Angiotensin IV Receptors in the Rat Prefrontal Cortex: Neuronal Expression and NMDA Inhibition

Background: N-methyl-D-aspartate type glutamate receptors (NMDARs) are fundamental to neuronal physiology and pathophysiology. The prefrontal cortex (PFC), a key region for cognitive function, is heavily implicated in neuropsychiatric disorders, positioning the modulation of its glutamatergic neurot...

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Main Authors: Zsolt Tamás Papp, Polett Ribiczey, Erzsébet Kató, Zsuzsanna E. Tóth, Zoltán V. Varga, Zoltán Giricz, Adrienn Hanuska, Mahmoud Al-Khrasani, Ákos Zsembery, Tibor Zelles, Laszlo G. Harsing, László Köles
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Biomedicines
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Online Access:https://www.mdpi.com/2227-9059/13/1/71
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Summary:Background: N-methyl-D-aspartate type glutamate receptors (NMDARs) are fundamental to neuronal physiology and pathophysiology. The prefrontal cortex (PFC), a key region for cognitive function, is heavily implicated in neuropsychiatric disorders, positioning the modulation of its glutamatergic neurotransmission as a promising therapeutic target. Our recently published findings indicate that AT<sub>1</sub> receptor activation enhances NMDAR activity in layer V pyramidal neurons of the rat PFC. At the same time, it suggests that alternative angiotensin pathways, presumably involving AT<sub>4</sub> receptors (AT4Rs), might exert inhibitory effects. Angiotensin IV (Ang IV) and its analogs have demonstrated cognitive benefits in animal models of learning and memory deficits. Methods: Immunohistochemistry and whole-cell patch-clamp techniques were used to map the cell-type-specific localization of AT4R, identical to insulin-regulated aminopeptidase (IRAP), and to investigate the modulatory effects of Ang IV on NMDAR function in layer V pyramidal cells of the rat PFC. Results: AT4R/IRAP expression was detected in pyramidal cells and GABAergic interneurons, but not in microglia or astrocytes, in layer V of the PFC in 9–12-day-old and 6-month-old rats. NMDA (30 μM) induced stable inward cation currents, significantly inhibited by Ang IV (1 nM–1 µM) in a subset of pyramidal neurons. This inhibition was reproduced by the IRAP inhibitor LVVYP-H7 (10–100 nM). Synaptic isolation of pyramidal neurons did not affect the Ang IV-mediated inhibition of NMDA currents. Conclusions: Ang IV/IRAP-mediated inhibition of NMDA currents in layer V pyramidal neurons of the PFC may represent a way of regulating cognitive functions and thus a potential pharmacological target for cognitive impairments and related neuropsychiatric disorders.
ISSN:2227-9059