فصلنامه علوم اعصاب شفای خاتم
سال چهارم شماره 4 (پیاپی 23، پاییز 1395)

Asymptomatic carotid artery stenosis is one of the factors that causes stroke. Other factors such as high blood pressure, cardiac diseases, smoking, diabetes, and physical inactivity may also cause the disease. Understanding and identifying the factors that cause carotid artery stenosis will help in prevention of acute stroke. Using data mining techniques, this study was aimed to discover the rules and relations that are effective in identifying asymptomatic carotid artery stenosis.
To find the best approach, logistic regression (LR), genetic algorithm (GA), and chi-square test were used to predict carotid artery stenosis in patients.
372 participants, 173 women (% 46.5) and 199 men (% 53.5), with an average age of 70.74± 5.29 were investigated. The results showed gender, smoking, coronary artery disease, high blood pressure, inactivity, prevention of pregnancy by medication, uremia (excessive amounts of urea and other nitrogenous compounds in the blood), and pulse rate environment are the significant risk factors for asymptomatic carotid artery. In addition, GA was a better method for this approach compared to LR.
Our study revealed that coronary artery disease and hypertension are important factors in predicting and prognosis of asymptomatic carotid artery stenosis.

Brain-derived neurotrophic factors (BDNF) play a role on induction and maintenance of memory and learning. The BDNF gene Val66Met polymorphism impairs expression of this protein. Due to difference between the neural principles operating during motor memory consolidation and the neural principles operating during practice (acquisition) and the effect of BDNF on both of these processes, the aim of the study was to study the effect of val66met polymorphism on acquisition and motor memory consolidation in the process of learning of throwing motor skill.
We randomly selected one hundred university students of Kashan , Iran (mean age: 21.6±2.2 years). After blood sampling, extraction of genomic DNA, implementation of polymerase chain reaction, analyzing of PCR by 1.5 percent Electrophoresis Gel, and in the end sequencing by ABI PRISM 7000 Sequencing Analyzer, 46 participants were identified without val66met polymorphism, and 54 participants identified affected by the polymorphism (met-carriers). 10 participants of each genetic group (20 people) after pre-test practiced backhand baseball pitch for six sessions. After 48 and 96 hours they participated in two consecutive retention tests.
Our data showed no difference between met-carriers and people without the polymorphism in acquisition and the first retention test. However, met-carriers were significantly weaker than people without the polymorphism in the second retention test.
These findings suggest that the BDNF val66met polymorphism has higher impact on motor learning in the consolidation phase than acquisition phase.

Astrocytes are the most abundant cells in the mammalian brain and play important roles in regulating neuronal signaling, protecting neurons, and determining the fate of neural precursors. Astrocytes are one of the best candidates for cell therapy. Three-dimensional (3D) scaffolds are a synthetic matrix which provided a biocompatible, biodegradable, and non-toxic 3D environment for a variety of cells. In the present study, we isolated astrocytes from rat neocortex and assessed the proliferation rate of astrocytes in 3D dimensional environment.
Astrocytes isolated from adult rat neocortex. The isolated cells was cultured in DMEM/F12 medium supplement with 10% FBS. Astrocytes were confirmed by expression of GFAP (glial fibrillary acidic protein), assessed by immunocytochemistry. After the 3th passage, the astrocytes were cultured in 3D and two - dimensional (2D) cultures and MTS assay was used to determined cell proliferation.
The expression of GFAP marker was confirmed by immunocytochemistry assay. Our results showed that surface plating of astrocytes with 0.15% Pura Matrix showed significantly greater cell proliferation in comparison with 2D culture.
These findings indicate the potential of the astrocytes which was cultured in 3D for using in cell transplantation.

Most decisions are based on the accumulation of discrete pieces of evidence. This evidence has usually been separated with the various intervals. Indeed, how the brain gathers and combines distinct pieces of information received at different times is need to be clarified. In order to investigate the kinship between brain function and human behavior, the behavioral experimental studies could be designed. Previous studies demonstrated that subjects gather and effectively combine discrete evidence to improve their accuracy. In addition, it has been shown that the latest information has a larger influence on decisions. However, it remains unclear that why this larger influence of the later pulses occurs and what can affect this influence.
Dealing with these questions a perceptual decision-making task has been implemented by the psychophysics’ toolbox in MATLAB. Subjects, during the task, were instructed to report the direction of motion in a noisy random dot stimulus with certain keys. Stimuli were presented in continuous (one pulse) or discrete (two continuousness pulses separated with different intervals) form. Each of these two forms of stimuli was presented randomly during each session. Each session has been included 300 trials. Each subject has done 3600 trials. Data have been analyzed by regression models.
We observed that in double-pulse trials, the strength of the second pulse was more crucial in the accuracy of responses compared to the first pulse. In addition, this accuracy was dependent on the differences between the strength of the first and the last pulses.
These findings suggest that a key factor which affects the importance of pulses is the strength of the previous pulse. As the difference between the motion strength increases, the effect of the second pulse on choice accuracy enhanced.

Cerebral ischemia, occurs when a blood clot has occluded a brain artery, is the third leading cause of mortality in the Western world. The present study was aimed to investigate the effects of Trichostatin A (TSA), a histone deacetylase inhibitor, on cognitive deficits and serum Bcl-2 level in an animal model of hypoxia-ischemia rat model (HI).
Thirty male Sprague dawley rats were randomly divided into the healthy control, HI䦩抝 and HI䴠 groups. The rats were suffered from the right common carotid artery ligation and 8% oxygen for 5 min to produce HI model. Two days after induction of ischemia, HI䴠 group received intraperitoneally TSA for 5 days. The Y maze test was used to assess the working memory. The ELISA test was performed to measure the serum Bcl-2 level.
The results showed amelioration of working memory in HI䴠 group compared to HI䦩抝 rats. In addition, a significant difference in the serum level of Bcl-2 was observed between HI䴠 and HI䦩抝 groups.
The data suggested TSA as a potential treatment for amelioration of cognitive deficits after brain ischemia.

Widespread agricultural use as well as increasing number of suicidal or accidental ingestion of paraquat in the last few years enhance the necessity to evaluate the mechanism of action and the complications, especially neuronal side-effects, of this herbicide. The aim of this study was to evaluate the histopathological alterations of the substantia nigra after paraquat intoxication in rats.
28 adult Wistar rats were randomly divided into three experimental and one control groups. Paraquat at different doses (10, 15 and 20 mg/kg) were injected intraperitoneally once a week for three consecutive weeks to experimental groups; normal saline was injected to control group. After 28 days, the brains were removed and sections from the compact part of the substantia nigra were stained by toluidine blue.
A significant enhancement of the number of dark neurons in the substantia nigra was observed in rats receiving 15 and 25 mg/kg of paraquat compared to control group.
Our findings point to the harmful effects of paraquat on neurons of the substantia nigra. This suggests paraquat toxicity as a risk factor for neurological disorders, such as Parkinson’s disease.

Personality is a relatively stable pattern of traits, tendencies, or attributes that partly stabilize behavior. More specifically, personality is comprised of a collection of traits or tendencies that leads to individual differences in behavior as well as behavior stability and durability over time in various situations. This study aimed at investigating the psychometric properties of HEXACO Personality Inventory in students.
This was a descriptive study of psychometric and validation test. A sample of 473 participants (242 females and 231 males), aged 15 to 19 years, were selected randomly among the students living in Sardasht, Iran.
Using Cronbach's alpha, the validity coefficients of the overall inventory, honesty and modesty, emotionality, extraversion, adaptability, Conscientiousness, and openness to experience were obtained as 0.692, 0.480, 0.708, 0.569, 0.631, 0.548, and 0.419, respectively. Moreover, results from analysis of the main components and varimax rotation showed that the questionnaire was saturated with 16 factors that together explained 59.161% of the variance. After implementation of the first-order confirmatory factor analysis, seven factors (namely emotionality, lack of self-worth, extraversion, honesty and modesty, adaptability, conscientiousness, and openness to experience) were confirmed. A significant difference was observed between the mean personality scores of male and female students.
Findings suggest that the HEXACO Personality Inventory has satisfactory validity and can be used for evaluation of the personality of Iranian students.

Traumatic brain injury is the leading cause of death and disability in young adults. Green tea Epigallocatechin-3-gallate (EGCG) supplementation favorably influenced many of the processes mention in the secondary insult of brain injury, including neuroinflammation and anti-oxidative damages in animal studies. In current study, we aimed to investigate the effect of EGCG on outcomes of traumatic brain injury.
In a clinical trial, 30 patients with head trauma hospitalized in the intensive care unit of Sina hospital, Tehran, Iran were randomly divided into two groups. These groups included 15 patients who received a single daily oral dose of EGCG (400 mg) for 7 days and control group of 15 patients received placebo (distilled water) for the same period. Protein level S100 B and GCS were investigated between the two groups.
EGCG increased Glasgow coma score scale. However EGCG had no significant effect on the level of protein S100B.
EGCG may play a neuroprotective effect in trumatic brain insulats.

Alzheimer’s disease (AD), as the most common age-related neurodegenerative disease, affects 2% of general elderly populations. Amyloid plaques and neurofibrillary tangles are two main hallmarks of AD that are usually associated with cerebral amyloid angiopathy. Imbalance between Aβ production from an amyloid precursor protein and its removal from the brain is the main cause of Aβ accumulation and its pathogenesis. Intra-neuronal Aβ aggreagates result in endolysosomal-autophagic dysfunctions followed by formation of authophagic vacuoles and damaged mitochondria in neurons. Studies have also shown that there is an intense crosstalk between Aβ and tau proteins. Aβ aggregates inside and outsides of neurons and intra-neuronal hyper-phosphorylated tau induce dendritic spines collapse and synaptic degeneration, which finally lead to memory loss in AD patients. The amyloid plaques at early stages of AD are detected in the neocortex and hippocampus which extended to the other brain areas associated with conversion from preclinical to symptomatic AD. Other pathologic factors, such as glia-mdiated inflammation and neuronal death, in AD lead to decrease in neuronal functions leading to cognitive impairments.
The better understanding of cellular and molecular mechanisms involved in AD and identifying sensitive and specific biomarkers can play main roles in early diagnosis, controlling the progression, and effective treatmnents of AD. In this study, we review the latest findings on pathophysiology of Aβ and tau proteins and their roles in pathogenesis of AD as well as their importance as targets for treatment of AD.

Autism spectrum disorders (ASD) are characterized by symptoms, such as impaired social interactions and communications as well as restricted and repetitive behaviors and interests, that are detectable in children from 30 months onwards. Since there is no definite treatment, creation of animal models that simulate the symptoms of these disorders are crucial in understanding the etiology and pathology of ASD and its treatment. One of the treatments that directly resulted from animal models is environmental enrichment therapy or sensory enrichment therapy.
Environmental enrichment therapy, compared to many common therapies for ASD, have a good efficacy in improving the symptoms and may reduce economic and social impacts on patients and their relatives.

Cognitive functions contains the processing of thoughts, memory, and attention. Deficiency in one or all of the abovementioned functions may cause behavioral changes that commonly is known as cognitive disorders. The most common cognitive disorders are Alzheimer's disease and Parkinson's disease. These diseases, in addition to the destruction of cognitive behavior (memory, learning and attention) are associated with disability of movement, a common symptom of cognitive impairment. These diseases are accompanied by many histological alterations, such as extracellular amyloid-β (Aβ) peptide-containing plaques, tau protein, astrocytic gliosis, and reactive micoglia. This histological changes are linked with the abnormalities of the receptors. The pathological effect in the structures and functions of neural receptors leads to dysregulation of intracellular pathways and cellular signals.
The intracellular signaling cascade regulated calcium ion flux, membrane excitability, and activation of various receptors. Neurotransmitters play an important role in facilitating the processes of learning and memory. Impairment of these receptors may cause cognitive changes.

Glial-derived growth factor (GDNF) is an important secretory protein that plays a crutial role in the growth and development of the central and peripheral nervous systems, especially the survival of dopaminergic adult neurons. Several investigations have shown the unique negative modulatoty role of GDNF in drug abuse.
This study is a brief description on GDNF and its positive effects as a potential target for the treatment of drug addiction.