فصلنامه علوم اعصاب شفای خاتم
سال دهم شماره 4 (پیاپی 53، پاییز 1401)

Changes in the morphology of dendrites and the function of nerve circuits in pain-sensing neurons in the dorsal horn of the spinal cord ultimately lead to neuropathic pain. Increased expression of Rac1 is associated with increased size and density of dendritic spines and increased pain threshold in multiple sclerosis (MS). This study aimed to investigate the effect of four weeks of physical activity in an enriched environment on Rac1 and structural changes of WDR neurons in the dorsal horn of the spinal cord, and pain sensitivity in the chronic course of experimental autoimmune encephalomyelitis (EAE), an animal model used to study the immunopathogenesis of MS.

Thirty female C57BL6 mice were randomly divided into three groups. The first group was induced with MOG35-55 peptide (EAE group), the second group received a saline injection (healthy control group), and the third group, after induction with MOG35-55, was placed in the cage of the enriched environment (group living in enriched environment + EAE). On day 30 post-induction (chronic period of the disease), the formalin test assessed pain sensitivity. Then the mice were anesthetized with ketamine and xylazine, and the spinal cord tissue was removed. Rac1 protein levels were measured by immunohistochemistry. The length and density of dendritic spines were assessed using the Golgi-Cox staining.

Our findings showed that living in an enriched environment significantly reduced RAC1 levels, the length and density of dendritic spines of WDR neurons in the dorsal horn of the spinal cord, and pain sensitivity compared to the EAE group.

Changing the environment and lifestyle to a happy and enriched environment and active lifestyle could reduce pain sensitivity in MS by preventing structural changes in pain-sensing neurons in the dorsal horn of the spinal cord.

Obliging to make decisions with only limited and sometimes insufficient evidence is one of the challenges that we face. Previous studies have examined the effect of evidence on performance, confidence, and response time. The question of what leads to a decision with insufficient evidence is still shrouded in ambiguity. This research tries to find an answer by experimenting with random dot motion tasks and using behavioral modeling.

A random dot motion psychophysics experiment was designed and 10 participants were asked to indicate the direction of dots and the degree of their confidence after observing the movement of the dots. In this experiment, the duration of stimulus display was variable and, in each trial, randomly had one of the six specified durations (80 to 720 milliseconds). As the stimulus display time varied, participants were exposed to sufficient and insufficient evidence to make a decision. The results of the participants' behavioral data were analyzed by psychometric functions and the participants' behavior was modeled using the drift-diffusion model.

Our behavioral data indicate that the duration of stimulus display has a significant impact on increasing accuracy and confidence as well as on reducing response time. Behavioral modeling results also showed that the decision components (i.e., threshold separation, drift rate, and none-decision time) are affected by changes in stimulus duration, and threshold separation is significantly affected. The threshold separation increases significantly as the stimulus shows increases.

Our investigation supports the hypothesis that the brain changes the decision threshold and adapts to the situation when making decisions based on insufficient evidence.

Math problem solving requires improving both details and generalities perception by the brain's parietal cortex and in turn, achieving this ability requires the development of cognitive abilities. The purpose of this study was to improve cognitive abilities in math problem-solving through combined neurofeedback and transcranial electrical stimulation therapy.

This study was a quantitative study of the single case type with the ABAB design. The statistical population was the ninth-grade high school students referring to two counseling centers in Karaj. Among them, 5 weak students in math problem-solving were selected purposefully and voluntarily. The entry criteria were age between 14 and 16 years, a math score below 13.5 from 20 in the previous semester. Furthermore, participants should not have a diagnosis of learning disorders and coexistence, medical treatment, and a math reinforcement course. The measurement tools were the fourth edition of the Wechsler IQ test, transcranial electrical stimulation devices, neurofeedback, and math exam scores between two academic semesters. The combined intervention of electrical stimulation and neurofeedback was performed for 50 minutes, two months, and twice a week with the aim of promoting alpha and theta waves and suppressing beta three waves in the parietal cortex. Percentage improvement formulas, Cohen's effect size, and visual analysis were used to analyze the data.

The results showed that the combined treatment was effective in the mentioned brain waves. On the other hand, cognitive factors in Wechsler's intelligence scale, including active memory, processing speed, perceptual reasoning, and verbal comprehension, as well as students' math exam scores showed a significant improvement.

The findings showed that transcranial stimulation of the parietal cortex and neuro-feedback brain training are able to increase the learning ability of students who have problems understanding the details and generalities of mathematics. Therefore, this non-invasive combined method can be used as an approach to improve the cognitive abilities of students who are weak in solving mathematical problems.

Psychological problems were the result of a person's interaction with the environment and include behaviors that cause social conflicts, dissatisfaction, and individual unhappiness. The present study aimed to provide a structural model for psychological problems based on disconnection and rejection domain and negative automatic thoughts with mediating role of loneliness.

The present study was descriptive correlation using structural equation modeling. The statistical population included all individuals with psychological symptoms that were referred to the Qom Counseling Centers in 1400. 250 patients with psychological problems were selected by the convenient sampling method and, they answered the questionnaires of Depression Anxiety Stress Scales (DASS), Young Schema Questionnaire (YSQ-L3), Automatic Thoughts Questionnaire (ATQ-30), and Acceptance and Action Questionnaire (AAQ-II). Data were analyzed using structural equation modeling and Smart Pls software.

The results of structural equation modeling showed that the model is relatively fit and can be generalized to the entire statistical society. The reliability, convergent validity, and divergent validity of the model were confirmed and the model fit was calculated (Gof = 0.42). The results of the mediating role of loneliness also showed that loneliness has a significant mediating role between disconnection and rejection and negative automatic thoughts with psychological problems.

Therapists and counselors at mental health and counseling centers can use this model to check the disconnection and rejection, negative automatic thoughts, and loneliness of patients, and perform the necessary diagnostic and treatment approaches.

The primary purpose of this study is to identify a network model to attract actual customers through neuromarketing and compare the insurance and mushroom industries.

The method of study is a descriptive survey. the statistical sample was 9 experts in neuroscience, marketing, insurance, and the mushroom industry selected by Judgmental sampling. The method of analysis is Multiple Attribute Decision Making. Data were collected by the library-questionnaire method. fuzzy Delphi was used to screen, FUZZY DEMATEL to determine the effect of factors, fuzzy network analysis to prioritize dimensions in Excel, and super decision.

Dimensions of neuromarketing were identified in 3 dimensions (physiological, personality, and social dimension) and 8 sub-criteria. In the insurance industry, the social dimension of the product (weight: 0.319) with the fulfillment of commitments (weight: 0.074), and in the mushroom industry, the physiological dimension of the product (weight: 0.346) with visual and auditory stimuli (weight: 0.0658) are the most effective dimension of neuromarketing in attracting actual customers.

In the insurance industry attention to intangible dimensions, like trust, has a greater role in attracting actual customers. In the mushroom industry, the physiological dimension and visual-auditory senses, which have a tangible nature, have an important role in attracting actual customers. This may be due to brain processes in dealing with tangible and intangible stimuli taken from senses that need to be monitored in specific brain areas using MRI and fMRI.

Patients with depression have difficulties with cognitive abilities and emotion regulation. The aim of this study was to investigate the effectiveness of autobiographical memory training on cognitive abilities, emotion regulation, and emotional dysphoria in depressed adolescent girls.

The research design was quasi-experimental with a pre-test-post-test design and follow-up with the control group. The statistical population of this study included all depressed adolescent girls in Yazd, Iran. The sample size based on the type of research was 26 adolescent girls who were selected by the available sampling method and randomly divided into two groups of 13 people. Trainee memory customization training was performed. Moreover, a follow-up period was performed to evaluate the stability of the results two months after the training. Both groups answered the Rescue Cognitive Abilities Questionnaire (2013), the Graz and Roemer (2004) Emotional Regulatory Questionnaire, and the Toronto Emotional Dysfunction Scale (1994) before and after the training process.

Biographical memory specificity training has a significant effect on cognitive abilities, emotion regulation, and emotional dysphoria in depressed adolescent girls. 

Autobiographical memory specificity training can be used as an indicator to diagnose and follow up on the consequences of depressive disorder.

The Covid-19 pandemic started in December 2019 and revealed various symptoms and complications, including neurological complications. Recently studies have suggested a possible link between this viral infection and Guillain-Barré syndrome (GBS).

Case Description: 

In this report, we present a patient who after being diagnosed with Covid-19 disease, suffers from ascending peripheral neuropathy. Various diagnostic procedures support the diagnosis of GBS.

After treatment with plasmapheresis, an acceptable response to treatment was observed.

Given the viral nature of COVID-19 disease and the evidence of GBS association with viral diseases, as well as the possibility of disease invasion to the respiratory system, if neurological symptoms begin in a COVID-19 patient, GBS should be included in the differential diagnosis.

In addition to the limitations imposed on the patient, ischemic stroke has high economic and social costs. Despite many efforts to treat these injuries, there is still no complete recovery and complete improvement in patients with ischemic stroke. Ischemic stroke is followed by a series of events, such as inflammation, increased oxidative stress, and the spread of damage, that can lead to mitochondrial damage, protein degradation, and cellular apoptosis. Any approach that can protect nerve cells from ischemic injuries can improve the healing process. One of these methods is the use of intracellular factors in the treatment of stroke, which can control various cellular pathways, such as apoptosis, division, and other pathways.

In this article, the role of some factors involved in improving the process of ischemic stroke and the treatment strategies with these factors are discussed.

The study of neural and cognitive pathways in addiction is one of the most important challenges of neuroscience. Addictive drugs stimulate the reward circuits, motivation, euphoria, cognitive changes, and motor activity. Several studies have shown that mesocorticolimbic pathway activity plays an important role in cognition and behavior activated by natural rewards and addictive substances. There is a significant relationship between substance-seeking behavior and decision-making, attention, learning, memory, reward, and substance use. The development of animal models of addiction is essential to our understanding of the substance addiction mechanisms and the cognitive symptoms that result from the continuation of addiction. In this study, we reviewed the various animal models of addiction and their contribution to our understanding of the pathophysiological mechanisms.

According to different routes of drug abuse in humans, there are different types of animal models that include different paradigms, such as inhaled, oral, and intravenous. Intracranial self-stimulation and conditioned animal models based on drug reward attempt to understand the neurobiological basis of addiction and subsequent drug-induced cognitive impairments. Conditioned place preference is one of the more widely used models to study the rewarding properties of drugs in the context of reward-related learning and measures an animal's ability to predict future rewards. Recently, these animal models have been used to simulate drug addiction to provide new perspectives for studying different phenomena, such as extinction, relapse, compulsive drug-seeking behavior, withdrawal syndrome, and drug-induced cognitive impairments. In summary, these innovations in animal modeling have allowed us to improve our knowledge of drug addiction and the biological basis of addiction-related cognitive disorders in the future.

The peripheral nervous system has an innate ability to regenerate itself, and several factors, including neurotrophic factors, play an important role in this process. Neurotrophic factors are molecules that affect the peripheral nervous system and play a vital role in nerve protection, growth, and regeneration. In severe injuries, internal nerve repair is not very effective. Given current treatments have many limitations and side effects. The use of some natural and herbal stimulants seems to have fewer side effects and accelerate the regeneration of the peripheral nerve. Therefore, it is important to pay attention to the role of neurotrophic factors and study the therapeutic effects of natural stimulants in the regeneration of peripheral nerves.

Neurotrophic factors could play an important role in repairing and supporting peripheral nerves. Moreover, the use of some natural stimulants as herbal medicines, due to less side effects, provide a suitable environment for the regeneration of peripheral nerves.