Papers by Abbas Ali Vafaei
Pharmacology, Biochemistry and Behavior, Apr 1, 2021
Fear extinction is defined as decline in conditioned fear responses that occurs with repeated and... more Fear extinction is defined as decline in conditioned fear responses that occurs with repeated and non-reinforced exposure to a feared conditioned stimulus. Experimental evidence suggests that the extinction of fear memory requires the integration of the medial prefrontal cortex (mPFC); nevertheless, the role of its sub-regions in regulating the expression and extinction of auditory fear has been rarely addressed in literature. The present study examined the roles of the infra-limbic (IL) and pre-limbic (PL) regions of the mPFC in the expression and extinction of auditory fear by temporally deactivating these regions using lidocaine (10 μg/0.5 μl) before training male Wistar rats in auditory fear-conditioning tasks. The results showed increased freezing levels and impaired extinction through deactivating the IL rather than the PL cortex. Given the role of the dopaminergic pathways in regulating fear memory, this study also investigated the role of D2 receptors located in the IL cortex in fear extinction. Fear extinction was improved in an inverted U-shape pattern through the intra-IL infusion of 15.125, 31.25, 62.5, 125, 250 and 500 ng/0.5 μl of the D2 receptor antagonist sulpiride. In other words, the moderate doses, i.e. 31.25, 62.5, 125, 250 ng/0.5 μl, enhanced auditory fear extinction, whereas the lowest and highest doses, i.e. 15.125 and 500 ng/0.5 μl, were ineffective. These findings demonstrated the key roles of the IL cortex and its dopamine D2 receptors in regulating auditory fear in rats.
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Koomesh, Jun 10, 2011
Introduction: Although past research has suggested that acute exposure to the extremely low-frequ... more Introduction: Although past research has suggested that acute exposure to the extremely low-frequency electromagnetic fields (ELFEFs) can impair cognitive functions, data on chronic exposure remained scare. Only a few studies investigated the effects of chronic ELFEFs on cognitive functions, but the results are controversial. Thus, the aim of the present study was to study whether chronic exposure to ELFEFs can affect cognitive functions and anxiety-like behaviors in rats. Materials and Methods: Thirty-five male Wistar were divided into control and exposed (10 or 100 uT). Exposed rats were continuously exposed to a 50 Hz magnetic field of 10 or 100 µT for four weeks. Then, cognitive functions of all rats were tested in the Morris water maze and passive avoidance tasks. Also, anxiety-related behaviors of all rats were examined in the elevated- plus maze and light-dark box. Results: No significant differences were found between control and exposed in learning acquisition, memory reten...
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Neuroscience, Oct 1, 2015
Prenatal morphine exposure throughout pregnancy can induce a series of neurobehavioral and neuroc... more Prenatal morphine exposure throughout pregnancy can induce a series of neurobehavioral and neurochemical disturbances by affecting central nervous system development. This study was designed to investigate the effects of an enriched environment on behavioral deficits and changes in hippocampal brain-derived neurotrophic factor (BDNF) levels induced by prenatal morphine in rats. On pregnancy days 11-18, female Wistar rats were randomly injected twice daily with saline or morphine. Offspring were weaned on postnatal day (PND) 21. They were subjected to a standard rearing environment or an enriched environment on PNDs 22-50. On PNDs 51-57, the behavioral responses including anxiety and depression-like behaviors, and passive avoidance memory as well as hippocampal BDNF levels were investigated. The light/dark (L/D) box and elevated plus maze (EPM) were used for the study of anxiety, forced swimming test (FST) was used to assess depression-like behavior and passive avoidance task was used to evaluate learning and memory. Prenatal morphine exposure caused a reduction in time spent in the EPM open arms and a reduction in time spent in the lit side of the L/D box. It also decreased step-through latency and increased time spent in the dark side of passive avoidance task. Prenatal morphine exposure also reduced immobility time and increased swimming time in FST. Postnatal rearing in an enriched environment counteracted with behavioral deficits in the EPM and passive avoidance task, but not in the L/D box. This suggests that exposure to an enriched environment during adolescence period alters anxiety profile in a task-specific manner. Prenatal morphine exposure reduced hippocampal BDNF levels, but enriched environment significantly increased BDNF levels in both saline- and morphine-exposed groups. Our results demonstrate that exposure to an enriched environment alleviates behavioral deficits induced by prenatal morphine exposure and up-regulates the decreased levels of BDNF. BDNF may contribute to the beneficial effects of an enriched environment on prenatal morphine-exposed to rats.
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Neurobiology of Learning and Memory, Sep 1, 2023
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The Neuroscience Journal of Shefaye Khatam, Apr 10, 2018
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Middle East Journal of Rehabilitation and Health, Apr 21, 2018
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Behavioural Brain Research, 2019
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Middle East Journal of Rehabilitation and Health, Jan 14, 2023
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Behavioural Brain Research, Mar 1, 2023
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Neurochemical Research, Sep 15, 2020
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Neuroscience, Aug 1, 2016
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Metabolic Brain Disease
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Pharmacology Biochemistry and Behavior
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Physiology & Behavior
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Scientia Iranica
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Middle East Journal of Rehabilitation and Health Studies, 2021
Background: Memory loss is the main disorder accompanied by Alzheimer's disease (AD). Objecti... more Background: Memory loss is the main disorder accompanied by Alzheimer's disease (AD). Objectives: We aimed to investigate the protective effects of aminoguanidine (Amg) on cell apoptosis in the hippocampal CA1 region and memory impairment in male rats received scopolamine (Scop). Methods: Thirty male Wistar rats (200 - 250 g) were randomly divided into the three groups of saline-saline group, Scop + saline, and Scop + Amg groups. The rats received intraperitoneal injection of Scop (3 mg/kg) for seven days, and subsequently, 100 mg/kg of Amg or normal saline were intraperitoneally administrated for 14 consecutive days. The Morris water maze test was used to study memory deficits. Finally, the animals were anesthetized, hippocampi were quickly removed, histological study was performed, and hippocampal cell apoptosis was evaluated by the cresyl violet staining and the terminal deoxynucleotidyl transferase dUTP nick end labeling test, respectively. Results: Scop injection resulted i...
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Iranian Journal of Basic Medical Sciences, 2021
Objective(s): A few experimental studies have shown the therapeutic effects of oxytocin on focal ... more Objective(s): A few experimental studies have shown the therapeutic effects of oxytocin on focal cerebral ischemia. In this study, the prophylactic effect of intranasal oxytocin on brain damage was investigated in a cerebral ischemic model. Materials and Methods: Intranasal oxytocin (8 IU/per mouse) was prescribed daily for one week. Cerebral ischemia was performed through bilateral common carotid artery occlusion (BCCAO) for 20 min and then blood flow was restored for 24 hr. Finally, neurological disorders, spatial learning and memory, neuronal death, and neuronal apoptosis were assessed in CA1, CA3, and dentate gyrus. Also, levels of interleukin-1β (IL-1β) and Tumor necrosis factor-alpha (TNFα) were measured in the hippocampus. Results: Induction of global ischemia leads to neurological disorders and impairment of spatial learning and memory that are improved by pre-treatment with oxytocin (P<0.01). Cresyl violet staining showed that pretreatment with oxytocin significantly red...
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با دقت در کتابهای دستور زبان فارسی، متوجه این موضوع میشویم که اکثر تقسیمبندیها در مورد صفت، ت... more با دقت در کتابهای دستور زبان فارسی، متوجه این موضوع میشویم که اکثر تقسیمبندیها در مورد صفت، تکراری و شبیه به هم هستند؛ بنابراین در این پژوهش در حوزۀ معنایی و با توجه به اختصاص یا عدم اختصاص (عمومیت) صفت به موصوفها، تقسیمبندی جدیدی از صفت صورتگرفته است و بر این اساس صفات به دو دستۀ خاص و عام تقسیم شدند؛ صفات خاص بر اساس اختصاص به حوزۀ معنایی خاص یا فقط یک موصوف خاص، به دو دستۀ «خاص نوع 1» و «خاص نوع 2» (خاص الخاص) تقسیم میشوند. صفات عام نیز بر اساس دامنۀ شمول تعلقپذیری به واژهها (موصوف) به سه دستۀ «عام کم فعال»، «عام نیمه فعال» و «عام فعال» تقسیم میشوند. برای دستیابی به مجموعهای از صفات و بررسی و تحلیل آنها، سه رمان «سمفونی مردگان» عباس معروفی، «سووشون» سیمین دانشور و «چشمهایش» بزرگ علوی به عنوان جامعۀ آماری برای استخراج صفات انتخاب شدند و بعد از استخراج، صفات به روش تحلیلی و توصیفی به صفات خاص و عام تقسیم شدند و مجددا صفات تقسیم شده بر اساس صفات بیانی (ساده/مطلق، فاعلی، مفعولی، نسبی و لیاقت) تقسیمبندی شدند و مشخص شد که هر کدام از صفات بیانی به کدام تقسیمبن...
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Journal of Gorgan University of Medical Sciences, 2020
Background and Objective: Alzheimer is the most common form of dementia in elderly persons. Oxida... more Background and Objective: Alzheimer is the most common form of dementia in elderly persons. Oxidative stress is one of the main pathological factors in Alzheimer’s disease. This study was done to investigate the effect of crosin on histological changes of hippocampus and memory impairment which induced by scopolamine in the male rats. Methods: In this experimental study, 30 male rats were randomly allocated into 3 groups including: control, scopolamine and scopolamine with crosin treated groups. Scopolamine with dose of 3 mg/kg/bw for one week and crocin with dose of 30mg/kg for two weeks were administered, intraperitoneally. The learning and spatial memory parameters were evaluated by Morris water maze test. Then the animals were sacrificed and their hippocampi were removed immediately for histological evaluation. Results: Scopolamine injection causes significantly increased the number of dark cells in CA1 region of hippocampus in compared to control group (P<0.05). Treatment wi...
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Papers by Abbas Ali Vafaei