeb.

The fungicide mancozeb increases oxygen-free radicals in the central nervous system. As an antioxidant, L-carnitine protects DNA and cell membranes from damage caused by oxygen-free radicals. The present study investigated how L-carnitine affected the acoustic startle response (ASR) in rats exposed to mancozeb. In this experimental study, male Wistar rats were gavaged orally with mancozeb (500, 1000, and 2000 mg/kg), L-carnitine (100, 200, and 400 mg/kg), or L-carnitine (200 mg/kg) + mancozeb (500 mg/kg) three times in 1 week. In the sham group, saline (0.9%, 10 mL/kg) was gavaged at a volume equivalent to that of the drugs. The control group did not receive any treatment. The results showed that locomotor activity and the percentage of prepulse inhibition in the mancozeb groups decreased compared to the sham group while these parameters increased in the L-carnitine group (200 mg/kg) compared to sham rats. In conclusion, mancozeb may increase the risk factor for cognitive diseases such as schizophrenia in people exposed to it while pretreatment with L-carnitine can attenuate the toxic effect.

Left Barrel Cortical Neurons Activity following Transplantation of Stem Cells into Right Lesioned-Barrel Cortex in Rats.

OBJECTIVE: Stem cells (SCs) can improve the functional defects of brain injury. Rodents use their whiskers to get tactile information from their surroundings. The aim of this study was to investigate whether the transplantation of SCs into the lesioned barrel cortex can help neuronal function in the contralateral cortex. MATERIALS AND METHODS: Sixteen male Wistar rats (200-230 g) were used in this experimental study. We induced a mechanical lesion in the right barrel cortex area of rats by removing this area by a 3 mm skin punch. Four groups containing one intact group of rats: group 1: control, and three lesion groups, group 2: lesion+un-differentiated dental pulp SCs (U-DPSCs), group 3: lesion+differentiated dental pulp SCs (D-DPSCs), and group 4: cell medium (vehicle) that were injected in the lesion area. Three weeks after transplantation of SCs or cell medium, the rats' responses of left barrel cortical neurons to controlled deflections of right whiskers were recorded by using the extracellular single-unit recordings technique. RESULTS: The results showed that the neural spontaneous activity and response magnitude of intact barrel cortex neurons in the lesion group decreased significantly (P<0.05) compared to the control group while ON and OFF responses were improved in the D-DPSCs (P<0.001) group compared to the vehicle group three weeks after transplantation. CONCLUSION: Transplantation of dental pulp mesenchymal SCs significantly improved the neural responses of the left barrel cortex that was depressed in the vehicle group.

Sex difference in cognitive behavioral alterations and barrel cortex neuronal responses in rats exposed prenatally to valproic acid under continuous environmental enrichment.

Autism spectrum disorder is a developmental disorder that can affect social interactions and sensory-motor behaviors. The present study investigates the effect of environmental enrichment (EE) on behavioral alterations and neuron responses associated with the barrel cortex of young adult female and male rats exposed prenatally to valproic acid (VPA). Pregnant female rats were pretreated with either saline or VPA (500 mg/kg, IP) on day 12.5 of gestation. Male and female pups were exposed to either EE or standard-setting (non-enrichment) conditions for 1 month (between postnatal day [PND] 30 and 63-65) and were divided into non-EE (control), EE, VPA, and VPA + EE groups. Three-chamber sociability and social novelty, acoustic startle reflex, and texture discrimination tests were conducted on PND 62. Responses of barrel cortex neurons of male pups were evaluated using the extracellular single-unit recording technique on PND 63-65. Results showed that the performance of rats of both sexes in social interactions, texture discrimination tasks, and acoustic startle reflex significantly decreased in the VPA groups compared with the control rats (P < 0.05). In this regard, EE attenuated the altered deficit performance observed in the VPA animals compared with the VPA-EE animals (P < 0.05). The performance of females was better than males in the discrimination tasks and acoustic startle reflex. In contrast, males were better than females in the three-chamber social interaction test. Additionally, the excitatory receptive field response magnitude of the barrel cortex neurons in the VPA + EE group increased compared with the VPA group (P < 0.05). The results suggest that continuous EE can attenuate cognitive function disturbances in autistic-like rats and, at least at the behavioral level, the effects depend on sex.

The potential impact of Covid-19 on CNS and psychiatric sequels.

Due to its high prevalence and fatality, the current Severe Acute Respiratory Syndrome-coronavirus-2 (SARS-CoV-2) virus, which first emerged in China in 2019, quickly spread around the world and immediately became a serious global health concern. Although respiratory issues were initially the most prominent symptom of coronavirus disease 2019 (COVID-19), it became obvious rapidly that COVID-19, like many other coronavirus family members, could affect the central nervous system (CNS). During the pandemic, CNS involvement expressed itself in a variety of forms, including insomnia, anosmia, headaches, encephalopathies, encephalitis, cerebrovascular accidents, cognitive and memory impairment, and increased psychiatric disorders. Almost everyone who has been infected has at least one of these neurological symptoms, demonstrating that the virus has a high ability to impact the CNS. As the coronavirus pandemic passes its second year, the manifestations it can cause in the long run, such as its psychological sequels, have not yet been thoroughly studied. Given the high importance of this issue in today's society and due to the lack of reliable knowledge about the COVID-19 landscape on psychiatric disorders, we intend to investigate coronavirus's possible effect on mental illnesses based on available literature. Because the majority of the psychological effects of the coronavirus can continue for a long period after the pandemic ends, our research can give insight into potential psychiatric sequels associated with COVID-19.

Chronically Pre-treatment of Pistachio Alters the Morphology of CA1 Hippocampus Neurons Following Transient Focal Cerebral Ischemia in Male Wistar Rats.

BACKGROUND: Consumption of antioxidants is effective on reducing the damage caused by cerebral ischemia. OBJECTIVES: We investigated the effect of Pistacia vera (pistachio) pretreatment on the morphology of the cornu ammonis (CA1) region of hippocampus neurons of the rats' hippocampus following transient focal cerebral occlusion of the middle cerebral artery (MCA). METHODS: In this study, 30  male Wistar rats were divided into 3 groups of control, ischemia, and pretreatment with pistachio (fed with pistachio at 6% of the diet for a five-week duration before the right MCA occlusion). Neurological scores of the rats were assessed using Baderson rating. Thereafter, the animals' balance and muscle power were assessed by Rotarod and forelimb wire-grip strength tests, respectively. Finally, histopathological and morphometrical characteristics of hippocampal neurons were studied using Hematoxylin-Eosin method. RESULTS: Neurological scores of the ischemia group significantly decreased compared to the control group (p<0.05), while pretreatment with pistachio significantly improved Baderson rating scores compared to the ischemia group (p<0.05). Although stroke significantly decreased the balance and muscular strength in the studied rats compared to the normal rats (p<0.05), pistachio's exposure significantly increased the balance and muscular strength compared to the ischemia group (p<0.05). Additionally, a significant decrease was observed in the volume of stroke and neuronal degradation in the pistachio-treated rats compared with the ischemia group (p<0.05). CONCLUSIONS: Pistachio consumption reduces the volume of infarction and neuronal damage and improves neurological disorders after ischemia. Therefore, pretreatment with pistachio would have a protective effect against stroke.

Temporal order judgment of multisensory stimuli in rat and human.

We do not fully understand the resolution at which temporal information is processed by different species. Here we employed a temporal order judgment (TOJ) task in rats and humans to test the temporal precision with which these species can detect the order of presentation of simple stimuli across two modalities of vision and audition. Both species reported the order of audiovisual stimuli when they were presented from a central location at a range of stimulus onset asynchronies (SOA)s. While both species could reliably distinguish the temporal order of stimuli based on their sensory content (i.e., the modality label), rats outperformed humans at short SOAs (less than 100 ms) whereas humans outperformed rats at long SOAs (greater than 100 ms). Moreover, rats produced faster responses compared to humans. The reaction time data further revealed key differences in decision process across the two species: at longer SOAs, reaction times increased in rats but decreased in humans. Finally, drift-diffusion modeling allowed us to isolate the contribution of various parameters including evidence accumulation rates, lapse and bias to the sensory decision. Consistent with the psychophysical findings, the model revealed higher temporal sensitivity and a higher lapse rate in rats compared to humans. These findings suggest that these species applied different strategies for making perceptual decisions in the context of a multimodal TOJ task.

Genetic and epigenetic modifications of F1 offspring's sperm cells following in utero and lactational combined exposure to nicotine and ethanol.

It is well established that maternal lifestyle during pregnancy and lactation affects the intrauterine programming of F1 offspring. However, despite the co-use of alcohol and nicotine is a common habit, the effects of exposure to both substances on the reproductive system of F1 male offspring and the underlying mechanisms of developmental programming have not been investigated. The present study aimed to examine pre- and postnatal concurrent exposure to these substances on genetic and epigenetic alterations of sperm cells as well as testis properties of F1 offspring compared with exposure to each substance alone. Pregnant dams in the F0 generation randomly received normal saline, nicotine, ethanol, and combinations throughout full gestation and lactation periods. Sperm cells and testes of F1 male offspring were collected at postnatal day 90 for further experiments. High levels of sperm DNA fragmentation were observed in all exposed offspring. Regarding epigenetic alterations, there was a significant increase in the relative transcript abundance of histone deacetylase 1 and 2 in all exposed sperm cells. Moreover, despite a decrease in the expression level of DNA methyltransferase (DNMT) 3A, no marked differences were found in the expression levels of DNMT1 and 3B in any of the exposed sperm cells compared to non-exposed ones. Interestingly, combined exposure had less prominent effects relative to exposure to each substance alone. The changes in the testicular and sperm parameters were compatible with genetic and epigenetic alterations. However, MDA level as an oxidative stress indicator increased in all exposed pups, which may be responsible for such outputs. In conclusion, maternal co-exposure to these substances exhibited epigenotoxicity effects on germline cells of F1 male offspring, although these effects were less marked relative to exposure to each substance alone. These counteracting effects may be explained by cross-tolerance and probably less impairment of the antioxidant defense system.

Transplantation of rat dental pulp stem cells facilities post-lesion recovery in the somatosensory whisker cortex of male Wistar rats.

Damage to somatosensory "barrel" cortex reduces the rats' behavioral sensitivity in discrimination of tactile stimuli. Here, we examined how transplantation of stem cells into the lesioned barrel cortex can help in recovery of sensory capacities. We induced mechanical lesions in the right barrel cortex area of male rats. Three days after lesioning, rats received one of three transplantation types: un-differentiated dental pulp stem cells (U-DPSCs) or differentiated dental pulp stem cells (D-DPSCs), or cell medium (vehicle). A fourth group of rats were control without any Surgery. For 4 consecutive weeks, starting one week after transplantation, we evaluated the rats' preference to explore novel textures as a measure of sensory discrimination ability, also measured the expression of glial fibrillary acidic protein (GFAP), Olig 2, nestin, neuronal nuclei (NeuN), brain-derived neurotrophic factor (BDNF) and neuroligin1 by immunohistochemistry and western blotting. Unilateral mechanical lesion decreased the rats' preferential exploration of novel textures compared to the control group across the 4-week behavioral tests. Following stem cell therapy, the rats' performance significantly improved at week 2-4 compared to the vehicle group. Compared to the control group, there was a significant decrease in the expression of nestin, NeuN, Olig 2, BDNF, neuroligin1 and a significant increase in the expression of GFAP in the vehicle group. The expression of the neural markers was significantly higher in DPSCs compared with the vehicle group whereas GFAP level was lower in DPSCs compared to vehicle. We found that DPSCs therapy affected a range of neuronal markers in the barrel cortex post lesion, and improved the rats' recovery for sensory discrimination.

Administering crocin ameliorates anxiety-like behaviours and reduces the inflammatory response in amyloid-beta induced neurotoxicity in rat.

Anxiety, hippocampus synaptic plasticity deficit, as well as pro-inflammatory cytokines, are involved in Alzheimer's disease (AD). The present study is designed to evaluate the possible therapeutic effect of crocin on anxiety-like behaviours, hippocampal synaptic plasticity and neuronal shape, as well as pro-inflammatory cytokines in the hippocampus using in vivo amyloid-beta (Aß) models of AD. The Aß peptide (1-42) was bilaterally injected into the frontal-cortex. Five hours after the surgery, the rats were given intraperitoneal (IP) crocin (30 mg/kg) daily up to 12 days. Elevated plus maze results showed that crocin treatment after bilateral Aß injection significantly increased the percentage of spent time into open arms, frequency of entries, and percentage of entries into open arms as compared with the Aß group. In the open field test, the Aß+crocin group showed a higher percentage of spent time in the centre and frequency of entries into central zone as compare with the Aß treated animals. Administering crocin increased the number of soma, dendrites and axonal arbores in the CA1 neurons among the rats with Aß neurotoxicity. Cresyl violet (CV) staining showed that crocin increased the number of CV-positive cells in the CA1 region of the hippocampus compared with the Aß group. Silver-nitrate staining indicated that crocin reduced neurofibrillary tangle formation induced by Aß. Crocin treatment attenuated the expression of TNF-α and IL-1ß mRNA in the hippocampus compared with the Aß group. Our results suggest that crocin attenuated Aß-induced anxiety-like behaviours and neuronal damage, and synaptic plasticity loss in hippocampal CA1 neurons may via its anti-inflammatory effects.

Pharmacological mechanism of immunomodulatory agents for the treatment of severe cases of COVID-19 infection.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) is a world-wide pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To date, treatment of severe COVID-19 is far from clear. Therefore, it is urgent to develop an effective option for the treatment of patients with COVID-19. Most patients with severe COVID-19 exhibit markedly increased serum levels of pro-inflammatory cytokines, including interferon (IFN)-α, IFN-γ, and interleukin (IL)-1ß. Immunotherapeutic strategies have an important role in the suppression of cytokine storm and respiratory failure in patients with COVID-19. METHODS: A systematic search in the literature was performed in PubMed, Scopus, Embase, Cochrane Library, Web of Science, as well as Google Scholar preprint database using all available MeSH terms for Coronavirus, SARS-CoV-2, anti-rheumatoid agents, COVID-19, cytokine storm, immunotherapeutic drugs, IFN, interleukin, JAK/STAT inhibitors, MCP, MIP, TNF. RESULTS: Here, we first review common complications of COVID-19 patients, particularly neurological symptoms. We next explain host immune responses against COVID-19 particles. Finally, we summarize the existing experimental and clinical immunotherapeutic strategies, particularly anti-rheumatoid agents and also plasma (with a high level of gamma globulin) therapy for severe COVID-19 patients. We discuss both their therapeutic effects and side effects that should be taken into consideration for their clinical application. CONCLUSION: It is suggested that immunosuppressants, such as anti-rheumatoid drugs, could be considered as a potential approach for the treatment of cytokine storm in severe cases of COVID-19. One possible limitation of immunosuppressant therapy is their inhibitory effects on host anti-viral immune response. So, the appropriate timing of administration should be carefully considered.

Crocin attenuates the granular cells damages on the dentate gyrus and pyramidal neurons in the CA3 regions of the hippocampus and frontal cortex in the rat model of Alzheimer's disease.

Amyloid ß-peptides (Aß) are considered as a major hallmark of Alzheimer's disease (AD) that can induce synaptic loss and apoptosis in brain regions, particularly in the cortex and the hippocampus. Evidence suggests that crocin, as the major component of saffron, can exhibit neuromodulatory effects in AD. However, specific data related to their efficacy to attenuate the synaptic loss and neuronal death in animal models of AD are limited. Hence, we investigated the efficacy of crocin in the CA3 and dentate gyrus (DG) regions of the hippocampus and also in frontal cortex neurons employing a rat model of AD. Male Wistar rats were randomly divided into control, sham, AD model, crocin, and AD model + crocin groups, with 8 rats per group. AD model was established by injecting Aß1-42 into the frontal cortex rats, and thereafter the rats were administrated by crocin (30 mg/kg) for a duration of 12-day. The number of live cells, neuronal arborization and apoptosis were measured using a Cresyl violet, Golgi-Cox and TUNEL staining, respectively. Results showed that, the number of live cells in the hippocampus pyramidal neurons in the CA3 and granular cells in the DG regions of the AD rats significantly decreased, which was significantly rescued by crocin. Compared with the control group, the axonal, spine and dendrites arborization in the frontal cortex and CA3 region of the AD model group significantly decreased. The crocin could significantly reverse this arborization loss in the AD rats (P < 0.05). The apoptotic cell number in the CA3 and DG regions in the AD model group was significantly higher than that of the control group (P < 0.05), while crocin significantly decreased the apoptotic cell number in the AD group (P < 0.05). Conclusion. Crocin can improve the synaptic loss and neuronal death of the AD rats possibly by reducing the neuronal apoptosis.

Focal unilateral mechanical lesion in barrel cortex impairs rat's abilities to discriminate textures.

PURPOSE/AIM OF THE STUDY: Whiskers are important sensory organs that play a key role in rodents' discriminative and exploration behaviours and unilateral injuries of the somatosensory cortex related to whisker barrel cortex can change the activity of neurons in the intact contralateral barrel cortex. We evaluated the effects of unilateral mechanical lesion of right barrel cortex on novel texture discrimination in behavioural test and neuronal responses of left barrel cortex. MATERIALS AND METHODS: Ten days after a unilateral mechanical lesion in the right barrel cortex, adult male rats were experimented regarding three paired different textures in novel texture discrimination test dependent on whiskers. In addition, responses of left barrel cortical neurons to controlled deflections of right whiskers were recorded using extracellular single-unit recordings technique. RESULTS: Data analysis showed that the discrimination ratio and preference indexes as criteria to find a novel texture significantly decreased in the lesion group compared to the intact rats (p < .05). In electrophysiological level, the barrel neural cortical spontaneous activity and the ON and OFF response magnitude of intact barrel cortex neurons in the lesion group decreased compared to the intact group (p < .05). CONCLUSIONS: The present study showed that unilateral mechanical lesion in the rats' barrel cortex cause a decrease in their abilities for discriminating textures, as well as, the anaesthetized rats whose response properties of intact barrel cortical area changed to whisker deflection, too. These changes can influence on the ability of rats to differentiate textures.

Alcohol and nicotine co-Administration during pregnancy and lactation periods alters sensory discrimination of adult NMRI mice offspring.

The present study investigated the impacts of alcohol, nicotine, and their co-administration during pregnancy and lactation on sensory information processing including visual, tactile, and auditory discrimination in adult NMRI mice offspring. Pregnant mice were injected with saline or 20% alcohol (3 g/kg), or nicotine (1 mg/kg) or their co-administration alcohol+nicotine, intraperitoneally until the end of lactation. The offspring were separated from their mothers after lactation period on postnatal day (PND) 28. The locomotor activity, novel object recognition-dependent on visual system (NOR-VS), novel texture discrimination- dependent on somatosensory system (NTR-SS), and acoustic startle reflex were evaluated in PND90. The results revealed no statistical significance for locomotor activity of alcohol, nicotine, and co-administration alcohol+nicotine groups compared to the saline group in the open field task. The results, however, showed a significant decline in the ability of novel object discrimination in the nicotine and co-administration alcohol + nicotine groups compared to the saline group (P < 0.05) in the NOR-VS task. In the NTR-SS and acoustic startle reflex tasks, texture discrimination and the prepulse inhibition abilities in the offspring administered with nicotine and alcohol alone were reduced when compared to the saline group. Also, co-administration of alcohol+nicotine groups showed a decline in the aforementioned tests compared to the saline group (P <0.05). Administration of alcohol and nicotine during fetal and postpartum development disrupts sensory processing of inputs of visual, tactile, and auditory systems in adult mice.

Effect of mild and chronic neonatal hypothyroidism on sensory information processing in a rodent model: A behavioral and electrophysiological study.

Thyroid hormones are essential for neonatal brain development. It is well established that absence of thyroid hormones during critical periods of development can alter sensory functions such as visual and auditory processing, but there are few studies on rat somatosensory system development at mild, long-term, and irreversible neonatal hypothyroidism. Thus, the current study was conducted to investigate whether chronic thyroid hormone insufficiency would alter different cognitive aspects of tactile information processing and sensory motor filtering at behavioral or neuronal levels. Neonatal Wistar male rats were exposed to 0 and 6 ppm of propylthiouracil for 150 days. Behavioral tests including tactile discrimination tests and acoustic startle reflex test were performed. Using extracellular single unit recording technique, barrel cortex neurons' excitatory and inhibitory responses to controlled displacement of whiskers were evaluated. Results indicated that percentage of correct choice in tactile learning and discrimination of a new texture decreased in hypothyroid group compared to the control group (P < 0.05). In addition, acoustic startle reflex of hypothyroid group significantly decreased compared to the control rats when the prepulse intensity was 71 dB (P < 0.05). Data obtained from electrophysiological tests showed that spontaneous activity and response magnitude of barrel cortex neurons decreased in hypothyroid group compared to the control group (P < 0.05). It is concluded that, thyroid hormones can regulate tactile and auditory sensory processing in male rats, and mild and long-term absence of these hormones can result in deficiency in natural functions of these sensory systems.

Movento effects on learning and hippocampal brain-derived neurotrophic factor protein of adult male rats.

Spirotetramat is a toxic commercially known as Movento used to control pistachio psylla pests. In the present study, the effects of Movento on passive avoidance learning of rats and their ability to explore the novel object in the novel object recognition test were investigated. The changes in the concentration of hippocampal brain-derived neurotrophic factor (BDNF) proteins were evaluated, too. Male Wistar rats were gavaged at different dosages of the Movento (50, 100, 250, 500, 1000, 1250, and 1500 mg/kg) or saline for 7 days (administered every 2 days). We showed that Movento caused 50 and 100% mortality at the dose of 1250 and 1500 mg/kg, respectively. At the dose of 1000 mg/kg, Movento significantly decreased locomotor activity (P < 0.05). These rats also displayed a significant decrease in the number of training trials in the shuttle box and the ability to recognize a novel object compared with the control group (P < 0.01). The BDNF protein level of hippocampus also showed a significant decrease in the Movento (1000 mg/kg) compared with the control group (P < 0.01) while the number of pancellular necrosis pyramidal CA1 cells increased significantly in the Movento group (P < 0.001). We concluded that exposure to Movento can decline sensory, motor, and learning in rats.

Comparison of pre-pulse inhibition, tactile discrimination learning and barrel cortical neural response in adult male rats following chronic exposure to morphine, methadone and buprenorphine.

Chronic exposure to opioids is the most common treatment plan to reduce the pain. In this study, the stereotyped behaviors and cognitive functions related to different types of tactile and auditory inputs were investigated in the rats following chronic exposure to the morphine, methadone, and buprenorphine. Here, three addicted groups received morphine, methadone, and buprenorphine while the control rats received saline for 21 days. Our results demonstrated that the opioid-treated groups showed stereotyped behaviors including grooming and rearing. In the behavioral level, prepulse inhibition and preference indices were not changed significantly in the opioids-treated groups compared to those of the saline group as two criteria for acoustic startle reflex and tactile discrimination, respectively. In the neuronal level, chronic morphine and methadone treatment changed the response properties of the barrel cortical neurons to the whisker deflections in the experimental groups compared to the saline group. Thus, it was concluded that the excitatory receptive fields of neurons in the barrel cortex can be changed as a result of chronic exposure to morphine and methadone.

The Efficacy of Teaching English as a Foreign Language to Iranian Students with Autism Spectrum Disorder on Their Social Skills and Willingness to Communicate.

OBJECTIVES: This applied research is the first practical study of teaching English as a foreign language (EFL) to students with autism spectrum disorder (ASD) in Iran. We examined the effect of a well-designed foreign language learning setting in facilitation of social skills and willingness to communicate in children with ASD. MATERIALS & METHODS: A mixed-method research design was used. Using stratified sampling, a limited sample of 18 students were chosen from Kerman Province, southeastern Iran in 2014 categorized in three levels of ASD for each group of experimental and control; matched pairs were used to ensure homogeneity of participants in two groups. Each participant received 15 sessions with totaling 67 h of language learning. First 10 sessions were in the form of tutorials and the last 5 sessions were held in the form of paired classes with a peer. Before and after the sessions, caregivers and parents completed a questionnaire on students' social skills; the English instructor also rated participants' willingness to communicate. RESULTS: Teaching a foreign language had a positive main effect on social skills from caregivers' and parents' view compared to those of controls, significantly (P<0.05). From the instructor's view, there was additionally a significant improvement in the students with ASD's willingness to communicate in classroom settings compared to the control group (P<0.05). CONCLUSION: Optimum foreign language pedagogy for students with ASD is applied as an effective context enhancing children's capabilities in social skills and willingness to communicate, provoked through a motivational foreign setting modulation in a novel environment. Suggestions on enhancing joint attention during the curriculum are provided.