No abstract

Posttraumatic stress disorder (PTSD) is a debilitating mental condition occurring after a tragedy or a traumatic experience, such as rape, assault, natural disasters, war, car or plane accidents, etc. PSTD can cause a number of symptoms, such as fear, high anxiety, hyperarousal, bad dreams, night mares, etc., existing for a long time after the traumatic event. Within recent years, the spread of PTSD has been increased in the whole world, especially in Asia (Middle East), particularly among soldiers who have taken part in military conflicts. This situation confirms the importance of understanding the way of PTSD development and of the improvement of its treatment. This paper is a review of the literature related to the respective topics. Like other anxiety disorders, PTSD is related to disruption of the endocrine system, particularly disintegration of the hypothalamus-pituitary-adrenal axis (HPAA). People suffering from PTSD are characterized by elevated levels of corticotropinreleasing hormone, low basal cortisol levels, and enhanced negative feedback suppression of the HPAA. At present, certain plant-derived compounds are considered a new important source to treat PTSD. For example, remedies obtained from saffron are such possible means. According to our findings, saffron components may considerably affect some parts of the HPAA for reduction of stress-induced corticosterone release.

Extracellular beta-amyloid (Aβ) accumulation and deposition is the main factor, which causes synaptic loss and eventually cells death in Alzheimer's disease (AD). Memory loss and long-term potentiation (LTP) dysfunction in the hippocampus are involved in the AD. The involvement of crocin, as the main and active constituent of saffron extract in learning and memory processes, has been proposed. Here we investigated the probable therapeutic effect of crocin on memory, LTP, and neuronal apoptosis using in vivo Aβ models of the AD. The Aβ peptide (1-42) was bilaterally administered into the frontal-cortex using stereotaxic apparatus. Five hours after surgery, rats were given intraperitoneal crocin (30 mg/kg) daily, which repeated for 12 days. Barnes maze results showed that administration of crocin significantly improves spatial memory indicators such as latency time to achieving the target hole and the number of errors when compared to Aβ-group. Passive avoidance test revealed that crocin significantly increased the step-through-latency compared to Aβ-treated alone. These learning deficits in Aβ-treated animals correlated with a reduction of LTP in hippocampal CA1 synapses in freely moving rats, which crocin improved population spike amplitude and mean field excitatory postsynaptic potentials (fEPSP) slope reduction induced by Aβ. Neuronal apoptosis was detected by TUNEL assay and the expression levels of c-Fos proteins were examined by Western blotting. Crocin significantly reduced the number of TUNEL-positive cells in the CA1 region and decreased c-Fos in the hippocampus compared to Aβ-group. In vivo Aβ treatment altered significantly the electrophysiological properties of CA1 neurons and crocin further confirmed a neuroprotective action against Aβ toxicity.

Aim Recent cognitive neuroscience research shows that noninvasive brain stimulation can modify a wide range of behaviors in healthy people. Such regulation effects on human behaviors provide new insights into the neurobiology of cognitive processes and establish causal brain–behavior relations. Here, we aimed to examine the effects of transcranial electrical stimulation (TES) of the prefrontal cortex on risk‐taking. Methods We performed a systematic search on the PubMed, Web of Science, and Cochrane databases with appropriate keywords for original studies reporting the use of TES to modulate risk‐taking behavior in healthy individuals. Then, in the meta‐analysis phase, a random‐effects model was used to measure the pooled effect size (ES). Results Twenty articles were evaluated as eligible studies, including 16 articles on transcranial direct current stimulation (tDCS), two on transcranial alternating current stimulation, one on transcranial pulsed current stimulation, and one on high‐definition tDCS. A meta‐analysis showed a pooled estimated standardized ES of −0.20 (95% confidence interval [CI], –0.39 to −0.01), which indicates a small ES for active tDCS over the dorsolateral prefrontal cortex (DLPFC) in comparison to sham stimulation (z = 2.31, P = 0.03) in terms of less risky behaviors. Subgroup analysis showed that there is no significant ES for bilateral DLPFC stimulation (d = −0.01; 95%CI, –0.28 to 0.26), but a significant near‐medium ES for unilateral DLPFC stimulation (d = −0.41; 95%CI, –0.71 to −0.10). Conclusion Our findings support a significant impact of neuroregulation of the DLPFC on risk‐taking behavior in healthy individuals. Unilateral noninvasive electrical stimulation of the DLPFC can result in a conservative risk‐averse response style, probably through modulating plasticity of the relevant brain networks, including cortical and subcortical structures, as well as increasing subcortical dopaminergic activity.

Context: Post-traumatic stress disorder (PTSD) is a chronic psychiatric disorder that occurs as a result of an accident or lifethreatening event. The purpose of our study was to examine the prevalence of PTSD in the Iranian population from 2000 to 2015 through a meta-analysis of the published studies to review the epidemiologic evidence of PTSD after disasters and wars and to examine PTSD determinants. Evidence Acquisition:The electronic databases including PubMed, Embase, Web of Science, Magiran, etc. were explored to find related papers. Two authors independently reviewed and extracted data via an extraction sheet, and disagreements were resolved by holding a meeting with a third author. Meta-analysis was performed using "metaprop" command in STATA 11 software. Studies with < 25 participants were excluded from our analysis. Results:Ultimately, 47 studies were included in this meta-analysis. Primary PTSD was investigated in 44 studies and secondary PTSD in six studies. Forty studies investigated natural PTSD and five studies technical PTSD. PTSD related to childbirth, job, earthquake, war, burn, accident, and rape events were investigated in seven, six, nine, nine, two, two, and two studies, respectively, and their pooled prevalence were 25%, 30%, 58%, 47%, 40%, 11%, and 74%, respectively. Conclusion:The results revealed that the burden of PTSD among the Iranian population exposed to wars and disasters is high. PTSD was correlated with a range of factors including demographic and background factors and characteristics of the event exposure.