Basic and Clinical Neuroscience
Volume:14 Issue: 2, Mar-Apr 2023

Phantom limb pain (PLP) as neuropathic pain affects the life of amputees. It is believed an efficient PLP treatment should consider the underlying neurological mechanisms. Hereby, we investigated brain activity in PLP and its relationships to the psychological and cognitive dimensions of chronic pain. We investigate differences in resting brain activities between amputees with and without pain. We hypothesize significant differences in the motor cortex and parietal cortex activity that are related to pain perception. Also, we hypothesize two groups have significant differences in cognitive and psychological components.

Behavioral assessment (psychological status, life satisfaction, and pain level) and EEG signals of 19 amputees (12 without pain and 7 with pain) were recorded. Data were statistically compared between the two groups. Also, the association between behavioral and neurophysiological data was computed. 

The results showed a significant decrease in the pain group for the beta and gamma waves, as well as, for the theta and delta waves in the posterior temporal on both sides, during the eye-open condition. The eyes-closed condition showed that the delta waves were decreased on the right side of the cortex. Also, data showed a significant difference in the correlation of pain features with brain waves between the two groups. 

Significant differences were mostly observed in regions related to pain perception rather than the motor cortex. This can be due to the learned strategies to deal with pain and the degree of pain. Results showed maladaptive cognitive processes had a relationship with brain wave activities. According to the result of brain wave activities, it seems that cognitive factors have a role in the experience of PLP rather than neuroplasticity through amputation.

It is reported that migraine may be a risk factor for brain cancers. Since one of the best ways to assess this possible relationship is to study the molecular mechanism, here the common central dysregulated proteins between these diseases are investigated via network analysis.

The dysregulated proteins of migraine and gliosarcoma are extracted from the STRING database and interacted via Cytoscape software, version 3.7.2. to form two separate networks. Central nodes of the networks are compared to find the common central district proteins. First neighbors of the common central proteins are studied. 

The number of 11 hub bottlenecks was identified for each of the migraine and gliosarcoma cancer networks. Albumin (ALB) and interleukin 6 (IL6) were introduced as common differentially expressed central proteins. Kininogen 1 (KNG1), vascular endothelial growth factor A (VEGFA), and neurofibromatosis type I (NF1) the first neighbors of ALB-IL6 were connected to the central nodes of networks of the two studied diseases.

ALB and IL6 can be considered molecular links between migraine and brain cancers.

Functional near-infrared spectroscopy (fNIRS) is an imaging method in which a light source and detector are installed on the head; consequently, the re-emission of light from human skin contains information about cerebral hemodynamic alteration. The spatial probability distribution profile of photons penetrating tissue at a source spot, scattering into the tissue, and being released at an appropriate detector position, represents the spatial sensitivity. 

Modeling light propagation in a human head is essential for quantitative near-infrared spectroscopy and optical imaging. The specific form of the distribution of light is obtained using the theory of perturbation. An analytical solution of the perturbative diffusion equation (DE) and finite element method (FEM) in a Slab media (similar to the human head) makes it possible to study light propagation due to absorption and scattering of brain tissue. 

The simulation result indicates that sensitivity is slowly decreasing in the deep area, and the sensitivity below the source and detector is the highest. The depth sensitivity and computation time of both analytical and FEM methods are compared. The simulation time of the analytical approach is four times larger than the FEM. 

In this paper, an analytical solution and the performance of FEM methods when applied to the diffusion equation for heterogeneous media with a single spherical defect are compared. The depth sensitivity along with the computation time of simulation has been investigated for both methods. For simple and Slab modes of the human brain, the analytical solution is the right candidate. Whenever the brain model is sophisticated, it is possible to use FEM methods, but it costs a higher computation time.

Iron oxide nanoparticles (Fe2O3-NPs) are small magnetic particles that are widely used in different aspects of biology and medicine in modern life. Fe2O3-NP accumulated in the living cells due to the absence of an active system to excrete the iron ions and damages cellular organelles by high reactivity.

Herein cytotoxic effects of Fe2O3-NP with a size of 50 nm on the primary culture of neonatal rat hippocampus were investigated using 2,5-diphenyltetrazolium bromide (MTT) assay. Pathophysiological signs of Alzheimer’s disease such as amyloid precursor protein (APP) expression, Aβ aggregation, soluble APPα, and APPβ secretion were also investigated in hippocampal cells treated with various concentrations of nanoparticle (NP) for different exposure times.

Our results revealed that Fe2O3-NP treatment causes oxidative stress in cells which is accompanied by upregulation of the APP and Aβ in a concentration-dependent manner. NP exposure also leads to more secretion of sAPPβ rather than sAPPα, leading to increased activation of β-secretase in NP-received cells. All the harmful effects accumulate in neurons that cannot be renovated, leading to neurodegeneration in Alzheimer’s disease.

This study approved iron-based NPs could help to develop Alzheimer’s and related neurological disorders and explained why some of the iron chelators have therapeutic potential in Alzheimer’s disease.

The right and left-hand motor imagery (MI) analysis based on the electroencephalogram (EEG) signal can directly link the central nervous system to a computer or a device. This study aims to identify a set of robust and nonlinear effective brain connectivity features quantified by transfer entropy (TE) to characterize the relationship between brain regions from EEG signals and create a hierarchical feature selection and classification for discrimination of right and lefthand MI tasks.

TE is calculated among EEG channels as the distinctive, effective connectivity features. TE is a model-free method that can measure nonlinear effective connectivity and analyze multivariate dependent directed information flow among neural EEG channels. Then four feature subset selection methods namely relief-F, Fisher, Laplacian, and local learningbased clustering (LLCFS) algorithms are used to choose the most significant effective connectivity features and reduce redundant information. Finally, support vector machine (SVM) and linear discriminant analysis (LDA) methods are used for classification.

Results show that the best performance in 29 healthy subjects and 60 trials is achieved using the TE method via the Relief-F algorithm as feature selection and support vector machine (SVM) classification with 91.02% accuracy.

The TE index and a hierarchical feature selection and classification can be useful for the discrimination of right- and left-hand MI tasks from multichannel EEG signals.

Research evidence indicates that maladaptive reorganization of the brain plays a critical role in amplifying pain experiences and pain chronification; however, no clear evidence of change exists in brain wave activity among patients with chronic low back pain (CLBP). The objective of this study was to assess brain wave activity in patients with CLBP, compared to healthy controls. 

Twenty-five patients with CLBP and twenty-four healthy controls participated in the study. A quantitative electroencephalography device was used to assess brain wave activity in eyes-open and eyes-closed (EO and EC) conditions. The regional absolute and relative power of brain waves were compared between the groups.

Our results showed a significant increase in the absolute power of theta (F=5.905, P=0.019), alpha (F=5.404, P=0.024) waves in patients with CLBP compared to healthy subjects in both EC and EO conditions. Patients with CLBP showed a reduced delta absolute power in the frontal region (F=5.852, P=0.019) and augmented delta absolute power in the central region (F=5.597, P=0.022) in the EO condition. An increased delta absolute power was observed in the frontal (F=7.563 P=0.008), central (F=10.430, P=0.002), and parietal (F=4.596, P=0.037) regions in patients with CLBP compared to the healthy subjects in the EC condition. In the EC condition, significant increases in theta relative power (F=4.680, P=0.036) in the parietal region were also found in patients with CLBP.

The increased absolute power of brain waves in people with CLBP may indicate cortical overactivity and changes in the pain processing mechanisms in these patients.

The study of the relationship between bilingualism and the possible impact it might have on the control aspect of intelligence of adults in general and preschool children, in particular, has always been the subject of controversy for researchers. This research, following the related findings and gaps in the literature and inspired by Craik and Bialystok’s (2005) framework, tries to divulge whether bilingualism could be related to the control aspect of intelligence. As our secondary goal, we also tried to see whether there are correlations between different tests assessing control. 

In this descriptive correlational study, via the convenience sampling method, we selected our participants.

In doing so, 10 age-gender-matched Mazandarani-speaking monolinguals and the same matched bilinguals have been selected. Moreover, the literacy and socioeconomic status of subjects have been controlled. The tests for assessing subjects’ executive control included day-night Stroop, the dimensional change card sort (DCCS), test of variables of attention (TOVA), and the computerized attention network test (ANT). Our participants' performance in language proficiency task as well as control tasks was demonstrated. Furthermore, via the conduction of the Pearson correlation statistics, the relationships between the participants' performance in diverse control tasks and language task were investigated. 

The results showed that bilinguals outperform monolinguals in all control tests except DCCS. 

Bilingualism could provide children with an executive control advantage promoting them in tasks demanding thought and action control.

A neurodevelopmental disorder, autism is typically identified with three primary behavioral consequences, such as social impairment, communication problems, and limited or stereotypical behavior. Because of its co-morbidity and lack of therapeutic options, autism is a global economic burden. A short chain of fatty acid, propionic acid is formed biologically by the gut microbiome. Propionic acid levels that are too high can cause leaky intestines, which can lead to autism-like symptoms.

To induce autism, male Albino Wistar rats were given propionic acid (250 mg/kg/po on the 21st, 22nd, and 23rd postnatal days). Rats also received a ryanodine receptor antagonist (Ruthenium red: 3 mg/kg/po; postnatal 21st to 50th day) to see what influence it had on propionic acid-induced autism. Anxiety, social behavior, and repeated behaviors were all assessed, as well as oxidative stress, inflammatory indicators, neuro signaling proteins, and blood-brain barrier permeability.

Ruthenium red was found to counter the propionic acid-induced increases in anxiety, repetitive behavior prefrontal cortex levels of IL-6, TNF-α, TBARS, Evans blue leakage, and water content along with decreases in social behavior, IL-10, and GSH followed by hippocampus CREB and BDNF levels. 

Ryanodine receptor antagonists presented a neuroprotective effect in propionic acid-induced conditions like autism by modulatory effects on social and repetitive behavior, oxidative stress, neuroinflammation, and neuroprotein changes. Ryanodine receptors can be further explored in depth to manage autism as a condition.

Glioblastoma multiforme (GBM) is an aggressive case of primary brain cancer which remains among the most fatal tumors worldwide. Although, some in vitro and in vivo models have been developed for a better understanding of GBM behavior; a natural model of GBM would improve the efficiency of experimental models of human GBM tumors. We aimed the present study to examine the survival and durability of U87 cells in the brain of wild-type rats.

U87 cells were intracranially implanted in twenty-one wild-type rats. Tumor size and morphology as well as infiltration of immune cells were investigated at three-time points by H&E and immunohistochemistry (IHC).

The results demonstrated that the inoculation of GBM cells led to the infiltration of host defense system cells which caused immunological regression of the tumor mass after six weeks. While the tumors successfully developed without any sign of host defense invasion in the second week of GBM inoculation. Also, a decrease in tumor size and infiltration of immune system cells were observed in the fourth week.

These data remarkably suggest that time plays a crucial role in activating the immune system against human GBM tumors in rats; it shows that the regression of tumor mass depends on a time slope.

The purpose of this study is to analyze the multiple sclerosis research in Science Citation Index-Expanded from 1992 to 2019 in order to determine the top features, trends, and topics. 

In this scientometric study, research population was all articles related to multiple sclerosis in the Web of Science from 1992 to 2019. These articles were retrieved from the Science Citation Index-Expanded and analyzed based on various indicators and characteristics. 

There was a significant increase in the number of articles from 408 in 1992 to 2756 in 2019. A sum of 42,112 articles related to multiple sclerosis has been published in 3,032 journals, which were classified among the 131 Web of Science categories. The top two categories were clinical neurology and neurosciences. Multiple Sclerosis Journal published the most articles. Articles published in the Neurology Journal also had the highest citation per publication. Most of the articles were in English, while 23 other languages were used in the articles. Articles in Japanese and English with 7 and 6.9 authors have a higher average of authors than articles in other languages. English language articles received more citations than articles in other languages. The frequency of used keywords in title, abstract, author keywords, and keywords plus analysis showed that “therapy”, “disability”, “neurodegeneration”, “demyelination” and “MRI” show an increasing trend in the multiple sclerosis articles.

The result of this study can help the policy makers and researchers realize the panorama of multiple sclerosis research and design future research.

Emotion recognition is the main component of social cognition and has various patterns in different cultures and nationalities. The present study aimed to investigate emotion recognition patterns among Iranians using the Cambridge neuro-psychological test automated battery (CANTAB) as a valid neuropsychological test. 

In this descriptive-analytical study, 117 males and females (Mean±SD of age 32.1±6.4) were initially assessed by computerized intelligence and progressive matrices of RAVEN-2. Furthermore, the excitement recognition subtest taken from the Cambridge neuro-psychological test automated battery (CANTAB) was performed. The correct response of participants to each of the six basic emotions as well as the recognition time was used for analysis. 

The maximum correct response rate was 75.83% related to happy emotion. The correct responses for sadness, surprise, disgust, anger, and fear were 70%, 68.48%, 47.84%, 42.54%, and 38.26%, respectively. Moreover, the shortest recognition time was related to disgust at 322 ms, while sadness with a mean response time of 1800 ms and fear response time at 1529 ms indicated the longest recognition time. In addition, participants recognized happiness with a mean response time of 1264 ms better than other emotions; however, post-hoc t-test analyses showed that only the correct responses for sadness and surprised emotions did not differ significantly, (t(112)=-0.59, P=0.55, d=0.05). These results suggested that different emotions have various correct responses. However, sadness and surprise did not differ.

The findings of this study could be beneficial for evaluating cognitive elements, as well as cognitive abilities and inabilities among the Iranian population. Moreover, the findings could be used for investigating social cognition in this population.

Video games affect the stress system and cognitive abilities in different ways. Here, we evaluated electrophysiological and biochemical indicators of stress and assessed their effects on cognition and behavioral indexes after playing a scary video game.

Thirty volunteers were recruited into two groups as control and experimental. The saliva and blood samples were collected before and after intervention (watching/playing the scary game for control and experimental groups respectively). To measure cortisol and salivary alpha-amylase (sAA) levels, oxytocin (OT), and brain-derived neurotrophic factor (BDNF) plasma levels, dedicated ELISA kits were used. Electroencephalography recording was done before and after interventions for electroencephalogram (EEG)-based emotion and stress recognition. Then, the feature extraction (for mental stress, arousal, and valence) was done. Matrix laboratory (MATLAB) software, version 7.0.1 was used for processing EEG-acquired data. The repeated measures were applied to determine the intragroup significance level of difference.

Scary gameplay increases mental stress (P<0.001) and arousal (P<0.001) features and decreases the valence (P<0.001) one. The salivary cortisol and alpha-amylase levels were significantly higher after the gameplay (P<0.001 for both). OT and BDNF plasma levels decreased after playing the scary game (P<0.05 for both).

We conclude that perceived stress considerably elevates among players of scary video games, which adversely affects the emotional and cognitive capabilities, possibly via the strength of synaptic connections, and dendritic thorn construction of the brain neurons among players.

Brain atrophy is associated with physical disability in multiple sclerosis (MS), but there is a great variability between different studies and methodologies, and its use is still limited to research projects. We aimed to analyze the relationship between several volumetric measurements and physical disability and cognitive functioning in MS patients in a clinical practice setting. 

This is a cross-sectional study. A total of 41 patients (31 relapsing-remitting MS, 6 secondary-progressive MS, and 4 primary-progressive MS) were included. Whole brain volume (WBV), gray matter volume (GMV), and T2 lesion load (T2L) were obtained using Icometrix® software. Physical disability was measured with the Expanded Disability Status Scale (EDSS), and cognitive status was evaluated with the brief repeatable battery of neuropsychological tests (BRB-N). The relationship between brain volumes and EDSS was analyzed through linear multivariate regression. The association between volumetry measurements and the number of affected cognitive domains was studied with negative binomial regression.

GMV was associated with age (b=-1.7, p=0.014) and with EDSS (b=-7.55, p=0.013). T2L was associated with EDSS (b=2.29, p=0.032). The number of affected cognitive domains was associated with clinical phenotype, worse in primary progressive MS (PPMS). There was not correlations between cognitive impairment and cerebral volumes.

Brain atrophy measurement is feasible in clinical practice setting, and it is helpful in monitoring the EDSS progression. Primary progressive phenotype is associated with greater risk of cognitive dysfunction.