Search results for " Intraventricular"
showing 10 items of 17 documents
Molecular mechanisms underlying the neuroprotective role of atrial natriuretic peptide in experimental acute ischemic stroke
2018
Abstract Along with its role in regulating blood pressure and fluid homeostasis, the natriuretic peptide system could be also part of an endogenous protective mechanism against brain damage. We aimed to assess the possibility that exogenous atrial natriuretic peptide (ANP) could protect against acute ischemic stroke, as well as the molecular mechanisms involved. Three groups of rats subjected to transient middle cerebral artery occlusion (tMCAO, intraluminal filament technique, 60 min) received intracerebroventricular vehicle, low-dose ANP (0.5 nmol) or high-dose ANP (2.5 nmol), at 30 min reperfusion. Neurofunctional condition, and brain infarct and edema volumes were measured at 24 h after…
Neuroprotective potential of antihyperglycemic drug metformin in streptozocin-induced rat model of sporadic Alzheimer's disease.
2020
Abstract The earliest hallmarks of sporadic Alzheimer's disease (sAD) are impaired glucose metabolism, chronic neuroinflammation, diminished synaptic plasticity and subsequent cognitive decline. The safest antidiabetic drug metformin has shown both glucose metabolism-improving and cognition-enhancing action in type 2 diabetes patients and diabetic model animals. However, metformin has not been previously studied in intracerebroventricular streptozocin (STZ)-induced model of sAD. Therefore, our aim was to assess the preventive action of metformin in sAD model-rats. Firstly, the actions of metformin (75 and 100 mg/kg) on cognitive functions and sociability were examined. Secondly, we wanted t…
Does Endovascular Treatment with Curative Intention Have Benefits for Treating High-Grade Arteriovenous Malformation versus Radiosurgery? Efficacy, S…
2021
Background The treatment of high-grade arteriovenous malformations (AVMs) remains challenging. Microsurgery provides a rapid and complete occlusion compared with other options but is associated with undesirable morbidity and mortality. The aim of this study was to compare the occlusion rates, incidence of unfavorable outcomes, and cost-effectiveness of embolization and stereotactic radiosurgery (SRS) as a curative treatment for high-grade AVMs. Methods A retrospective series of 57 consecutive patients with high-grade AVM treated with embolization or SRS, with the aim of achieving complete occlusion, was analyzed. Demographic, clinical, and angioarchitectonic variables were collected. Both t…
Intraventricular insulin decreases kappa opioid-mediated sucrose intake in rats.
2002
The hormone insulin acts in the central nervous system (CNS) as a regulator of body adiposity and food intake. Recent work from our laboratory has provided evidence that one way by which insulin may decrease food intake is by decreasing the rewarding properties of food. Evidence from others suggests that endogenous opioids may mediate the palatable properties of foods, and insulin may decrease nonfood-related reward via interaction with some CNS kappa opioid systems. In the present study we examined the ability of insulin to interact with exogenous or endogenous kappa opioids to modulate feeding of palatable sucrose pellets by nondeprived rats. Insulin (5 mU intracerebroventricular (i.c.v.)…
GABA, receptor mediated fast synaptic inhibition in the rabbit brain-stem respiratory system
1991
The involvement of GABA mediated neurotransmission in the central control of respiration was investigated by administration of the specific GABAA receptor agonist muscimol and the specific GABAA receptor antagonist biculline into the fourth cerebral ventricle of the rabbit. Cycle-triggered averaging of the phrenic nerve activity (PNA) was used to quantify drug-induced changes of the central respiratory pattern. Muscimol reduced the peak amplitude of PNA and increased the duration of the respiratory phases. High amounts of muscimol led to a long-lasting but reversible central apnea. Bicuculline very effectively blocked the effects of externally applied muscimol. Blockade of intrinsically act…
Differential expression levels of Sox9 in early neocortical radial glial cells regulate the decision between stem cell maintenance and differentiation
2021
ABSTRACTRadial glial progenitor cells (RGCs) in the dorsal forebrain directly or indirectly produce excitatory projection neurons and macroglia of the neocortex. Recent evidence shows that the pool of RGCs is more heterogeneous than originally thought and that progenitor subpopulations can generate particular neuronal cell types. Using single cell RNA sequencing, we have studied gene expression patterns of two subtypes of RGCs that differ in their neurogenic behavior. One progenitor type rapidly produces postmitotic neurons, whereas the second progenitor remains relatively quiescence before generating neurons. We have identified candidate genes that are differentially expressed between thes…
Clusterin and LRP2 are critical components of the hypothalamic feeding regulatory pathway.
2012
Hypothalamic feeding circuits are essential for the maintenance of energy balance. There have been intensive efforts to discover new biological molecules involved in these pathways. Here we report that central administration of clusterin, also called apolipoprotein J, causes anorexia, weight loss and activation of hypothalamic signal transduction-activated transcript-3 in mice. In contrast, inhibition of hypothalamic clusterin action results in increased food intake and body weight, leading to adiposity. These effects are likely mediated through the mutual actions of the low-density lipoprotein receptor-related protein-2, a potential receptor for clusterin, and the long-form leptin receptor…
Functional Evaluation of THIQ, a Melanocortin 4 Receptor Agonist, in Models of Food Intake and Inflammation
2007
The central melanocortinergic system plays an important role in regulating different aspects of energy homeostasis and the immunomodulatory response. In the present study, we evaluated the in vivo activities of food intake suppression and anti-inflammatory activity of THIQ, which has been proposed to possess high and selective melanocortin-4 receptor agonistic activity in vitro. The results showed that THIQ (0.1, 0.3 and 1 nmol/rat, intracerebroventricularly) is less effective in reducing food intake and body weights of rats than the non-selective melanocortin receptor agonist melanotan II. Electron paramagnetic resonance measurements in mice brain tissue showed that THIQ at doses of 0.001 …
Single intracerebroventricular progranulin injection adversely affects the blood–brain barrier in experimental traumatic brain injury
2021
Progranulin (PGRN) is a neurotrophic and anti-inflammatory factor with protective effects in animal models of ischemic stroke, subarachnoid hemorrhage, and traumatic brain injury (TBI). Administration of recombinant (r) PGRN prevents exaggerated brain pathology after TBI in Grn-deficient mice, suggesting that local injection of recombinant progranulin (rPGRN) provides therapeutic benefit in the acute phase of TBI. To test this hypothesis, we subjected adult male C57Bl/6N mice to the controlled cortical impact model of TBI, administered a single dose of rPGRN intracerebroventricularly (ICV) shortly before the injury, and examined behavioral and biological effects up to 5 days post injury (dp…
Analgesic and thermic effects, and cerebrospinal fluid and plasma pharmacokinetics, of intracerebroventricularly administered morphine in normal and …
1998
Abstract The relationship between asthma and opioids has barely been investigated. This study examines whether active sensitization of rats changes the analgesic and thermic effects of intracerebroventricular morphine or the pharmacokinetics of the drug. Morphine (5, 10 and 20 μg) was given intracerebroventricularly to sensitized (active immunization to ovalbumin and Al(OH)3 then airway challenge with ovalbumin after 12 days) and normal (i.e. non-sensitized) male Sprague-Dawley rats. The tail-flick latencies and changes in colon temperature were determined before morphine injection and at 30 min intervals for a period of 300 min afterwards. Results were expressed as the area under the time-…