The Effect of Noise Pollution Exposure during Pregnancy on Long Term Potentiation Induction in Pyramidal Neurons of Hippocampus CA1 area in Male Rat Offsprings

Abstract: Background: It is believed that cognitive processing is easily disturbed by incompatible environmental stimulations. Many studies have shown that prenatal stress affects fetal brain development. The aim of this study was to evaluate the effect of noise pollution exposure during conception period on neural activity of hippocampus CA1 area in male rat offspring. Methods: Four groups of rats including a control group with natural pregnancy and without any stress and three groups of pregnant rats exposed to daily noise stress (intensity >95 dB, between 8 A.M - 2 P.M) with durations of 1, 2 and 4 hour (s) in the last week of pregnancy were included in the study. Then, in male offsprings of these groups, fEPSP resulted from Schaffer collateral neurons of CA1 were recorded and evaluated in baseline state and after LTP induction with tetanic stimulation. Results: Our results showed that prenatal exposure to traffic noise pollution at 3rd gestational week, reduces amplitude (P<0.0001) and slope of baseline synaptic activity in hippocampus CA1 area (P<0.0001) and furthermore interferes in hippocampal LTP in comparison with control group. The serum level of corticostrone in the two stressed groups (2 and 4 hours) of rats in comparison to the control showed significant increase. But, prenatal exposure to 1- hour noise pollution caused no significant difference in serum corticostrone level. Conclusions: Based on the obtained results, daily exposure to noise pollution in the third trimester of pregnancy for 1, 2 and 4 hour (s), attenuates fEPSP features of hippocampus CA1 area pyramidal neurons of offsprings. Keywords: Noise pollution, Pregnancy, Long-term potentiation, Hippocampus, Offspring, Ra

Prenatal urban traffic noise exposure impairs spatial learning and memory and reduces glucocorticoid receptor expression in the hippocampus of male rat offspring

Introduction: Exposure to noise stress during early life may permanently affect the structure and function of the central nervous system. The aim of this study was to evaluate the effects of prenatal exposure to urban traffic noise on the spatial learning and memory of the rats' offspring and the expression of glucocorticoid receptors (GRs) in their hippocampi. Methods: Three g\roups of pregnant rats were exposed to recorded urban traffic noise for 1, 2 or 4 h/day during the last week of pregnancy. At the age of 45 days, their male offspring were introduced to the Morris water maze (MWM) for assessment of spatial learning and memory. The corticosterone levels were measured in the offspring's sera by radioimmunoassay, and the relative expression of glucocorticoid and mineralocorticoid receptors (MRs) in their hippocampi was evaluated via RT-PCR. Results: Facing urban traffic noise for 2 and 4 h/day during the third trimester of pregnancy caused the offspring to spend more time and to travel a larger distance than the controls to find the target platform. Analogously, these two groups were inferior to their control counterparts in the probe test. Also, prenatal noise stress elevated the corticosterone concentration in the sera of the rats' offspring and dose-dependently decreased the relative expression of the mRNA of both GRs and MRs in their hippocampi. Conclusions: Urban traffic noise exposure during the last trimester of pregnancy impairs spatial learning and memory of rat offspring and reduces GRs and MRs gene expression in the hippocampus

Prenatal urban traffic noise exposure impairs spatial learning and memory and reduces glucocorticoid receptor expression in the hippocampus of male rat offspring

Introduction: Exposure to noise stress during early life may permanently affect the structure and function of the central nervous system. The aim of this study was to evaluate the effects of prenatal exposure to urban traffic noise on the spatial learning and memory of the rats' offspring and the expression of glucocorticoid receptors (GRs) in their hippocampi. Methods: Three g\roups of pregnant rats were exposed to recorded urban traffic noise for 1, 2 or 4 h/day during the last week of pregnancy. At the age of 45 days, their male offspring were introduced to the Morris water maze (MWM) for assessment of spatial learning and memory. The corticosterone levels were measured in the offspring's sera by radioimmunoassay, and the relative expression of glucocorticoid and mineralocorticoid receptors (MRs) in their hippocampi was evaluated via RT-PCR. Results: Facing urban traffic noise for 2 and 4 h/day during the third trimester of pregnancy caused the offspring to spend more time and to travel a larger distance than the controls to find the target platform. Analogously, these two groups were inferior to their control counterparts in the probe test. Also, prenatal noise stress elevated the corticosterone concentration in the sera of the rats' offspring and dose-dependently decreased the relative expression of the mRNA of both GRs and MRs in their hippocampi. Conclusions: Urban traffic noise exposure during the last trimester of pregnancy impairs spatial learning and memory of rat offspring and reduces GRs and MRs gene expression in the hippocampus

A causal inference study: The impact of the combined administration of Donepezil and Memantine on decreasing hospital and emergency department visits of Alzheimer’s disease patients

Alzheimer’s disease is the most common type of dementia that currently affects over 6.5 million people in the U.S. Currently there is no cure and the existing drug therapies attempt to delay the mental decline and improve cognitive abilities. Two of the most commonly prescribed such drugs are Donepezil and Memantine. We formally tested and confirmed the presence of a beneficial drug-drug interaction of Donepezil and Memantine using a causal inference analysis. We applied doubly robust estimators to one of the largest and high-quality medical databases to estimate the effect of two commonly prescribed Alzheimer’s disease (AD) medications, Donepezil and Memantine, on the average number of hospital or emergency department visits per year among patients diagnosed with AD. Our results show that, compared to the absence of medication scenario, the Memantine monotherapy, and the Donepezil monotherapy, the combined use of Donepezil and Memantine treatment significantly reduces the average number of hospital or emergency department visits per year by 0.078 (13.8%), 0.144 (25.5%), and 0.132 days (23.4%), respectively. The assessed decline in the average number of hospital or emergency department visits per year is consequently associated with a substantial reduction in medical costs. As of 2022, according to the Alzheimer’s Disease Association, there were over 6.5 million individuals aged 65 and older living with AD in the US alone. If patients who are currently on no drug treatment or using either Donepezil or Memantine alone were switched to the combined used of Donepezil and Memantine therapy, the average number of hospital or emergency department visits could decrease by over 613 thousand visits per year. This, in turn, would lead to a remarkable reduction in medical expenses associated with hospitalization of AD patients in the US, totaling over 940 million dollars per year

The Role of Multi-wall Carbon Nanotubes on Fracture Mechanism of Epoxy Nanocomposite

In order to investigate the role of multi-wall carbon nanotubes (MWCNTs) on fracture mechanism of epoxy nanocomposites, a series of tensile standard specimens reinforced with different carbon nanotube contents (0, 0.3, 0.6 and 1 wt%) were produced. The fracture surfaces of the produced nanocomposites were evaluated using scanning electron microscope (SEM). The results show that the surface fracture of epoxy nanocomposites comprised of three regions, i.e. mirror, transition and final propagation zones. The extension of all zones depends strongly on curing agent as well asMWCNTs content. The mirror zone is disappeared as curing agent and MWCNTs content increases, while the transition zone depends on the nucleation rate of secondary microcrack. The pattern of final propagation zone becomes coarser as MWCNTs are added to epoxy system

The effect of noise pollution exposure during pregnancy on long term potentiation induction in pyramidal neurons of hippocampus CA1 area in male rat offsprings

Background: It is believed that cognitive processing is easily disturbed by incompatible environmental stimulations. Many studies have shown that prenatal stress affects fetal brain development. The aim of this study was to evaluate the effect of noise pollution exposure during conception period on neural activity of hippocampus CA1 area in male rat offspring. Methods: Four groups of rats includ ing a control group with natural pregnancy and without any stress and three groups of pregnant rats exposed to daily noise stress (inte nsity &gt;95 dB, between 8 A.M - 2 P.M) with durations of 1, 2 and 4 hour (s) in the last week of pregnancy were included in the study. Then, in male offsprings of these groups, fEPSP resulted from Schaffer collateral neurons of CA1 were recorded and evaluated in baseline state and after LTP induction with tetanic stimulation. Results: Our results showed that prenatal exposure to traffic noise pollution at 3rd gestational week, reduce s amplitude (P&lt;0.0001) and slope of baseline synaptic activity in hippocampus CA1 area (P&lt;0.0001) and furthermore interfere s in hippocampal LTP in comparison with control group. The serum level of corticostrone in the two stressed groups (2 and 4 hours) of rats in comparison to the control showed significant increase. But, prenatal exposure to 1- hour noise pollution caused no significant difference in serum corticostrone level. Conclusions: Based on the obtained results, daily exposure to noise pollution in the third trimester of pregnancy for 1, 2 and 4 hour (s), attenuates fEPSP features of hippocampus CA1 area pyramidal neurons of offsprings