مهیار جان‌احمدی

[ 1 ] - مدلسازی عملکردی نقش آستروسیت‌ها در همزمانی فعالیت سلول‌های عصبی

در این مقاله، به مدلسازی عملکردی نقش آستروسیت‌ها که دسته مهمی از سلول‌های گلیال به شمار می‌روند به عنوان تنظیم کننده‌های سیناپسی در همزمان شدن فعالیت سلول‌های عصبی پرداخته می‌شود. ایده اصلی استفاده همزمان از مدل‌های جمعیت نورونی کورتیکال و تالاموکورتیکال ارائه شده توسط سافژینسکی و همکاران (2004) با در نظر گرفتن ایده بازخورد داخلی ...

[ 2 ] - یک مدل الکتروشیمیایی جدید برای مسیر مرکب قلبی بر مبنای جزییات کانالهای یونی غشا

در این مقاله، یک مدل جدید برای قلب ارایه شده است که نحوه تولید و گسترش زمانی و مکانی پتانسیل عمل از بخشهای مرکزی و محیطی ضربان ساز تا کل قلب را بر مبنای رفتار کانالهای یونی غشا های تحریک پذیر سلولهای متنوع قلبی مشخص می نماید. این چنین مدلی می تواند بستر و زمینه مناسبی برای پاسخگویی به طیف گسترده تری از ضرورتهای پژوهشی و آموزشی در فیزیولوژی، الکتروفیزیولوژی، فارماکولوژی و مهندسی پزشکی با استفاده...

[ 3 ] - The comparison of the effects of acute and repeated morphine administration on fast synaptic transmission in magnocellular neurons of supraoptic nucleus, plasma vasopressin levels, and urine volume of male rats

The activity of the magnocellular neurons (MCNs) of supraoptic nucleus (SON) is regulated by a variety of excitatory and inhibitory inputs. Opioids are one of the important compounds that affect these inputs at SON synapses. In this study, whole-cell patch clamp recording of SON neurons was used to investigate the effect of acute and repeated morphine administration on spontaneous inhibitory an...

[ 4 ] - The Effect of Paxilline on Early Alterations of Electrophysiological Properties of Dentate Gyrus Granule Cells in Pilocarpine-Treated Rats

The dentate gyrus of hippocampus has long been considered as a focal point for studies on mechanisms responsible for the development of temporal lobe epilepsy (TLE). Change in intrinsic properties of dentate gyrus granule cells (GCs) has been considered as an important factor responsible in temporal lobe seizures. In this study, we evaluated the intrinsic properties of GCs, during acute phase o...

[ 5 ] - The comparison of the effects of acute and repeated morphine administration on fast synaptic transmission in magnocellular neurons of supraoptic nucleus, plasma vasopressin levels, and urine volume of male rats

The activity of the magnocellular neurons (MCNs) of supraoptic nucleus (SON) is regulated by a variety of excitatory and inhibitory inputs. Opioids are one of the important compounds that affect these inputs at SON synapses. In this study, whole-cell patch clamp recording of SON neurons was used to investigate the effect of acute and repeated morphine administration on spontaneous inhibitory an...

[ 6 ] - The Effect of Paxilline on Early Alterations of Electrophysiological Properties of Dentate Gyrus Granule Cells in Pilocarpine-Treated Rats

The dentate gyrus of hippocampus has long been considered as a focal point for studies on mechanisms responsible for the development of temporal lobe epilepsy (TLE). Change in intrinsic properties of dentate gyrus granule cells (GCs) has been considered as an important factor responsible in temporal lobe seizures. In this study, we evaluated the intrinsic properties of GCs, during acute phase o...

[ 7 ] - Antibiotic Supplements Affect Electrophysiological Properties and Excitability of Rat Hippocampal Pyramidal Neurons in Primary Culture

Introduction: Antibiotic supplements are regularly used in neuronal culture media to control contamination however, they can interfere with the neuronal excitability and affect electrophysiological properties. Therefore, in this study, the effect of penicillin/streptomycin supplements on the spontaneous electrophysiological activity of hippocampal pyramidal neurons was examined. Methods: Electr...

[ 8 ] - اثر سلولی عصاره برگ ترخون (Artemisia dracunculus L.) بر فعالیت صرعی القاء شده توسط پنتیلن تترازول در نورونهای حلزون

ترخون (Artemisia dracunculus)، گیاه چند ساله‌ای از خانواده Asteraceae است که به دلیل بوی خوش برگهایش به‌عنوان چاشنی غذا استفاده می‌شود. در طب ایران باستان، بخشهای هوایی خشک شده این گیاه به‌صورت خوراکی برای درمان صرع بکار می‌رفته است. صرع یکی از رایج‌ترین بیماریهای نورولوژیک است. در مطالعه حاضر، با استفاده از ثبت داخل سلولی اثر عصاره الکلی ترخون و مکانیسم سلولی احتمالی اثر آن بر ضد فعالیت صرع‌زا...

[ 9 ] - Effect of repeated transcranial magnetic stimulation during epileptogenesis on spontaneous activity of hippocampal CA1 pyramidal neurons in rats

Introduction: Considering the antiepileptogenic effects of repeated transcranial magnetic stimulation (rTMS), the effect of rTMS applied during amygdala kindling on spontaneous activity of hippocampal CA1 pyramidal neurons was investigated. Materials and Methods: A tripolar electrode was inserted in basolateral amygdala of Male Wistar rats. After a recovery period, animals received daily kindl...

[ 10 ] - Neuroprotective effect of minocycline on PTZ-induced epileptiform activity and alterations of the shape of action potentials in snail neurons assessed by using intracellular recordings

Introduction: Epilepsy is a neurological disorder that affects 1-2% of the world population and about 30% of patients are resistant to antiepileptic drug therapy. Therefore, new treatment alternatives are needed. In the present study, the possible neuroprotective effect of minocycline against epileptiform activity induced by pentylenetetrazole (PTZ) was assessed. Methods: Conventional intra...

[ 11 ] - Aspirin changes short term synaptic plasticity in CA1 area of the rat hippocampus

Introduction: The prostaglandin E2 (PGE2), a cyclooxygenase (COX) product, play critical roles in the synaptic plasticity. Therefore, long term use of COX inhibitors may impair the synaptic plasticity. Considering the wide clinical administration of aspirin and its unknown effects on information processing in the brain, the effect of aspirin and sodium salicylate on the short term synaptic p...

[ 12 ] - Electrophysiological study of amygdale-induced changes in the excitability of CA1 hippocampal pyramidal neurons in male adult rats

Introduction: Many studies have shown that amygdala kindling produces synaptic potentiation by induction of changes in the neuronal electrophysiological properties and inward currents both in epileptic focus and in the areas which are in connection with the epileptic focus and have important role in seizure development and progression such as hippocampal CA1 region. However, cellular mechani...

[ 13 ] - Electrophysiological investigation of the cellular effect of anethole, the chief constitute of anise, on F1 neuronal excitability in garden snail

Introduction: Anethole is the main constituent of Pimpinella anisum L. (anise), a herbaceous annual plant which has several therapeutic effects. In the folk medicine, anise is employed as an antiepileptic drug. Specifically, this study was focused on the cellular effect of anethole, an aromatic compound in essential oils from anise and camphor. Anethole has various physiological effects on t...

[ 14 ] - Is the pain modulatory action of 17β-estradiol in locus coeruleus of male rats is mediated by GABAA receptors?

Introduction: Estradiol is a neuroactive steroid, which is found in several brain areas such as locus coeruleus (LC). Estradiol modulates nociception by binding to its receptors and also by allosteric interaction with other membranebound receptors like glutamate and GABAA receptors. LC is involved in noradrenergic descending pain modulation. Methods: In order to study the effect of 17β-estra...

[ 15 ] - Changes in motor and learning behaviors of rats prenatally exposed to WIN 55212-2, a cannabinoid receptor agonist

Abstract* Introduction: Cannabis consumption during pregnancy may affect fetal growth, motor performance, memory and cognitive functions. Methods: Primiparous pregnant Wistar rats were randomly assigned to 4 treatment groups (6 rats per group) consisting of control and sham groups as well as 2 groups treated with Win. Win treated groups received daily s.c. injections of 0.5 or 1 mg/kg WIN ...

[ 16 ] - The modulatory effects of orexin B on the calcium channels activity in neuronal cells of Helix aspersa (garden snail)

Introduction: The functional effects of orexin-B on the calcium spikes and excitability of the neuronal soma membrane of garden snail, Helix aspersa were studied. Methods: Conventional intracellular recording, under the current clamp conditions was performed to examine the effects of orexin-B on the configuration and electrophysiological properties of calcium spikes. Results: Application o...

[ 17 ] - The effects of supraphysiological levels of testosterone on neural networks upstream of gonadotropin-releasing hormone neurons

Objective(s): Several pathological conditions are associated with hyper-production of testosterone; however, its impacts are not well understood. Hence, we evaluated the effects of supraphysiological levels of testosterone on gonadotropin-releasing hormone (GnRH) system in the hypothalamus of male rats. Also, we assessed the expression of two excitatory (kisspeptin and...

[ 18 ] - Role of Opioid System in Empathy-like Behaviours in Rats

Background: Empathy is defined as the ability to simulate the mental states of others. Recent studies havedemonstrated empathy-like behaviors in other animals including rats and mice. The objective of the currentstudy was to evaluate the effect of acute administration of morphine and naloxone on cognition andnociception changes fo...

[ 19 ] - The Role of Adrenergic Receptors on Neural Excitability and Synaptic Plasticity: A Narrative Review

Adrenergic receptors have an important role in neural excitability and synaptic plasticity. Despite a lot of studies on these receptors, their exact role in brain disorders accompanied with hyperexcitability has not been determined. There are also controversies on their role in synaptic plasticity. In this review article, the important studies done in this regard have been reviewed to achieve a...

[ 20 ] - Kisspeptin-13 Improves Spatial Memory Consolidation and Retrieval against Amyloid-β Pathology

It has been shown that brain glucose metabolism impairment, obesity, and diabetes couldlead to cognitive decline and Alzheimer’s disease (AD) pathogenesis. Kisspeptin (KP) a G-proteincoupled receptor neuropeptide, has been suggested as a link between energy balance andreproduction. Some studies have shown that the attenuation of KP signaling decreases metabolismand energ...

[ 21 ] - Kisspeptin-13 Improves Spatial Memory Consolidation and Retrieval against Amyloid-β Pathology

It has been shown that brain glucose metabolism impairment, obesity, and diabetes couldlead to cognitive decline and Alzheimer’s disease (AD) pathogenesis. Kisspeptin (KP) a G-proteincoupled receptor neuropeptide, has been suggested as a link between energy balance andreproduction. Some studies have shown that the attenuation of KP signaling decreases metabolismand energ...

[ 22 ] - Hypothalamic KiSS1/GPR54 Gene Expressions and Luteinizing Hormone Plasma Secretion in Morphine Treated Male Rats

Objective The inhibitory effects of Morphine and the stimulatory influence of kisspeptin signaling have been demonstrated on GnRH/LH release. Hypothalamic kisspeptin is involved in relaying the environmental and metabolic information to reproductive axis. In the present study the role of kisspeptin/GPR54 signaling system was investigated on relaying the inhibitory effects of morphine on LH horm...