Allopregnanolone (Allo) is a positive allosteric modulator of the GABA receptor, and amiloride (Ami) is a competitive antagonist of the GABA receptor. The purpose of this work was to study the combined effect of Allo and Ami on functional activity of GABA receptor. The GABA-induced chloride current (I) was measured in isolated Purkinje cells of rat cerebellum using the patch-clamp technique and a system of fast application. Our results indicate that Allo suppresses the inhibitory effect of Ami on I, the IC value of Ami concentration-response curve was increased from 164 to 547 µM (P < 0.001) in the presence of Allo. Next, GABA concentration-response curves (EC = 5.8 µM) were constructed in the presence of Allo (EC = 1.2 µM), Ami (EC = 25.5 µM), and the combination of Allo+Ami (EC = 3.2 µM). Changes in EC values as a percentage relative to the control were calculated. The blocking effect of Ami is reduced in the presence of Allo (340% vs 150%, P < 0.01) and the potentiating effect of Allo does not change in the presence of Ami (78% vs 87%, P > 0.05). The results suggest that there is an allosteric relationship between the Allo and Ami binding sites on GABA receptor that operates in one direction, from Allo sites to Ami site, but not vice versa.
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http://dx.doi.org/10.1007/s12013-024-01654-6 | DOI Listing |
Neuropharmacology
December 2024
Department of Experimental Physiology and Pathophysiology, Medical University of Białystok, ul. Mickiewicza 2A, 15-222 Białystok, Poland.
Although angiotensin 1-7 (Ang 1-7) and its role as a part of the "protective" axis of the renin-angiotensin system are well described in the literature, the mechanisms of its angiotensin II-like pressor and tachycardic effects following its acute central administration are not fully understood. It was the aim of the present study to examine which receptors contribute to the aforementioned cardiovascular effects. Ang 1-7 and antagonists for glutamate, GABA, vasopressin, thromboxane A (TP), α-adrenergic, and P2X purinoceptors or modulators of oxidative stress were injected into the paraventricular nucleus of the hypothalamus (PVN) of urethane-anesthetized male Wistar rats.
View Article and Find Full Text PDFZh Nevrol Psikhiatr Im S S Korsakova
December 2024
Siberian State Medical University, Tomsk, Russia.
The article presents theses of the resolution of the Interdisciplinary Council of Experts in Psychiatry and Neurology (Moscow, 2024) on the issue of comorbid anxiety disorders (AD) in patients with neurological pathologies. The authors highlight the high prevalence of comorbid ADs and their significant negative impact on the course of underlying diseases, such as epilepsy, pain syndromes and post-stroke conditions. Modern approaches to the diagnosis and treatment of ADs in this group of patients are discussed.
View Article and Find Full Text PDFCell Biochem Biophys
December 2024
Research Center of Neurology, Moscow, Russia.
Allopregnanolone (Allo) is a positive allosteric modulator of the GABA receptor, and amiloride (Ami) is a competitive antagonist of the GABA receptor. The purpose of this work was to study the combined effect of Allo and Ami on functional activity of GABA receptor. The GABA-induced chloride current (I) was measured in isolated Purkinje cells of rat cerebellum using the patch-clamp technique and a system of fast application.
View Article and Find Full Text PDFProg Neurobiol
December 2024
Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei, PR China. Electronic address:
In response to stressors, individuals manifest varied behavioral responses directed toward satisfying physiological survival needs. Although the enduring effects of adolescent stress on both humans and animals are well-documented, the underlying mechanisms remain insufficiently elucidated. Utilizing immunofluorescence, viral injections, and brain slice electrophysiological recordings, we have delineated that heightened excitability among glutamatergic neurons in the basolateral amygdala (BLA) is responsible for inducing heightened exploratory behaviors in adolescent mice subjected to mild, chronic restraint stress.
View Article and Find Full Text PDFBiochem Biophys Res Commun
December 2024
Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Química, Cátedra de Química Biológica, Córdoba, Argentina; CONICET, Instituto de Investigaciones Biológicas y Tecnológicas (IIByT). Córdoba, Argentina. Electronic address:
Monoterpenes (MTs), the major constituents of plant essential oils, cover a broad spectrum of biological activities through their interaction with biomembranes. MTs are highly hydrophobic substances with a net electrical dipole, but are not clearly amphipathic. As a result, they aggregate at increasing concentrations in aqueous media, and in membrane environments their behavior changes from dynamics modulators to disruptors.
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