Basic and Clinical Neuroscience
Volume:14 Issue: 3, May-Jun 2023

Sexual addiction is known as a disorder that afflicts a person with difficulty in controlling or delaying sexual behaviors. To prevent social, physical, and psychological consequences, validated screening tests are needed to diagnose this disorder. One of these tests is established by Carnes with the name of sexual addiction screening test-revised (SAST-R). In this study, SAST-R has been translated and verified in the Persian language.

The original screening test was translated into the Persian language and also back-translated for matching by two separate expert teams. The data was collected through an online survey of 1268 participants who were in the age range of 18 to 65 years (Mean±SD 29.44±6.90), and 56.1% and 43.9% of the population were women and men, respectively. Three questionnaires, including the SAST-R, the hypersexual behavior consequences scale, and the Connor-Davidson resilience scale as the principal, convergent, and divergent tests were administered to the participants.

The reliability of the test’s internal consistency (Cronbach α=0.883), split-half (Cronbach α=0.779), and Guttman (lambda coefficients were between 0.773 to 0.883) tests were used. In addition, 4 methods of content validity (sexual hyperactivity specialist approved), convergent structure validity (P<0.001, R=0.731), the validity of divergent structure (P<0.09, R=-0.132), and factor validity (comparative fit index=0.884, goodness of fit index=0.873, root mean square error of approximation=0.047) were measured and confirmed the validity of the test.

The Persian version of SAST-R is a reliable preclinical tool to assess the severity of sexual desire in patients.

Febrile seizure is a temperature-related seizure that affects the QT interval. The purpose of this study was to evaluate the changes in the QT interval caused by febrile convulsion (FC) compared with healthy children. 

This case-control study examined 180 children equally distributed between patients and controls. The study was conducted at the Ali Ebne Abi Talib Hospital in Zahedan City, Iran. The disease was diagnosed and confirmed based on standard definitions of FC. QT interval was measured by ECG and interpreted by a pediatric cardiologist, and collected data were analyzed using SPSS software, version 19 with a 0.05 significant level.

Among the ECG parameters, HR, R in aVL, S in V3, LVM, QTd, QTc, and QTcd were significantly different in children with FCs compared to their peers. From those who had abnormal QTd, FC children were more frequent which was not significant (χ2=1.053, P=0.248), while children with FC had significantly more abnormality regarding QTc (χ2=13.032, P<0.001) and QTcd (χ2=21.6, P<0.001). In children with FC, those who were less than 12 months had the highest level of HR which was not significant (χ2=4.59, P=0.101). Similar trends occurred for R in aVL and S in V3 that were higher in the age group >24 months (P>0.05). Children in the age group of >24 months had significantly had the highest LVM (χ2=52.674, P<0.001) and the other QT parameters were the same in FC children with different age groups (P>0.05).

It is concluded that dispersion corrected QT, corrected QT, and dispersion QT changed significantly in children with FC in comparison with the healthy children with constant values in children with FC in different age groups.

The brain waves pattern in primary insomniacs is different from healthy subjects. Studies have shown that binaural beats can alter the pattern of brain waves in healthy individuals; however, the efficacy of binaural beats in altering the pattern of brain waves in primary insomniacs has not yet been investigated. This study aims to evaluate the efficacy of theta binaural beat on the absolute power of theta activity in primary insomniacs.

This study was a randomized clinical trial with experimental and control groups. The primary insomniacs received theta binaural beats in the experimental group while the control group received white noise. Their brain waves were recorded by electroencephalogram for 25 min; the first 5 min was without stimulus (first block), the next was followed by 15 min of receiving stimulus (binaural beat or white noise), and the last 5 min without stimulus (fifth block). The Matlab software, version R2019a, EEGLAB toolbox, and SPSS software, version 24 were used to analyze the data.

The absolute power of theta activity in the experimental group was significantly higher in the last block compared to the first block in all brain lobes (P<0.05). The largest changes in theta activity were in the temporal and parietal lobes, and the last one was in the prefrontal lobe. In the control group, none of the brain lobes showed significant differences in the last block compared to the first block.

Theta binaural beat can alter the absolute power of theta activity in primary insomniacs. The implications of the study are discussed.

Emerging evidence has shown that the glucagon-like peptide-1 (GLP-1) agonist can be used to treat Alzheimer disease; however, knowledge of its neural targets is limited. To understand the neural substrates of GLP-1, we have done whole brain mapping for GLP-1 and its receptor (GLP-1R), in 30 human brains.

GLP-1 expression was studied by immuno-histochemistry and confirmed by the western blot method. The GLP-1R gene expression was studied by reverse transcription polymerase chain reaction.

GLP-1 expression was observed in most of the cortical areas (maximum in frontal, prefrontal and parietal cortex), diencephalon, and brainstem, but not in the cerebellum. Protein expression studies validated these results. The highest expression of GLP-1R was found in the frontal cortex. The orbitofrontal cortex and cerebellum had negligible expression. Hippocampus demonstrated a significant presence of GLP-1R but patchy immunoreactivity to GLP-1. GLP-1R presence in most of the human cortical regions and absence in the cerebellum is the major deviation from the animal brain. Sites that might be of interest in Alzheimer have been identified. GLP-1 demonstrated an age-related decline in most of the areas after the fifth decade. At 60 years, GLP-1 was not found in any of the cortical areas except in the prefrontal cortex; however, it was present in the sub-cortical areas.

Age-related profiling of GLP-1 in various brain areas has been analyzed, which can have an important bearing on understanding Alzheimer disease. This study provides a detailed description of GLP-1 and an brain mapping for the first time and may lead to novel treatment options targeting the GLP-1 receptors.

Schizophrenia is a severe psychotic brain disorder. One of the potential mechanisms underlying this disease may be volumetric changes in some brain regions. The present study aimed to employ magnetic resonance imaging (MRI) to estimate and quantitatively analyze the brain of patients with schizophrenia compared to the controls.

This case-control study was conducted on MRI scans of 20 patients with schizophrenia and 20 healthy controls in Zahedan City, Southeastern Iran. MRIs with 4 mm slice thickness and 5 mm intervals in coronal and sagittal planes were captured. Then, quantitative parameters, including volume and volume density of various brain regions, were estimated in both groups using Cavalieri’s point counting method. Data analyses were performed using the Mann-Whitney U test. 

The findings of this investigation revealed that volumes of gray matter, hippocampus, and gray/white matter in patients with schizophrenia were significantly lower than the controls (P˂0.05). The volumes of lateral ventricles in patients with schizophrenia (36.60±4.32 mm3) were significantly higher than the healthy individuals (30.10±7.98 mm3). However, there were no statistically significant differences between the two groups regarding the changes in the brain’s total volume, cerebral hemispheres, white matter, brain stem, cerebellum, and corpus callosum (P˃0.05). 

Volumetric estimations on brain MRI-based stereological technique can be helpful for elucidation of structural changes, following up the treatment trends, and evaluating the therapeutic situations in schizophrenia patients. Volumetric alternations in specific brain areas might be linked to cognitive impairments and the severity of symptoms in patients with schizophrenia. Further research is needed in this regard.

Evidence indicates that medial septum nicotinic receptors regulate cognitive processes. Ghrelin is a gut hormone that regulates energy homeostasis. Ghrelin is also produced in the brain and is involved in cognitive function. This study aims to evaluate the effects of medial septal administration of ghrelin on the amnestic effect of morphine in rats.In addition, the possible relationship between the medial septal ghrelin and acetylcholine nicotinic receptors on the amnestic effect of morphine is evaluated.

The rats were implanted at the medial septum area and were microinjected with ghrelin and nicotinic receptor agents. The step-through type inhibitory avoidance apparatus was used for memory retrieval assessment.

The results showed that the administration of morphine after the training phase impaired memory consolidation. Post-training intra-septal injection of the same doses of either ghrelin or nicotine did not change memory performance; however, their co-application with morphine (significant dose: 7.5 mg/kg subcutaneous injection) increased the step-through latency and improved memory consolidation. Moreover, post-training co-application of low doses of the two agonists could not affect morphine-induced memory impairment.

These results indicated no interaction between medial septal ghrelin and nicotinic receptors on the amnestic effect of morphine in rats.

Neuropathic pain is a common and painful somatosensory nervous system disease, and its treatment remains a medical challenge. Evidence demonstrates that gut microbiota alters in neuropathic pain and, therefore, improvement of the gut flora may affect the disease. The present study aimed to evaluate the antinociceptive effect of probiotics in neuropathic pain and oxidative biomarkers’ responsiveness to the probiotic treatment.

Using chronic constriction injury (CCI) of the rats' sciatic nerve, neuropathic pain was induced. Investigating the analgesic effect of the probiotics mixture, 40 male rats were randomly assigned to 4 groups (n=10 for each): Sham-operated (SM), and CCI model rats orally received 1 mL saline (CS), or 100 mg/kg gabapentin (CG) or 1 mL probiotics mixture (CP) Lactobacillus plantarum, Lactobacillus delbrueckii, Lactobacillus acidophilus, Lactobacillus rhamnosus, and Bifidobacterium bifidum (109 CFU of each) daily. Using behavioral tests, the pain was assessed on days 1, 4, 7, 14, and 21 of the study. Finally, the biochemical evaluation of sciatic nerve tissue was done.

Probiotics decreased cold and mechanic allodynia and thermal hyperalgesia. Reducing lipid peroxidation levels and increasing total antioxidant capacity, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity were also significant in the probiotics group.

These findings suggest that probiotics have analgesic effects on the CCI model of neuropathic pain via increasing the antioxidant capacity of the rats’ sciatic nerve.

Temporal lobe epilepsy (TLE) is the most prevalent form of drug-resistant epilepsy with concurrent cognitive impairment. Prevention, earlier diagnosis, and personalized management of cognitive deficits in TLE require more understanding of underlying structural and functional brain Ialterations. No study has evaluated the performance of TLE patients in different cognitive domains based on their structural brain lesions.

In this study, 69 refractory TLE patients underwent magnetic resonance imaging (MRI) epilepsy protocol and several neuropsychological tests, consisting of the Wechsler adult intelligence scale-revised, Rey-Osterrieth complex figure test, verbal fluency test, digit span test, spatial span test, Wechsler memory scale-III, design fluency test, Rey visual design learning test, auditory-verbal learning test, and trail making test. MRI findings were classified into the following groups: Focal cortical dysplasia, gliosis, atrophy, mesial temporal sclerosis (MTS), tumor, vascular malformation, and other lesions or normal. Results of neuropsychological tests were compared between MRI groups using a generalized linear model with gamma distribution and log link.

Patients with MTS showed better performance in general intellectual functioning, working memory, attentional span, and auditory-verbal learning compared to patients with non-MTS MRI lesions. Atrophy and focal cortical dysplasia had the largest differences from MTS.

Cognitive performance of refractory TLE patients varies concerning structural brain alterations. Further neuroimaging studies of TLE lead to prevention and more accurate management of cognitive decline in clinical settings.

Schizophrenia (SZ) is a chronic brain disorder characterized by diverse cognitive dysfunctions due to abnormal brain connectivity. Evaluating these connectivity alterations between and within such networks (intra- and inter-connectivity) may improve the understanding of disrupted information processing patterns in SZ patients. 

Resting-state fMRI analysis was performed on 24 SZ patients and 27 matched healthy controls. A functional connectivity matrix was constructed for each participant based on 129 gray matter regions. All regions were classified into eight distinct functional networks. Afterward, all functional connections were segregated into inter- and intra-network connections considering the eight networks. The Mean values of connectivity weights and nodal strength were examined for within- and between-network connections in SZ patients and healthy controls. 

This analysis revealed that the within-network connections in the somatomotor  (SM) network significantly reduced (P<0.001) in SZ patients. Additionally, intra-network connections within the visual and the ventral attention (VA) networks were significantly lower (P<0.01) in the SZ group. Moreover, disrupted intra-network connectivity was detected between the following network pairs: The visual-limbic, the somatomotor-limbic, the dorsal attention-limbic, and the ventral attention-dorsal attention system. 

The results showed an extensive reduction in functional connectivity strength for SZ patients, with a particularly significant decrease in intra-network connections when compared to the inter-networks. These findings can impact the understanding of the important dysregulated connections that are implicated in the incidence of schizophrenia.

Cognitive control plays a role in human behavior and mental processes and affects paranormal beliefs. This study aims to investigate the role of cognitive control in paranormal beliefs using the go/no-go task.

A total of 92 people were selected based on low, middle, and high scores in the revised paranormal belief scale (R-PBS) and assigned to 3 groups. The groups included 30 severe paranormal believers (13 females with a mean age of 25.3 years), 31 mild paranormal believers (14 females with a mean age of 26.4 years), and 31 skeptics (16 females with a mean age of 25.8 years). All participants were tested on the go/no-go task. A multivariate analysis of variance was conducted with the given groups (severe paranormal believers, mild paranormal believers, and skeptics) as the independent variable and the go/no-go subscales scores as dependent variables.

The findings showed a significant difference between the mean scores in errors of go (F(2, 89)=7.20, P=0.01), errors of no-go (F(2, 89)=11.81, P=0.01), and reaction time (F(2, 89)=21.46, P=0.01) between the groups.

The severe and mild paranormal believers had lower accuracy and slower reaction times than the skeptics group. Therefore, severe paranormal believers and mild paranormal believers had a weakness in all go/no-go subscale scores. This finding suggests that paranormal beliefs may be related to poor cognitive control.

Sensory processing is profoundly regulated by brain neuromodulatory systems. One of the main neuromodulators is serotonin which influences higher cognitive functions, such as different aspects of perceptual processing. Accordingly, malfunction in the serotonergic system may lead to visual illusion in psychiatric disorders, such as autism and schizophrenia. This study aims to investigate the serotonergic modulation of visual responses of neurons to stimulus orientation in the primary visual cortex. 

Eight-week-old naive mice were anesthetized and a craniotomy was done on the region of interest in the primary visual cortex. Spontaneous and visual-evoked activities of neurons were recorded before and during the electrical stimulation of the dorsal raphe nucleus using in vivo whole-cell patch-clamp recording. The square-wave grating of 12 orientations was presented. The data were analyzed and the Wilcoxon signed-rank test was used to compare the data of two conditions that belong to the same neurons, with or without electrical stimulation. 

The serotonergic system changed the orientation tuning of nearly 60% of recorded neurons by decreasing the mean firing rate in two independent visual response components, namely gain and baseline response. It also increased the mean firing rate in a small number of neurons (about 20%). Additionally, it left the preferred orientation and sensitivity of neurons unchanged.

Serotonergic modulation showed a bidirectional effect. It causes predominately divisive and subtractive decreases in the visual responses of the neurons in the primary visual cortex that can modify the balance between internal and external sensory signals and result in disorders.

Negative early-life experiences (e.g. having an aggressive father) can leave long-lastingimpacts on the behavior. However, it is not clear if they influence learning and memory. 

In this study, we investigated the influences that the presence of an aggressive father had on the level of passive avoidance learning and spatial memory. We also studied the changes in the dopamine receptor D2 (DRD2) and peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α) gene expression in the hippocampus. Then, we evaluated if a DRD2 antagonist (sulpiride, 0.125, 0.25, or 0.5 μg/rat) could modulate these changes. 

We found that the subjects exposed to early-life stress made by aggressive fathers had impaired passive avoidance learning and spatial memory compared to subjects with normal fathers. Treatment with sulpiride improved passive avoidance learning and spatial memory in rats with aggressive fathers. The rats with aggressive fathers also had higher expression of the DRD2 gene in their hippocampus than those with normal fathers, while the PGC-1α gene expression was not different among groups. Treatment with sulpiride (0.125, 0.25, or 0.5 μg/rat) reduced the DRD2 gene expression in those with aggressive fathers to the normal level compared to those with normal fathers. 

These data suggest that having and living in a shared place with an aggressive father, even without any physical contact, can detrimentally affect passive avoidance learning and spatial memory which is accompanied by the increased expression of the DRD2 gene. Also, sulpiride as a dopaminergic antagonist could reverse this process.