PROJECT 2 (Pickel): Hypothalamic plasticity enabling slow pressor hypertension Neurohumoral output neurons in the hypothalamic paraventricular nucleus (PVN) are activated by glutamateand Angll-containing neuronal inputs from the subfornical organ (SFO), a brain structure responsive to circulating angiotensin 11 (Angll). These inputs target PVN output neurons that increase hormonal release from the pituitary and sympathetic activity through monosynaptic projections to the thoracic spinal cord. Slow pressor hypertension can be induced by chronic systemic infusion of low doses of Angll (600 ng/kg/min) or by chronic exposure to intermittent hypoxia (CIH). The CIH-induced sympathetic activation and elevation in arterial pressure is dependent on plasticity in the carotid body, but also on changes in glutamate NMDA receptor-dependent transmission in the brain. Chronic exposure to Angll or CIH may result in NMDA receptor-dependent long-term facilitation of glutamatergic transmission in the PVN spinal projection neurons, which is enabled in part by suppression of opposing inhibitory neurons. NADPH oxidase generated reactive oxygen species (ROS) are important modulators of NMDA receptor mediated synaptic plasticity, and are also mediators of the intracellular signaling for Angll, a neuropeptide present in the glutamatergic SFO inputs to the PVN and active mainly through the Angll type-1 (ATi) receptor. Project 2 will test the central hvpothes s that plasticitv in pre-svmpathetic output and inhibitorv neurons of the PVN enables the development of slow pressor hvpertension through mechanisms that are dependent on postsvnaptic NMDA receptors and influenced bv both Angll and ROS.
Aim 1 will examine the basal distribution and function of NMDA and ATi receptors in PVN neurons identified as projecting to the thoracic spinal cord by retrograde transport.
Aim 2 will determine whether changes in the surface/synaptic availability of the essential NMDA NR1 subunit and NMDA currents are concomitants of Angll or CIH hypertension, both of which are attenuated by a spatial-temporal deletion of postsynaptic NR1 in the PVN.
Aim 3 will determine whether the development of Angll and/or CIH hypertension is linked to NADPH oxidase generated ROS in the PVN. This research will be conducted in male mouse models using in vivo measurement of arterial pressure (tail-cuff or radiotelemetry), high resolution electron microscopic immunolabeling, patch-clamp recording, and ROS imaging. Project 2 is interdependent with each of the other projects and reliant on all core facilities of this PPG.

Public Health Relevance

The results will provide new insight into the role of NMDA receptor-dependent synaptic plasticity and NADPH oxidase-generated free radicals in the maladaptive changes that occur in chronically activated neurohumoral output neurons of the PVN. This is crucial for understanding Angll and/or CIH slow pressor hypertension and for devising new therapies for treating cardiovascular and cerebrovascular dysfunctions in hypertensive patients.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL096571-05
Application #
8502530
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Project Start
Project End
Budget Start
2013-07-01
Budget End
2014-06-30
Support Year
5
Fiscal Year
2013
Total Cost
$321,199
Indirect Cost
$131,140
Name
Weill Medical College of Cornell University
Department
Type
DUNS #
060217502
City
New York
State
NY
Country
United States
Zip Code
10065
Ma, Qian; Yang, Jianmin; Milner, Teresa A et al. (2017) SorCS2-mediated NR2A trafficking regulates motor deficits in Huntington's disease. JCI Insight 2:
McEwen, Bruce S; Milner, Teresa A (2017) Understanding the broad influence of sex hormones and sex differences in the brain. J Neurosci Res 95:24-39
Marques-Lopes, Jose; Tesfaye, Ephrath; Israilov, Sigal et al. (2017) Redistribution of NMDA Receptors in Estrogen-Receptor-?-Containing Paraventricular Hypothalamic Neurons following Slow-Pressor Angiotensin II Hypertension in Female Mice with Accelerated Ovarian Failure. Neuroendocrinology 104:239-256
Faraco, Giuseppe; Park, Laibaik; Zhou, Ping et al. (2016) Hypertension enhances A?-induced neurovascular dysfunction, promotes ?-secretase activity, and leads to amyloidogenic processing of APP. J Cereb Blood Flow Metab 36:241-52
Mazid, Sanoara; Hall, Baila S; Odell, Shannon C et al. (2016) Sex differences in subcellular distribution of delta opioid receptors in the rat hippocampus in response to acute and chronic stress. Neurobiol Stress 5:37-53
Garzón, Miguel; Pickel, Virginia M (2016) Electron microscopic localization of M2-muscarinic receptors in cholinergic and noncholinergic neurons of the laterodorsal tegmental and pedunculopontine nuclei of the rat mesopontine tegmentum. J Comp Neurol 524:3084-103
Harward, Stephen C; Hedrick, Nathan G; Hall, Charles E et al. (2016) Autocrine BDNF-TrkB signalling within a single dendritic spine. Nature 538:99-103
Van Kempen, Tracey A; Narayan, Ankita; Waters, Elizabeth M et al. (2016) Alterations in the subcellular distribution of NADPH oxidase p47(phox) in hypothalamic paraventricular neurons following slow-pressor angiotensin II hypertension in female mice with accelerated ovarian failure. J Comp Neurol 524:2251-65
Almey, Anne; Milner, Teresa A; Brake, Wayne G (2016) Estrogen receptor ? and G-protein coupled estrogen receptor 1 are localized to GABAergic neurons in the dorsal striatum. Neurosci Lett 622:118-23
Marques-Lopes, Jose; Lynch, Mary-Katherine; Van Kempen, Tracey A et al. (2015) Female protection from slow-pressor effects of angiotensin II involves prevention of ROS production independent of NMDA receptor trafficking in hypothalamic neurons expressing angiotensin 1A receptors. Synapse 69:148-65

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