30 research outputs found
Involvement of the nucleus accumbensshell presynaptic NMDA receptors on anxiolytic-like behaviors induced by NMDA in adult male Wistar rat
    Glutamatergic system stimulationthe nucleus accumbens shell, may affect anxiety-related behaviors, aversive learning and memory. Glutamate receptors are differentially distributed in pre- and postsynaptic sites contributing to neuronal communications.The present study aimed to examine the possible involvement of the NAc shell presynaptic NMDA receptors on NMDA induced responses, using the elevated-plus maze (EPM) task in maleWistar rats. Bilateral guide cannulae were implanted to allow microinjection of glutamatergic agonist (NMDA) or ca+2 channel blocker (SKF96365 hydrochloride) agents. Pretest intra-NAc shell infusion of NMDA induced anxiolytic-like behaviors and impaired the EPM-associated memory upon test and retest, respectively. In addition our findings showed that, the intra-NAc shell infusion of Ca+2 channel blocker at applied doses, does not alter the anxiety-like response and aversive memory upon test and retest, respectively. Furthermore, infusing the subthreshold dose SKF prior to the injection of effective doses of NMDA, reduced the anxiolytic-like response and improved the aversive memory impairment which had already been induced by intra-NAc shell NMDA injection. Our study showed that,inhibition of the neurotransmitter exocytosis from pre-synaptic neuron via Ca+2 channel blockade bySKF96365 decreases affected induced by NMDA in the NAc shell region, indicating the involvement of the pre-synaptic NMDA receptors in NMDA induced responses.Therefore, NMDA's ability to increase anxiolytic-like behaviors and the aversive memory impairment may be the result of an action on pre-synaptic glutamatergic receptors which in turn decrease the glutamate effect at synaptic terminal level
Antimicrobial Effects of Four Intracanal Medicaments on Enterococcus Faecalis: An in Vitro Study
Introduction: The aim of this in vitro study was to evaluate the antimicrobial activity of four intracanal medicaments on Enterococcus Faecalis (E. Faecalis). Methods and Materials: Fifty extracted single-rooted human teeth were prepared with standard method. After contaminating the canals with E. Faecalis, the samples were divided into one control and four experimental groups (n=10). The teeth in each group were treated with one of the experimental medicaments, including calcium hydroxide (CH), 2% chlorhexidine (CHX), triple antibiotic paste (TAP) and nanosilver (NS). In control group, canals were filled with neutral gel. Microbial samples were obtained from the roots after 7 days and optical density of the cultures was determined after 24h incubation. Optical density values were analyzed with one-way analysis of variance and Tukey’s post hoc tests. Results: CHX gel and TAP were significantly more effective against E. Faecalis than CH, which was also significantly more efficient than NS and normal saline. In the paper cone samples, CHX gel was more effective than TAP; however, samples obtained with #2 and 4 Gate Glidden drills, indicated that TAP was much more efficient than CHX gel. Normal saline and NS had similar effects on E. Faecalis. Conclusion: Nanosilver gel was not efficient enough against E. Faecalis; however, TAP and CHX gel showed better antibacterial efficacy than CH and can be used as an alternative intracanal medicament in root canal therapies
The role of glutamatergic pathway between septum and hippocampus in the memory formation
The N-methyl-D-aspartate (NMDA) receptor is a subtype of glutamate receptor that is presented in highest density in the hippocampus and septum. NMDA receptors of the septum and the hippocampus are involved in cognitive performance, especially in learning and memory processes. The septum nucleus and hippocampal formation are two regions of the limbic system. The septum and the hippocampus are anatomically and functionally connected to each other. These areas made the septo-hippocampal and hippocampo-septal pathways, which are
implicated in the cognitive processes. The activity of septal and hippocampal neurons is modulated by several neurotransmitters such as glutamate. Thus, changes in the glutamatergic transmission in the septum and hippocampus may influence learning and memory processes in these pathways
Multi-frequency piezomagnetoelastic energy harvesting in the monostable mode
The present article investigates effects of the multi-frequency excitation on the output power of a piezomagnetoelastic energy harvester. The piezomagnetoelastic power generator is assumed to operate in the mono-stable mode. A perturbation technique based on the method of multiple scales is employed to develop an analytical solution to nonlinear differential equations governing the system dynamics. In addition, a Runge-Kutta numerical scheme is used to solve the differential equations. It is shown that the perturbation solution is in a close agreement with the numerical solution. The system response is determined for several cases including super-harmonic, combination and simultaneous resonances. The steady-state output voltage is then obtained for each case and compared with that of a single-frequency excitation. Due to nonlinearities present in the system, a multi-frequency excitation gives rise to complicated phenomena such ascombination and simultaneous resonances. It is found out that exploiting these resonances can significantly increase the amount of energy harvested
Critical Role of CA1 Nicotinic Receptors on Memory Acquisition Deficit Under Induction of Total Sleep Deprivation and REM Sleep Deprivation
Objective: Sleep disorder or sleep deprivation (SD) is a common issue in today’s society. Numerous evidences show that sleep is essential for proper brain performance and cognitive processes; on the other hand, cognitive functions have a broad range with learning and long-term memory as the most important ones related to attention. Since many studies show that cholinergic system has a significant role in sleep, learning, and memory, this study aims to investigate the impacts of CA1 Cholinergic Nicotinic Receptors on memory acquisition deficit which is stimulated by total sleep deprivation (TSD) and REM sleep deprivation (RSD).Methodology: In this study a water box or a multi-platform apparatus was used in order to induce total sleep deprivation (TSD) or REM sleep deprivation (RSD). In order to investigate interactions of cholinergic system and hippocampus-dependent memory, nicotinic receptor agonist (nicotine) or nicotinic receptor antagonist (mecamylamine) was injected in hippocampal CA1. Results: According to the results of this study, 24 hours TSD or RSD decreased memory acquisition and injection of nicotine (0.0001  or mecamylamine (0.001  in TSD and RSD sham groups didn’t change memory acquisition. However, injection of sub-threshold dose of nicotine (0.0001  and mecamylamine (0.001  could reduce negative effects of SD in both TSD and RSD.Discussion; According to the present study, cholinergic nicotinic receptors are effective in learning and memory improvement.
Comparison of diagnosis of VUR nephropathy by urinary level of ceruloplasmin with DMSA-Scan in children
Background: Children with vesicoureteral reflux (VUR) are at risk of recurrent pyelonephritis, kidney scars, hypertension, and renal failure. Currently, VUR complications can be diagnosed by different imaging methods such as sonography, intravenous pyelography and dimercaptosuccinic acid (DMSA) scan, having certain limitations. Urinary level of ceruloplasmin (Cp) might be an effective non-radiological method. The aim of this study was to compare the urinary level of Cp with DMSA scan in the diagnosis of VUR complications.
Methods: The present cross-sectional study was conducted in Pediatric Research Center of Qom University of Medical Sciences and Health Services, Iran. Subjects consisted of 61 children with VUR, diagnosed by voiding cystoureterography (VCUG) and undergone either DMSA scan or urine Cp measurement. VUR stages and complications of the cases were evaluated using serum and urinary renal parameters. Data were analyzed using SPSS 22.
Results: Among them, 80.3% were girls with a mean age of 7.2±3.8 years. Mean Cp urine level was statistically different between VUR sides in DMSA scan (unilateral: 269.56 vs. bilateral: 450.42 µg/dL) (P=0.034, r =0.273), but was not statistically different among various VUR degrees (P=0.102, r=0.211), different ages and genders (P>0.05).
Conclusions: Urinary level of Cp was not statistically different among VUR degrees, but was higher in bilateral VUR cases, indicating Cp can be used as a safe, non-invasive, and cheap measurement tool for screening test. Further studies are required to confirm Cp as an effective method
Bushehr Elderly Health (BEH) Programme, phase I (cardiovascular system)
Purpose: The main objective of the Bushehr Elderly
Health Programme, in its first phase, is to investigate
the prevalence of cardiovascular risk factors and their
association with major adverse cardiovascular events.
Participants: Between March 2013 and October
2014, a total of 3000 men and women aged
≥60 years, residing in Bushehr, Iran, participated in
this prospective cohort study ( participation
rate=90.2%).
Findings to date: Baseline data on risk factors,
including demographic and socioeconomic status,
smoking and medical history, were collected through a
modified WHO MONICA questionnaire. Vital signs and
anthropometric measures, including systolic and
diastolic blood pressure, weight, height, and waist and
hip circumference, were also measured. 12-lead
electrocardiography and echocardiography were
conducted on all participants, and total of 10 cc
venous blood was taken, and sera was separated and
stored at –80°C for possible future use. Preliminary
data analyses showed a noticeably higher prevalence of
risk factors among older women compared to that in
men.
Future plans: Risk factor assessments will be
repeated every 5 years, and the participantswill be
followed during the study to measure the occurrence
of major adverse cardiac events. Moreover, the second
phase, which includes investigation of bone health and
cognition in the elderly, was started in September
2015. Data are available at the Persian Gulf Biomedical
Research Institute, Bushehr University of Medical
Sciences, Bushehr, Iran, for any collaboratio