Hypothalamic paraventricular nucleus augments baroreflex sensitivity, role of angiotensin II.

The hypothalamic paraventricular nucleus (PVN) is an important brain region involved in control of the cardiovascular system. Direct injection of angiotensin II (AngII) into the PVN produces a short or long pressor response. This study was performed in anesthetized rats to find whether the parvocellular part of the paraventricular nucleus (PVNp) affects the baroreflex.

In the parvocellular part of paraventricular nucleus, glutamatergic and GABAergic neurons mediate cardiovascular responses to AngII.

Angiotensinergic, GABAergic, and glutamatergic neurons are present in the parvocellular region of the paraventricular nucleus (PVNp). It has been shown that microinjection of AngII into the PVNp increases arterial pressure (AP) and heart rate (HR). The presence of synapses between the angiotensinergic, GABAergic, and glutamatergic neurons has been shown in the PVNp.

Another controller system for arterial pressure. AngII-vasopressin neural network of the parvocellular paraventricular nucleus may regulate arterial pressure during hypotension.

Angiotensin II (AngII) immunoreactive cells, fibers and receptors, were found in the parvocelluar region of paraventricular nucleus (PVNp) and AngII receptors are present on vasopressinergic neurons. However, the mechanism by which vasopressin (AVP) and AngII may interact to regulate arterial pressure is not known. Thus, we tested the cardiovascular effects of blockade of the AngII receptors on AVP neurons and blockade of vasopressin V1a receptors on AngII neurons.

Roles of glutamate and GABA of the Kölliker-Fuse nucleus in generating the cardiovascular chemoreflex.

The Kölliker-Fuse (KF) nucleus is a part of the parabrachial complex, located in the dorsolateral pons. It is involved in the chemoreflex-evoked cardiovascular and respiratory changes, but the role of GABA and glutamate in cardiovascular chemoreflex has not been shown yet. This study was performed to determine the role of GABA, glutamate, and their interaction in the KF, in cardiovascular chemoreflex in anesthetized rat.

The neurological manifestations of COVID-19: a review article.

Results: Various neurological manifestations have been reported in the literature associated with COVID-19, which in the current study are classified into Central Nervous System (CNS) related manifestations including headache, dizziness, impaired consciousness, acute cerebrovascular disease, epilepsy, and Peripheral Nervous System (PNS) related manifestations such as hyposmia/anosmia, hypogeusia/ageusia, muscle pain, and Guillain-Barre syndrome.

Conclusion: During the current context of COVID-19 pandemic, physicians should be aware of wide spectrum of neurological COVID-19 sign and symptoms for early diagnosis and isolation of patients. In this regard, COVID-19 has been associated with many neurological manifestations such as confusion, anosmia, and ageusia.

Functions of AT1 and AT2 angiotensin receptors in the paraventricular nucleus of the rat, correlating single-unit and cardiovascular responses.

The paraventricular hypothalamic nucleus (PVN) is a complex structure with both neuroendocrine and autonomic functions including cardiovascular control. The PVN contains angiotensin II (AngII) immunoreactive cells, fibers, as well as AT1 and AT2 receptors of AngII. We microinjected AngII into the PVN of normotensive anesthetized rats and simultaneously recorded blood pressure, heart rate (HR) and single-unit responses.

Interaction of GABA and norepinephrine in the lateral division of the bed nucleus of the stria terminals in anesthetized rat, correlating single-unit and cardiovascular responses.

The bed nucleus of the stria terminalis (BST) consists of multiple anatomically distinct nuclei. The lateral division, which receives dense noradrenergic innervation, has been implicated in cardiovascular regulation and modulation of responses to stress. This study is performed to identify the cardiovascular and single-unit responses of the lateral BST to norepinephrine (NE), involved adrenoceptors, and possible interaction with GABAergic system of the BST in urethane-anesthetized rats.

Contribution of amygdala to the pressor response elicited by microinjection of angiotensin II into the bed nucleus of the stria terminalis.

The bed nucleus of the stria terminalis (BST) is part of the limbic system located in the rostral forebrain. BST is involved in behavioral, neuroendocrine and autonomic functions, including cardiovascular regulation. The amygdala, plays an important role in mediating the behavioral and physiological responses associated with fear and anxiety, including cardiovascular responses.

Endogenous angiotensin II in the paraventricular nucleus regulates arterial pressure during hypotension in rat, a single-unit study.

The hypothalamic paraventricular nucleus (PVN) controls cardiovascular regulation through vasopressin and sympathetic system. The PVN contains angiotensin II (AngII) and AngII receptors. We have already shown that microinjection of AngII into PVN produced a pressor response concomitant with an increase in firing rate of some PVN neurons.

Angiotensin II in the paraventricular nucleus stimulates sympathetic outflow to the cardiovascular system and make vasopressin release in rat.

The hypothalamic paraventricular nucleus (PVN) plays essential roles in neuroendocrine and autonomic functions, including cardiovascular regulation. It was shown that microinjection of angiotensin II (AngII) into the PVN produced a pressor response. In this study, we explored the probable mechanisms of this pressor response.

Vasopressin and sympathetic system mediate the cardiovascular effects of the angiotensin II in the bed nucleus of the stria terminalis in rat.

The bed nucleus of the stria terminalis (BST) is involved in cardiovascular regulation. The angiotensin II (Ang II) receptor (AT1), and angiotensinogen were found in the BST. In our previous study we found that microinjection of Ang II into the BST produced a pressor response.

GABA modulates baroreflex in the ventral tegmental area in rat.

There are some reports demonstrating the cardiovascular functions of the ventral tegmental area (VTA). About 20-30% of the VTA neurons are GABAergic, which might play a role in baroreflex modulation. This study was performed to find the effects of GABA(A), GABA(B) receptors and reversible synaptic blockade of the VTA on baroreflex.

Mechanism of the cardiovascular effects of the GABAA receptors of the ventral tegmental area of the rat brain.

The ventral tegmental area (VTA) contains GABA terminals involved in the regulation of the cardiovascular system. Previously, we demonstrated that blocking GABAA but not GABAB receptors produced a pressor response accompanied by marked bradycardia. This study was performed to find the possible mechanisms involved in these responses by blocking ganglionic nicotinic receptors, peripheral muscarinic receptors or peripheral V1 vasopressin receptors.

Cardiovascular responses of the anterior claustrum; its mechanism; contribution of medial prefrontal cortex.

The anterior claustrum (CLa) has bilateral connections with the areas involved in cardiovascular regulation, though its role in cardiovascular control is not yet understood. This study was performed to find the cardiovascular responsive region of the CLa by stimulating all parts of the CLa with l-glutamate, and to find the possible mechanisms mediating its responses in urethane-anesthetized rats. We also investigated the possible involvement of the medial prefrontal cortex in the cardiovascular responses of the CLa.

Effects of hypertension on hemodynamic response and serum nitrite concentration during graded hemorrhagic shock in rats.

Background: Hypertensive patients have higher morbidity and mortality from hemorrhage. In this study, we investigated hemodynamic responses and serum nitrite concentrations during graded hemorrhagic shock and resuscitation in hypertensive (HT) and normotensive (NT) rats.

Methods: Thirteen male rats were divided into two groups, namely HT (n = 6) and NT (n = 7).

Role of cuneiform nucleus in regulation of sympathetic vasomotor tone in rats.

The cuneiform nucleus (CnF) is a sympathoexcitatory area involved in the central cardiovascular regulation. Its role in the maintaining vasomotor tone has, however, not yet been clarified. In the present study the effects of cobalt chloride (CoCl(2)) a nonselective synapse blocker and NMDA and non-NMDA glutamate receptors on resting mean arterial blood pressure and heart rate of CnF have been evaluated.

Hemodynamic responses and serum nitrite concentration during uncontrolled hemorrhagic shock in normotensive and hypertensive rats.

Background: We evaluated the effect of hypertension on hemodynamic responses and serum nitrite concentrations in normotensive (NT) and deoxycorticosteron acetate (DOCA)-Salt hypertensive (HT) rats.

Methods: Uncontrolled hemorrhagic shock was induced in NT and HT rats (n=7 each) by preliminary bleed of 25 ml/kg followed by a 75% tail amputation. The mean arterial pressure (MAP), heart rate and serum nitrite were measured pre-hemorrhage and during hemorrhage.

Protective role of selective nitric oxide synthase inhibitor for treatment of decompensated hemorrhagic shock in normotensive and hypertensive rats.

Introduction: Different vasoactive factors can modulate cardiovascular adaptation to hemorrhagic shock including Nitric Oxide (NO). In this study we investigated the effect of the NO synthase inhibitor for treatment of decompensated hemorrhagic shock in normotensive and hypertensive rats.

Methods: Twenty-four male Wistar rats were divided into two groups: The normotensive and hypertensive groups.

The role of the cholinergic system of the bed nucleus of the stria terminalis on the cardiovascular responses and the baroreflex modulation in rats.

The bed nucleus of the stria terminalis (BST) is a limbic structure involved in cardiovascular regulation and modulation of responses to stress. The BST contains high levels of muscarinic receptors. This study was performed to find the effects of cholinergic system of the BST on the cardiovascular regulation and the baroreflex modulation in rats.

Effect of glutamate stimulation of the cuneiform nucleus on cardiovascular regulation in anesthetized rats: role of the pontine Kolliker-Fuse nucleus.

Cuneiform nucleus (CnF) is a reticular nucleus of the midbrain involved in cardiovascular function and stress. There is no report on the cardiovascular effects of the glutamatergic system in the CnF. In the present study, we investigated the cardiovascular effects of glutamate and its NMDA and AMPA/kainate receptors in the CnF.

Regularly firing neurons in the inferior colliculus have a weak interaural intensity difference sensitivity.

The spike discharge regularity may be important in the processing of information in the auditory pathway. It has already been shown that many cells in the central nucleus of the inferior colliculus fire regularly in response to monaural stimulation by the best frequency tones. The aim of this study was to find how the regularity of units was affected by adding ipsilateral tone, and how interaural intensity difference sensitivity is related to regularity.

Vasopressin and sympathetic systems mediate the cardiovascular effects of the GABAergic system in the bed nucleus of the stria terminalis.

The bed nucleus of the stria terminalis (BST) is an important part of the limbic system. It has been shown that chemical stimulation of the BST elicited cardiovascular depressive and bradycardic responses. It was also demonstrated that GABA is present in the BST, though its role in cardiovascular control is not yet understood.

Glutamatergic systems in the bed nucleus of the stria terminalis, effects on cardiovascular system.

The bed nucleus of the stria terminalis (BST) is a part of the limbic system. Two studies have shown that microinjection of L: -glutamate in the BST elicited cardiovascular depressive and bradycardic responses, but in one study, both pressor and depressor responses were observed in the chemical stimulation of BST by glutamate in the urethane-anesthetized rats. Also, the roles of glutamate receptor subtypes have not been investigated yet.

Reactive oxygen metabolites and anti-oxidative defenses in aspirin-induced gastric damage in rats: Gastroprotection by Vitamin E.

Objective: It has been proposed that neutrophil infiltration and oxygen radicals may be the important prime events that lead to mucosal injury induced by aspirin. Vitamin E acts as a potent antioxidant, and is capable of scavenging free radicals. The aim of this study was to evaluate the oxygen metabolites and anti-oxidative defenses in acute gastric damage induced by aspirin and to find the effects of Vitamin E.

Effects of stress on exacerbation of diabetes mellitus, serum glucose and cortisol levels and body weight in rats.

Objective: The effects of stress on the serum glucose, serum cortisol levels and body weight were investigated to clarify the possible link between the stress and diabetes.

Methods: The experiments were performed on nondiabetic and streptozotocin diabetic rats divided to control, sham and stressed groups. Water immersion was used as stressor.