Ivabradine, a selective inhibitor of the sinoatrial pacemaker, is used in clinical practice to reduce heart rate. However, its potential effect on the neuroendocrine stress response has not been investigated. Therefore, we determined the effect of administering ivabradine to rats on cardiovascular parameters and plasma levels of epinephrine, norepinephrine, and corticosterone.
View Article and Find Full Text PDFThe mechanisms responsible for the anti-inflammatory effects of antidepressants are only partially understood. Published data indicate that the vagal anti-inflammatory pathway could be involved in mediating this effect. Therefore, we investigated the influence of subdiaphragmatic vagotomy on the anti-inflammatory effect of fluoxetine in rats injected with lipopolysaccharide (LPS) to induce an inflammatory response.
View Article and Find Full Text PDFBrain acetylcholinesterase (AChE) variant AChE expression increases with acute stress, and this persists for an extended period, although the timing, strain and laterality differences, have not been explored previously. Acute stress transiently increases acetylcholine release, which in turn may increase activity of cholinesterases. Also the AChE gene contains a glucocorticoid response element (GRE), and stress-inducible AChE transcription and activity changes are linked to increased glucocorticoid levels.
View Article and Find Full Text PDFNeuroendocrine and behavioral stress responses are orchestrated by corticotropin-releasing hormone (CRH) and norepinephrine (NE) synthesizing neurons. Recent findings indicate that stress may promote development of neurofibrillary pathology in Alzheimer's disease. Therefore, we investigated relationships among stress, tau protein phosphorylation, and brain NE using wild-type (WT) and CRH-knockout (CRH KO) mice.
View Article and Find Full Text PDFBackground: Brain norepinephrine (NE) plays an important role in the modulation of stress response and neuroinflammation. Recent studies indicate that in Alzheimer's disease (AD), the tau neuropathology begins in the locus coeruleus (LC) which is the main source of brain NE. Therefore, we investigated the changes in brain NE system and also the immune status under basal and stress conditions in transgenic rats over-expressing the human truncated tau protein.
View Article and Find Full Text PDFNeuroendocrine stress response is regulated by several feedback loops. Since it has been suggested that afferent vagal pathways contribute to these feedback loops, we examined the effect of surgical subdiaphragmatic vagotomy on both baseline and stress-induced increases in plasma epinephrine, norepinephrine, and corticosterone levels in vagotomized and sham-operated Sprague Dawley rats. On either the 3rd or 14th day following vagotomy, the animals were exposed to acute immobilization stress and blood from the jugular vein was collected both before and during stress exposure.
View Article and Find Full Text PDFWhile the parasympathetic nervous system appears to be involved in the regulation of tumor progression, its exact role is still unclear. Therefore, using a rat BP6-TU2 fibrosarcoma tumor model, we investigated the effect of (1) reduction of vagal activity produced by subdiaphragmatic vagotomy; and (2) enhancement of vagal activity produced by continuous delivery of electric impulses to the cervical part of the vagus nerve on tumor development and survival of tumor-bearing rats. We also evaluated the expression of cholinergic receptors within in vitro cultivated BP6-TU2 cells.
View Article and Find Full Text PDFStress may accelerate onset of neurodegenerative diseases in vulnerable subjects and, vice versa, neurodegeneration affects the responsiveness to stressors. We investigated the neuroendocrine response to immobilization stress in normotensive Wistar-Kyoto rats (WKY), spontaneously hypertensive rats (SHR), and transgenic rats of respective WKY and SHR strains overexpressing human truncated tau protein. Plasma levels of epinephrine, norepinephrine, and corticosterone were determined.
View Article and Find Full Text PDFBrain coenzyme Q10 (CoQ10) concentration can influence the activity of several brain regions, including those which participate in the regulation of cardiovascular circadian rhythms, food intake, neuroendocrine stress response, activity and sleep regulation. However, the effect of supplemented ubiquinol (reduced CoQ) into brain regions is not known. This study determined baseline levels of ubiquinone (oxidized CoQ) in various rat brain regions and proved the bioavailability of the liposomal ubiquinol to selected brain regions after its administration into right brain ventricle.
View Article and Find Full Text PDFTau protein misfolding is a pathological mechanism, which plays a critical role in the etiopathogenesis of neurodegeneration. However, it is not entirely known what kind of stimuli can induce the misfolding. It is believed that physical and emotional stresses belong to such risk factors.
View Article and Find Full Text PDFThe etiopathogenesis of depression is a highly complex process characterized by several neurobiological alterations including decreased monoamine neurotransmission in the brain, dysregulated hypothalamic-pituitary-adrenal axis activity, decreased neuronal plasticity, and chronic inflammation in the brain and peripheral tissues. Experimental and clinical studies indicate that the vagus nerve may influence these processes. The importance of the vagus nerve in the etiopathogenesis of depression is further supported by its involvement in the induction of sickness behavior, as well as by clinical studies confirming a beneficial effect of vagus nerve stimulation in depressed patients.
View Article and Find Full Text PDFThere have been several reports on tumour tissue innervation, the effect of neurotransmitters on tumour growth, the development of metastases, and the effect of altered nervous-system activity on tumour cell proliferation. In this personal view, we summarise recent findings related to the interactions between the nervous system and tumour cells and suggest further research into the role of the nervous system in the aetiopathogenesis of cancer. Data showing the transmission of signals between the brain and tumour tissue create a complex view of the nervous system in the aetiopathogenesis of cancer.
View Article and Find Full Text PDFThere is no doubt that the nervous system is involved in the etiopathogenesis of various pathological states and diseases. Interactions between the nervous, endocrine, and immune systems might represent the anatomical and functional basis for understanding the pathways and mechanisms that enable the brain to modulate the progression of disease. The aim of this article is to encourage us to shift our current opinion of the etiopathogenesis of disease to one of highly complex interactions between peripheral tissues and the brain and in this way introduce new diagnostic and therapeutic approaches.
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