J Psychiatr Res
January 2015
Activation of glucocorticoid receptor signaling in the stress response to traumatic events has been implicated in the pathogenesis of stress-associated psychiatric disorders such as post-traumatic stress disorder (PTSD). Elevated startle response and hyperarousal are hallmarks of PTSD, and are generally considered to evince fear (DSM V). To further examine the efficacy of corticosterone in treating hyperarousal and elevated fear, the present study utilized a learned helplessness stress model in which rats are restrained and subjected to tail shock for three days.
View Article and Find Full Text PDFThe metabolic mechanisms underlying the development of exaggerated fear in post-traumatic stress disorder (PTSD) are not well defined. In the present study, alteration in the expression of genes associated with mitochondrial function in the amygdala of an animal model of PTSD was determined. Amygdala tissue samples were excised from 10 non-stressed control rats and 10 stressed rats, 14 days post-stress treatment.
View Article and Find Full Text PDFTelomeres play a central role in cell fate and aging by adjusting the cellular response to both biological and psychological stress. Human telomeres are regions of tandem TTAGGG repeats at chromosomal ends that protect chromosomes from degradation, fusion, and recombination. They are made up of approximately 1000-2500 copies of the repeated DNA sequence.
View Article and Find Full Text PDFIdentification of biomarkers representing the evolution of the pathophysiology of Post Traumatic Stress Disorder (PTSD) is vitally important, not only for objective diagnosis but also for the evaluation of therapeutic efficacy and resilience to trauma. Ongoing research is directed at identifying molecular biomarkers for PTSD, including traumatic stress induced proteins, transcriptomes, genomic variances and genetic modulators, using biologic samples from subjects' blood, saliva, urine, and postmortem brain tissues. However, the correlation of these biomarker molecules in peripheral or postmortem samples to altered brain functions associated with psychiatric symptoms in PTSD remains unresolved.
View Article and Find Full Text PDFThe startle reaction (also known as the startle response, the startle reflex, or the alarm reaction) is the psychological and physiological response to a sudden unexpected stimulus, such as a flash of light, a loud noise (acoustic startle reflex), or a quick movement near the face. Abnormalities of startle response have been observed in many stress-related mental disorders, such as schizophrenia and post-traumatic stress disorder (PTSD). However, the molecular mechanisms of startle in stress-associated conditions--for example, whether the startle reaction is associated with any gene variance--is still unknown.
View Article and Find Full Text PDFWhile the actions of glucocorticoids on brain function have been comprehensively studied, understanding of the underlying genomic mechanisms is advancing slowly. Recently, it was found that p11 is associated with traumatic stress and depression, and glucocorticoids regulate expression of the p11 gene. The ligand-activated glucocorticoid receptor (GR) interacts with two glucocorticoid response elements (GREs) in the p11 promoter region to up-regulate the p11 gene.
View Article and Find Full Text PDFLeak channels regulate neuronal activity and excitability. Determining which leak channels exist in neurons and how they control electrophysiological behavior is fundamental. Here we investigated TASK channels, members of the two-pore domain K(+) channel family, as a component of the K(+)-dominated leak conductance that controls and modulates rhythm generation at cellular and network levels in the mammalian pre-Bötzinger complex (pre-BötC), an excitatory network of neurons in the medulla critically involved in respiratory rhythmogenesis.
View Article and Find Full Text PDFThe effects of pudendal nerve stimulation on reflex bladder activity were investigated in cats with chronic spinal cord injury (6-12 months) under alpha-chloralose anesthesia. Electrical stimulation of the pudendal nerve on one side at different frequencies and intensities induced either inhibitory or excitatory effects on bladder activity. The inhibitory effect peaked at a stimulation frequency of 3 Hz and gradually decreased at lower or higher frequencies.
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