Implication of nitrergic system in the anticonvulsant effects of ferulic acid in pentylenetetrazole-induced seizures in male mice

OBJECTIVES

Seizures are abnormal discharge of neurons in the brain. Ferulic acid (FA) is a phenolic compound with antioxidant and neuroprotective effects. The present study aimed to investigate the role of the nitrergic system in the anticonvulsant effect of FA in pentylenetetrazol (PTZ)-induced seizures in male mice.

METHODS

64 male Naval Medical Research Institute (NMRI) mice weighing 25-29 g were randomly divided into eight experimental groups (n=8). FA at doses 5, 10, and 40 mg/kg alone and in combination with L-nitro-arginine methyl ester (L-NAME) (nitric oxide synthase inhibitor) or L-arginine (L-arg) (nitric oxide [NO] precursor) was administrated (intraperitoneal). PTZ was injected (i.v. route) 30 min after drugs administration (1 mL/min). Seizure onset time was recorded and the nitrite levels of prefrontal cortex and serum were determined by the Griess method.

RESULTS

FA at doses of 10 and 40 mg/kg significantly increased the seizure threshold as well as reduced the serum and brain NO levels in comparison to the saline-received group. Co-administration of the effective dose of FA (10 mg/kg) plus L-arg significantly decreased the seizure threshold in comparison to the effective dose of FA alone. Co-injection of the sub-effective dose of FA (5 mg/kg) with L-NAME significantly increased the seizure threshold as well as significantly decreased the brain NO level in comparison to the sub-effective dose of FA alone.

CONCLUSIONS

We showed that the nitrergic system, partially at least, mediated the anticonvulsant effect of FA in PTZ-induced seizures in mice. We concluded that L-NAME potentiated while L-arg attenuated the anticonvulsant effect of FA.

Intraperitoneal injection of buprenorphine on anxiety-like behavior and alteration in expression of Gfap and Nrf2 in methamphetamine treated rats

The effects of buprenorphine (BUP) on anxiety-like behavior and the expression of the glial fibrillary acidic protein (Gfap) and nuclear factor erythroid 2-related factor 2 (Nrf2) in methamphetamine (METH)-treated rats were investigated in this study. Twenty-eight male Wistar rats were randomly divided into four groups including control (saline), METH (10.00 mg kg^-1), BUP (10.00 mg kg^-1), and BUP+METH groups and treated for five days. On the final day of treatment, gene expression levels and anxiety were evaluated using elevated plus-maze (EPM). According to the results, five days of METH injection reduced open arm exploration in the EPM. In contrast, the open arm entries and the time spent in the open arms were increased in the BUP+METH group compared to the METH group. The expression levels of Gfap and Nrf2 were lower in METH-treated rats compared to controls, whereas Gfap and Nrf2 expression levels were higher in the METH+BUP-treated rats compared to the METH-treated rats, however, it was similar to the controls. These findings suggested that co-administration of BUP+METH could decrease anxiety-like behavior through increasing the activity of the antioxidant protection system and might have therapeutic potential for preventing anxiety in METH users.

Population-level risks of alcohol consumption by amount, geography, age, sex, and year: a systematic analysis for the Global Burden of Disease Study 2020

BACKGROUND

The health risks associated with moderate alcohol consumption continue to be debated. Small amounts of alcohol might lower the risk of some health outcomes but increase the risk of others, suggesting that the overall risk depends, in part, on background disease rates, which vary by region, age, sex, and year.

METHODS

For this analysis, we constructed burden-weighted dose-response relative risk curves across 22 health outcomes to estimate the theoretical minimum risk exposure level (TMREL) and non-drinker equivalence (NDE), the consumption level at which the health risk is equivalent to that of a non-drinker, using disease rates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2020 for 21 regions, including 204 countries and territories, by 5-year age group, sex, and year for individuals aged 15-95 years and older from 1990 to 2020. Based on the NDE, we quantified the population consuming harmful amounts of alcohol.

FINDINGS

The burden-weighted relative risk curves for alcohol use varied by region and age. Among individuals aged 15-39 years in 2020, the TMREL varied between 0 (95% uncertainty interval 0-0) and 0·603 (0·400-1·00) standard drinks per day, and the NDE varied between 0·002 (0-0) and 1·75 (0·698-4·30) standard drinks per day. Among individuals aged 40 years and older, the burden-weighted relative risk curve was J-shaped for all regions, with a 2020 TMREL that ranged from 0·114 (0-0·403) to 1·87 (0·500-3·30) standard drinks per day and an NDE that ranged between 0·193 (0-0·900) and 6·94 (3·40-8·30) standard drinks per day. Among individuals consuming harmful amounts of alcohol in 2020, 59·1% (54·3-65·4) were aged 15-39 years and 76·9% (73·0-81·3) were male.

INTERPRETATION

There is strong evidence to support recommendations on alcohol consumption varying by age and location. Stronger interventions, particularly those tailored towards younger individuals, are needed to reduce the substantial global health loss attributable to alcohol.

FUNDING

Bill & Melinda Gates Foundation.

The comparison of omega-3 and flaxseed oil on serum lipids and lipoproteins in hyperlipidemic male rats

Hyperlipidemia affects a significant number of patients despite treatment with cholesterol-lowering drugs. Due to the low efficacy of synthetic drugs, there is a need for new agents with low side effects. Therefore, the effects of flaxseeds oil and animal omega-3 on the hyperlipidemic rats were investigated. Forty male Wistar rats were assigned to four groups (n = 10): 1) control group that was fed with a standard diet (pallets). 2) high-fat diet (HFD) control group that was fed with high-fat food for 42 days, 3) Omega-3 group that received HFD for 21 days, followed by HFD + omega-3 capsule (600 mg/kg; 21 days/gavage), and 4) flaxseed oil group that received HFD for 21 days, followed by HFD + flaxseed oil (10 ml/kg; 21 days/gavage). Blood samples were collected three times and at the stages one to third of the experiment from the rats' tail. The results showed that high levels of fat significantly increased cholesterol, triglyceride (TG), and low-density lipoprotein (LDL) in the flaxseed, HFD control, and omega-3 groups in the second stages of the experiment. Inverse, omega-3 or flaxseed oil supplementation decreased cholesterol, TG, and LDL levels and increased high-density lipoprotein (HDL) level in comparison with the HFD control group in the third stages of the experiment. There was no significant difference in the studied parameters between the flaxseed- and omega-3-treated groups. It can be concluded that flaxseed oil similar to omega-3 is effective in the treatment of hyperlipidemia.

Thymus persicus (Ronniger ex Rech. f.) Jalas alleviates nociceptive and neuropathic pain behavior in mice: Multiple mechanisms of action

ETHNOPHARMACOLOGICAL RELEVANCE

Thymus persicus (Roniger ex Reach F.) is an Iranian endemic medicinal plant of which essential oil and various products have numerous food and pharmaceutical applications (headache and fever treatments).

OBJECTIVE

This modern research included Swiss mice to investigate the anti-nociceptive and anti-neuropathic effects of Thymus persicus aerial parts essential oil (TPEO).

MATERIALS AND METHODS

To determine TPEO's anti-nociceptive function in the formalin-induced paw licking (FML), researchers looked at the L-arginine/NO/cGMP/KATP channel signaling pathway as well as multiple receptors as with serotonin, morphine, dopamine, and peroxisome proliferator-activated receptors. The CVC or cervical spinal cord contusion exemplar has also been used to induce neuropathic pain.

RESULTS

TPEO (50, 100, and 150 mg/kg) relative to control mice in the phase-II of FML provided strong antinociception (p < 0.05, p < 0.01, p < 0.001, respectively). Furthermore, methylene blue, glibenclamide, Nω-nitro-L-arginine methyl ester, naloxonazine, nor-binaltorphimine, prazosin, yohimbine, and ondansetron pre-treating restored the TPEO anti-nociceptive activity in the FML (phase-II) exemplar (p < 0.05). In phase-II of the FML exemplar, carvacrol (one of the active components of TPEO) also greatly reduced pain (p < 0.001). Likewise, in CVC mice, TPEO altered mechanical allodynia and hyperalgesia.

CONCLUSION

It was attained magnificently that TPEO could exerts antinociceptive effects through the involvement of L-arginine/NO/cGMP/KATP signaling pathway, adrenergic, opioid, and serotonin receptors. Moreover, it is demonstrate that anti-neuropathic activity of TPEO may be mediated by inflammatory function.

Physospermum cornubienseL. alleviates nociceptive and neuropathic pain: Evidences and possible mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

In Iranian/Persian folkloric medicine, Physospermum cornubiense (Shokaran Baghi in Persian) is used for the treatment of pain and inflammation.

OBJECTIVE

This modern examination included Swiss mice to investigate the anti-neuropathic and anti-nociceptive effects of Physospermum cornubiense essential oil (PCEO).

MATERIALS AND METHODS

To determine PCEO 's anti-nociceptive function in formalin-induced paw licking (FML) paradigm, researchers looked at the arginine-nitric oxide and potassium channels pathway in addition to involvements of more specific examples of receptors such as adrenergic, opioid, cannabinoid, peroxisome proliferator-activated (PPA), and transient receptor potential vanilloid. The CVC or cervical spinal cord contusion exemplar has also been used to induce neuropathic pain.

RESULTS

PCEO (450mg/kg) relative to control mice in the phase_ II of FML exemplar provided strong antinociception (p < 0.001). Furthermore, pre-treatments with arginine, glibenclamide, methylene blue, L-NAME, SNP, GW6471, naloxonazine, and GW9662 (p < 0.05) returned the PCEO antinociceptive response in the FML (inflammatory phase) model. Orally limonene administration significantly diminished (p < 0.001) acute pain in inflammatory phase of FML test. Moreover, the von Frey test indicated that both PCEO and limonene could return neuropathic pain (mechanical allodynia) in CVC mice.

CONCLUSION

The results obtained from this study, together with literature, give evidence of properties of PCEO for therapy of antinociceptive and neuropathic pain.

Comparing the Effects of Long-term Exposure to Extremely Low-frequency Electromagnetic Fields With Different Values on Learning, Memory, Anxiety, and β-amyloid Deposition in Adult Rats

Introduction: Extremely Low-Frequency Electromagnetic Fields (ELF-EMFs) have gathered significant consideration for their possible pathogenicity. However, their effects on the nervous system’s functions were not fully clarified. This study aimed to assay the impact of ELF-EMFs with different intensities on memory, anxiety, antioxidant activity, β-amyloid (Aβ) deposition, and microglia population in rats. Methods: Fifty male adult rats were randomly separated into 5 groups; 4 were exposed to a flux density of 1, 100, 500, and 2000 microtesla (µT), 50 Hz frequency for one h/day for two months, and one group as a control group. The control group was without ELF-EMF stimulation. After 8 weeks, passive avoidance and Elevated Plus Maze (EPM) tests were performed to assess memory formation and anxiety-like behavior, respectively. Total free thiol groups and the index of lipid peroxidation were evaluated. Additionally, for detection of Aβ deposition and stained microglia in the brain, anti-β-amyloid and anti-Iba1 antibodies were used. Results: The step-through latency in the retention test in ELF-EMF exposure groups (100500 & 2000 µT) was significantly greater than the control group (P<0.05). Furthermore, the frequency of the entries into the open arms in ELF-EMF exposure groups (especially 2000 µT) decreased than the control group (P<0.05). No Aβ depositions were detected in the hippocampus of different groups. An increase in microglia numbers in the 100, 500, and 2000 µT groups was observed compared to the control and one µT group. Conclusion: Exposure to ELF-EMF had an anxiogenic effect on rats, promoted memory, and induced oxidative stress. No Aβ depositions were detected in the brain. Moreover, the positive impact of ELF-EMF was observed on the microglia population in the brain.

Synergism effect of swimming exercise and genistein on the inflammation, oxidative stress, and VEGF expression in the retina of diabetic-ovariectomized rats

AIMS

Retinal neovascularization is one of the visual disorders during the postmenopausal period or types two diabetes. Physical activities and also phytoestrogens with powerful antioxidant features have been widely considered to improve nervous system diseases. Therefore, this study investigated the effects of genistein, swimming exercise, and their co-treatment on retina angiogenesis, oxidative stress, and inflammation in diabetic-ovariectomized rats.

MAIN METHODS

Wistar rats were randomly divided into six groups (n = 8 per group): sham, ovariectomized group (OVX), OVX + diabetes (OVX.D), OVX.D+ genistein (1 mg/kg, eight weeks; daily SC), OVX.D + exercise (eight weeks), and OVX.D+ genistein+exercise (eight weeks). At the end of 8 weeks, the retina was removed under anesthesia. The assessed effects of treatment were by measuring MiR-146a and miR-132 expression via RT-PCR, the protein levels of ERK, MMP-2, VEGF, and NF-κB via western blotting, inflammation, and oxidative stress markers levels via the Eliza.

KEY FINDINGS

The results showed miR-132, miR-146b, and MMP-2, NF-κB, ERK, VEGF, TNF-α, IL-1β proteins, and MDA factor in the OVX.D group were increased, but glutathione (GSH) was decreased in comparison with the sham and OVX groups. Both exercise and genistein treatment has reversed the disorder caused by diabetes. However, the combination of exercise and genistein was more effective than each treatment alone.

SIGNIFICANCE

It can be concluded that the interaction of exercise and genistein on microRNAs and their target protein was affected in the inflammation, stress oxidative, and extracellular matrix metalloproteinase pathways, can leading to a decrease in impairment of retinal neovascularization of the ovariectomized diabetic rats.

Diabetic neovascularization defects in the retina are improved by genistein supplementation in the ovariectomized rat

Genistein seems to have a protective and therapeutic effect on conditions associated with neovascular growth in the retina. This study investigated the angiogenesis, antioxidant, and anti-inflammatory effect of genistein on the retinas in ovariectomized diabetic rats. In this study, 40 female albino Wistar rats were divided into four groups (n = 8 per group): sham, ovariectomized group (OVX), OVX + diabetes (OVX.D), and OVX.D + genistein (OVX.D.G). OVX induced by removal of bilateral ovaries and then high-fat diet (HFD) and a low dose of streptozotocin (STZ) (1 mg/kg; intraperitoneal (IP) injection) was used for diabetes induction (OVX.D) with 8 weeks of genistein treatment (OVX.D.G). At the end of 8 weeks, the retina was removed under anesthesia. The samples were used to measure extracellular signal-regulated kinase (ERK), matrix metalloproteinase 2 (MMP-2), vascular endothelial growth factor (VEGF), and nuclear factor NF-kappa-B (NF-κB) by western blotting and inflammatory factors ELISA and oxidative stress. Measurements of glutathione (GSH) and malondialdehyde (MDA) showed that OVX and especially OVX.D significantly decreased GSH and increased MDA level in the retina, but genistein reversed these effects in OVX.D.G groups. Also, OVX and OVX.D significantly increased VEGF, MMP-2, p-ERK, NF-κB, interleukin-1beta (IL-1β), and tumor necrosis factor alpha (TNFα) expression in the retina of OVX and OVX.D groups in comparison to the sham group (p < 0.05). However, a significant reduction of these proteins was observed in the genistein-treated group (p < 0.05). In conclusion, bilateral ovariectomy and subsequently estrogen deficiency caused the development of inflammation, neovascularization, and then retinopathy in STZ-induced diabetic ovariectomized rats. On the basis of the results, genistein administration may be a practical approach for improving symptoms and complications of ovariectomized diabetic retinopathy.

Effect of exercise intensity and duration on the levels of stress hormones and hypothalamic-pituitary-gonadal axis in adult male rats: an experimental study

PURPOSE

The effect of exercise on stress has been demonstrated in several studies which have shown that exercise intensity and duration have various effects on the reproductive axis. This study evaluated the effect of different intensities and durations of exercise on the hormonal indices of stress, such as corticosterone (CORT), norepinephrine (NEP), and also reproductive performance indices, including gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), and testosterone (T).

METHODS

In this experimental study, 30 adult Wistar rats were randomly divided into five groups as follows: no-exercise, RME-1 (regular moderate exercise for 1 month), RME-6 (regular moderate exercise for 6 months), RIE-1 (regular intensive exercise for 1 month), and RIE-6 (regular intensive exercise for 6 months). At the end of the experiment, the serum levels of the abovementioned hormones and hypothalamic expression of the Gnrh gene were measured using the enzyme-linked immunosorbent assay and the real-time polymerase chain reaction method, respectively.

RESULTS

The levels of stress hormones, including CORT and NEP, increased only in the RIE-1 group compared with the no-exercise group. In addition, an increase was observed in T hormone levels in the RME-1 group compared with those in the no-exercise group, whereas LH and T hormone levels showed a greater decrease in the RIE-6 group than in the no-exercise group. Gnrh expression levels showed an increase and a decrease in the RME-1 and RIE-6 groups compared with the no-exercise group, respectively.

CONCLUSION

These results confirmed the effects of different intensities and durations of exercise on sex hormone levels.

Short-term regular moderate exercise improved male hypothalamic-pituitary-gonadal axis function via the reduction of hypothalamic neurokinin B expression in adult rats

Introduction: In the arcuate nucleus, kisspeptin, neurokinin-B and pro-dynorphin (KNDy) neurons control the function of gonadotropin-releasing hormone (GnRH) neurons. Early investigations indicated that exercise with various intensities affects luteinizing hormone (LH) and testosterone (T) in different ways. Meanwhile the molecular mechanisms underlying its function not yet been fully understood. Accordingly, the present study evaluated the role of alterations in the levels of KNDy mRNA upstream of GnRH neurons in conveying the effects of various short-term exercise intensities on the male hypothermic-pituitary-gonadal (HPG) axis. Methods: Twenty-one adult Wistar rats were randomly divided into 3 groups: control, one-month regular moderate exercise (ME) and one-month regular intensive exercise (IE). In ME (22m/min) and IE (35m/min) groups, the rats were treated 5 days a week for 60min each day. Finally, we assessed serum levels of LH and T using the ELIZA technique and KNDy and Gnrh mRNA expression by the real-time PCR method. Results: The results revealed that in ME group the expression of Nkb was reduced and the expression of Gnrh mRNA and the LH and T serum levels were increased. However, intensive exercise did not change the serum levels of LH and T or the relative expression of kiss1, Nkb, Pdyn and Gnrh genes. Conclusion: The results suggested that monthly moderate exercise improved male reproductive axis function, while intensive exercise did not have an adverse effect on the reproductive axis. These various effects on the male HPG axis may be propagated by the change in hypothalamic Nkb gene expression.

Dual-signaling electrochemical ratiometric strategy for simultaneous quantification of anticancer drugs

A novel and unique ratiometric electrochemical sensing strategy for highly reliable and selective simultaneous quantification of Irinotecan (IRI) and 5-Fluorouracil (5-FU) has been developed based on Pd-Au/MWCNT-rGO nanocomposite. Introduction of Pd-Au/MWCNT-rGO significantly improved the speed of electron transport, specific surface area, and electrical catalytic ability of sensing system due to synergistic effect of Pd-Au bimetallic nanoparticles and MWCNT-rGO hybrid structure. The assay strategy was based on the use of ferrocene (Fc) as reference electroactive substance and IRI and 5-FU as analytes with three oxidation peaks at different potentials (Fc at +0.20 V, IRI at +0.58 V, and 5-FU at +1.17 V). The oxidation peak currents of the IRI and 5-FU were gradually enhanced while that of Fc remained almost constant with continuous adding of IRI and 5-FU. By using I_IRI/I_Fc and I_5-FU/I_Fc signals as output, the designed ratiometric system showed good performance with a wide linear range of 0.05-40 μM for IRI and 0.05-75 μM for 5-FU and low detection limit of 0.0061 μM and 0.0094 μM for IRI and 5-FU, respectively. This study proved that ratiometric strategy is able to eliminate disturbance caused by the sensing environment and possess high sensitivity, reproducibility, stability, and selectivity toward anticancer drugs detection, over potential interferents as well as opens a new procedure for reliable and selective simultaneous analysis of other analytes.

Improved solid phase extraction for selective and efficient quantification of sunset yellow in different food samples using a novel molecularly imprinted polymer reinforced by Fe3O4@UiO-66-NH2

The overuse of synthetic dyes in food products has gradually increased in recent years, resulting food safety and human health has become a global issue. An innovative design of a magnetic molecularly imprinted polymer (Fe3O4@UiO-66-NH2@MIP) for efficient, fast, and selective determination of sunset yellow (SY) from different food products was described in this study. The absorption properties of Fe3O4@UiO-66-NH2@MIP were elucidated by adsorption kinetics, isotherms, reusability, and selectivity experiments. Because of the incorporation of porous Fe3O4@UiO-66-NH2nanocomposite into molecularly imprinted polymer an efficient nanosorbent with a short equilibrium time, a high adsorption capacity, and a good imprinting factor was finally obtained. The porous Fe3O4@UiO-66-NH2@MIP are also used for quantification of the SY. Under optimal conditions, good linearity (R2 0.9964) in the range of 1.0-120 mg L-1 and a low limit of detection (0.41 mg L-1) was observed with satisfactory recoveries (92.50-106.1%) and excellent reusability (RSD ≤ 6.6% after 12 cycles).

Conjugated Linoleic Acid-Curcumin Attenuates Cognitive Deficits and Oxidative Stress Parameters in the Ethidium Bromide-Induced Model of Demyelination

Oxidative stress has been shown to play an important role in the pathogenesis of multiple sclerosis (MS). Curcumin (CUR), an antioxidant compound, can be a potent treatment for neurodegenerative diseases, such as MS. CUR has poor bioavailability; therefore, it is used in nanoforms to increase its bioavailability. In the present study, the effects of CUR and conjugated linoleic acid-CUR (Lino-CUR) on spatial memory and oxidative stress in a putative animal model of MS were investigated. Forty-nine adult male Wistar rats (250 ± 50 g) were randomly divided into seven groups (n = 7): control, sham, ethidium bromide (EB), CUR (20 and 40 μg/kg) + EB, and Lino-CUR (20 and 40 μg/kg) + EB groups. Following MS induction, the groups were treated for 5 consecutive days. Finally, spatial memory and levels of oxidative stress parameters were assessed. Treatment with CUR and Lino-CUR at two doses significantly improved spatial memory and reduced oxidative stress parameters in the experimental models of MS. Furthermore, the effects of high dose (40 μg/kg) of Lino-CUR were more remarkable. These findings suggest that the microinjection of CUR in its synthetic form Lino-CUR significantly ameliorated spatial memory, through the reduction of oxidative stress markers in the brain of studied animals as a rat model of MS.

Antinociceptive activity of Cnicus benedictus L. leaf extract: a mechanistic evaluation

Background and purpose:

Cnicus benedictus, a medicinal herb, traditionally had been used for the treatment of stomachache pain. In this study, the possible efficacy of Cnicus benedictus leaf methanolic extract (CBHE) and also cnicin, one of its major constituents, was measured on pain.

Experimental approach:

In this study, pain assessment tests include writhing, tail-flick (TF), and formalin- induced paw licking test (FIPLT) were used. To understand the possible mediated anti-nociceptive mechanism of CBHE, the opioid mechanism(s), and involvement of the L-arginine/ nitric oxide/cGMP/ATP-sensitive potassium channel pathway (LNCaP) were scrutinized.

Findings/Results:

In TF and writhing tests, CBHE (150 and 300 mg/kg, i.p) remarkably exhibited an anti-nociceptive effect compared to that of the control. Furthermore, CBHE (150 and 300 mg/kg, i.p) in comparison with the control showed a noteworthy anti-nociceptive effect (P < 0.01) in the tonic phase of FIPLT. In the writhing test, administration of selective opioid antagonist (naltrindole, nor-binaltorphimine, and naloxonazine) attenuated the anti-nociceptive effect of CBHE (300 mg/kg) in comparison with control. Moreover, pre-treatment with Nω-nitro-L-arginine methyl ester hydrochloride, L-arginine hydrochloride, and glibenclamide significantly blocked the CBHE (300 mg/kg) anti-nociception (P < 0.05) while administration of sodium nitroprusside remarkably potentiated (P < 0.05) the antinociception induced by CBHE in the tonic phase of the FIPLT. Besides, cnicin (30 mg/kg) showed noteworthy anti-nociceptive effects in writhing, TF, and FIPLT paradigms.

Conclusion and implications:

Taken together, we elucidate that both CBHE and cnicin demonstrated antinociceptive effects in behavioral tests. The possible mechanisms of CBHE antinociception may involve in various neural signaling and modulatory pathways including LNCaP and opioidergic mechanisms.

Synergistic effects of quercetin and regular exercise on the recovery of spatial memory and reduction of parameters of oxidative stress in animal model of Alzheimer's disease

It has widely been reported that the brain in Alzheimer's disease (AD) is affected by increased oxidative stress, and this may have a role in the pathogenesis of this disorder. Quercetin, a polyphenol extensively found in nature, has recently been considered. Also, physical activities have a paradoxical effect on brain function in older adults. Therefore, this study aimed at investigating the synergic effects of quercetin (as chemical treatment) and exercise (as physical treatment) on AD-induced learning and memory impairment. Fifty-six adult male Wistar rats were randomly assigned into one of the following eight groups (n=7): The Control, Sham (saline), AD (intracerebroventricular administration of streptozotocin (STZ)), AD+80 mg/kg Quercetin (STZ+Q80), Quercetin vehicle (1 % Ethanol)+STZ, Exercise pretreatment (EX)+STZ, Off the treadmill+STZ, and EX+Q80+STZ. Quercetin administration was done intraperitoneally for 21 days after STZ injection. The rats ran on the treadmill for one hour a day for 60 days at a speed of 20-22 m/min. After the treatment, the spatial memory and levels of oxidative stress parameters were evaluated. The results showed that STZ caused spatial memory impairment and increased oxidative stress in the hippocampus. Exercise pretreatment or Quercetin injection improved the spatial memory impairment and oxidative stress caused by STZ injection. However, the combination of quercetin and exercise pretreatment was more effective. It can be concluded that the combined exercise pretreatment and Quercetin injection affected the antioxidant defense system and improved STZ-induced memory impairment.

Alteration level of hippocampus BDNF expression and long-term potentiation upon microinjection of BRL15572 hydrochloride in a rat model of methamphetamine relapse

Methamphetamine (METH) relapse affects the function of the serotonergic system, which this system important for synaptic plasticity and brain-derived neurotrophic factor (BDNF) level. While there is a clear distribution of serotonin receptors in the reward and memory areas but the function of 5-HT_1D receptor isn't known. This article assessed effects of BRL15572 hydrochloride (5-HT_1D receptor antagonist) on behavior, long-term potentiation (LTP), and BDNF level in reinstated METH-rats. Conditioned place preference was induced by injecting METH (5 mg/kg; i.p.) or saline on the conditioning days. On the last day of extinction, they received priming METH [simultaneously with BRL (2 μg/5 μl; i.c.v.) or vehicle] or saline or saline + vehicle. Preference scores, LTP components and expression of BDNF were measured on the following day. The preference score of METH treatment increased dramatically more than the sham group and co-administration of BRL + METH couldn't decrease the preference score than the METH group. Also, METH treatment increased the population spike relative to the sham group, whereas the treatment METH + BRL attenuated this parameter than METH group. Furthermore, BDNF expression significantly increased in the METH group although it decreased markedly upon treatment with BRL. These results suggest that future studies should evaluate the potential of 5-HT_1D antagonist for METH-reinstatement behaviors.

Different doses of methamphetamine alter long-term potentiation, level of BDNF and neuronal apoptosis in the hippocampus of reinstated rats

Methamphetamine (METH) is a psychostimulant. The precise mechanisms of its effects remain unknown and current relapse treatments have low efficacy. However, brain-derived neurotrophic factor (BDNF) and neuronal plasticity are essential contributors, despite paradoxical reports and a lack of comprehensive studies. Therefore, we investigated the effects of different doses of METH on long-term potentiation (LTP), BDNF expression and neuronal apoptosis in the hippocampus of reinstated rats. Rats were injected intraperitoneally with METH (1, 5, or 10 mg/kg) or saline, and trained in a conditioned place preference paradigm. Following implementation of the reinstatement model, electrophysiology, western blotting and TUNEL assay were performed to assess behavior, LTP components, BDNF expression, and neuronal apoptosis, respectively. The results demonstrated that the preference scores, population spike amplitude and BDNF expression markedly decreased in the METH (10 mg/kg) group compared with the other groups. In contrast, METH (5 mg/kg) significantly increased these factors more than the control group. There was no change in variables between METH (1 mg/kg) and the control group. Also, apoptosis of the hippocampus was increased in the METH (10 mg/kg) group compared with the METH (5 mg/kg) group. These results suggest that alterations in synaptic plasticity, expression of BDNF and neuronal apoptosis in the hippocampus has a vital role in the context-induced reinstatement of METH seeking.

Intracerebroventricular microinjection of the 5-HT1F receptor agonist LY 344864 inhibits methamphetamine conditioned place preference reinstatement in rats

Relapse following a prolonged period of drug cessation is a key barrier in the treatment of methamphetamine (METH) addiction, for which pharmacological treatment exhibits little efficacy. Previous studies have suggested that this process involves alterations in levels of serotonin (5-HT) in the brain. Although the 5-HT1F receptor has been implicated in the reward pathway, its physiological functions remain unknown. In the present study, we examined the effect of the 5-HT1F agonist LY 344864 on the reinstatement of METH-seeking behavior in rats using a conditioned place preference (CPP) paradigm. The CPP paradigm was first used to determine the effective doses of LY and METH. Four groups were then conditioned with METH (5 mg/kg; i.p.), while the sham group received saline. METH-induced CPP was subsequently extinguished. On the 13th day of extinction, the rats received either METH (0, 1, or 2.5 mg/kg; i.p.) plus vehicle or priming METH plus LY (2 μg/5 μL; i.c.v.). On reinstatement day, preference scores were calculated as the difference in time spent in the drug-paired and vehicle-paired compartments. Rats conditioned with the lowest effective dose of METH (5 mg/kg) exhibited significant differences in pre- and post-testing preference scores. Preference scores were significantly higher in the saline + METH group than in the control group. Furthermore, preference scores were significantly higher in rats that had received priming METH treatment, and pre-treatment with LY significantly attenuated the reinstatement of METH-seeking behavior. These findings suggest that future studies should evaluate the therapeutic potential of 5-HT1F agonists for preventing relapse in individuals with METH addiction.

Effect of a 5-HT1D receptor agonist on the reinstatement phase of the conditioned place preference test and hippocampal long-term potentiation in methamphetamine-treated rats

Methamphetamine (METH)-seeking relapse is associated with memory and synaptic plasticity changes. Serotonin is a key neuromodulator in this process. While there is a known distribution of 5-HT_1D receptors in reward and memory areas, such as the hippocampus, its physiological function is currently unknown. Here, we evaluated effect of a 5-HT_1D receptor agonist, PNU142633, on the reinstatement of METH-seeking behavior and long-term potentiation. Rats were implanted with a cannula into lateral ventricle, then treated with saline or METH (5 mg/kg) during the acquisition phase of the conditioned place preference (CPP) test. On day 13 of the extinction phase, METH groups were divided into four groups: METH (0: saline, 1, or 2.5 (priming METH) mg/kg; i.p.) + vehicle (5 µl/rat) or a priming dose of METH (2.5 mg/kg; i.p.) + PNU (2 µg/5 µl; i.c.v.) and their preference scores were calculated on reinstatement day (day 14). Immediately following this, electrophysiology was performed to assay the field excitatory postsynaptic potential (fEPSP) slope and population spike (PS) amplitude between groups. The results showed that CPP induction by METH gradually declined to extinction on days 12 and 13. A priming METH treatment significantly increased preference for the METH-paired chamber when compared with other groups, but pre-treatment with PNU significantly attenuated this effect. PS amplitude and fEPSP slopes in vehicle + priming METH rats were greater when compared with other groups. Furthermore, PNU attenuated the priming METH-induced increase in PS amplitude. These findings suggest that PNU can decrease synaptic transmission and prevent METH reinstatement in rats.

Decreased nitric oxide levels in the hippocampus may play a role in learning and memory deficits in ovariectomized rats treated by a high dose of estradiol

The effects of a high estradiol dose on memory and on nitric oxide metabolites in hippocampal tissues were investigated. Sham-Est and OVX-Est Groups were treated with 4 mg/kg of estradiol valerate for 12 weeks. Time latency and path length were significantly higher in the Sham-Est and OVX-Est Groups than in the Sham and OVX Groups, respectively (p<0.001). The animals in the Sham-Est and OVX-Est Groups spent lower time in the target quadrant (Q1) than those of the Sham and OVX Groups during the probe trial test (p<0.05 and <0.001, respectively). Significantly lower nitric oxide metabolite levels in the hippocampi of the Sham-Est and OVX-Est Groups were observed than in the Sham and OVX ones (p<0.001). These results suggest that decreased nitric oxide levels in the hippocampus may play a role in the learning and memory deficits observed after treatment with a high dose of estradiol, although the precise underlying mechanisms remain to be elucidated.

Different effects of scopolamine on learning, memory, and nitric oxide metabolite levels in hippocampal tissues of ovariectomized and Sham-operated rats

Different effects of scopolamine on learning, memory, and nitric oxide (NO) metabolites in hippocampal tissues of ovariectomized (OVX) and sham-operated rats were investigated. The animals in the Sham-Scopolamine (Sham-Sco) and OVX-Scopolamine (OVX-Sco) Groups were treated with 2 mg/kg scopolamine before undergoing the Morris water maze, while the animals in the Sham and OVX Groups received saline. The time latency and path length were significantly higher in both the Sham-Sco and the OVX-Sco Groups, in comparison with the Sham and OVX Groups, respectively (p<0.001). Significantly lower NO metabolite levels in the hippocampi of the Sham-Sco Group were observed, compared with the Sham Group (p<0.001), while there was no significant difference between the OVX-Sco and OVX Groups. The decreased NO level in the hippocampus may play a role in the learning and memory deficits induced by scopolamine. However, it seems that the effect of scopolamine on hippocampal NO differs between situations of presence and absence of ovarian hormones.

The effects of olibanum administered to methimazole-treated dams during lactation on learning and memory of offspring rats

The effect of olibanum administered during lactation to methimazole-treated dams on the learning of offspring was evaluated. The animals were treated for 60 days from the first day of lactation period: group 1--tap water, group 2-0.03% methimazole and groups 3 and 4-0.03% methimazole with 0.25% or 0.125% olibanum, respectively. The serum thyroxin level in the offspring of group 2 was significantly lower than that of group 1. However, there was no difference compared to groups 3 and 4. In a Morris water maze, the distance and time latency to reach the platform in offspring of group 2 was significantly higher than groups 1, 3 and 4. In probe trial, the time spent in target quadrant (Q₁) by offspring of group 2 was lower than groups 1, 3 and 4. It is suggested that impaired learning and memory in the offspring of hypothyroid rats may be prevented by olibanum.

Congenital bony fusion (absence) of the knee: a case report

Congenital knee ankylosis is a rare condition which might be accompanied with other abnormalities or not. To our knowledge, there is no report on true bony ankylosis of the knee. The only ones in the literature include fibrous knee ankylosis. Thus this seems to be the first presentation of true congenital bony fusion of the knee joint.