Corticotropin-releasing factor potentiates glutamatergic input and excitability of presympathetic neurons in the hypothalamus in spontaneously hypertensive rats. (1st June 2023)

• Record Type: Journal Article
• Authors: Ma, Hongyu; Cui, Ziye; Guo, Xinqi; Zhao, Qiyue; Zhang, Ying; Guan, Yue; Yang, Peiyun; Zhu, Huaibing; Wang, Sheng; Zhang, Xiangjian; Zhang, Yi; Pan, Hui-Lin; Ma, Huijie
• Is Part Of: Neuropharmacology. Volume 230(2023)
• Publication Date: 2023-06-01
• Subjects: Autonomic nervous system -- Electrophysiology -- Sympathetic nervous system -- Synaptic plasticity -- Corticotropin-releasing factor; Neuropsychopharmacology -- Periodicals; Autonomic Agents -- Periodicals; Neuropsychopharmacologie -- Périodiques; Neuropsychopharmacology; Periodicals; Electronic journals; 615.78
• DOI: 10.1016/j.neuropharm.2023.109506
• Languages: English
• ISSNs: 0028-3908

Abstract

Abstract: Hyperactivity of presympathetic neurons in the hypothalamic paraventricular nucleus (PVN) plays a key role in generating excess sympathetic output in hypertension. However, the mechanisms driving hyperactivity of PVN presympathetic neurons in hypertension are unclear. In this study, we determined the role of corticotropin-releasing factor (CRF) in the PVN in augmented glutamatergic input, neuronal excitability and sympathetic outflow in hypertension. The number of CRF or c-Fos immunoreactive neurons and CRF/c-Fos double-labeled neurons in the PVN was significantly greater in spontaneously hypertensive rats (SHRs) than in normotensive Wistar-Kyoto (WKY) rats. Blocking glutamatergic input reduced the CRF-potentiated excitability of spinally projecting PVN neurons. Furthermore, CRF knockdown via Crispr/Cas9 in the PVN decreased the frequencies of spontaneous firing and miniature excitatory postsynaptic currents (mEPSCs) in spinally projecting PVN neurons in SHRs. In addition, the mRNA and protein levels of CRFR1, but not CRFR2, in the PVN were significantly higher in SHRs than in WKY rats. Blocking CRFR1 with NBI-35965, but not blocking CRFR2 with Antisauvagine-30, reduced the frequencies of spontaneous firing and mEPSCs of spinally projecting PVN neurons in SHRs. Also, microinjection of NBI-35965 into the PVN significantly reduced arterial blood pressure (ABP) and renal sympathetic nerve activity (RSNA) in anesthetized SHRs, but not in WKY rats. However, microinjection of Antisauvagine-30 into the PVN had no effect on ABP or RSNA in WKY rats and SHRs. Our findings suggest that endogenous CRF in the PVN potentiates glutamatergic input and firing activity of PVN presympathetic neurons via CRFR1, resulting in augmented sympathetic outflow in hypertension. Highlights: CRF expression and activity of CRF-expressing neurons in the PVN are increased in SHRs. CRF potentiates the excitability of PVN presympathetic neurons by enhancing glutamatergic input in SHRs. Endogenous CRF in the PVN potentiates synaptic glutamatergic input to PVN presympathetic neurons in SHRs. CRFR1, but not CRFR2, in the PVN is critically involved in the heightened sympathetic outflow in SHRs.