hashem haghdoost-yazdi

Early diagnosis of Parkinson›s disease can play an important role in improving its prognosis. Due to controversies about the serum level of corticosterone and phosphate in parkinsonian rats, this study was designed to measure and evaluate the levels of corticosterone and phosphate as possible biomarkers of early diagnosis in rats with 6-OHDA-induced parkinsonism.

Forty rats were divided into three groups: control (n = 10), sham (n = 10), and 6-OHDA (n = 20). The rats in the 6-OHDA and sham groups underwent stereotaxic surgery to be injected with 6-OHDA and its carrier into their medial forebrain bundle (MFB). Apomorphine-induced rotational and cylinder tests were done to examine parkinsonism progression and sensory-motor function. Corticosterone and phosphate serum levels were measured in the serum and striatum.

Net contralateral rotations and asymmetry scores in the fourth, sixth, and eighth weeks after surgery compared with the second week showed a gradual increase in the 6-OHDA group. The serum levels of corticosterone were 90 ± 13 before surgery, and they declined to 88 ± 36 and 55 ± 9 ng/L in the second and eighth weeks after surgery, respectively. The serum levels of phosphate were 6 ± 0.22 before surgery, and they decreased to 5.2 ± 0.13 and 5 ± 0.12 mg/dl in the second and eighth weeks after surgery, respectively. The serum levels of phosphate and corticosterone remained relatively unchanged in the sham and control groups.

In conclusion, the progressive death of dopaminergic neurons is accompanied by decreased serum corticosterone and phosphate levels. Thus, the serum level of corticosterone can be used as a biomarker in diagnosing Parkinson’s disease. In contrast, serum phosphate levels were still within the normal range and cannot be used as a biomarker.

Alzheimer’s disease (AD) patients suffer from anxiety and depression. Pioglitazone (PIOG) is effective in the treatment of neurodegenerative diseases. The present study aimed to investigate the therapeutic efficacy of PIOG on anxiety and depression symptoms in the Streptozotocin (STZ) rat model of AD.

All the animals were divided into six groups: Control, DMSO, PIOG, sham-operated, STZ, and STZ plus DMSO or PIOG. For induction of AD, STZ (3mg/kg, 5μl/injection site) was injected into the lateral ventricles. After injection of PIOG (10 μl) or DMSO for 21 days, the behavioral tests were performed using sucrose preference, light-dark box, and elevated plus maze test.

The results showed that the STZ injection significantly reduced the entries, duration of presence in the light compartment and open arm of the elevated plus maze, and a percentage of sucrose preference compared to the control group. PIOG treatment in STZ-treated rats significantly increased the entries, duration of presence in the light compartment and open arm of the elevated plus maze, and a percentage of sucrose preference that indicated anti-depression and anxiolytic-like effects.

Based on our findings, the PIOG injection can reduce anxiety and depression-related behaviors in Alzheimer's rats.

Copper (Cu) involves in oxidation-reduction reactions, and its aggregation in the brain induces oxidative stress. However, previous studies reported a correlation between Cu plasma level and the risk of Parkinson’s disease (PD). In this study, the association between serum Cu level and dopaminergic neuronal death in substantia nigra was assessed in a 6- hydroxydopamine animal model of PD.

The 6-OHDA was injected into the medial forebrain bundle of rats by stereotaxic surgery. Behavioral tests were carried out in the second, fourth, and eighth weeks after the toxin injection to assess the severity of PD. Bloodletting was performed in the eighth week after the toxin injection. Then, dopaminergic neuron death in substantia nigra was evaluated by immunohistochemistry. Copper content was determined by atomic absorption spectrophotometry.

The severity of behavioral symptoms increased gradually after the toxin injection. However, there was no significant difference in serum copper levels among the experimental groups. According to the severity of behavioral symptoms, 6-OHDAtreated rats were divided into two subgroups symptomatic and asymptomatic. DAergic cell survival in symptomatic and asymptomatic subgroups was 83±16 and 45±10 %, respectively, which was lower than that in the control group. The serum copper level in the symptomatic subgroup was significantly lower than in the asymptomatic and solvent groups.

In conclusion, the decrease in serum copper level leads to intensive dopaminergic neuronal death in the substantia nigra.

Background and Aim:

 It has been reported that lithium (Li) has neuroprotective effects in neurodegenerative diseases. In this study, we investigated the association between serum Li level and Parkinson’s disease induced by 6-hydroxypapamine (6-OHDA) in rats.

6-OHDA was injected into the medial forebrain bundle by stereotoxic surgery. Apomorphine- induced rotational and cylinder tests were carried out before the toxin injection and in the second and sixth weeks thereafter. Blood samples were collected from the heart of the animals in the seventh week. The survival of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc) was determined using immunohistochemistry. Li was measured by ion selective electrode method (ISE).

There was no significant difference in the serum Li levels between control and 6-OHDA-treated rats. Based on the severity of the rotational behavior, the 6- OHDA- treated rats were divided into two subgroups: symptomatic (with severe behavioral symptoms) and asymptomatic (with no or mild behavioral symptoms). In the symptomatic and asymptomatic subgroups, SNc DA neuronal loss was 83 ± 16% and 45± 10%, respectively. Serum li level in the asymptomatic subgroup was significantly higher than that in the symptomatic subgroup and control group.

Serum Li level increased in the mild to moderate damage to SNc DA neurons but returned to normal value in severe neuronal damage. Therefore, an increase in serum Li level can predict subclinical SNc DA neuronal death and helps in making early diagnosis of PD.

The present study aimed at evaluating the association between the -429T/C and -374T/A polymorphisms of RAGE (Receptor for Advanced Glycation End Products) gene promoter and diabetic nephropathy as well as examining its possible application as candidate markers of diabetic nephropathy among the population of Qazvin, Iran.

In this study, the diabetic patients were divided into the two groups of with or without nephropathy. The frequency of genotype and allele were determined using TETRA-Primer ARMS-PCR. Hardy-Weinberg equilibrium test and correlation of polymorphisms, odds ratio (OR), and FAMHAP software were used for haplotype analysis.

Based on our data, the CC genotype of -429T/C polymorphism may play a protective role against the development of nephropathy (OR=0.586, 95%; CI: 0.158-2.167) while, the AA genotype may be associated with increased risk of the disease (OR=1.889, 95%; CI: 0.454-7.854). Allele’s analysis revealed that the C allele of -429T/C polymorphism maybe protective against the appearance of nephropathy (OR=0.794, 95%; CI: 0.48-1.314) whereas, the A allele may be related to increased risk for nephropathy (OR=1.452, 95%; CI: 0.783-2.695). Haplotype analysis demonstrated that there was no significant correlation between the two -429T/C and -374T/A SNPs (χ2=5.125, p value=0.135). However, it was found that the CA haplotype may have a protective effect against the development of nephropathy (OR=0.48, 95%; CI: 0.14-1.64) while, the TA haplotype may increase the risk of the disease (OR=2.06, 95%; CI:1.01-4.23).

Overall, no correlation between the -374T/A and -429T/C polymorphisms and the haplotypes in RAGE gene and the occurrence of diabetic nephropathy, was established.

In this study, using evaluation of the expression of two specific proteins of endoplasmic reticulum (ER) stress, GRP78 and CHOP in the striatum and substantia nigra (SN) in the 6-hydroxydopamine (6-OHDA) animal model of Parkinson’s disease (PD), the role of this stress was evaluated in the progress of Parkinson's disease (PD). 

6-OHDA was injected into medial forebrain bundle. Behavioral tests were carried out in the second, forth, sixth and eighth weeks after the toxin. In the eighth week, the brain of some rats was perfused and immunohistochemical (IHC) assessments were performed to evaluate the survival of dopaminergic neurons in SN and also the expression of GRP78 and CHOP in striatum. The brain of other rats was freshly removed and the expression of GRP78 and CHOP in SN was evaluated using western blotting.

The severity of behavioral symptoms increased progressively in 6-OHDA- treated rats and reached to maximum in the eighth week. IHC assessments revealed that more than 80% of dopaminergic neurons in SN were lost in these rats. These assessments also showed that only 5% of the cells in striatum of control rats expressed GRP78 and CHOP. On the other hand, about 42% of these cells in 6-OHDA- treated rats expressed these proteins. Furthermore, expression of GRP78 and CHOP in SN of 6-OHDA- treated rats increased 400% as compared to control rats.

ER stress involves in progress of 6-OHDA-induced parkinsonism in rat indicating this stress may have a role in progress of PD in human beings.

Parkinson’s Disease (PD) associates with changes in sex hormones; however, it remains unknown whether this is either a cause for or a result of the disease. To further evaluate it, we investigated if the development of 6-Hydroxydopamine (6-OHDA)-induced Parkinsonism changes the serum levels of testosterone and prolactin or not. 

6-OHDA was injected into the medial forebrain bundle using stereotaxic surgery. The development of Parkinsonism was evaluated by apomorphine-induced rotational test and the immunofluorescence labeling of Dopaminergic (DA) neurons in substantia nigra. The necessary blood samples were collected before the toxin and in the third and sixth weeks afterward. The hormones levels were determined using Enzyme-Linked Immunosorbent Assay (ELISA) kits.

The severity of rotations was different among 6-OHDA-treated rats; accordingly, they were divided into two subgroups of severe and mild parkinsonian rats. The degeneration of DA neurons was observed in both subgroups; however, it was significantly less in the mild group. In the sixth week after the toxin, testosterone level increased but only in the severe subgroup. Prolactin increased in both subgroups in the third week after the toxin but returned to normal in the sixth week. There was no association between the pre-toxin levels of these hormones and the intensity of Parkinsonism.

Our findings indicated that the development of 6-OHDA-induced Parkinsonism increases the serum levels of testosterone and prolactin. Increased prolactin occurred earlier and was observed in rats with less DA neuronal loss. Therefore, prolactin levels can predict the death of DA neurons before the clinical signs of PD were revealed.

Cystatin C (CysC) is an indicator of renal function, and has been recently reported that associates with neurodegenerative diseases. To investigate the role of this substance in Parkinson's disease (PD), we evaluated the association between serum levels of CysC and other markers of renal function with 6-hydroxydopamine (6-OHDA) induced Parkinsonism in rat.

The 6-OHDA was microinjected into the medial forebrain bundle by stereotaxic surgery. After behavioral tests, immunofluorescence and biochemical studies were carried out to determine the number of survived dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc) and striatal dopamine level. The blood samples were collected from the caudal vain and the heart of animals. CysC was measured using the enzyme-linked immunosorbent assay (ELISA) kits.

There was no difference in serum level of CysC between the 6-OHDA treated and control groups, as well as before and after the toxin in the 6-OHDA group. Also, no association was found between CysC and DA neuronal death in SNc or striatal dopamine level. In addition, there was no significant difference in serum levels of creatinine, urea and potassium ions between the control and 6-OHDA treated groups.

Since the death of DA neurons in SNc is the main pathophysiological mechanism underlying in the development of both 6-OHDA induced Parkinsonism and PD in human being, CysC and other markers of renal function cannot reflect DA neuronal death and accordingly cannot use for early diagnosis of PD.

 Hydrogen Sulfide (H2S), a novel endogenous gasotransmitter, plays an important role in neuromodulation and memory performance and also protects neurons against neurotoxin-induced neurodegeneration.  This study aimed to investigate the potential neuroprotective effects of Sodium Hydrosulfide (NaHS), on motor learning in a unilateral 6-Hydroxydopamine (6-OHDA) rat model of Parkinson’s Disease.  Male Wistar rats were subjected to unilateral injection of 6-OHDA (15 μg) into the Medial Forebrain Bundle (MFB) and then treated with NaHS for 25 days. Animals were divided into control, sham, sham plus NaHS, Parkinson (6-OHDA), Parkinson plus vehicle (saline), and Parkinson plus NaHS (2.8 and 5.6 mg/kg, IP) groups, (N=8). One-way ANOVA followed by turkey’s test was applied for statistical analyses of the data.  The riding time in fixed and accelerating speed rotarod were significantly decreased in Parkinson rats (6-OHDA group) compared to controls in all training days (P<0.001). Treatment with NaHS (2.8 and 5.6 mg/kg/d) reversed these decreases in a dose-dependent manner, so no significant differences were found in these parameters between the control and Parkinson plus NaHS groups during the accelerating speed rotarod test.  In the Parkinson rats, NaHS administration enhanced and improved the endurance time in the rotarod test. These results demonstrate that NaHS treatment enhances rat motor balance and coordination and suggest treatment with NaHS attenuates motor impairments in the Parkinson rats.

Diabetes mellitus cause cognitive defects. Royal Jelly has been claimed to improve the neurological damage caused by diabetes. In this study, the effect of oral administration of royal jelly on memory and passive avoidance learning was studied in diabetic male rats.
This experimental study was conducted in Qazvin University of Medical Sciences on 48 male Wistar rats. The animals were divided into control, diabetic without treatment, diabetic recipient of glibenclamide (600 μg/kg) and three diabetic groups treated with 50, 100 and 200 mg/kg royal jelly (n=8). Diabetes was induced in the animals by intraperitoneal injection of streptozotocin (60mg/kg/ip). Treatment in the groups performed by gavage from the onset of hyperglycemia for 30 days. At the end of the test, the passive avoidance learning and memory and blood glucose were measured. Data were analyzed by by SPSS software using ANOVA and post-hoc LSD tests, and p Diabetes reduced the latency time of dark room entering. Royal jelly treatment delayed the entrance to the dark room significantly at 24 h, 48 h and 2 weeks after the shock, especially at doses of 100 (p According to the results, diabetes causes memory impairment, and royal jelly administration can reduce the memory impairment due to diabetes.

Studies suggest that ATP-sensitive potassium (KATP) channels are a potential pharmacotherapeutic target for neuroprotection in neurodegenerative diseases. The current study aimed at evaluating the effect of pretreatment with glibenclamide (Glib) and B vitamins supplement on the severity of behavioral symptoms in 6-hydroxydopamine (OHDA)-induced Parkinsonism. Also malondialdehyde (MDA) concentration was measured in the blood and brain suspensions to find probable neuroprotective mechanism of Glib.
The 6-OHDA was injected into striatum of rats by stereotaxic surgery. Treatment with Glib and B vitamins was started before the surgery and continued up to 3 weeks after that. Development and severity of Parkinsonism were evaluated by conventional behavioral tests. MDA values were measured spectrophotometrically using thiobarbituric acid and MDA standard curve.
Pretreatments with Glib, at both doses of 1 and 5 mg/kg or B vitamins significantly ameliorated severity of the behavioral symptoms. Pretreatment with a combination of Glib and B vitamins was more effective than pretreatment with Glib or B vitamins alone. Also, pretreatment with B vitamins, Glib, or a combination of them reduced MDA concentration in the brain suspensions. Decrease in MDA concentration in the group of rats that received a combination of B vitamins and Glib was more prominent than that of the Glib groups.
As severity of the behavioral symptoms in the 6-OHDA-induced Parkinsonism reflects the degree of the lesion in Substantia Nigra (SN) dopaminergic neurons, it is suggested that Glib pretreatment has neuroprotective effect against 6-OHDA-induced neurotoxicity. The current study data also showed that this effect may be mediated by antioxidant effect of Glib.

Parkinson is a brain’s degenerative disease. Evidence shows that the levels of homocysteine increases in the Parkinson's disease. In this study, the success of cell transplantation was evaluated by comparison between serum homocysteine levels and behavioral symptoms in experimentally Parkinson's induced by 6-hydroxy dopamine (6- OHDA).
This experimental study was conducted in 2014 on male Wistar rats. The rats initially were Parkinsonism through stereotaxic 6- OHDA microinjection into right middle frontal areas of right hemisphere. Parkinson's was confirmed by apomorphine-induced rotation test. Then the rats treated with stem cell transplantation and the effect of treatment was assessed again. The total level of homocysteine was measured before, six weeks after 6- HDOA injection and ten weeks after cell transplantation. Data were analyzed using paired t-tests, ANOVA and Tukey test.
The total level of homocysteine didn’t change significantly in rats with higher number of rotations. But ten weeks after cell transplantation, the level of homocysteine decreased significantly.
Considering the direct correlation between the severity of rotational behavior and the degree of lesion in the substantia nigra (SN), our data indicate that higher tHcy values can predict higher SN dopaminergic neurodegeneration.

Due to different types of stress، it is important to recognize its adverse effects on the nervous system. This study was done to investigate the effect of three types of common stresses in modern living environment i. e. electromagnetic waves، immobilization and disturbance، individually and combined on pain threshold in infant rats. In this experimental study، 40 pregnant female Sprague rats and all their male infants were studied. Female rats were divided into 5 control، electromagnetic stress، immobilization stress، disturbance stress and combined stress groups. From eighth day of gestation، pregnant rats of stress groups were exposed to stress for 10 consecutive days. 75 days postpartum (after maturity)، male rats were subjected to formalin pain test. Measuring the pain intensity was done via scale «zero» (putting the feet on the ground completely)، «1» (putting the paw on the ground)، «2» (raising the feet) and «3» (biting or licking the feet). Data were analyzed using one-way ANOVA and Tukey''s post hoc tests. The mean of pain severity at the acute phase of the formalin test between each stress groups and the control group was not significant (p>0. 05). The mean of pain severity of the interphase stage of the formalin test was significant only between the electromagnetic stress and the control groups (p<0. 05). The mean of pain severity at the chronic stage of formalin test was significant between each of the combined stress (p<0. 01) and the immobility stress (p<0. 05) groups and the control group. Stress during pregnancy affects the pain behavior of the mature rats.

Several lines of evidence show that high plasma level of homocysteine (Hcy) induces development or exacerbates Parkinson’s disease. B vitamins are necessary for Hcy metabolism and control plasma level of Hcy. In the present study، we studied the effect of B vitamin supplementation on the 6-hydroxydopamine (6-OHDA) -induced Parkinsonism in rat. Rats were nourished with B vitamin supplements from 1 month before the surgery till the end of experiment. 6-OHDA was injected into the striatum of rat brains by stereotaxic surgery. Development and severity of the Parkinsonism were assessed by three conventional behavioral tests. Serum level of Hcy was measured before the surgery and at the end of experiment. Supplement of B complex significantly attenuated behavioral symptoms of the Parkinsonism. Supplement of B6 improved rotational behavior of the rats but had no effect on the swing and rotarod tests. Supplements of B12 and combination of B6، B12 and folate had no remarkable effect. Supplements of B6، B12 and B complex decreased serum level of Hcy before the surgery. In the end of the experiment، however، there was no significant difference for serum level of Hcy between experimental groups. Our results indicate that high intake of B complex can provide anti-Parkinsonism effect which is not mediated by lowering plasma Hcy.

High levels of homocysteine (Hcy) might accelerate dopaminergic cell death through oxidative stress and excitotoxicity. Folate plays an important role in the control of plasma levels of Hcy. In this study, effect of supplementation with folic acid on the 6-hydroxydopamine (6-OHDA)-induced Parkinsonism in rat and also serum level of Hcy was investigated. Rats were fed with folic acid supplements from 1 month before stereotaxic injection of 6-OHDA until to the end of experiments. 6-OHDA was injected into the striatum and development and severity of the Parkinsonism were assessed by conventional behavioral tests. Serum levels of Hcy before surgery and at the end of the behavioral tests were measured. Our results show that 10-fold supplementation, but not 2-fold supplementation of folic acid, significantly attenuates severity of 6-OHDA-induced Parkinsonism. 5-fold supplementation of folic acid also slightly decreased behavioral symptoms of Parkinsonism. Measurement of Hcy levels of sera before surgery show that high intake of folate has no effect on the plasma concentrations of Hcy. However, Hcy in the group of rats that received 10-fold supplement of folic acid was significantly higher than the control group at the end of the behavioral tests. Our results indicate that high intake of folic acid provides anti-Parkinsonism effect in a dose dependent manner, but this effect is not mediated by lowering plasma Hcy.

It is known that acute and chronic stress induce hormonal and neuronal changes which affecting both pain threshold and nociceptive behaviours. Orexin plays an important role in modulation of pain and stress. Considering pain modulation during stress and the role of orexin in pain and stress, orexin might be involved in pain modulation during stress.We evaluated the involvement of orexin receptor-1in acute immobilization stress on the tonic pain model. Adult male, Wistar rats (200–300 g), placed in a stereotaxic apparatus and canulla were inserted into their left cerebral ventricle. After 1 week of recovery, animals were initially submitted to one session of acute restraint stress (30 min) and immediately submitted to formalin injection in the hind paw to evaluate nociceptive behaviours. Orexin receptor 1 antagonist (SB 334867) was injected intracerebroventricularly, 5 minute before formalin injection, while the solvent was injected in the control group. two percent formalin produced typical biphasic pain responses in rats that was observed for more than 1 hour. Acute exposure to restraint stress reduced the nociceptive behaviour by chemical stimulation in phase 1, interphase and phase 2. The short-term stress induced analgesia was reflected in a decrease in the nociceptive behaviour during phase 1, whereas the long-term stress induced analgesia was reflected in a decrease in the nociceptive behaviours during phase 2. Pretreatment with orexin receptor 1 antagonist (SB 334867) attenuated the antinociceptive behavioral effect of restraint stress. Our results indicate that orexin receptor 1 antagonist attenuated antinociceptive effect of restraint stress assessed by formalin. These findings show that orexin receptor 1 might mediate an opioid-independent stress-induced analgesia.

Calcium spikes play important roles in the control of neuronal spontaneous activity. Cerebellar Purkinje neurons fire spontaneous calcium spikes. In this study, the role of potassium channels in the regulation of these spikes was studied. Brain slices from the cerebellum of young rats were prepared and the Purkinje cells were visualized using an upright microscope. Using borosilicate micropipettes and Axoclamp 2B amplifier, intracellular recordings were taken from the cells. The role of different K+ channels in the regulation of calcium spikes configuration was determined using different K+ channels blockers and precise analysis of the recorded calcium spikes in the presence of blockers. Application of wide-range 4-aminophyridine and tetraethylammonium blockers increased duration and amplitude of afterhyperpolarization (AHP) of the calcium spikes and converted them from one-peak spike to two- or multiple-peaks spikes. Blockade of small conductance calcium dependent potassium channels increased duration of the spikes but had no effect on the AHP amplitude Blockade of large conductance calcium dependent potassium channels increased duration of the calcium spikes and decreased the AHP amplitude. Our results showed that properties of the calcium spikes in the cerebellar Purkinje neurons were largely controlled by different potassium channels, including calcium dependent types.