Basic and Clinical Neuroscience
Volume:13 Issue: 3, May-Jun 2022

In the present study, the effects of prenatal stress on spatial learning and memory deficit and its relationship with hippocampal insulin resistance were examined in male and female offspring. 

Female NMRI mice were mated with males overnight, and the 0-day of pregnancy was detected (Gestational day 0-GD0). The pregnant mice were then randomly divided into stress and control groups. The stress group received stress from the GD0 to GD10. On post natal day 30 (PND30), the offspring were divided into 4 subgroups, namely: male-control, female-control, male-stress, and female-stress. Barnes maze method was used for spatial learning evaluation. Plasma cortisol and insulin levels were measured at the beginning of the experiments. At the end of the experiments, the animals’ brains were removed, and their hippocampus was extracted. The hippocampus was homogenized, and its insulin and insulin-receptor contents were evaluated. 

The stressed animals needed more time for reaching to target hole. In addition, they spend more distance to find the target hole, which was more pronounced in the male offspring. Both plasma and hippocampal insulin content were reduced in the stressed groups. Moreover, the hippocampal insulin receptors protein was reduced in the stressed animals. There was a positive relationship between plasma and hippocampal content and memory deficit in the stressed groups.

These results indicated that prenatal stress could induce spatial learning and memory deficit in offspring, which is associated with plasma and hippocampal insulin and receptor content reduction (hippocampal insulin resistance) in these animals.

Studies have repeatedly stated the importance of individual differences in the problem of emotion recognition. The primary focus of this study is to predict Heart Rate Variability (HRV) changes due to affective stimuli from the individual characteristics. These features include age (A), gender (G), linguality (L), and sleep (S). In addition, the best combination of individual variables was explored to estimate emotional HRV.

To this end, HRV indices of 47 college students exposed to images with four emotional categories of happiness, sadness, fear, and relaxation were analyzed. Then, a novel predictive model was introduced based on the regression equation.

The results show that different emotional situations provoke the importance of different individual variable combinations. The best variables arrangements to predict HRV changes due to emotional provocations are LS, GL, GA, ALS, and GALS. However, these combinations were changed according to each subject separately.

The suggested simple model effectively offers new insight into emotion studies regarding subject characteristics and autonomic parameters.

We have reported that thymol and carvacrol can improve cognitive abilities in Alzheimer Disease (AD) rat models. However, the mechanism of their action is not yet fully understood. Recently, our in vitro results suggested that PC12 cell death induced by Aβ25-35 can be protected by thymol and carvacrol via Protein Kinase C (PKC) and Reactive Oxygen Species (ROS) pathways. So, we hypothesize that the mechanisms of thymol and carvacrol in improving the learning impairment in the AD rat model may be related to their effects on PKC. So, the activity of PKC and protein expression levels of PKCα were examined in the hippocampal cells of the AD rat model.

To examine the thymol and carvacrol effects, we performed a behavioral test in AD rat models induced by Aβ25–35 neurotoxicity. To access the underlying mechanism of the protective effects, western blotting was performed with antibodies against PKCα. We also measured the PKC activity assay by Elisa. Histopathological studies were carried out in the hippocampus with Hematoxylin and Eosin (H&E) staining. 

The escape latency increased in Aβ-received rats compared to the control group, and thymol and carvacrol reversed this deficit. Furthermore, these compounds could enhance the PKC activity and increase the PKCα expression ratio. Moreover, H&E staining showed that Aβ caused shrinkage of the CA1 pyramidal neurons. However, thymol and carvacrol treatments could prevent this effect of Aβ peptides.

This study suggests that Amyloid-Beta (Aβ) results in memory decline and histochemical disturbances in the hippocampus. Moreover, these results revealed that thymol and carvacrol could have protective effects on cognition in AD-like models via PKC activation.

Success in anesthesia administration relieves the perception of pain during surgery. Lidocaine is the most commonly used local anesthetic agent in clinical medicine. Moreover, anesthetic agents’ temperature changes can influence cell membrane permeability. Here, the effectiveness of different temperatures of Lidocaine (Lid.) on anesthesia success rate has been investigated in rats.

Wistar male rats were pretreated by fast injection of lidocaine or saline into the hind paw or intradermal cheek at Room Temperature (RT) and Body Temperature (BT) (22°C and 37°C, respectively). Then, rat behaviors were evaluated by formalin-induced hind paw pain and orofacial pain tests, respectively. Moreover, using a single-unit recording technique, the spontaneous activity of the marginal nerve was recorded at room temperature in the RT-Lid. and BT-Lid. groups.

Data analysis revealed that lidocaine had significant antinociceptive effects in both the BT-Lid. and RT-Lid. groups compared to the control groups (P<0.05). Also, the number of spikes in the BT-Lid. and RT-Lid. groups were significantly lower than their baselines (P<0.05). However, lidocaine at body temperature decreased the total time spent licking the hind paw, the number of lip rubbings, and the number of spikes firing by about 10%-15% compared to room temperature.

In both behavioral and neural levels of the study, our results showed that an increase in the temperature of lidocaine toward body temperature could increase anesthesia success rate compared to administration of lidocaine at room temperature. These findings can be considered in the treatment of patients.

Sialic acid is pivotal in various critical physiological events at molecular and cellular levels and pathological processes. Changes in sialic acid concentration are observed in many pathological processes; for example, some available data exist on the evaluated level of sialic acid and neurodegenerative prevalence. Presumably, sialic acid can play a significant role in regulating a diverse range of uncovered neurodegeneration factors and downstream targets. matrix metalloproteinases 9 (MMP9) is one factor that changes the exposure of different concentrations of sialic acid solution. Hence, we aimed to examine the possible effect of sialic acid solution exposure on the glial cell line in the expression patterns of miR-320a and let-7e as two upstream factors. 

Human glial cell line was prepared from the Pasteur Institute of Iran and cultured in a dulbecco’s modified eagle medium (DMEM) with 10% fetal bovine serum (FBS). The IC50 value of sialic acid was obtained by colorimetric assay for assessing cell metabolic activity 3-(4,5-Dimethylthiazol-2-yl (MTT), and the glial cell line was treated with sialic acid in 300, 500, 1000 µg/mL for 24 h to investigate the effect of the sialic acid ligand on the expression pattern of the miR-320a and let-7e. Total RNA was isolated from approximately 10×106 glial cells and was used from each sample for complementary dna (cDNA) synthesis. For quantitative analysis of miR-320a and let-7e, we used real-time polymerase chain reaction (PCR), and for statistical analysis, the SPSS v. 21 software was applied. 

Analyzing the real-time data revealed that the expression of miR-320a and let-7e was significantly increased (P<0.0001) in 300, 500, and 1000 µg/mL treated glial cells by sialic acid compared to the control group. 

A possible linkage of sialic acid on miR-320a and let-7e regulation was observed in the glial cell line as proinflammatory factors in the inflammation pathway.

This study aims to compare the positive and negative symptoms of schizophrenia in patients who had psychotic symptoms more than one month after discontinuation of methamphetamine abuse. These factors were analyzed by the positive and negative syndrome scale (PANSS) questionnaire.

Sixty participants were selected from patients referred to Iran Psychiatric Hospital with psychotic symptoms (delusions or hallucinations, disorganized behavior, and speech). The control group was 30 patients with schizophrenia based on a semi-structured interview according to DSM-IV-TR (SCID). Thirty patients with a prolonged methamphetamine-induced psychotic disorder were also placed in the case group. For both groups of patients, questionnaires of PANSS, Brief Psychiatric Rating Scale (BPRS), and Global Assessment Of Functioning (GAF) were filled out after obtaining the companions’ consent. The scale scores were compared between groups. We used the Mann-Whitney and the Chi-square test to evaluate the mean values of PANSS, BPRS, and GAF scores between the two groups.

here was an insignificant difference in positive and general pathology scores between the two groups, but the total score of negative symptoms in the schizophrenia group was significantly higher than in the group of prolonged methamphetamine psychotic disorders (P=0.034). Average scores of uncooperativeness (0.008), difficulty in abstract thinking (0.004), motor retardation (0.002), unusual thought content (0.001), and hostility (0.011) in the schizophrenia group were significantly higher than those in the prolonged methamphetamine psychosis.

The results showed that most of the disturbances in patients with schizophrenia might be more influenced by the expression of cognitive disabilities than those with methamphetamine psychosis. The difference in negative symptom scores suggests that schizophrenia and prolonged methamphetamine psychotic disorder can be two different disorders.

Evidence suggests that gestational exposure to Lipopolysaccharide (LPS) results in fetal zinc deficiency and eventually neurodevelopmental abnormalities. In this study, we utilized a rat model of Maternal Immune Activation (MIA) to investigate the possible neuroprotective effects of zinc supplementation during pregnancy on hippocampal astrocytes activation as well as inflammatory cytokines expression in adult offspring.

Pregnant rats received intraperitoneal injections of either LPS (0.5 mg/kg) or saline on Gestational Days (GD) 15 and 16, and orally gavaged with zinc sulfate (30 mg/kg) during pregnancy. Astrocyte density and histological assessment were evaluated in the hippocampus of adult offspring on Postnatal Days (PND) 60 to 62. Also, the mRNA levels of IL-6, TNF-α, IL-1β, NF-κB, and GFAP were measured using qPCR analysis.

Prenatal exposure to LPS resulted in upregulated expression levels of IL-6, TNF-α, NF-κB, and GFAP in the hippocampus of adult pups. Moreover, the offspring from the LPS group showed an increased astrocyte density in the CA1 region with no histological alterations in CA1 and CA3 areas. However, maternal zinc supplementation ameliorated the LPS-induced inflammatory alterations.

This study supports the premise that zinc supplementation during pregnancy might be an early treatment option to inhibit hippocampal inflammation induced by the maternal immune response to infectious agents.

Drug craving is a major problem in addiction treatment. Neuroimaging research has revealed various areas for drug craving, among which two key areas are the Dorsolateral Prefrontal Cortex (DLPFC) and the cerebellum. The DLPFC is involved in different cognitive tasks, such as inhibitory control over seductive options that promise an immediate reward. The cerebellum is related to cognition and memory and activated by drug-related cues. Therefore, we decided to study the effect of Transcranial Direct Current Stimulation (tDCS) on six different protocols in reducing drug craving and increasing cognitive functions in methamphetamine addicts. 

The present study is quasi-experimental, with a pre-test-post-test design and a control group. Based on a simple sampling method, 15 male methamphetamine addicts were recruited from two rehabilitation centers in Tehran City, Iran. The participants were aged 18-65 years with a minimum of 12-month history of methamphetamine dependence. The Visual Analog Scale (VAS), the go/no-go task and the n-back task were administered before and after a single session of tDCS. The tDCS was applied on six protocols: 1) the right DLPFC anodal and the left DLPFC cathodal stimulation, 2) the right DLPFC cathodal and the left DLPFC anodal stimulation, 3) the right DLPFC anodal and the right arm cathodal stimulation, 4) the left DLPFC anodal and the left arm cathodal stimulation, 5) the right cerebellar hemisphere (O2) anodal and the left cerebellar hemisphere (O1) cathodal stimulation, and 6) the right cerebellar hemisphere (O2) cathodal and the left cerebellar hemisphere (O1) anodal stimulation. The data were analyzed by covariance method using SPSS software v. 22.

Study results indicated that while single-session tDCS effects on craving were not significant, it increased cognitive inhibition, especially in protocol 2: the right DLPFC cathodal and the left DLPFC anodal stimulation.

Single-session tDCS affects craving insignificantly, but it can increase cognitive inhibition significantly. These findings support the results of previous studies on the effects of brain stimulation on reducing drug craving in other drug-type settings.

The death of neurons and cerebral edema are the main consequences of stroke. However, inflammatory processes play key roles in aggravating cerebral damage following a stroke. This study aimed to investigate the effects of Viola odorata extract (VOE) on the infarct volume (IV), neurologic deficits (ND), and the expression of NF-κB and VCAM-1 in the Middle Cerebral Artery Occlusion (MCAO) model.

The animals were randomly separated into 6 groups: (1) control group, (2) vehicle-treated group, (3) MCAO group, (4) VOE25 group, (5) VOE50 group, and (6) VOE75 group (n= 12). VOE (25, 50, and 75 mg/kg) and distilled water were administered daily for 30 days. Two hours after the last gavage, the rats were exposed to MCAO for 60 minutes. Twenty-four hours later, IV, ND, and NF-κB/VCAM-1 expressions were evaluated.

Viola odorata extract exhibited excellent neuroprotective effects by reducing IV (mainly in the core and subcortex areas), and induced downregulation of NF-κB and VCAM-1 expression.

Viola odorata could also activate intracellular pathways, reducing the expression of NF-κB and VCAM-1. It is useful for developing a novel medical herb for treating cerebral ischemia.

Stress is a reaction to unwanted events disturbing body homeostasis and its pathways and target areas. Stress affects the brain through the lateral hypothalamic area (LHA), the orexinergic system that mediates the effect of corticotropin-releasing hormone (CRH) through CRH Receptor Type 1 (CRHr1). Therefore, this study explores the outcome of stress exposure on anxiety development and the involvement of the LHA through LHA-CRHr1.

Male Wistar rats (220-250 g) implanted with a cannula on either side of the LHA received acute or chronic stress. Subsequently, exploratory behavior was examined using the Open Field (OF), and anxiety was tested by Elevated Plus Maze (EPM). Before sacrifice, the cerebrospinal fluid (CSF) and the blood were sampled. Nissl stain was performed on fixed brain tissues.

Acute stress reduced exploration in of and increased anxiety in EPM. LHA-CRHr1 inhibition reversed the variables to increase the exploration and decrease anxiety. In contrast, chronic stress did not show any effect on anxiety-related behaviors. Chronic stress decreased the cell population in the LHA, which was prevented by the CRHr1 inhibition. However, the CRHr1 inhibition could not reverse the chronic stress-induced increase in the CSF orexin level. Furthermore, plasma corticosterone levels increased through acute or chronic stress, impeded by the inhibition of CRHr1. 

Our results recognize LHA-CRHr1 as a capable candidate that modulates acute stress-induced anxiety development and chronic stress-induced changes in the cellular population of the region.

Neuropathy is a condition in which the Peripheral Nervous System (PNS) is disordered. Studying the effects of antioxidants on the performance improvement of this system is vital. This study aimed to investigate the effects of date extract on Nerve Conduction Velocity (NCV), Distal Motor Latency (DML), and wave height of the sciatic nerve in male rats.

This laboratory study used 24 male Wistar rats weighing 250-300 g, divided into the test and control groups. The test group received 10% date extract daily, at 4 mL /kg of body weight, for three weeks. In the beginning, nerve Conduction Velocity (NCV), Distal Motor Latency (DML), and wave height of the sciatic nerve were examined in all animals and re-examined for NCV three weeks later. P-values lower than 0.05 were considered significant. 

Sciatic NCV and wave height were significantly increased; however, compared to the control group, DML of the knee significantly declined in the test group.

The compositions of date extract accelerate electrical signal transmission.

Morin hydrate (MH) is a bioflavonoid component of many fruits and vegetables. Our previous research demonstrated that MH provides neuroprotection in mouse models of acute restraint stress and sleep deprivation by attenuating hippocampal neuronal damage and enhancing memory. Based on these findings, our study investigated the role of MH in chronic stress-induced neuronal and biochemical perturbations in BALB/c mice.

Male BALB/c mice were divided into 6 groups (n=6). Groups 1 and 2 received vehicle (10 mL/kg normal saline), groups 3-5 received MH (5, 10, 20 mg/kg IP), while group 6 received ginseng (25 mg/kg) daily and 30 minutes afterward were restrained in a plastic cylindrical restrainer for 14 days. 

Immobility time in the forced swim test increased in the MH-treated group, indicating an antidepressant-like effect. Also, a reduction in frequency and duration of open arms exploration was observed in the elevated plus-maze (EPM) test in stressed mice, and administration of MH (5, 10, 20 mg/kg, IP) reversed these effects. An increase in blood levels of glucose, triglycerides, total cholesterol, and brain malondialdehyde and nitrite levels was observed in the stressed groups, which was reversed by MH. Furthermore, MH reversed the stress-induced reduction in HDL cholesterol and glutathione (GSH) levels and attenuated stress-induced alterations in the prefrontal cortex and hippocampus. 

Our findings suggest that MH attenuated chronic restraint stress-behavioral and biochemical perturbations, probably due to its capability to decrease oxidative stress and brain neuronal damage

Several studies have demonstrated that orexins may regulate different forms of affective and cognitive processes during wakefulness. The Orbitofrontal Cortex (OFC) and Anterior Cingulate Cortex (ACC), as an essential part of the Prefrontal Cortex (PFC), have a crucial role in cognitive processes such as reward and decision-making. They also have a high amount of orexin receptor type 1 (OX1Rs). 

In the present study, we inhibited OX1Rs in this area after a 10-min baseline recording to find out the role of OX1Rs in the OFC neuron’s firing rate. Next, we inhibited the lateral hypothalamus (LH) as the primary source of orexinergic neurons. Afterward, using a single-unit recording technique in rats, we detected the effects of the lateral hypothalamus on the firing rate and activity pattern of the ACC or OFC neurons.

Data showed that the blockade of OX1Rs in the OFC could excite 8 and inhibit 1 neuron(s) out of 11. In addition, the blockade of OX1Rs in the ACC could excite 6 and inhibit 3 neurons out of 10. LH inactivation excited 5 out of 12 neurons and inhibited 6 in the ACC. It also excited 8 and inhibited 6 neurons out of 14 in the OFC. These data suggest that the blockade of OX1Rs excites 72% of the neurons, but LH inactivation had a stimulating effect on only 50% of neurons in two main subregions of the PFC. 

Accordingly, PFC neurons may receive the orexinergic inputs from the LH and indirectly from other sources.

Studies on pain are generally conducted for two

first, to study patients with pain who have physical changes due to nerve and muscle lesions, and second, to regain the appropriate kinematic post-pain pattern. The present study aimed to investigate the effect of pain on the coordination variability pattern and throwing accuracy.

The study participants included 30 people aged 18-25 years who volunteered to participate in the study. Participants practiced and acquired skills in 10 blocks of 15 trials. In the test phase associated with pain, Individuals were randomly divided into three groups: local pain, remote pain, and control. In their respective groups, participants were tested in a 15-block trial, 24 hours, and 1 week after acquisition.

The results revealed that pain did not affect the throwing accuracy (P=0.456). Besides, in the phase of acceleration in throwing, movement variability in the pain-related groups in the shoulder and elbow joints (P=0.518), elbow and wrist (P=0.399), and the deceleration and dart drop phase movement variability in the pain-related groups in the shoulder and elbow joints (P=0.622), elbow and wrist (P=0.534). 

Based on the results, the accuracy and coordination variability in pain-related groups were similar. However, to confirm these results, more research is needed on performing motor functions in the presence of pain.