جستجوی مقالات مرتبط با کلیدواژه « prenatal stress » در نشریات گروه « پزشکی »

Prenatal stress (PS) can adversely affect cognitive and psychological functions in the offspring. This study aimed to determine the effect of PS and extremely low-frequency electromagnetic field (ELF-EMF) on spatial memory, serum corticosterone, brain-derived neurotrophic factor (BDNF) concentrations, and hippocampal BDNF levels in adult male offspring. 

Female Wistar rats were randomly divided into four groups (n=6): Control, Stress, ELF-EMF (exposure to ELF-EMF), and S+EMF (simultaneous exposure to stress and the ELF-EMF) groups. Animals received interven-tions for 21 days before and 21 days during pregnancy (a total of 42 days). On the offspring’s 90th postnatal day (PND), spatial memory was tested using Morris Water Maze, serum Corticosterone and BDNF levels were measured by the ELISA method, and hippocampal BDNF levels were measured by Western blotting. 

PS did not affect spatial memory in the adult male offspring; however, it significantly (P<0.05) increased se-rum corticosterone levels compared to the control and EMF groups. Simultaneous induction of stress with ELF-EMF disrupted the memory acquisition phase. Serum and hippocampal BDNF levels increased signifi-cantly (P<0.05) in the EMF group compared to the stress group. 

Based on our findings, PS can increase serum corticosterone levels without affecting spatial memory. Howev-er, induction of ELF-EMF with stress has a destructive effect on spatial memory with no change in the corti-costerone levels. Compared to stress, prenatal exposure to ELF-EMF increases serum and hippocampal BDNF levels. Further studies are needed to determine the underlying mechanisms of these findings.

In the present study, the effects of prenatal stress on spatial learning and memory deficit and its relationship with hippocampal insulin resistance were examined in male and female offspring. 

Female NMRI mice were mated with males overnight, and the 0-day of pregnancy was detected (Gestational day 0-GD0). The pregnant mice were then randomly divided into stress and control groups. The stress group received stress from the GD0 to GD10. On post natal day 30 (PND30), the offspring were divided into 4 subgroups, namely: male-control, female-control, male-stress, and female-stress. Barnes maze method was used for spatial learning evaluation. Plasma cortisol and insulin levels were measured at the beginning of the experiments. At the end of the experiments, the animals’ brains were removed, and their hippocampus was extracted. The hippocampus was homogenized, and its insulin and insulin-receptor contents were evaluated. 

The stressed animals needed more time for reaching to target hole. In addition, they spend more distance to find the target hole, which was more pronounced in the male offspring. Both plasma and hippocampal insulin content were reduced in the stressed groups. Moreover, the hippocampal insulin receptors protein was reduced in the stressed animals. There was a positive relationship between plasma and hippocampal content and memory deficit in the stressed groups.

These results indicated that prenatal stress could induce spatial learning and memory deficit in offspring, which is associated with plasma and hippocampal insulin and receptor content reduction (hippocampal insulin resistance) in these animals.

Stress during pregnancy is able to bring extensive effects on neurobehavioral development in offspring. The GABAergic system plays a pivotal role in neuronal excitability, which can be affected by prenatal stress (PS). This study aimed to evaluate impact of the PS on γ2 subunit of gamma-aminobutyric acid A (GABAA) receptor gene expression in the hippocampus and seizure induced by pentylenetetrazol (PTZ) in developing rats.

In this experimental study, female Wistar rats were exposed to restraint stress during gestation and their offspring were studied on postnatal days 14 and 21 (P14 and P21, respectively) for epileptic behaviors and γ2 GABAA receptor subunit gene expression. Quantitative real-time PCR was used for evaluating the γ2 GABAA receptor subunit gene expression in rat pups. Meanwhile, PTZ was injected into the pups, and seizure behaviors were recorded for 60 min.

The results showed that γ2 subunit mRNA expression significantly increased in the hippocampus of the stressed pups. The expression level of γ2 subunit was higher on P21 compared to that on P14 in both groups. Number of seizures with tonic–clonic features increased in pups of stressed group compared to the control group. Prenatal stress significantly caused an increase in the total score of seizure on P21.

The effect of PS on seizure susceptibility is age-specific; the increased γ2 subunit level in the hippocampus might be, at least in part, the underlying mechanism for PS-induced augmentation of seizures in immature rats.

Stressful events during pregnancy may affect cognitive and somatic development in infants and increase the risk of developmental disorders in future. This study aimed at assessing the correlation between prenatal stress with salivary cortisol and leptin levels with a focus on infant development.

In this prospective correlative study, 80 infants whose mothers were admitted to clinics during pregnancy were evaluated. The pregnant women were included during 24-28 weeks of pregnancy and assessed using the perceived stress scale until delivery. Following delivery, growth and development of infants were evaluated using the Ages and Stages Questionnaire (ASQ) at birth as well as 2, 4 and 6 months after birth. For assessing leptin and cortisol levels, cord blood and salivary samples were collected at birth and 6 months after birth, respectively.

The mean perceived stress score (PSS) during pregnancy was associated with infant development and weight at 2 and 6 months of age, respectively. Moreover, there was a negative association between leptin level at 6 months of age and infant height at 2, 4 and 6 months after birth. Finally, a negative correlation was observed between cortisol level at 6 months of age and infant height at 2 months following birth.

The results indicated that the PSS of the mothers negatively correlated with the infants’ growth, development and cortisol and leptin levels. Thus, prenatal stress probably affects growth and development in infancy through effects on the neuroendocrine system. Leptin might be an appropriate biomarker for determination of growth and development in infancy.