sayyed alireza talaei

The prevalence of substance abuse (SA) among youth has increased in recent years. However, limited data exist about SA among medical sciences students. Therefore, this study assessed SA prevalence and contributing factors among medical sciences students. This cross-sectional study was conducted in 2019. Participants were 238 medical sciences students randomly selected from Kashan University of Medical Sciences, Kashan, Iran. The data collection instrument was the SA prevalence assessment questionnaire developed by the Mental Health Center of the Ministry of Health of Iran. Data were analyzed using the SPSS (v. 22.0) software. The most commonly abused substances were waterpipe tobacco (31.9%), cigarettes (20.2%), and alcoholic beverages (10.5%). Most participants with a history of SA had started SA before entering university. The prevalence rates of waterpipe tobacco smoking, cigarette smoking, and alcohol consumption were 9.2%, 8.8%, and 4.2% in the past month and 16.4%, 18.1%, and 7.6% in the past year, respectively. The prevalence of SA among dormitory students and students with lower grade point averages was significantly higher than among non-dormitory students and students with higher grade point averages. The onset age of SA was mainly before eighteen years, so strategies are needed to reduce SA in secondary schools. Moreover, strategies are needed to prevent and reduce SA at universities, particularly among dormitory students and students with lower grade point averages. University authorities should use effective educational and counseling programs to prevent student SA.

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.

Alpha-lipoic acid (ALA) is an antioxidant with radioprotective properties. We designed the current work to assess the neuroprotective function of ALA in the presence of oxidative stress induced by radiation in the brainstem of rats. 

Experimental approach:

Whole-brain radiations (X-rays) was given at a single dose of 25 Gy with or without pretreatment with ALA (200 mg/kg BW). Eighty rats were categorized into four groups: vehicle control (VC), ALA, radiation-only (RAD), and radiation + ALA (RAL). The rats were given ALA intraperitoneally 1 h before radiation and killed following 6 h, thereafter superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and total antioxidant capacity (TAC) in the brainstem were measured. Furthermore, a pathological examination was carried out after 24 h, 72 h, and five days to determine tissue damage.

The findings indicated that MDA levels in the brainstem were 46.29 ± 1.64 μM in the RAD group and decreased in the VC group (31.66 ± 1.72 μM). ALA pretreatment reduced MDA levels while simultaneously increasing SOD and CAT activity and TAC levels (60.26 ± 5.47 U/mL, 71.73 ± 2.88 U/mL, and 227.31 ± 9.40 mol/L, respectively). The greatest pathological changes in the rat’s brainstems were seen in RAD animals compared to the VC group after 24 h, 72 h, and 5 days. As a result, karyorrhexis, pyknosis, vacuolization, and Rosenthal fibers vanished in the RAL group in three periods.

Conclusion and implications:

 ALA exhibited substantial neuroprotectivity following radiation-induced brainstem damage.

Internet addiction is one of the problems that has arisen with the advancement of technology, which has negative effects on people's physical and mental health. This study aimed to investigating the effect of using the internet and social networks in students of Kashan University of Medical Sciences.

In this cross-sectional study, 238 students of Kashan University of Medical Sciences were selected by stratified random method in 2019. To collect data, a standard questionnaire prepared by the professors and experts of the mental health center of the Ministry of Health was used. The data was analyzed through SPSS and using chi-square test.

The findings showed that 16.1% of students were addicted to social networks, which was 18.4% and 12.7% among women and men, respectively. Also, it can be mentioned that male students use more online and offline computer games than female students (P<0.05). The rate of use of dormitory students for searching news and surfing the web and downloading movies and music was more than students of living at home (P<0.05), also.

Considering that 16.1% of students devote at least 8 hours of their time daily to use the internet, this can be a reason for their academic failure. Hence, it is necessary to hold educational workshops about the advantages and disadvantages of internet.

Traditionally, Nigella sativa L. has been known as a medical intervention to treat numerous diseases. This study aimed at investigating the antihyperalgesic effect of black seed oil (BSO) in an experimental model of neuropathic pain.

Chronic constriction injury (CCI) was performed under anesthesia. The sciatic nerve was ligated with four loose ties. Two separate protocols were used to administer BSO. In chronic treatment, rats were given daily doses of BSO (250, 500, and 1000 mg/kg p.o.) from the 1st day until the 21st post-CCI day. While, in acute treatment, BSO (250, 500, and 1000 mg/kg p.o.) was administered only on the 7th, 14th, and 21st days. CCI and sham groups were given almond oil according to the same schedule. Behavioral scores were determined by evaluation of the paw withdrawal in the plantar, Von Frey, and acetone tests, on the 7th, 14th, and 21st days.

Our results showed that CCI leads to significant allodynia and hyperalgesia in the ipsilateral paw after surgery. Chronic administration of BSO (500 and 1000 mg/kg) obviously attenuated heat hyperalgesia and mechanical allodynia. However, daily administration of BSO did not alter cold allodynia. Nevertheless, when BSO was administered, 30 min before the pain assessment tests, hypersensitivity was not improved in the treated animals.

These results demonstrated BSO can inhibit neuropathic pain progression and suggests a potential use of BSO to manage hyperalgesia and allodynia. However, additional research is necessary to approve BSO effectiveness, in neuropathic pain conditions.

Facing environmental factors during early postnatal life, directly or indirectly via mother-infant relationships, profoundly affects the structure and function of the mammals’ Central Nervous System (CNS).

This study aimed to evaluate the effect of morphine consumption during the lactation period on short-term synaptic plasticity of the hippocampal Cornu Ammonis 1 (CA1) neurons in rat offspring.

In addition to a group of control mother rats (CO), three groups subcutaneously received 5 (M5), 10 (M10), or 20 (M20) mg/kg morphine every 12 hours during the lactation period. At 45 days old, following the stimulation of the Schaffers’ collaterals, basic field Excitatory Post-Synaptic Potentials (fEPSPs) were recorded in their offspring’s hippocampal CA1 neuronal circuits. After the construction input/output curve, paired-pulse stimulations with the inter-stimulus intervals of 20, 80, and 200 ms were applied to determine the short-term synaptic plasticity, and the paired-pulse ratio was evaluated.

The baseline synaptic responses of the rats CA1 neurons whose mothers received 10 and 20 mg/kg morphine twice daily during the lactation period decreased compared to the CO animals (P<0.01 & P<0.001, respectively). Furthermore, compared to the controls, the Paired-Pulse Ratio (PPR) of the CA1 neural circuits of M10 and M20 rats at 20 and 80 ms Inter-Stimulus Intervals (ISI) decreased (P<0.01).

Morphine exposure during the lactation period has a detrimental impact on the primary synaptic activity and short-term synaptic plasticity of the hippocampal CA1 neuronal circuits of rats’ offspring.

Non-alcoholic fatty liver disease (NAFLD) includes a range of liver damage from early steatosis to cirrhosis. Although NAFLD prevalence in the world is increasing, but there is no effective treatment for it.

The aim of this study was to evaluate the effect of combined extract of jujube, chicory and silymarin on NAFLD induced by high-fat diet (HFD) in rats.

In this experimental study 40 male rats randomly were divided in two groups: a negative control group (n = 8) and a high-fat diet group (n = 32). After 4 months of feeding with HFD, rats were assigned into 4 groups (n = 8) including an HFD group and three groups receiving HFD and the extract at 100, 200 and 400 mg/kg for 2 months. Finally, lipid profile, liver enzymes activity and liver histology were investigated.

High-fat diet increased cholesterol, triglyceride and LDL and decreased HDL levels (P<0.001). This diet also increased serum activity hepatic enzymes and lipid accumulation in liver tissue. Receiving the extract improved lipid profile and hepatic enzyme activity, dose-dependently. Histopathology of liver confirmed the change induced by HFD and protective effect of extract.

Treatment with combined extracts of jujube, chicory and silymarin improves high-fat diet (HFD) induced NAFLD in rats.

In addition to genetic factors, environmental phenomena during postnatal age highly affect development and, in turn, function of the brain. The present work evaluates if morphine consumption during lactation period influences the spatial performances and synaptic plasticity in rats at neonatal period of age. Three groups of mothers were subcutaneously administered by 5 (M5), 10 (M10) or 20 (M20) mg/kg morphine every 12 hours during the lactation period. At 45 days old, their offspring were introduced to Morris water maze for assessment of spatial learning and memory. Basic field excitatory post-synaptic potentials (fEPSPs) were recorded in the CA1 area of hippocampus and, then, long term potentiation (LTP) was induced by tetanic stimulation. We found that the M10 and M20 rats spent more time and traveled longer distance to find the hidden platform of maze when compared to the control animals (P The present study provides behavioral and electrophysiological proofs for negative effect of morphine on the hippocampal-related function in the neonatally morphine-exposed rats.

Despite the very good medicinal properties of lavender essential oil and licorice extract, some factors, such as allergic reaction and being biodegradable, limit the application of them as candidates for pharmacotherapeutic treatments. Nano-emulsification is one of the ways to overcome these limitations. The aim of this study was to investigate the effects of nanoemulsion cream containing lavender essential oil and licorice extract on healing of deep skin wound in rat model. In this experimental study, nanoemulsion cream containing lavender essential oil and licorice extract was made using self-emulsifying method. To investigate its effect on wound healing process, a full-thickness skin wound was produced on 85 male Wistar rats. The wound area was digitally photographed at 2nd, 5th, 7th, 10th, and 14th days after surgery using a digital camera; then, the area was quantified using an image analysis system (Image J). Moreover, the expression of transforming growth factor-beta1 (TGF-β1), type I collagen (Col I), and Col III genes was evaluated using real-time polymerase chain reaction (real-time PCR) at days 2, 7, and 14. Findings: Nanoemulsion cream significantly decreased the surface area of the wounds faster than lavender essential oil and licorice extract cream (P < 0.010) and phenytoin (P < 0.050). Moreover, real-time PCR showed that topical treatment of wounds with nanomulsion cream increased the expression of TGF-β1, Col I, and Col III genes in rat’s skin (P < 0.01). Nanoemulsion cream containing lavender essential oil and licorice extract exhibits a promising wound healing potential towards excisional wound models in rats.

Non-alcoholic fatty liver disease (NAFLD) is one of the most important chronic liver diseases that is spreading worldwide. However, there is no effective treatment for it. So, the aim of this study was to evaluate the effect of combined extract of Ziziphus jujube Mill., Cynara scolymus L. and and Cichorium intybus L. on NAFLD induced by high-fat diet (HFD) in rats.

In this experimental study 40 male rats randomly were divided in two groups: a sham group (n=8) and a high-fat diet group (n=32). After 4 months of feeding HFD, rats suffering from fatty liver into 4 groups (n=8) including a HFD group and the three groups receiving HFD and a dose of the combined extract (100, 200 or 400 mg/kg) for 2 months. Finally, lipid profile, activity of serum liver enzymes and liver histology were investigated.

Remarkably, high-fat diet caused hypertriglyceridemia, hyper¬cholesterol¬emia, increased serum level of hepatic enzymes and accumulated fat in liver. The combined extract at a dose of 200 mg/kg improved lipid profile, hepatic enzyme activity, and histological changes in the liver.

Conclusively, the findings of this study show that combined extract of Ziziphus jujube Mill., Cynara scolymus L. and and Cichorium intybus L. could improve serum and histological characteristics of non-alcoholic fatty liver disease induced by HFD.

The number of diabetic patients in adult population is increasing. All this population are at risk of developing diabetic foot ulcers (DFUs) that are associated with unwanted ailments and high mortality. In spite of current therapies for DFUs, further therapies are needed to help the patients.
The efficacy of herbal cream containing Pelargonium graveolens and Oliveria decombens essential oils was evaluated topically for treatment of DFUs in rat animal model in comparison with two other herbal formulas containing each essential oil alone, placebo (the basic formula without active ingredients) and normal saline as control groups. After anesthesia of diabetic rats (n=75) induced by streptozotocin (STZ), diabetic wounds were visible on the hind dorsal surface of the foot. The treatments were initiated on Day 1 and repeated 3 times a day for thirteen consecutive days. On day 1, 3, 5, 8 and 13, the wound sizes were determined and assessed histologically.
Three herbal formulations reduced the size of wounds in rats with DFUs, while the cream containing combined herbals of O. decumbens and P. graveolens essential oils had the highest tissue repair in DFU rat models.
Due to better wound healing effects of combined herbal cream containing O. decumbens and P. graveolens essential oils, it can be recommended in treatment of DFUs.

Onion (Allium cepa) is a plant with anti-diabetic and antioxidant properties. The aim of this study was to evaluate the protective effects of red onion ethanolic extract on learning and memory impairments in animal model of diabetes.
Material and For induction of diabetes, streptozotocin (55 mg/kg) was injected intraperitoneally to male Wistar rats. Thirty two male Wistar rats were randomly divided to 4 groups (n=8). Diabetic rats located to 3 groups including 2 treatment groups with onion ethanolic extract (125 and 250 mg/kg/day) for 4 weeks and one diabetic control group. In addition, the fifth group was considered as health control group. Finally, learning and memory changes were evaluated in the Morris water maze and passive avoidance tests.
Our finding showed that escape latency and traveled distance was significantly increased in diabetic control compared with health control. The administration of onion extracts at 125 and 250 mg/kg significantly decreased the escape latency and traveled distance. In addition, the induction of diabetes caused a significant impairment in memory consolidation compared with health rats. However, animals received extract at 125 mg/kg spent longer time and traveled greater distance in target quarter compared with diabetic control. Our data in passive avoidance test also showed that diabetes reduced step-through latency in animals. However, administration of onion ethanolic extract onion ethanolic extract led to increased step-through latency in diabetic rats.
Our finding showed that oral administration of red onion ethanolic extract improves learning and memory performances impaired by streptozotocin in diabetic rats.

Glutamate is the most widespread excitatory neurotransmitter in the mammalian central nervous system (CNS) and plays major role in the pathogenesis of ischemia brain injury.Glutamate transporters have a major role in glutamate removal and maintain its concentration below excitotoxic levels. Although estrogen’s and progesterone’s neuroprotective effects were well-described, the exact molecular mechanism has yet to be determined. This study has investigated estrogen and progesterone effect on glutamate transporters expression in the ischemic penumbra/peri-infarct region in rat.
Adult male Wistar rats were subjected to transient middle cerebral artery occlusion (tMCAO) for 1 h. Estrogen and progesterone combination was immediately injected after tMCAO subcutaneously. Sensorimotor functional tests for evaluating behavioral deficits and TTC staining for measurement of infarct volume were performed 24 h after MCAO. Real-time PCR technique was used for gene expression analysis of glutamate transporters EAAT2 and EAAT3.
The combination of estrogen and progesterone could significantly reduce lesion volume. Also, hormone therapy could improve ischemic neurological disorders. After hormone therapy, gene expression of glutamate transporters EAAT2 and EAAT3 did not show significant changes.
Combined estrogen–progesterone treatment significantly reduces neurological deficits and infarct volume; these effects are independent of the glutamate transporters signaling pathways.

Neuropathic pain is a chronic pain that affects on the patient’s quality of life. Use of herbal instead of synthetic drugs recently has been increased due to side effects of synthetic drugs and herbal effective components. Flavonoids are herbal compounds that have analgesic and anti-inflammatory effects. Because Allium cepa L. has a great amount of flavonoids, this study has been designed to evaluate analgesic effects of alcoholic extract of Allium cepa L. on neuropathic pain behavior in chronic constriction injury model in rats.
In this experimental study, neuropathic pain induced by chronic constriction injury (CCI model) in Rats. Animals were randomly divided into 4 groups (n=10 for each): Sham, CCI model, receiving red onion hydroalcoholic extract at a dose of 100 mg/kg and a group receiving gabapentin (100 mg/kg). Red onion extract and gabapentin were administered by gavage for 21 days. Using thermal hyperalgesia, mechanical and thermal allodynia tests, the analgesic effects of extract have been measured.
Findings of this study revealed that CCI surgery on rats induced hyperalgesia, mechanical and thermal allodynia. Daily intakes of alcoholic extract of red onion and gabapentin significantly increase the paw withdrawal latency; increase the threshold to mechanical allodynia and decrease in response to acetone.
Oral use of alcoholic extract of Allium cepa L. reduces neuropathic pain behavior in CCI model in rats.

Change in visual experience impairs circadian rhythms. In this study¡ The effects of visual deprivation during critical period of brain development and melatonin intake on synaptic plasticity of hippocampal CA1 neurons were evaluated.
This experimental study was done on male rats kept in standard 12 hour light/dark condition (Light Reared-LR) or in complete darkness (Dark Reared-DR). Each group¡ was divided into 3 sub groups of 2¡ 4 and 6 week old rats (n=16). Excitatory post synaptic field potentials were recorded from dendrite of CA1 area neurons. Then¡ half of animals in each group received melatonin via ICV and field potentials recording was repeated. Finally¡ using tetanic stimulation¡ Long-term potentiation (LTP) was induced.
The amplitude of basic responses of the LR animals decreased with age incaease (P Visual deprivation during critical period of brain development increases basic responses of rat’s CA1 neurons and inhibits LTP induction in these neurons¡ time dependently. Also¡ the visual deprivation opposes the destructive effects of melatonin on LTP induction in CA1 neurons in a time-dependent manner.

Parkinson's disease (PD) is a progressive neurological disorder associated with motor disabilities and cognitive dysfunction as well. Evidence indicates that PD occurs less frequently in women than men, confirming a role for steroid hormones in protection of dopaminergic nigrostriatal neurons. It is reported that soy genistein, an estrogen agonist phytoestrogen, display neuroprotective effects against neuronal death. In this study we evaluated the effect of genistein in animal models of Parkinsonism (P) and Parkinsonism ovariectomized (OP).
The experiments were carried out on the control, P and OP animals. Learning and memory abilities were evaluated using Morris water maze. The latency and speed of locating the platform were measured as cognitive indices. Motor behaviors were assessed by testing the animals in rota rod and the latency to fall from the rod was scored.
We found that Parkinsonism leads to the cognitive and motor disabilities; ovariectomy intensified these disorders. Whereas genistein treatment improved the maze performances in both P and OP animals it failed to influence the kinetic problems. Genistein displayed a neuroprotective effect on dopaminergic neurons.
Positive impact of genistein on the spatial learning and memory may reflect its effects on the nigrostriatal pathway and striatum. Nevertheless, ineffectiveness of genistein on the motor disorders, despite its neuroprotective impacts, led us to conclude that the cognitive improvement by genistein may also contribute to its effects in other areas of brain.

Boswellia serrata and Melissa officinalis is traditionally used for its memory enhancing effects.
In this study, we evaluated the protective effects of combined form of these extracts on memory improvement of scopolamine treated rats by the Morris water maze method.
Two groups (group 1 and 2) of animals were pretreated with combined extracts of B. serrata and M. officinalis (200, 400 mg/Kg body weight) for four weeks and then, 30 minutes before starting the experiment scopolamine was injected (0.1 mg/kg body weight) intraperitoneally to pretreated animals. The control group was the animals that were injected by scopolamine and pre treated with distilled water (group 3). The normal group was treated with distilled water alone (group 4).
For time spent and distance, there was no substantial difference between groups 1, 2 and 4, while they had statistical difference with group 3 (P = 0.001). The spatial memory evaluation showed no significant difference between treated groups and normal group.
Therefore, the combination of the two extracts had the ability to improve memory as its traditional use.

There are few reports have demonstrated the effect of a change-in-light experience on the structure and function of hippocampus. A change-in-light experience also affects the circadian pattern of melatonin secretion. This study aimed to investigate developmental effect of exogenous melatonin on synaptic plasticity of hippocampus of light deprived rats.
The effects of intracerebroventricular (ICV) injection of 2μg/5μl melatonin was evaluated on the basic and tetanized field excitatory post-synaptic potentials (fEPSPs) recorded in the hippocampal CA3-CA1 pathway of normal light-reared (LR) and dark-reared (DR) rats at 2, 4, and 6 weeks of age. Using RT-PCR and western blotting, developmental changes in the expression of melatonin receptors, MT1 and MT2, in the hippocampus were also evaluated.
The amplitude of basic responses decreased across age in the LR rats. While light deprivation increased the amplitude of baseline fEPSPs, it decreased the degree of potentiation in post-tetanus responses. Melatonin injection also increased the amplitude of fEPSPs and suppressed the induction of long-term potentiation in both LR and DR rats. The expression of melatonin receptors increased in the hippocampus during brain development, and dark rearing reversed the expression patterns of both receptors.
Although melatonin changed basic and tetanized responses of CA1 neurons across age during critical period of brain development, the pattern of its effects did not match the expression pattern of melatonin receptors in the hippocampus. Thus, the effects of melatonin on hippocampal neuronal responses may be exerted through other ways, like intercellular molecules and nuclear hormone receptors.

Aims: As effective herbal materials, flavonoids and the phenolic compounds are with anti-pain and anti-inflammatory effects. Based on the studies, there is a huge amount of polyphenols and flavonoids in the leaves of Morus alba L. Therefore, the aim of this study was to investigate the anti-pain effects of alcoholic extract of the leaves of Morus alba L. on the rats.
In the experimental study, 32 male Wistar rats were divided into 4 groups including control group and groups receiving 100, 200, and 400mg/kg alcoholic extract of the leaves of Morus alba L. There was 4-week daily extract gavage. The anti-pain effect of the extract was investigated through thermal hyperalgesia, writhing, tail flick, and formalin tests. Data was analyzed by SPSS 16 software using one-way ANOVA and Tukey’s post-hoc tests.
Findings: Daily use of 100, 200, and 400mg/kg of alcoholic extract of the leaves of Morus alba L. for 4 weeks led to significant increases in the mean foot withdrawal latency (p Oral consumption of the alcoholic extract of the leaves of Morus alba L. leads to a reduction in pain feeling in the rats. In addition, the anti-pain effect of 200mg/kg dose is higher than other doses.

Melatonin modulates the function of nervous system and its secretion is dependent to circadian rhythms and visual signals. The melatonin receptors are founded in many areas of the brain. During critical period of the brain development, the structure of mammals’ brain is intensely affected by peripheral sensory signals. The aim of this study was to evaluate the effect of interaction of age and visual deprivation during critical period of brain development on melatonin receptors expression in rats’ hippocampus. This experimental study was carried on 2 groups (n=36) of male Wistar rats kept in standard 12 hour light/dark condition (Light Reared-LR) or in complete darkness (Dark Reared-DR). The rats of each groups, were introduced into the experiments at 2, 4 and 6 weeks old of age. Expression of mRNA of both melatonin receptors, MT1 and MT2, in the hippocampus was evaluated by RT-PCR and using Western Blot technique, protein expression of those receptors was investigated. Data were analyzed by one-way ANOVA with Tukey post hoc tests. The relative expression of mRNA and protein of MT1 and MT2 receptors increased about 36% in the LR animals from 2 to 6 weeks old of age (p<0.001). The visual deprivation caused a decrease of 35% and 50% in expression of MT1 and MT2 from 2 to 6 weeks old of age, respectively (p<0.001 for both comparison). The relative expression of both melatonin receptors in rats’ hippocampus increases across aging during critical period of brain development and visual deprivation reverses the pattern of melatonin receptors expression.

Visual deprivation during critical period of brain development inhibits the GABAergic system growth and completion in visual cortex. Because parts of visual signals are transferred to hippocampus through the visual cortex, the aim of this experiment was to study the effects of visual deprivation during critical period of brain development on expression of Glutamic Acid Decarboxylase enzyme in rats’ hippocampus.

This study was carried on 2 groups (n=36) of male rats kept in standard 12 hour light/dark cycle (Light reared, LR) or in complete darkness (Dark reared, DR). Each group, in turn, was divided into 3 aged-based subgroups of 2, 4 and 6 weeks old rats. Using RT-PCR and Western Blot techniques, expression of both isoforms of Glutamic Acid Decarboxylase enzyme were investigated in hippocampus.

Relative expression of mRNA and protein of GAD65 and GAD67 enzymes increased in the LR animals, time dependently. However, although the expression of both enzymes increased in the DR animals by aging, but, the expression was much lower in compare to the LR rats.

Visual deprivation during critical period of brain development inhibits the expression of GAD65 and GAD67 enzymes in rat hippocampus and delays GABAergic system development.

Environmental signals have an essential role in the maturation of neural circuits during critical period of brain development. It has been shown that, change in visual signals during critical period of brain development changes structure and function of glutamate receptors in the visual cortex. After processing in visual cortex, part of visual signals goes to the hippocampus and makes memories. The aim of this study was evaluating effects of visual deprivation during critical period of brain development on AMPA receptor subunits expression in rats’ hippocampus.

This experimental study was done in Physiology Research Center, Kashan University of Medical Sciences at winter 2014 on male Wistar rats. Animals were divided to 2 groups (n= 36 for each) were kept in standard 12 hours light/12 hours dark condition (light reared, LR) or in complete darkness (dark reared, DR) from birth to the end of the experiments. Using reverse transcription polymerase chain reaction (RT-PCR) and Western blotting techniques respectively, expression of mRNA and protein of GluR1 and GluR2 subunits was evaluated in rats’ hippocampus at ages 2, 4 and 6 weeks in both groups. After quantification of the expressions, the data were compared by two way analysis of variance.

The relative expression of GluR1 subunit decreased about 24% (P=0.004) in the hippocampus of 6 WLR rats in comparison to 2 WLR ones. The relative expression of the other AMPA receptor subunit, GluR2, also increased about 190% in the hippocampus of the 6WLR animals when compared to the 2 WLR rats (P< 0.0001). Dark rearing increased the relative expression of both subunits of AMPA receptors, GluR1 and GluR2, about 20 percent (P= 0.01) in the hippocampus of 6 WDR rats in comparison to 2 WLR animals.

Dark rearing of rats during critical period of brain development changes the relative expression and also arrangement of both AMPA receptor subunits, GluR1 and GluR2 in the hippocampus, age dependently.

Changes in the visual experience during the critical periods of brain development lead to the dysfunction of the visual cortex.The visual cortex is a major supplier of sensory input in the mammalian hippocampus. This study aimed to investigate the effects of visual deprivation on the synaptic plasticity of CA1 neurons in this area. This experimental study was conducted on 48 male Wistar rats who had been classified into the two main groups of a 12-12 Light Reared (LR) and Dark Reared (DR) since birth.To perform the experiments, the rats were categorized under 3 subgroups of 2, 4 and 6 weeks of age. Excitatory postsynaptic potentials (EPSP) were recorded for 30 minutes from the dendrites of neurons in the CA1 area. Afterwards, long-term potentiation (LTP) was induced through Tetanic stimulation. Finally, the amplitude of the responses were measured before and after the Tetanic stimulation. The amplitude of basic responses in the 2WLR and 6WLR group were 1.28± 0.05 Mv and 1.09 ± 0.03 Mv, respectively (p<0.0001) while the range increased from 1.30 ±0.30 Mv in the 2WDR group to 1.50 ± 0.4 Mv in the 6WDR group (p<0.0001). Upon LTP induction, the highest rise in the amplitude response was observed at the age of 2 weeks in the animals. However, the increasing responses in both groups of LR and DR diminished with age (p<0.0001). Visual deprivation during the critical periods of brain development might lead to an increase in the basal synaptic activity of hippocampal CA1 neurons through an age-related process. Although it does not interrupt the induction of LTP in neurons, it might reduce its intensity and stability.

Neuropathic pain is one of the common complications of diabetes mellitus which is caused by impairment in nerve conductivity. The role of flavonoid and polyphenol compounds in treatment of neuropathic pain has been revealed، and extract of onion contains significant amounts of these compounds. The aim of this study was to investigate the effect of alcoholic extract of onion on diabetic neuropathic pain in streptozotocin-diabetic rats. In this experimental study، 40 male Wistar rats were divided into 5 groups: normal control، diabetic control and groups receiving alcoholic extract of onion (125، 250 and 500 mg/kg/day). After injection of streptozotocin (55 mg/kg)، the extract was administered for 3 weeks. At days 0، 7، 14 and 21 after injection of streptozotocin، assessment of neuropathic pain was performed by thermal allodynia، mechanical allodynia، hyperalgesia and formalin test. Behavioral responses to thermal and mechanical stimuli in diabetic control rats showed significant reduction (P<0. 05). Oral administration of alcoholic extract of onion at doses of 125 and 250 led to improvement in diabetic neuropathic pain in all 4 tests. However، dose of 500 mg didn’t improve neuropathic pain. Oral administration of alcoholic extract of Iranian red onion improves diabetic neuropathic pain in rats.

Environmental signals have a crucial role in development of brain’s structure and function during critical period of brain development. Gt was wvaluated the devebpmental effeck in developmental effect of visual deprivation on synaptic plasticity of Dentate Gyrus neurons was evaluated. This experimental study was carried on 2 groups (n=48) rats kept in standard 12-hour light/dark condition (Light Reared-LR) or in complete darkness (Dark Reared-DR) since birth throughout the study. Each group, in turn, was divided into 3 groups of 2, 6 and 10 weeks old subgroup (n=8 for each). Stimulating the perforant path, field potentials were recorded in the Dentate Gyrus area for 30 minutes. Then, the tetanic stimulation was applied to the Schaffer collaterals and the field potentials were pooled for 120 minutes post-tetanus in all animals. The basic responses of the LR animals decreased and the amplitude of the DR rats increased, across aging. After the LTP induction, amplitude of responses increased in all groups but the amount and stability of them were lower dark reared in animals than the LR ones. Change in environmental visual signals impairs basic response and LTP induction in neurons of Dentate Gyrus area of hippocampus.