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Santollo J, Daniels D. Fluid transitions. Neuropharmacology 2024; 256:110009. [PMID: 38823577 PMCID: PMC11184821 DOI: 10.1016/j.neuropharm.2024.110009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 05/21/2024] [Accepted: 05/23/2024] [Indexed: 06/03/2024]
Abstract
Water is critical for survival and thirst is a powerful way of ensuring that fluid levels remain in balance. Overconsumption, however, can have deleterious effects, therefore optimization requires a need to balance the drive for water with the satiation of that water drive. This review will highlight our current understanding of how thirst is both generated and quenched, with particular focus on the roles of angiotensin II, glucagon like-peptide 1, and estradiol in turning on and off the thirst drive. Our understanding of the roles these bioregulators play has benefited from modern behavioral analyses, which have improved the time resolution of intake measures, allowing for attention to the details of the patterns within a bout of intake. This has led to behavioral interpretation in ways that are helpful in understanding the many controls of water intake and has expanded our understanding beyond the dichotomy that something which increases water intake is simply a "stimulator" while something that decreases water intake is simply a "satiety" factor. Synthesizing the available information, we describe a framework in which thirst is driven directly by perturbations in fluid intake and indirectly modified by several bioregulators. This allows us to better highlight areas that are in need of additional attention to form a more comprehensive understanding of how the system transitions between states of thirst and satiety.
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Affiliation(s)
- Jessica Santollo
- Department of Biology, University of Kentucky, Lexington, KY 40506, USA.
| | - Derek Daniels
- Department of Biology, University at Buffalo, State University of New York, Buffalo, NY 14260, USA; Center for Ingestive Behavior Research, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
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2
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Xu L, Ma X, Wang Y, Chen Z. Sodium intake: a double-edged sword wielded by the brain. SCIENCE CHINA. LIFE SCIENCES 2024; 67:1545-1547. [PMID: 38664353 DOI: 10.1007/s11427-023-2536-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 01/25/2024] [Indexed: 06/19/2024]
Affiliation(s)
- Lingyu Xu
- Key Laboratory of Neuropharmacology and Pharmaceutical Sciences, Zheiiang Chinese Medical University, Hangzhou, 310053, China
| | - Xiaolong Ma
- Key Laboratory of Neuropharmacology and Pharmaceutical Sciences, Zheiiang Chinese Medical University, Hangzhou, 310053, China
| | - Yi Wang
- Key Laboratory of Neuropharmacology and Pharmaceutical Sciences, Zheiiang Chinese Medical University, Hangzhou, 310053, China
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Pharmaceutical Sciences, Zheiiang Chinese Medical University, Hangzhou, 310053, China.
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China.
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Kuralay A, McDonough MC, Resch JM. Control of sodium appetite by hindbrain aldosterone-sensitive neurons. Mol Cell Endocrinol 2024; 592:112323. [PMID: 38936597 DOI: 10.1016/j.mce.2024.112323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Accepted: 06/25/2024] [Indexed: 06/29/2024]
Abstract
Mineralocorticoids play a key role in hydromineral balance by regulating sodium retention and potassium wasting. Through favoring sodium, mineralocorticoids can cause hypertension from fluid overload under conditions of hyperaldosteronism, such as aldosterone-secreting tumors. An often-overlooked mechanism by which aldosterone functions to increase sodium is through stimulation of salt appetite. To drive sodium intake, aldosterone targets neurons in the hindbrain which uniquely express 11β-hydroxysteroid dehydrogenase type 2 (HSD2). This enzyme is a necessary precondition for aldosterone-sensing cells as it metabolizes glucocorticoids - preventing their activation of the mineralocorticoid receptor. In this review, we will consider the role of hindbrain HSD2 neurons in regulating sodium appetite by discussing HSD2 expression in the brain, regulation of hindbrain HSD2 neuron activity, and the circuitry mediating the effects of these aldosterone-sensitive neurons. Reducing the activity of hindbrain HSD2 neurons may be a viable strategy to reduce sodium intake and cardiovascular risk, particularly for conditions of hyperaldosteronism.
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Affiliation(s)
- Ahmet Kuralay
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA, USA
| | - Miriam C McDonough
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA; Molecular Medicine Graduate Program, University of Iowa, Iowa City, IA, USA
| | - Jon M Resch
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA, USA; Molecular Medicine Graduate Program, University of Iowa, Iowa City, IA, USA.
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Mathieu NM, Tan EE, Reho JJ, Brozoski DT, Muskus PC, Lu KT, Wackman KK, Grobe JL, Nakagawa P, Sigmund CD. Genetic Deletion of β-Arrestin 2 From the Subfornical Organ and Other Periventricular Nuclei in the Brain Alters Fluid Homeostasis and Blood Pressure. Hypertension 2024; 81:1332-1344. [PMID: 38629290 PMCID: PMC11096025 DOI: 10.1161/hypertensionaha.124.22874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 04/07/2024] [Indexed: 05/18/2024]
Abstract
BACKGROUND ANG (angiotensin II) elicits dipsogenic and pressor responses via activation of the canonical Gαq (G-protein component of the AT1R [angiotensin type 1 receptor])-mediated AT1R in the subfornical organ. Recently, we demonstrated that ARRB2 (β-arrestin 2) global knockout mice exhibit a higher preference for salt and exacerbated pressor response to deoxycorticosterone acetate salt. However, whether ARRB2 within selective neuroanatomical nuclei alters physiological responses to ANG is unknown. Therefore, we hypothesized that ARRB2, specifically in the subfornical organ, counterbalances maladaptive dipsogenic and pressor responses to the canonical AT1R signaling. METHODS Male and female Arrb2FLOX mice received intracerebroventricular injection of either adeno-associated virus (AAV)-Cre-GFP (green fluorescent protein) to induce brain-specific deletion of ARRB2 (Arrb2ICV-Cre). Arrb2FLOX mice receiving ICV-AAV-GFP were used as control (Arrb2ICV-Control). Infection with ICV-AAV-Cre primarily targeted the subfornical organ with few off targets. Fluid intake was evaluated using the 2-bottle choice paradigm with 1 bottle containing water and 1 containing 0.15 mol/L NaCl. RESULTS Arrb2ICV-Cre mice exhibited a greater pressor response to acute ICV-ANG infusion. At baseline conditions, Arrb2ICV-Cre mice exhibited a significant increase in saline intake compared with controls, resulting in a saline preference. Furthermore, when mice were subjected to water-deprived or sodium-depleted conditions, which would naturally increase endogenous ANG levels, Arrb2ICV-Cre mice exhibited elevated saline intake. CONCLUSIONS Overall, these data indicate that ARRB2 in selective cardiovascular nuclei in the brain, including the subfornical organ, counterbalances canonical AT1R responses to both exogenous and endogenous ANG. Stimulation of the AT1R/ARRB axis in the brain may represent a novel strategy to treat hypertension.
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Affiliation(s)
| | - Eden E. Tan
- SUPREMES Program, Marquette University & Medical College of Wisconsin, Milwaukee, WI
| | - John J. Reho
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, WI
| | | | | | - Ko-Ting Lu
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
| | - Kelsey K. Wackman
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
| | - Justin L. Grobe
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, WI
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI
| | - Pablo Nakagawa
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI
| | - Curt D. Sigmund
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI
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Khan MSH, Kim SQ, Ross RC, Corpodean F, Spann RA, Albarado DA, Fernandez-Kim SO, Clarke B, Berthoud HR, Münzberg H, McDougal DH, He Y, Yu S, Albaugh VL, Soto P, Morrison CD. FGF21 acts in the brain to drive macronutrient-specific changes in behavioral motivation and brain reward signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.05.583399. [PMID: 38798313 PMCID: PMC11118293 DOI: 10.1101/2024.03.05.583399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Dietary protein restriction induces adaptive changes in food preference, increasing protein consumption over carbohydrates or fat. We investigated whether motivation and reward signaling underpin these preferences. In an operant task, protein-restricted male mice increased their responding for liquid protein rewards, but not carbohydrate, fat, or sweet rewards. The protein restriction-induced increase in operant responding for protein was absent in Fgf21-KO mice and mice with neuron-specific deletion of the FGF21 co-receptor beta-Klotho (KlbCam2ka) mice. Fiber photometry recording of VTA dopamine neurons revealed that oral delivery of maltodextrin triggered a larger activation of dopamine neurons as compared to casein in control-fed mice, while casein produced a larger response in protein-restricted mice. This restriction-induced shift in nutrient-specific VTA dopamine signaling was lost in Fgf21-KO mice. These data demonstrate that FGF21 acts in the brain to induce a protein-specific appetite by specifically enhancing the reward value of protein-containing foods and the motivation to consume them.
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Affiliation(s)
| | - Sora Q. Kim
- Pennington Biomedical Research Center, Baton Rouge, LA 70808
| | - Robert C. Ross
- Pennington Biomedical Research Center, Baton Rouge, LA 70808
- Department of Surgery, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Florina Corpodean
- Pennington Biomedical Research Center, Baton Rouge, LA 70808
- Department of Surgery, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Redin A. Spann
- Pennington Biomedical Research Center, Baton Rouge, LA 70808
| | | | | | - Blaise Clarke
- Pennington Biomedical Research Center, Baton Rouge, LA 70808
| | | | - Heike Münzberg
- Pennington Biomedical Research Center, Baton Rouge, LA 70808
| | | | - Yanlin He
- Pennington Biomedical Research Center, Baton Rouge, LA 70808
| | - Sangho Yu
- Pennington Biomedical Research Center, Baton Rouge, LA 70808
| | - Vance L. Albaugh
- Pennington Biomedical Research Center, Baton Rouge, LA 70808
- Department of Surgery, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Paul Soto
- Department of Psychology, Louisiana State University, Baton Rouge, LA 70810
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Okuno-Ozeki N, Kohama Y, Taguchi H, Kawate Y, Umehara M, Minamida A, Yamauchi-Sawada H, Sunahara Y, Matoba Y, Nakamura I, Nakai K, Nakata T, Kirita Y, Taniguchi T, Tamagaki K, Hirao T, Matoba S, Kusaba T. Aversion to a High Salt Taste is Disturbed in Patients With CKD. Kidney Int Rep 2024; 9:1254-1264. [PMID: 38707820 PMCID: PMC11069016 DOI: 10.1016/j.ekir.2024.02.1393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/08/2024] [Accepted: 02/12/2024] [Indexed: 05/07/2024] Open
Abstract
Introduction A reduced salt intake is a vital lifestyle modification in the management of hypertension. Initiatives aimed at decreasing the intake of salt are based on the preference by humans for a salt taste. Salt intake behavior appears to be affected by the balance between attraction to a low salt taste and aversion to a high salt taste. However, aversion to a high salt taste has not yet been quantitively investigated in both healthy individuals and patients with chronic kidney disease (CKD). Methods Assessments of gustatory and aversion thresholds for salt, bitter, sour, and sweet tastes were performed using a stimulant-impregnated test strip in healthy subjects and patients with CKD. Results In a pilot taste test of 125 healthy subjects, the number of participants with an aversive reaction increased at higher salt concentrations. The threshold for normal taste perception was arbitrarily defined as 10% NaCl, with 47.2% of healthy subjects displaying an aversive reaction. In taste tests performed by 70 patients with CKD, 10% were unable to recognize a salt taste, even at the highest concentration (20% NaCl), suggesting a significant impairment in taste perception in patients with CKD. Only 15.7% of patients with CKD exhibited a normal aversion to NaCl, whereas 78.6% showed the complete loss of aversion to salt. Conclusion The present results confirmed the anticipated aversive response to a high salt taste in humans and demonstrated its impairment in patients with CKD, implying that patients with CKD have reduced resistance to a high salt intake.
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Affiliation(s)
- Natsuko Okuno-Ozeki
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yusuke Kohama
- Research and Development Headquarters, House Foods Group Inc. Chiba, Japan
| | - Hiromu Taguchi
- Research and Development Headquarters, House Foods Group Inc. Chiba, Japan
| | - Yuka Kawate
- Department of Nutrition, Kyoto Katsura Hospital, Kyoto, Japan
| | - Minato Umehara
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Atsushi Minamida
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Hiroko Yamauchi-Sawada
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yasuto Sunahara
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yayoi Matoba
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Itaru Nakamura
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Kunihiro Nakai
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Tomohiro Nakata
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yuhei Kirita
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Takuya Taniguchi
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Keiichi Tamagaki
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Takashi Hirao
- Research and Development Headquarters, House Foods Group Inc. Chiba, Japan
| | - Satoaki Matoba
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Tetsuro Kusaba
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
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Zhou S, Makashova O, Chevillard PM, Josey V, Li B, Prager-Khoutorsky M. Constitutive cell proliferation and neurogenesis in the organum vasculosum lamina terminalis and subfornical organ of adult rats. J Neuroendocrinol 2024; 36:e13377. [PMID: 38418229 DOI: 10.1111/jne.13377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 02/08/2024] [Accepted: 02/09/2024] [Indexed: 03/01/2024]
Abstract
Neurogenesis continues throughout adulthood in the subventricular zone, hippocampal subgranular zone, and the hypothalamic median eminence (ME) and the adjacent medio-basal hypothalamus. The ME is one of the circumventricular organs (CVO), which are specialized brain areas characterized by an incomplete blood-brain barrier and, thus, are involved in mediating communication between the central nervous system and the periphery. Additional CVOs include the organum vasculosum laminae terminalis (OVLT) and the subfornical organs (SFO). Previous studies have demonstrated that the ME contains neural stem cells (NSCs) capable of generating new neurons and glia in the adult brain. However, it remains unclear whether the OVLT and SFO also contain proliferating cells, the identity of these cells, and their ability to differentiate into mature neurons. Here we show that glial and mural subtypes exhibit NSC characteristics, expressing the endogenous mitotic maker Ki67, and incorporating the exogenous mitotic marker BrdU in the OVLT and SFO of adult rats. Glial cells constitutively proliferating in the SFO comprise NG2 glia, while in the OVLT, both NG2 glia and tanycytes appear to constitute the NSC pool. Furthermore, pericytes, which are mural cells associated with capillaries, also contribute to the pool of cells constitutively proliferating in the OVLT and SFO of adult rats. In addition to these glial and mural cells, a fraction of NSCs containing proliferation markers Ki67 and BrdU also expresses the early postmitotic neuronal marker doublecortin, suggesting that these CVOs comprise newborn neurons. Notably, these neurons can differentiate and express the mature neuronal marker NeuN. These findings establish the sensory CVOs OVLT and SFO as additional neurogenic niches, where the generation of new neurons and glia persists in the adult brain.
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Affiliation(s)
- Suijian Zhou
- Department of Physiology, McIntyre Medical Sciences Building, McGill University, Montreal, Québec, Canada
| | - Olena Makashova
- Department of Physiology, McIntyre Medical Sciences Building, McGill University, Montreal, Québec, Canada
| | - Pierre-Marie Chevillard
- Department of Physiology, McIntyre Medical Sciences Building, McGill University, Montreal, Québec, Canada
| | - Vanessa Josey
- Department of Physiology, McIntyre Medical Sciences Building, McGill University, Montreal, Québec, Canada
| | - Banruo Li
- Department of Physiology, McIntyre Medical Sciences Building, McGill University, Montreal, Québec, Canada
| | - Masha Prager-Khoutorsky
- Department of Physiology, McIntyre Medical Sciences Building, McGill University, Montreal, Québec, Canada
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Hiyama TY. Brain sodium sensing for regulation of thirst, salt appetite, and blood pressure. Physiol Rep 2024; 12:e15970. [PMID: 38479999 PMCID: PMC10937250 DOI: 10.14814/phy2.15970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 02/29/2024] [Indexed: 03/17/2024] Open
Abstract
The brain possesses intricate mechanisms for monitoring sodium (Na) levels in body fluids. During prolonged dehydration, the brain detects variations in body fluids and produces sensations of thirst and aversions to salty tastes. At the core of these processes Nax , the brain's Na sensor, exists. Specialized neural nuclei, namely the subfornical organ (SFO) and organum vasculosum of the lamina terminalis (OVLT), which lack the blood-brain barrier, play pivotal roles. Within the glia enveloping the neurons in these regions, Nax collaborates with Na+ /K+ -ATPase and glycolytic enzymes to drive glycolysis in response to elevated Na levels. Lactate released from these glia cells activates nearby inhibitory neurons. The SFO hosts distinct types of angiotensin II-sensitive neurons encoding thirst and salt appetite, respectively. During dehydration, Nax -activated inhibitory neurons suppress salt-appetite neuron's activity, whereas salt deficiency reduces thirst neuron's activity through cholecystokinin. Prolonged dehydration increases the Na sensitivity of Nax via increased endothelin expression in the SFO. So far, patients with essential hypernatremia have been reported to lose thirst and antidiuretic hormone release due to Nax -targeting autoantibodies. Inflammation in the SFO underlies the symptoms. Furthermore, Nax activation in the OVLT, driven by Na retention, stimulates the sympathetic nervous system via acid-sensing ion channels, contributing to a blood pressure elevation.
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Affiliation(s)
- Takeshi Y. Hiyama
- Department of Integrative PhysiologyTottori University Graduate School and Faculty of MedicineYonagoJapan
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Kim HK, Choi SH, Kim DH, Jeong YT. Comprehensive mapping of Epithelial Na + channel α expression in the mouse brain. Brain Struct Funct 2024:10.1007/s00429-023-02755-3. [PMID: 38305875 DOI: 10.1007/s00429-023-02755-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 12/29/2023] [Indexed: 02/03/2024]
Abstract
Epithelial sodium channel (ENaC) is responsible for regulating Na+ homeostasis. While its physiological functions have been investigated extensively in peripheral tissues, far fewer studies have explored its functions in the brain. Since our limited knowledge of ENaC's distribution in the brain impedes our understanding of its functions there, we decided to explore the whole-brain expression pattern of the Scnn1a gene, which encodes the core ENaC complex component ENaCα. To visualize Scnn1a expression in the brain, we crossed Scnn1a-Cre mice with Rosa26-lsl-tdTomato mice. Brain sections were subjected to immunofluorescence staining using antibodies against NeuN or Myelin Binding Protein (MBP), followed by the acquisition of confocal images. We observed robust tdTomato fluorescence not only in the soma of cortical layer 4, the thalamus, and a subset of amygdalar nuclei, but also in axonal projections in the hippocampus and striatum. We also observed expression in specific hypothalamic nuclei. Contrary to previous reports, however, we did not detect significant expression in the circumventricular organs, which are known for their role in regulating Na+ balance. Finally, we detected fluorescence in cells lining the ventricles and in the perivascular cells of the median eminence. Our comprehensive mapping of Scnn1a-expressing cells in the brain will provide a solid foundation for further investigations of the physiological roles ENaC plays within the central nervous system.
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Affiliation(s)
- Ha Kyeong Kim
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, Republic of Korea
- Department of Pharmacology, Korea University College of Medicine, Seoul, 02841, Republic of Korea
| | - Sang-Hyun Choi
- Department of Pharmacology, Korea University College of Medicine, Seoul, 02841, Republic of Korea
| | - Dong-Hoon Kim
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, Republic of Korea
- Department of Pharmacology, Korea University College of Medicine, Seoul, 02841, Republic of Korea
| | - Yong Taek Jeong
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, Republic of Korea.
- Department of Pharmacology, Korea University College of Medicine, Seoul, 02841, Republic of Korea.
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Matsuda T, Kobayashi K, Kobayashi K, Noda M. Two parabrachial Cck neurons involved in the feedback control of thirst or salt appetite. Cell Rep 2024; 43:113619. [PMID: 38157299 DOI: 10.1016/j.celrep.2023.113619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 11/20/2023] [Accepted: 12/08/2023] [Indexed: 01/03/2024] Open
Abstract
Thirst and salt appetite are temporarily suppressed after water and salt ingestion, respectively, before absorption; however, the underlying neural mechanisms remain unclear. The parabrachial nucleus (PBN) is the relay center of ingestion signals from the digestive organs. We herein identify two distinct neuronal populations expressing cholecystokinin (Cck) mRNA in the lateral PBN that are activated in response to water and salt intake, respectively. The two Cck neurons in the dorsal-lateral compartment of the PBN project to the median preoptic nucleus and ventral part of the bed nucleus of the stria terminalis, respectively. The optogenetic stimulation of respective Cck neurons suppresses thirst or salt appetite under water- or salt-depleted conditions. The combination of optogenetics and in vivo Ca2+ imaging during ingestion reveals that both Cck neurons control GABAergic neurons in their target nuclei. These findings provide the feedback mechanisms for the suppression of thirst and salt appetite after ingestion.
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Affiliation(s)
- Takashi Matsuda
- Homeostatic Mechanism Research Unit, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
| | - Kazuto Kobayashi
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima, Fukushima 960-1295, Japan
| | - Masaharu Noda
- Homeostatic Mechanism Research Unit, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan.
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11
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Yang G, Jia M, Li G, Zang YY, Chen YY, Wang YY, Zhan SY, Peng SX, Wan G, Li W, Yang JJ, Shi YS. TMEM63B channel is the osmosensor required for thirst drive of interoceptive neurons. Cell Discov 2024; 10:1. [PMID: 38172113 PMCID: PMC10764952 DOI: 10.1038/s41421-023-00628-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 11/18/2023] [Indexed: 01/05/2024] Open
Abstract
Thirst plays a vital role in the regulation of body fluid homeostasis and if deregulated can be life-threatening. Interoceptive neurons in the subfornical organ (SFO) are intrinsically osmosensitive and their activation by hyperosmolarity is necessary and sufficient for generating thirst. However, the primary molecules sensing systemic osmolarity in these neurons remain elusive. Here we show that the mechanosensitive TMEM63B cation channel is the osmosensor required for the interoceptive neurons to drive thirst. TMEM63B channel is highly expressed in the excitatory SFO thirst neurons. TMEM63B deletion in these neurons impaired hyperosmolarity-induced drinking behavior, while re-expressing TMEM63B in SFO restored water appetite in TMEM63B-deficient mice. Remarkably, hyperosmolarity activates TMEM63B channels, leading to depolarization and increased firing rate of the interoceptive neurons, which drives drinking behavior. Furthermore, TMEM63B deletion did not affect sensitivities of the SFO neurons to angiotensin II or hypoosmolarity, suggesting that TMEM63B plays a specialized role in detecting hyperosmolarity in SFO neurons. Thus, our results reveal a critical osmosensor molecule for the generation of thirst perception.
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Affiliation(s)
- Guolin Yang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurosurgery, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, Jiangsu, China
- Department of Anesthesiology, Pain and Perioperative Medicine, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu, China
- Guangdong Institute of Intelligence Science and Technology, Hengqin, Zhuhai, Guangdong, China
| | - Min Jia
- Department of Anesthesiology, Pain and Perioperative Medicine, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Guizhou Li
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu, China
| | - Yan-Yu Zang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurosurgery, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, Jiangsu, China
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu, China
| | - Yang-Yang Chen
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu, China
| | - Yue-Ying Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurosurgery, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, Jiangsu, China
- Guangdong Institute of Intelligence Science and Technology, Hengqin, Zhuhai, Guangdong, China
| | - Shi-Yu Zhan
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurosurgery, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, Jiangsu, China
- Guangdong Institute of Intelligence Science and Technology, Hengqin, Zhuhai, Guangdong, China
| | - Shi-Xiao Peng
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu, China
| | - Guoqiang Wan
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu, China
| | - Wei Li
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurosurgery, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, Jiangsu, China.
| | - Jian-Jun Yang
- Department of Anesthesiology, Pain and Perioperative Medicine, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
| | - Yun Stone Shi
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurosurgery, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, Jiangsu, China.
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu, China.
- Guangdong Institute of Intelligence Science and Technology, Hengqin, Zhuhai, Guangdong, China.
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12
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Zhang Y, Pool AH, Wang T, Liu L, Kang E, Zhang B, Ding L, Frieda K, Palmiter R, Oka Y. Parallel neural pathways control sodium consumption and taste valence. Cell 2023; 186:5751-5765.e16. [PMID: 37989313 PMCID: PMC10761003 DOI: 10.1016/j.cell.2023.10.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 09/04/2023] [Accepted: 10/19/2023] [Indexed: 11/23/2023]
Abstract
The hedonic value of salt fundamentally changes depending on the internal state. High concentrations of salt induce innate aversion under sated states, whereas such aversive stimuli transform into appetitive ones under sodium depletion. Neural mechanisms underlying this state-dependent salt valence switch are poorly understood. Using transcriptomics state-to-cell-type mapping and neural manipulations, we show that positive and negative valences of salt are controlled by anatomically distinct neural circuits in the mammalian brain. The hindbrain interoceptive circuit regulates sodium-specific appetitive drive , whereas behavioral tolerance of aversive salts is encoded by a dedicated class of neurons in the forebrain lamina terminalis (LT) expressing prostaglandin E2 (PGE2) receptor, Ptger3. We show that these LT neurons regulate salt tolerance by selectively modulating aversive taste sensitivity, partly through a PGE2-Ptger3 axis. These results reveal the bimodal regulation of appetitive and tolerance signals toward salt, which together dictate the amount of sodium consumption under different internal states.
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Affiliation(s)
- Yameng Zhang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Allan-Hermann Pool
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA; Departments of Neuroscience and Anesthesia and Pain Management and Peter O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Tongtong Wang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Lu Liu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Elin Kang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Bei Zhang
- Spatial Genomics, Inc., Pasadena, CA, USA
| | - Liang Ding
- Spatial Genomics, Inc., Pasadena, CA, USA
| | | | - Richard Palmiter
- Departments of Biochemistry and Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Yuki Oka
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
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13
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Kallupi M, Ciccocioppo R. Cue-induced reinstatement of seeking behavior in male rats is independent from the rewarding value of the primary reinforcer: Effect of mGluR5 blockade. Neuropharmacology 2023; 240:109694. [PMID: 37659439 PMCID: PMC11094430 DOI: 10.1016/j.neuropharm.2023.109694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/04/2023]
Abstract
Environmental conditioning factors have a profound impact on alcohol-seeking behavior and the maintenance of alcohol use in individuals with alcohol dependence. Cues associated with alcohol, depending on the perceived value of the primary reinforcer, gain salience and can trigger relapse. This study investigates the correlation between the reward magnitude of the primary reinforcer and the reinstatement evoked by cues predictive of their availability in male rats. Rat self-administration procedures were used to test reinstatement, with reinforcers consisting of 10% alcohol, 10% sucrose, or 2% sodium chloride (NaCl) experienced under need-state conditions. The effect of MTEP ([(2-methyl-1,3-thiazol-4-yl) ethynyl] pyridine), a selective metabotropic glutamate receptor 5 (mGluR5) antagonist, on motivation and reinstatement behaviors was also evaluated. RESULTS: demonstrate that under Fixed Ratio 1 (FR1) schedule, the three reinforcers maintain operant responding with the following order of magnitude 10% sucrose >2% NaCl >10% alcohol > water. Under a progressive ratio (PR) schedule of reinforcement, rats exhibit a significantly higher breakpoint for 2% NaCl (under Na-depletion), followed by 10% sucrose and 10% alcohol. After extinction, a significant reinstatement is observed with the magnitude order of 10% sucrose >10% alcohol >2% NaCl. However, only re-exposure to alcohol-paired cues induced significant reinstatement of alcohol-seeking after 4 and 8 months. Treatment with MTEP significantly reduces reinstatement of responding across all reinforcers, with the strongest effect observed on alcohol-seeking. These findings suggest that mGluR5 plays a general role in controlling cue-reactivity, but the effect is prominent in the case of alcohol compared to natural rewards. In conclusion, the results demonstrate a remarkable dissociation between the rewarding magnitude of the primary reinforcer and its ability to trigger relapse upon presentation of a cue previously associated with it. Importantly, alcohol, despite having lower intrinsic motivational value compared to a natural reward (sucrose) or a consummatory stimulus experienced under need state conditions (NaCl), can elicit more robust and longer-term reinstatement of seeking responses. Finally, our data demonstrate a significant involvement of the mGluR5 system in the regulation of seeking behavior.
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Affiliation(s)
- Marsida Kallupi
- Department of Psychiatry, University of California, San Diego, USA.
| | - Roberto Ciccocioppo
- School of Pharmacy, Pharmacology Unit, University of Camerino, Camerino, Italy
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14
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Mukai Y, Okubo TS, Lazarus M, Ono D, Tanaka KF, Yamanaka A. Prostaglandin E 2 Induces Long-Lasting Inhibition of Noradrenergic Neurons in the Locus Coeruleus and Moderates the Behavioral Response to Stressors. J Neurosci 2023; 43:7982-7999. [PMID: 37734949 PMCID: PMC10669809 DOI: 10.1523/jneurosci.0353-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 09/23/2023] Open
Abstract
Neuronal activity is modulated not only by inputs from other neurons but also by various factors, such as bioactive substances. Noradrenergic (NA) neurons in the locus coeruleus (LC-NA neurons) are involved in diverse physiological functions, including sleep/wakefulness and stress responses. Previous studies have identified various substances and receptors that modulate LC-NA neuronal activity through techniques including electrophysiology, calcium imaging, and single-cell RNA sequencing. However, many substances with unknown physiological significance have been overlooked. Here, we established an efficient screening method for identifying substances that modulate LC-NA neuronal activity through intracellular calcium ([Ca2+]i) imaging using brain slices. Using both sexes of mice, we screened 53 bioactive substances, and identified five novel substances: gastrin-releasing peptide, neuromedin U, and angiotensin II, which increase [Ca2+]i, and pancreatic polypeptide and prostaglandin D2, which decrease [Ca2+]i Among them, neuromedin U induced the greatest response in female mice. In terms of the duration of [Ca2+]i change, we focused on prostaglandin E2 (PGE2), since it induces a long-lasting decrease in [Ca2+]i via the EP3 receptor. Conditional knock-out of the receptor in LC-NA neurons resulted in increased depression-like behavior, prolonged wakefulness in the dark period, and increased [Ca2+]i after stress exposure. Our results demonstrate the effectiveness of our screening method for identifying substances that modulate a specific neuronal population in an unbiased manner and suggest that stress-induced prostaglandin E2 can suppress LC-NA neuronal activity to moderate the behavioral response to stressors. Our screening method will contribute to uncovering previously unknown physiological functions of uncharacterized bioactive substances in specific neuronal populations.SIGNIFICANCE STATEMENT Bioactive substances modulate the activity of specific neuronal populations. However, since only a limited number of substances with predicted effects have been investigated, many substances that may modulate neuronal activity have gone unrecognized. Here, we established an unbiased method for identifying modulatory substances by measuring the intracellular calcium signal, which reflects neuronal activity. We examined noradrenergic (NA) neurons in the locus coeruleus (LC-NA neurons), which are involved in diverse physiological functions. We identified five novel substances that modulate LC-NA neuronal activity. We also found that stress-induced prostaglandin E2 (PGE2) may suppress LC-NA neuronal activity and influence behavioral outcomes. Our screening method will help uncover previously overlooked functions of bioactive substances and provide insight into unrecognized roles of specific neuronal populations.
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Affiliation(s)
- Yasutaka Mukai
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Aichi 464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Tatsuo S Okubo
- Chinese Institute for Brain Research, Beijing 102206, China
| | - Michael Lazarus
- International Institute for Integrative Sleep Medicine (WPI-IIIS) and Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Daisuke Ono
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Aichi 464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Kenji F Tanaka
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku, Tokyo 160-8582, Japan
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Aichi 464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
- Chinese Institute for Brain Research, Beijing 102206, China
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku, Tokyo 160-8582, Japan
- National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan
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15
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Hernández-Pérez OR, Hernández VS, Zetter MA, Eiden LE, Zhang L. Nucleus of the lateral olfactory tract: A hub linking the water homeostasis-associated supraoptic nucleus-arginine vasopressin circuit and neocortical regions to promote social behavior under osmotic challenge. J Neuroendocrinol 2023; 35:e13202. [PMID: 36283814 PMCID: PMC10027625 DOI: 10.1111/jne.13202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/14/2022] [Accepted: 09/14/2022] [Indexed: 11/30/2022]
Abstract
Homeostatic challenges may alter the drive for social interaction. The neural activity that prompts this motivation remains poorly understood. In the present study, we identify direct projections from the hypothalamic supraoptic nucleus to the cortico-amygdalar nucleus of the lateral olfactory tract (NLOT). Dual in situ hybridization with probes for pituitary adenylate cyclase-activating polypeptide (PACAP), as well as vesicular glutamate transporter (VGLUT)1, VGLUT2, V1a and V1b, revealed a population of vasopressin-receptive PACAPergic neurons in NLOT layer 2 (NLOT2). Water deprivation (48 h, WD48) increased sociability compared to euhydrated subjects, as assessed with the three-chamber social interaction test (3CST). Fos expression immunohistochemistry showed NLOT and its main efferent regions had further increases in rats subjected to WD48 + 3CST. These regions strongly expressed PAC1 mRNA. Microinjections of arginine vasopressin (AVP) into the NLOT produced similar changes in sociability to water deprivation, and these were reduced by co-injection of V1a or V1b antagonists along with AVP. We conclude that, during challenge to water homeostasis, there is a recruitment of a glutamatergic-multi-peptidergic cooperative circuit that promotes social behavior.
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Affiliation(s)
- Oscar R. Hernández-Pérez
- Department of Physiology, School of Medicine, National Autonomous University of Mexico, Mexico
- Authors contributed equally to this work
| | - Vito S. Hernández
- Department of Physiology, School of Medicine, National Autonomous University of Mexico, Mexico
- Authors contributed equally to this work
| | - Mario A. Zetter
- Department of Physiology, School of Medicine, National Autonomous University of Mexico, Mexico
| | - Lee E. Eiden
- National Institute of Mental Health, National Institute of Health, Bethesda, MD, USA
| | - Limei Zhang
- Department of Physiology, School of Medicine, National Autonomous University of Mexico, Mexico
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16
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Shin Y, Kim S, Sohn JW. Serotonergic regulation of appetite and sodium appetite. J Neuroendocrinol 2023; 35:e13328. [PMID: 37525500 DOI: 10.1111/jne.13328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 06/27/2023] [Accepted: 07/15/2023] [Indexed: 08/02/2023]
Abstract
Serotonin is a neurotransmitter that is synthesized and released from the brainstem raphe nuclei to affect many brain functions. It is well known that the activity of raphe serotonergic neurons is changed in response to the changes in feeding status to regulate appetite via the serotonin receptors. Likewise, changes in volume status are known to alter the activity of raphe serotonergic neurons and drugs targeting serotonin receptors were shown to affect sodium appetite. Therefore, the central serotonin system appears to regulate ingestion of both food and salt, although neural mechanisms that induce appetite in response to hunger and sodium appetite in response to volume depletion are largely distinct from each other. In this review, we discuss our current knowledge regarding the regulation of ingestion - appetite and sodium appetite - by the central serotonin system.
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Affiliation(s)
- Yurim Shin
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Seungjik Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Jong-Woo Sohn
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
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17
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Todini L, Fantuz F. Thirst: neuroendocrine regulation in mammals. Vet Res Commun 2023; 47:1085-1101. [PMID: 36932281 DOI: 10.1007/s11259-023-10104-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 03/13/2023] [Indexed: 03/19/2023]
Abstract
Animals can sense their changing internal needs and then generate specific physiological and behavioural responses in order to restore homeostasis. Water-saline homeostasis derives from balances of water and sodium intake and output (drinking and diuresis, salt appetite and natriuresis), maintaining an appropriate composition and volume of extracellular fluid. Thirst is the sensation which drives to seek and consume water, regulated in the central nervous system by both neural and chemical signals. Water and electrolyte homeostasis depends on finely tuned physiological mechanisms, mainly susceptible to plasma Na+ concentration and osmotic pressure, but also to blood volume and arterial pressure. Increases of osmotic pressure as slight as 1-2% are enough to induce thirst ("homeostatic" or cellular), by activation of specialized osmoreceptors in the circumventricular organs, outside the blood-brain barrier. Presystemic anticipatory signals (by oropharyngeal or gastrointestinal receptors) inhibit thirst when fluids are ingested, or stimulate thirst associated with food intake. Hypovolemia, arterial hypotension, Angiotensin II stimulate thirst ("hypovolemic thirst", "extracellular dehydration"). Hypervolemia, hypertension, Atrial Natriuretic Peptide inhibit thirst. Circadian rhythms of thirst are also detectable, driven by suprachiasmatic nucleus in the hypothalamus. Such homeostasis and other fundamental physiological functions (cardiocircolatory, thermoregulation, food intake) are highly interdependent.
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Affiliation(s)
- Luca Todini
- Scuola di Bioscienze e Medicina Veterinaria, Università di Camerino, Via della Circonvallazione 93/95, 62024, Matelica, MC, Italy.
| | - Francesco Fantuz
- Scuola di Bioscienze e Medicina Veterinaria, Università di Camerino, Via della Circonvallazione 93/95, 62024, Matelica, MC, Italy
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18
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Peltekian L, Gasparini S, Fazan FS, Karthik S, Iverson G, Resch JM, Geerling JC. Sodium appetite and thirst do not require angiotensinogen production in astrocytes or hepatocytes. J Physiol 2023; 601:3499-3532. [PMID: 37291801 DOI: 10.1113/jp283169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 06/02/2023] [Indexed: 06/10/2023] Open
Abstract
In addition to its renal and cardiovascular functions, angiotensin signalling is thought to be responsible for the increases in salt and water intake caused by hypovolaemia. However, it remains unclear whether these behaviours require angiotensin production in the brain or liver. Here, we use in situ hybridization to identify tissue-specific expression of the genes required for producing angiotensin peptides, and then use conditional genetic deletion of the angiotensinogen gene (Agt) to test whether production in the brain or liver is necessary for sodium appetite and thirst. In the mouse brain, we identified expression of Agt (the precursor for all angiotensin peptides) in a large subset of astrocytes. We also identified Ren1 and Ace (encoding enzymes required to produce angiotensin II) expression in the choroid plexus, and Ren1 expression in neurons within the nucleus ambiguus compact formation. In the liver, we confirmed that Agt is widely expressed in hepatocytes. We next tested whether thirst and sodium appetite require angiotensinogen production in astrocytes or hepatocytes. Despite virtually eliminating expression in the brain, deleting astrocytic Agt did not reduce thirst or sodium appetite. Despite markedly reducing angiotensinogen in the blood, eliminating Agt from hepatocytes did not reduce thirst or sodium appetite, and in fact, these mice consumed the largest amounts of salt and water after sodium deprivation. Deleting Agt from both astrocytes and hepatocytes also did not prevent thirst or sodium appetite. Our findings suggest that angiotensin signalling is not required for sodium appetite or thirst and highlight the need to identify alternative signalling mechanisms. KEY POINTS: Angiotensin signalling is thought to be responsible for the increased thirst and sodium appetite caused by hypovolaemia, producing elevated water and sodium intake. Specific cells in separate brain regions express the three genes needed to produce angiotensin peptides, but brain-specific deletion of the angiotensinogen gene (Agt), which encodes the lone precursor for all angiotensin peptides, did not reduce thirst or sodium appetite. Double-deletion of Agt from brain and liver also did not reduce thirst or sodium appetite. Liver-specific deletion of Agt reduced circulating angiotensinogen levels without reducing thirst or sodium appetite. Instead, these angiotensin-deficient mice exhibited an enhanced sodium appetite. Because the physiological mechanisms controlling thirst and sodium appetite continued functioning without angiotensin production in the brain and liver, understanding these mechanisms requires a renewed search for the hypovolaemic signals necessary for activating each behaviour.
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Affiliation(s)
- Lila Peltekian
- Department of Neurology, University of Iowa, Iowa City, IA, USA
| | | | | | | | | | - Jon M Resch
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Joel C Geerling
- Department of Neurology, University of Iowa, Iowa City, IA, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
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19
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Jin X, Xie J, Yeh CW, Chen JC, Cheng CJ, Lien CC, Huang CL. WNK1 promotes water homeostasis by acting as a central osmolality sensor for arginine vasopressin release. J Clin Invest 2023; 133:e164222. [PMID: 37071482 PMCID: PMC10231991 DOI: 10.1172/jci164222] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 04/14/2023] [Indexed: 04/19/2023] Open
Abstract
Maintaining internal osmolality constancy is essential for life. Release of arginine vasopressin (AVP) in response to hyperosmolality is critical. Current hypotheses for osmolality sensors in circumventricular organs (CVOs) of the brain focus on mechanosensitive membrane proteins. The present study demonstrated that intracellular protein kinase WNK1 was involved. Focusing on vascular-organ-of-lamina-terminalis (OVLT) nuclei, we showed that WNK1 kinase was activated by water restriction. Neuron-specific conditional KO (cKO) of Wnk1 caused polyuria with decreased urine osmolality that persisted in water restriction and blunted water restriction-induced AVP release. Wnk1 cKO also blunted mannitol-induced AVP release but had no effect on osmotic thirst response. The role of WNK1 in the osmosensory neurons in CVOs was supported by neuronal pathway tracing. Hyperosmolality-induced increases in action potential firing in OVLT neurons was blunted by Wnk1 deletion or pharmacological WNK inhibitors. Knockdown of Kv3.1 channel in OVLT by shRNA reproduced the phenotypes. Thus, WNK1 in osmosensory neurons in CVOs detects extracellular hypertonicity and mediates the increase in AVP release by activating Kv3.1 and increasing action potential firing from osmosensory neurons.
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Affiliation(s)
- Xin Jin
- Department of Medicine, Division of Nephrology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Jian Xie
- Department of Medicine, Division of Nephrology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | | | - Jen-Chi Chen
- Department of Medicine, Division of Nephrology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Chih-Jen Cheng
- Department of Medicine, Division of Nephrology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Cheng-Chang Lien
- Institute of Neuroscience and
- Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chou-Long Huang
- Department of Medicine, Division of Nephrology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
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20
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Cao W, Yang Z, Liu X, Ren S, Su H, Yang B, Liu Y, Wilcox CS, Hou FF. A kidney-brain neural circuit drives progressive kidney damage and heart failure. Signal Transduct Target Ther 2023; 8:184. [PMID: 37169751 PMCID: PMC10175540 DOI: 10.1038/s41392-023-01402-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 02/16/2023] [Accepted: 02/24/2023] [Indexed: 05/13/2023] Open
Abstract
Chronic kidney disease (CKD) and heart failure (HF) are highly prevalent, aggravate each other, and account for substantial mortality. However, the mechanisms underlying cardiorenal interaction and the role of kidney afferent nerves and their precise central pathway remain limited. Here, we combined virus tracing techniques with optogenetic techniques to map a polysynaptic central pathway linking kidney afferent nerves to subfornical organ (SFO) and thereby to paraventricular nucleus (PVN) and rostral ventrolateral medulla that modulates sympathetic outflow. This kidney-brain neural circuit was overactivated in mouse models of CKD or HF and subsequently enhanced the sympathetic discharge to both the kidney and the heart in each model. Interruption of the pathway by kidney deafferentation, selective deletion of angiotensin II type 1a receptor (AT1a) in SFO, or optogenetic silence of the kidney-SFO or SFO-PVN projection decreased the sympathetic discharge and lessened structural damage and dysfunction of both kidney and heart in models of CKD and HF. Thus, kidney afferent nerves activate a kidney-brain neural circuit in CKD and HF that drives the sympathetic nervous system to accelerate disease progression in both organs. These results demonstrate the crucial role of kidney afferent nerves and their central connections in engaging cardiorenal interactions under both physiological and disease conditions. This suggests novel therapies for CKD or HF targeting this kidney-brain neural circuit.
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Affiliation(s)
- Wei Cao
- Division of Nephrology, Nanfang Hospital, Southern Medical University, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangdong Provincial Institute of Nephrology, Guangzhou, PR China
| | - Zhichen Yang
- Division of Nephrology, Nanfang Hospital, Southern Medical University, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangdong Provincial Institute of Nephrology, Guangzhou, PR China
| | - Xiaoting Liu
- Division of Nephrology, Nanfang Hospital, Southern Medical University, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangdong Provincial Institute of Nephrology, Guangzhou, PR China
| | - Siqiang Ren
- Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence; Key Laboratory of Mental Health of the Ministry of Education; Guangdong Province Key Laboratory of Psychiatric Disorders, Southern Medical University, Guangzhou, Guangdong, China
| | - Huanjuan Su
- Division of Nephrology, Nanfang Hospital, Southern Medical University, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangdong Provincial Institute of Nephrology, Guangzhou, PR China
| | - Bihui Yang
- Division of Nephrology, Nanfang Hospital, Southern Medical University, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangdong Provincial Institute of Nephrology, Guangzhou, PR China
| | - Youhua Liu
- Division of Nephrology, Nanfang Hospital, Southern Medical University, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangdong Provincial Institute of Nephrology, Guangzhou, PR China
| | - Christopher S Wilcox
- Division of Nephrology and Hypertension, Georgetown University Medical Central, Washington, DC, USA
| | - Fan Fan Hou
- Division of Nephrology, Nanfang Hospital, Southern Medical University, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangdong Provincial Institute of Nephrology, Guangzhou, PR China.
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21
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Wei Y, Khalaf AT, Rui C, Abdul Kadir SY, Zainol J, Oglah Z. The Emergence of TRP Channels Interactome as a Potential Therapeutic Target in Pancreatic Ductal Adenocarcinoma. Biomedicines 2023; 11:biomedicines11041164. [PMID: 37189782 DOI: 10.3390/biomedicines11041164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 05/17/2023] Open
Abstract
Integral membrane proteins, known as Transient Receptor Potential (TRP) channels, are cellular sensors for various physical and chemical stimuli in the nervous system, respiratory airways, colon, pancreas, bladder, skin, cardiovascular system, and eyes. TRP channels with nine subfamilies are classified by sequence similarity, resulting in this superfamily's tremendous physiological functional diversity. Pancreatic Ductal Adenocarcinoma (PDAC) is the most common and aggressive form of pancreatic cancer. Moreover, the development of effective treatment methods for pancreatic cancer has been hindered by the lack of understanding of the pathogenesis, partly due to the difficulty in studying human tissue samples. However, scientific research on this topic has witnessed steady development in the past few years in understanding the molecular mechanisms that underlie TRP channel disturbance. This brief review summarizes current knowledge of the molecular role of TRP channels in the development and progression of pancreatic ductal carcinoma to identify potential therapeutic interventions.
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Affiliation(s)
- Yuanyuan Wei
- Basic Medical College, Chengdu University, Chengdu 610106, China
| | | | - Cao Rui
- Basic Medical College, Chengdu University, Chengdu 610106, China
| | - Samiah Yasmin Abdul Kadir
- Faculty of Medicine, Widad University College, BIM Point, Bandar Indera Mahkota, Kuantan 25200, Malaysia
| | - Jamaludin Zainol
- Faculty of Medicine, Widad University College, BIM Point, Bandar Indera Mahkota, Kuantan 25200, Malaysia
| | - Zahraa Oglah
- School of Science, Auckland University of Technology (AUT), 55 Wellesley Street, Auckland 1010, New Zealand
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22
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Duriez A, Bergerot C, Cone JJ, Roitman MF, Gutkin B. Homeostatic Reinforcement Theory Accounts for Sodium Appetitive State- and Taste-Dependent Dopamine Responding. Nutrients 2023; 15:nu15041015. [PMID: 36839372 PMCID: PMC9968091 DOI: 10.3390/nu15041015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 02/09/2023] [Accepted: 02/11/2023] [Indexed: 02/22/2023] Open
Abstract
Seeking and consuming nutrients is essential to survival and the maintenance of life. Dynamic and volatile environments require that animals learn complex behavioral strategies to obtain the necessary nutritive substances. While this has been classically viewed in terms of homeostatic regulation, recent theoretical work proposed that such strategies result from reinforcement learning processes. This theory proposed that phasic dopamine (DA) signals play a key role in signaling potentially need-fulfilling outcomes. To examine links between homeostatic and reinforcement learning processes, we focus on sodium appetite as sodium depletion triggers state- and taste-dependent changes in behavior and DA signaling evoked by sodium-related stimuli. We find that both the behavior and the dynamics of DA signaling underlying sodium appetite can be accounted for by a homeostatically regulated reinforcement learning framework (HRRL). We first optimized HRRL-based agents to sodium-seeking behavior measured in rodents. Agents successfully reproduced the state and the taste dependence of behavioral responding for sodium as well as for lithium and potassium salts. We then showed that these same agents account for the regulation of DA signals evoked by sodium tastants in a taste- and state-dependent manner. Our models quantitatively describe how DA signals evoked by sodium decrease with satiety and increase with deprivation. Lastly, our HRRL agents assigned equal preference for sodium versus the lithium containing salts, accounting for similar behavioral and neurophysiological observations in rodents. We propose that animals use orosensory signals as predictors of the internal impact of the consumed good and our results pose clear targets for future experiments. In sum, this work suggests that appetite-driven behavior may be driven by reinforcement learning mechanisms that are dynamically tuned by homeostatic need.
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Affiliation(s)
- Alexia Duriez
- Group for Neural Theory, LNC2 DEC ENS, PSL University, 75005 Paris, France
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Clémence Bergerot
- Group for Neural Theory, LNC2 DEC ENS, PSL University, 75005 Paris, France
- Charité—Universitätsmedizin Berlin, Einstein Center for Neurosciences Berlin, 10117 Berlin, Germany
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Philippstraße 13, 10115 Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - Jackson J. Cone
- Hotchkiss Brain Institute, Department of Psychology, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Mitchell F. Roitman
- Department of Psychology, University of Illinois Chicago, Chicago, IL 60607, USA
| | - Boris Gutkin
- Group for Neural Theory, LNC2 DEC ENS, PSL University, 75005 Paris, France
- Correspondence: ; Tel.: +33-(0)6-8631-6231
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23
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Liu Y, Wei JA, Luo Z, Cui J, Luo Y, Mak SOK, Wang S, Zhang F, Yang Y, So KF, Shi L, Zhang L, Chow BKC. A gut-brain axis mediates sodium appetite via gastrointestinal peptide regulation on a medulla-hypothalamic circuit. SCIENCE ADVANCES 2023; 9:eadd5330. [PMID: 36791202 PMCID: PMC9931223 DOI: 10.1126/sciadv.add5330] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 01/17/2023] [Indexed: 05/29/2023]
Abstract
Salt homeostasis is orchestrated by both neural circuits and peripheral endocrine factors. The colon is one of the primary sites for electrolyte absorption, while its potential role in modulating sodium intake remains unclear. Here, we revealed that a gastrointestinal hormone, secretin, is released from colon endocrine cells under body sodium deficiency and is indispensable for inducing salt appetite. As the neural substrate, circulating secretin activates specific receptors in the nucleus of the solitary tracts, which further activates the downstream paraventricular nucleus of the hypothalamus, resulting in enhanced sodium intake. These results demonstrated a previously unrecognized gut-brain pathway for the timely regulation of sodium homeostasis.
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Affiliation(s)
- Yuchu Liu
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China
| | - Ji-an Wei
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China
| | - Zhihua Luo
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Jing Cui
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Yifan Luo
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China
| | - Sarah Oi Kwan Mak
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China
| | - Siqi Wang
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Fengwei Zhang
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China
| | - Yan Yang
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Kwok-Fai So
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
- Center for Brain Science and Brain-Inspired Intelligence, Guangdong-Hong Kong-Macao Greater Bay Area, Guangzhou, China
- Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, China
- State Key Laboratory of Brain and Cognitive Science, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China
| | - Lingling Shi
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Li Zhang
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
- Center for Brain Science and Brain-Inspired Intelligence, Guangdong-Hong Kong-Macao Greater Bay Area, Guangzhou, China
- Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, China
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Kikuchi E, Inui T, Su S, Sato Y, Funahashi M. Chemogenetic inhibition of the bed nucleus of the stria terminalis suppresses the intake of a preferable and learned aversive sweet taste solution in male mice. Behav Brain Res 2023; 439:114253. [PMID: 36509179 DOI: 10.1016/j.bbr.2022.114253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/05/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022]
Abstract
Conditioned taste aversion (CTA) is established by pairing a taste solution as a conditioned stimulus (CS) with visceral malaise as an unconditioned stimulus (US). CTA decreases the taste palatability of a CS. The bed nucleus of the stria terminalis (BNST) receives taste inputs from the brainstem. However, the involvement of the BNST in CTA remains unclear. Thus, this study examined the effects of chemogenetic inhibition of the BNST neurons on CS intake after CTA acquisition. An adeno-associated virus was microinjected into the BNST of male C57/BL6 mice to induce the inhibitory designer receptor hM4Di. The mice received a pairing of 0.2% saccharin solution (CS) with 0.3 M lithium chloride (2% BW, intraperitoneal). After conditioning, the administration of clozapine-N-oxide (CNO, 1 mg/kg) significantly enhanced the suppression of CS intake on the retrieval of CTA compared with its intake following saline administration (p < 0.01). We further assessed the effect of BNST neuron inhibition on the intake of water and taste solutions (saccharin, sucralose, sodium chloride, monosodium glutamate, quinine hydrochloride, and citric acid) using naïve (not learned CTA) mice. CNO administration significantly decreased the intake of saccharin and sucralose (p < 0.05). Our results indicate that BNST neurons mediate sweet taste and regulate sweet intake, regardless of whether sweets should be ingested or rejected. BNST neurons may be inhibited in the retrieval of CTA, thereby suppressing CS intake.
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Affiliation(s)
- Emi Kikuchi
- Department of Oral Physiology, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Hokkaido, Japan; Department of Orthodontics, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Tadashi Inui
- Department of Oral Physiology, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
| | - Shaoyi Su
- Department of Oral Physiology, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Yoshiaki Sato
- Department of Orthodontics, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Makoto Funahashi
- Department of Oral Physiology, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
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25
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Neurobehavioral Mechanisms of Sodium Appetite. Nutrients 2023; 15:nu15030620. [PMID: 36771327 PMCID: PMC9919744 DOI: 10.3390/nu15030620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/05/2023] [Accepted: 01/18/2023] [Indexed: 01/27/2023] Open
Abstract
The objectives of this paper are to first present physiological and ecological aspects of the unique motivational state of sodium appetite, then to focus on systemic physiology and brain mechanisms. I describe how laboratory protocols have been developed to allow the study of sodium appetite under controlled conditions, and focus on two such conditions specifically. The first of these is the presentation a sodium-deficient diet (SDD) for at least one week, and the second is accelerated sodium loss using SDD for 1-2 days coupled with the diuretic furosemide. The modality of consumption is also considered, ranging from a free intake of high concentration of sodium solution, to sodium-rich food or gels, and to operant protocols. I describe the pivotal role of angiotensin and aldosterone in these appetites and discuss whether the intakes or appetite are matched to the physiological need state. Several brain systems have been identified, most recently and microscopically using molecular biological methods. These include clusters in both the hindbrain and the forebrain. Satiation of sodium appetite is often studied using concentrated sodium solutions, but these can be consumed in apparent excess, and I suggest that future studies of satiation might emulate natural conditions in which excess consumption does not occur, using either SDD only as a stimulus, offering a sodium-rich food for the assessment of appetite, or a simple operant task.
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26
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Baumer-Harrison C, Breza JM, Sumners C, Krause EG, de Kloet AD. Sodium Intake and Disease: Another Relationship to Consider. Nutrients 2023; 15:535. [PMID: 36771242 PMCID: PMC9921152 DOI: 10.3390/nu15030535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/14/2023] [Accepted: 01/15/2023] [Indexed: 01/22/2023] Open
Abstract
Sodium (Na+) is crucial for numerous homeostatic processes in the body and, consequentially, its levels are tightly regulated by multiple organ systems. Sodium is acquired from the diet, commonly in the form of NaCl (table salt), and substances that contain sodium taste salty and are innately palatable at concentrations that are advantageous to physiological homeostasis. The importance of sodium homeostasis is reflected by sodium appetite, an "all-hands-on-deck" response involving the brain, multiple peripheral organ systems, and endocrine factors, to increase sodium intake and replenish sodium levels in times of depletion. Visceral sensory information and endocrine signals are integrated by the brain to regulate sodium intake. Dysregulation of the systems involved can lead to sodium overconsumption, which numerous studies have considered causal for the development of diseases, such as hypertension. The purpose here is to consider the inverse-how disease impacts sodium intake, with a focus on stress-related and cardiometabolic diseases. Our proposition is that such diseases contribute to an increase in sodium intake, potentially eliciting a vicious cycle toward disease exacerbation. First, we describe the mechanism(s) that regulate each of these processes independently. Then, we highlight the points of overlap and integration of these processes. We propose that the analogous neural circuitry involved in regulating sodium intake and blood pressure, at least in part, underlies the reciprocal relationship between neural control of these functions. Finally, we conclude with a discussion on how stress-related and cardiometabolic diseases influence these circuitries to alter the consumption of sodium.
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Affiliation(s)
- Caitlin Baumer-Harrison
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32603, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL 32610, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL 32610, USA
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Joseph M. Breza
- Department of Psychology, College of Arts and Sciences, Eastern Michigan University, Ypsilanti, MI 48197, USA
| | - Colin Sumners
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32603, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL 32610, USA
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Eric G. Krause
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL 32610, USA
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32610, USA
| | - Annette D. de Kloet
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32603, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL 32610, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL 32610, USA
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
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27
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Sodium Homeostasis, a Balance Necessary for Life. Nutrients 2023; 15:nu15020395. [PMID: 36678265 PMCID: PMC9862583 DOI: 10.3390/nu15020395] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Body sodium (Na) levels must be maintained within a narrow range for the correct functioning of the organism (Na homeostasis). Na disorders include not only elevated levels of this solute (hypernatremia), as in diabetes insipidus, but also reduced levels (hyponatremia), as in cerebral salt wasting syndrome. The balance in body Na levels therefore requires a delicate equilibrium to be maintained between the ingestion and excretion of Na. Salt (NaCl) intake is processed by receptors in the tongue and digestive system, which transmit the information to the nucleus of the solitary tract via a neural pathway (chorda tympani/vagus nerves) and to circumventricular organs, including the subfornical organ and area postrema, via a humoral pathway (blood/cerebrospinal fluid). Circuits are formed that stimulate or inhibit homeostatic Na intake involving participation of the parabrachial nucleus, pre-locus coeruleus, medial tuberomammillary nuclei, median eminence, paraventricular and supraoptic nuclei, and other structures with reward properties such as the bed nucleus of the stria terminalis, central amygdala, and ventral tegmental area. Finally, the kidney uses neural signals (e.g., renal sympathetic nerves) and vascular (e.g., renal perfusion pressure) and humoral (e.g., renin-angiotensin-aldosterone system, cardiac natriuretic peptides, antidiuretic hormone, and oxytocin) factors to promote Na excretion or retention and thereby maintain extracellular fluid volume. All these intake and excretion processes are modulated by chemical messengers, many of which (e.g., aldosterone, angiotensin II, and oxytocin) have effects that are coordinated at peripheral and central level to ensure Na homeostasis.
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28
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Santollo J, Daniels D, Leshem M, Schulkin J. Sex Differences in Salt Appetite: Perspectives from Animal Models and Human Studies. Nutrients 2023; 15:208. [PMID: 36615865 PMCID: PMC9824138 DOI: 10.3390/nu15010208] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/26/2022] [Accepted: 12/29/2022] [Indexed: 01/04/2023] Open
Abstract
Salt ingestion by animals and humans has been noted from prehistory. The search for salt is largely driven by a physiological need for sodium. There is a large body of literature on sodium intake in laboratory rats, but the vast majority of this work has used male rats. The limited work conducted in both male and female rats, however, reveals sex differences in sodium intake. Importantly, while humans ingest salt every day, with every meal and with many foods, we do not know how many of these findings from rodent studies can be generalized to men and women. This review provides a synthesis of the literature that examines sex differences in sodium intake and highlights open questions. Sodium serves many important physiological functions and is inextricably linked to the maintenance of body fluid homeostasis. Indeed, from a motivated behavior perspective, the drive to consume sodium has largely been studied in conjunction with the study of thirst. This review will describe the neuroendocrine controls of fluid balance, mechanisms underlying sex differences, sex differences in sodium intake, changes in sodium intake during pregnancy, and the possible neuronal mechanisms underlying these differences in behavior. Having reviewed the mechanisms that can only be studied in animal experiments, we address sex differences in human dietary sodium intake in reproduction, and with age.
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Affiliation(s)
- Jessica Santollo
- Department of Biology, University of Kentucky, Lexington, KY 40506, USA
| | - Derek Daniels
- Department of Biology, University at Buffalo, Buffalo, NY 14260, USA
| | - Micah Leshem
- School of Psychological Sciences, The University of Haifa, Haifa 3498838, Israel
| | - Jay Schulkin
- School of Medicine, University of Washington, Seattle, WA 98195, USA
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29
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Neuroscience: Secretin excites the thirst circuit. Curr Biol 2022; 32:R1318-R1320. [PMID: 36473444 DOI: 10.1016/j.cub.2022.10.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Peptides secreted by internal organs and by neurons in the brain are major regulators of eating and drinking. New work shows that the peptide hormone secretin influences drinking by adjusting the excitability of neurons in the brain's thirst circuit.
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30
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Zhang F, Mak SOK, Liu Y, Ke Y, Rao F, Yung WH, Zhang L, Chow BKC. Secretin receptor deletion in the subfornical organ attenuates the activation of excitatory neurons under dehydration. Curr Biol 2022; 32:4832-4841.e5. [PMID: 36220076 DOI: 10.1016/j.cub.2022.09.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 07/22/2022] [Accepted: 09/19/2022] [Indexed: 11/06/2022]
Abstract
In mammals, thirst is strongly influenced by the subfornical organ (SFO), a forebrain structure that integrates circulating signals including osmotic pressure and sodium contents. Secretin (SCT), a classical gastrointestinal hormone, has been implicated as a humoral factor regulating body-fluid homeostasis. However, the neural mechanism of secretin in the central nervous system in managing thirst remains unclear. In this study, we report that the local ablation of SCT receptor (SCTR) in the SFO reduces water but not salt intake in dehydrated mice and this effect could not be rescued by exogenous SCT administration. Electrophysiology with single-cell RT-PCR indicates that SCT elicits inward currents in the SFO neuronal nitric oxide synthase (SFOnNOS) neurons via SCTR in the presence of glutamate receptor antagonists. We further show that the SCTR in the SFO permits the activation of SFOnNOS neurons under distinct thirst types. Projection-specific gene deletion of SCTR in SFO to the median preoptic nucleus (MnPO) pathway also reduces water intake in dehydrated animals. SCT signaling thus plays an indispensable role in driving thirst. These data not only expand the functional boundaries of SCTR but also provide insights into the central mechanisms of homeostatic regulation.
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Affiliation(s)
- Fengwei Zhang
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Sarah O K Mak
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Yuchu Liu
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Ya Ke
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China; Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Hong Kong, China
| | - Feng Rao
- School of Life Sciences, Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Wing Ho Yung
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China; Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Hong Kong, China.
| | - Li Zhang
- Key Laboratory of CNS Regeneration (Ministry of Education), GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China; Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, China.
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31
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Durst und Trinken – Physiologie und Bedeutung für die Störungen des Wasserhaushalts. JOURNAL FÜR KLINISCHE ENDOKRINOLOGIE UND STOFFWECHSEL 2022. [DOI: 10.1007/s41969-022-00179-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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32
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Park A, Croset V, Otto N, Agarwal D, Treiber CD, Meschi E, Sims D, Waddell S. Gliotransmission of D-serine promotes thirst-directed behaviors in Drosophila. Curr Biol 2022; 32:3952-3970.e8. [PMID: 35963239 PMCID: PMC9616736 DOI: 10.1016/j.cub.2022.07.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/04/2022] [Accepted: 07/15/2022] [Indexed: 12/13/2022]
Abstract
Thirst emerges from a range of cellular changes that ultimately motivate an animal to consume water. Although thirst-responsive neuronal signals have been reported, the full complement of brain responses is unclear. Here, we identify molecular and cellular adaptations in the brain using single-cell sequencing of water-deprived Drosophila. Water deficiency primarily altered the glial transcriptome. Screening the regulated genes revealed astrocytic expression of the astray-encoded phosphoserine phosphatase to bi-directionally regulate water consumption. Astray synthesizes the gliotransmitter D-serine, and vesicular release from astrocytes is required for drinking. Moreover, dietary D-serine rescues aay-dependent drinking deficits while facilitating water consumption and expression of water-seeking memory. D-serine action requires binding to neuronal NMDA-type glutamate receptors. Fly astrocytes contribute processes to tripartite synapses, and the proportion of astrocytes that are themselves activated by glutamate increases with water deprivation. We propose that thirst elevates astrocytic D-serine release, which awakens quiescent glutamatergic circuits to enhance water procurement.
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Affiliation(s)
- Annie Park
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK
| | - Vincent Croset
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK; Department of Biosciences, Durham University, Durham DH1 3LE, UK.
| | - Nils Otto
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK
| | - Devika Agarwal
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK; MRC Computational Genomics Analysis and Training Programme (CGAT), MRC Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Christoph D Treiber
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK
| | - Eleonora Meschi
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK
| | - David Sims
- MRC Computational Genomics Analysis and Training Programme (CGAT), MRC Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Scott Waddell
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK.
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33
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Winter A, McMurray KMJ, Ahlbrand R, Allgire E, Shukla S, Jones J, Sah R. The subfornical organ regulates acidosis-evoked fear by engaging microglial acid-sensor TDAG8 and forebrain neurocircuits in male mice. J Neurosci Res 2022; 100:1732-1746. [PMID: 35553084 PMCID: PMC9812228 DOI: 10.1002/jnr.25059] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 04/06/2022] [Accepted: 04/23/2022] [Indexed: 01/07/2023]
Abstract
An important role of pH homeostasis has been suggested in the physiology of panic disorder, with acidosis as an interoceptive trigger leading to fear and panic. Identification of novel mechanisms that can translate acidosis into fear will promote a better understanding of panic physiology. The current study explores a role of the subfornical organ (SFO), a blood-brain barrier compromised brain area, in translating acidosis to fear-relevant behaviors. We performed SFO-targeted acidification in male, wild-type mice and mice lacking microglial acid-sensing G protein-coupled receptor-T-cell death-associated gene 8 (TDAG8). Localized SFO acidification evoked significant freezing and reduced exploration that was dependent on the presence of acid-sensor TDAG8. Acidosis promoted the activation of SFO microglia and neurons that were absent in TDAG8-deficient mice. The assessment of regional neuronal activation in wild-type and TDAG8-deficient mice following SFO acidification revealed significant acidosis and genotype-dependent alterations in the hypothalamus, amygdala, prefrontal cortex, and periaqueductal gray nuclei. Furthermore, mapping of interregional co-activation patterns revealed that SFO acidosis promoted positive hypothalamic-cortex associations and desynchronized SFO-cortex and amygdala-cortex associations, suggesting an interplay of homeostatic and fear regulatory areas. Importantly, these alterations were not evident in TDAG8-deficient mice. Overall, our data support a regulatory role of subfornical organ microglial acid sensing in acidosis-evoked fear, highlighting a centralized role of blood-brain barrier compromised nodes in interoceptive sensing and behavioral regulation. Identification of pathways by which humoral information can modulate fear behavior is relevant to panic disorder, where aberrant interoceptive signaling has been reported.
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Affiliation(s)
- Andrew Winter
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio, USA
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, Ohio, USA
| | - Katherine M. J. McMurray
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio, USA
- VA Medical Center, Cincinnati, Ohio, USA
| | - Rebecca Ahlbrand
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio, USA
- VA Medical Center, Cincinnati, Ohio, USA
| | - Emily Allgire
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio, USA
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, Ohio, USA
| | - Sachi Shukla
- Neuroscience Undergraduate Program, University of Cincinnati, Cincinnati, Ohio, USA
| | - James Jones
- Neuroscience Undergraduate Program, University of Cincinnati, Cincinnati, Ohio, USA
| | - Renu Sah
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio, USA
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, Ohio, USA
- VA Medical Center, Cincinnati, Ohio, USA
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Molecular neurobiological markers in the onset of sodium appetite. Sci Rep 2022; 12:14224. [PMID: 35987984 PMCID: PMC9392805 DOI: 10.1038/s41598-022-18220-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/08/2022] [Indexed: 12/02/2022] Open
Abstract
Sodium appetite is a motivational state involving homeostatic behavior, seeking the ingest of salty substances after sodium loss. There is a temporal dissociation between sodium depletion (SD) and the appearance of sodium appetite. However, the responsible mechanisms for this delay remain poorly elucidated. In the present study, we measured the temporal changes at two and 24 h after SD in the gene expression of key elements within excitatory, inhibitory, and sensory areas implicated in the signaling pathways involved in the onset of sodium appetite. In SD rats, we observed that the expression of critical components within the brain control circuit of sodium appetite, including Angiotensin-type-1 receptor (Agtr1a), Oxytocin-(OXT-NP)-neurophysin-I, and serotonergic-(5HT)-type-2c receptor (Htr2c) were modulated by SD, regardless of time. However, we observed reduced phosphorylation of mitogen-activated protein kinases (MAPK) at the paraventricular nucleus (PVN) and increased oxytocin receptor (Oxtr) mRNA expression at the anteroventral of the third ventricle area (AV3V), at two hours after SD, when sodium appetite is inapparent. At twenty-four hours after SD, when sodium appetite is released, we observed a reduction in the mRNA expression of the transient receptor potential channel 1gene (Trpv1) and Oxtr in the AV3V and the dorsal raphe nucleus, respectively. The results indicate that SD exerts a coordinated timing effect, promoting the appearance of sodium appetite through changes in MAPK activity and lower Trpv1 channel and Oxtr expression that trigger sodium consumption to reestablish the hydroelectrolytic homeostasis.
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Fernandes-Costa F, de Lima Flôr AF, de Andrade Braga V, Campos Cruz J. Lactate inhibited sodium intake in dehydrated rats. Appetite 2022; 175:106046. [PMID: 35461891 DOI: 10.1016/j.appet.2022.106046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 04/03/2022] [Accepted: 04/09/2022] [Indexed: 11/19/2022]
Abstract
Recent studies have suggested that glial cells, especially astrocytes, are involved in balanced hydromineral modulation. In response to increased extracellular Na+ concentration, astrocytic Nax channels are activated, promoting lactate production and release. Furthermore, previous in vitro studies have suggested that lactate and hypertonic Na + solution activate SFO GABAergic neurons involved in the salt-appetite central pathways. Here, we evaluated the role of lactate in dehydration-induced sodium and water intake. To this end, intracerebroventricular microinjection (icv) of l-lactate or α-cyano-4-hydroxycinnamic acid (α-CHCA, MCT lactate transporter inhibitor) was performed in rats subjected to 48 h of water deprivation (WD) and 1 h of partial rehydration after 48 h of WD (WD-PR). The rehydration protocol was used to distinguish the mechanisms of thirst and sodium appetite induced by WD. Then, water and sodium (0.3 M NaCl) intake were evaluated for 2 h. Our results showed that central α-CHCA induced an increase in sodium preference in WD rats. Furthermore, central lactate increased water intake but reduced sodium intake in WD-PR animals. In contrast, central lactate transporter inhibition did not change water or sodium intake in WD-PR rats. Our results suggest that lactate is involved in inhibitory mechanisms that induce sodium intake avoidance in dehydrated rats.
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Affiliation(s)
| | | | - Valdir de Andrade Braga
- Departamento de Biotecnologia, Centro de Biotecnologia, Universidade Federal da Paraíba, Brazil
| | - Josiane Campos Cruz
- Departamento de Biotecnologia, Centro de Biotecnologia, Universidade Federal da Paraíba, Brazil.
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Wu L, Wang G, Yang B, Liu X, Xie C, Feng X, Jin L, Zhou Z, Yang M, Zhou Z, Su C, Li Y, Song Y, Cao W. Urinary Matrix Metalloproteinase 7 Activated by Oxidative Stress Predicts Kidney Prognosis in Myeloperoxidase-Antineutrophil Cytoplasmic Antibody-Associated Vasculitis. Antioxid Redox Signal 2022; 37:246-256. [PMID: 35152729 DOI: 10.1089/ars.2021.0188] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Aims: Effective and applicable predictors of end-stage kidney disease (ESKD) are needed for patients with myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis (MPO-AAV) and kidney involvement. We investigated whether urinary matrix metalloproteinase-7 (uMMP7) was associated with kidney injury severity and incident ESKD in MPO-AAV. Results: A prospective two-stage study was conducted in 150 patients with newly diagnosed MPO-AAV in two independent cohorts. uMMP7 was measured on the days of initial and repeat kidney biopsies. In stage I, a higher initial uMMP7 level was associated with a lower estimated glomerular filtration rate (eGFR), higher level of proteinuria, and greater extent of kidney pathologic lesions. This elevated uMMP7 protein level is activated and potentially derived from the enhanced kidney production induced by oxidative stress. In stage II, uMMP7 at initial biopsy was independently associated with the incidence of ESKD over 6 years. The higher uMMP7 group (vs. lower) had an adjusted hazard ratio of 3.79 (95% confidence interval [CI], 1.49-6.09) for ESKD in the test cohort. Findings were similar in the validation cohort. A combination of data from the two cohorts revealed that adding uMMP7 into clinical or clinicopathologic models significantly improved risk discrimination for future ESKD. Innovation: An elevated uMMP7 level in MPO-AAV was independently associated with severe kidney injury and incident ESKD. Conclusions: uMMP7 in MPO-AAV improves identification of patients at risk of ESKD and may enable early and optimized therapy to improve outcomes. Antioxid. Redox Signal. 37, 246-256.
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Affiliation(s)
- Liling Wu
- State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China.,Division of Nephrology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, P.R. China
| | - Guobao Wang
- State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Bihui Yang
- State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Xiaoting Liu
- State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Chao Xie
- Division of Nephrology, The First People's Hospital of Foshan, Foshan, P.R. China
| | - Xiaodan Feng
- Division of Nephrology, Guangzhou Development District Hospital, Guangzhou, P.R. China
| | - LinWei Jin
- Division of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, P.R. China
| | - Zhuoyu Zhou
- State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Manqiu Yang
- State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Zhanmei Zhou
- State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Cailing Su
- State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Yajing Li
- State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Yali Song
- Center for Reproductive Medicine, Dongguan Maternal and Child Health Care Hospital, Southern Medical University, Dongguan, P.R. China
| | - Wei Cao
- State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
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Mecawi AS, Varanda WA, da Silva MP. Osmoregulation and the Hypothalamic Supraoptic Nucleus: From Genes to Functions. Front Physiol 2022; 13:887779. [PMID: 35685279 PMCID: PMC9171026 DOI: 10.3389/fphys.2022.887779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 04/18/2022] [Indexed: 11/13/2022] Open
Abstract
Due to the relatively high permeability to water of the plasma membrane, water tends to equilibrate its chemical potential gradient between the intra and extracellular compartments. Because of this, changes in osmolality of the extracellular fluid are accompanied by changes in the cell volume. Therefore, osmoregulatory mechanisms have evolved to keep the tonicity of the extracellular compartment within strict limits. This review focuses on the following aspects of osmoregulation: 1) the general problems in adjusting the "milieu interieur" to challenges imposed by water imbalance, with emphasis on conceptual aspects of osmosis and cell volume regulation; 2) osmosensation and the hypothalamic supraoptic nucleus (SON), starting with analysis of the electrophysiological responses of the magnocellular neurosecretory cells (MNCs) involved in the osmoreception phenomenon; 3) transcriptomic plasticity of SON during sustained hyperosmolality, to pinpoint the genes coding membrane channels and transporters already shown to participate in the osmosensation and new candidates that may have their role further investigated in this process, with emphasis on those expressed in the MNCs, discussing the relationships of hydration state, gene expression, and MNCs electrical activity; and 4) somatodendritic release of neuropeptides in relation to osmoregulation. Finally, we expect that by stressing the relationship between gene expression and the electrical activity of MNCs, studies about the newly discovered plastic-regulated genes that code channels and transporters in the SON may emerge.
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Affiliation(s)
- André Souza Mecawi
- Laboratory of Molecular Neuroendocrinology, Department of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Wamberto Antonio Varanda
- Department of Physiology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Melina Pires da Silva
- Laboratory of Cellular Neuroendocrinology, Department of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
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Uchida Y, Hikida T, Yamashita Y. Computational Mechanisms of Osmoregulation: A Reinforcement Learning Model for Sodium Appetite. Front Neurosci 2022; 16:857009. [PMID: 35663557 PMCID: PMC9160331 DOI: 10.3389/fnins.2022.857009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 04/15/2022] [Indexed: 11/30/2022] Open
Abstract
Homeostatic control with oral nutrient intake is a vital complex system involving the orderly interactions between the external and internal senses, behavioral control, reward learning, and decision-making. Sodium appetite is a representative system and has been intensively investigated in animal models of homeostatic systems and oral nutrient intake. However, the system-level mechanisms for regulating sodium intake behavior and homeostatic control remain unclear. In the current study, we attempted to provide a mechanistic understanding of sodium appetite behavior by using a computational model, the homeostatic reinforcement learning model, in which homeostatic behaviors are interpreted as reinforcement learning processes. Through simulation experiments, we confirmed that our homeostatic reinforcement learning model successfully reproduced homeostatic behaviors by regulating sodium appetite. These behaviors include the approach and avoidance behaviors to sodium according to the internal states of individuals. In addition, based on the assumption that the sense of taste is a predictor of changes in the internal state, the homeostatic reinforcement learning model successfully reproduced the previous paradoxical observations of the intragastric infusion test, which cannot be explained by the classical drive reduction theory. Moreover, we extended the homeostatic reinforcement learning model to multimodal data, and successfully reproduced the behavioral tests in which water and sodium appetite were mediated by each other. Finally, through an experimental simulation of chemical manipulation in a specific neural population in the brain stem, we proposed a testable hypothesis for the function of neural circuits involving sodium appetite behavior. The study results support the idea that osmoregulation via sodium appetitive behavior can be understood as a reinforcement learning process, and provide a mechanistic explanation for the underlying neural mechanisms of decision-making related to sodium appetite and homeostatic behavior.
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Affiliation(s)
- Yuuki Uchida
- Department of Information Medicine, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
- Medical and Dental Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takatoshi Hikida
- Laboratory for Advanced Brain Functions, Institute for Protein Research, Osaka University, Osaka, Japan
- *Correspondence: Takatoshi Hikida,
| | - Yuichi Yamashita
- Department of Information Medicine, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
- Yuichi Yamashita,
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Fernandes-Costa F, de Lima Flôr AF, Falcão MSF, de Moura Balarini C, de Brito Alves JL, de Andrade Braga V, de Campos Cruz J. Central interaction between nitric oxide, lactate and glial cells to modulate water and sodium intake in rats. Brain Res Bull 2022; 186:1-7. [PMID: 35487385 DOI: 10.1016/j.brainresbull.2022.04.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 04/07/2022] [Accepted: 04/23/2022] [Indexed: 12/23/2022]
Abstract
The "astrocyte-to-neuron lactate shuttle" (ANLS) mechanism is part of the central inhibitory pathway to modulate sodium intake. An interaction between the GABAergic neurons and nitric oxide (NO) in the subfornical organ (SFO) in salt-appetite inhibition has been suggested. In addition, NO is a key molecule involved in astrocytic energy metabolism and lactate production. In the present study, we hypothesized there is an interaction between astrocytic lactate and central NO to negatively modulate water and sodium intake through the ANLS mechanism. The results showed that central Nω-nitro-L-arginine methyl ester (L-NAME, NO-synthase inhibition) induced an increase in water and sodium intake. These responses were attenuated by previous central microinjection of fluorocitrate (FCt, a reversible glial inhibitor). Interestingly, L-NAME-induced water and sodium intake were also decreased by previous microinjection of lactate but did not change after inhibition of the ANLS mechanism by α-cyano 4-hydroxycinnamic acid (α-CHCA), an inhibitor of the MCT lactate transporter. Our results suggest a central interaction between NO, glial cells, and lactate to modulate water and sodium intake.
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Affiliation(s)
| | | | | | | | | | | | - Josiane de Campos Cruz
- Biotechnology Center, Department of Biotechnology, Federal University of Paraiba, João Pessoa, Brazil; Department of Physiology and Pathology, Federal University of Paraiba, João Pessoa, Brazil; Department of Nutrition, Federal University of Paraiba, João Pessoa, Brazil; Department of Biotechnology, Federal University of Paraiba, João Pessoa, Brazil.
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40
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Subfornical organ interleukin 1 receptor: A novel regulator of spontaneous and conditioned fear associated behaviors in mice. Brain Behav Immun 2022; 101:304-317. [PMID: 35032573 PMCID: PMC9836229 DOI: 10.1016/j.bbi.2022.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 12/25/2021] [Accepted: 01/07/2022] [Indexed: 01/14/2023] Open
Abstract
Impaired threat responding and fear regulation is a hallmark of psychiatric conditions such as post-traumatic stress disorder (PTSD) and Panic Disorder (PD). Most studies have focused on external psychogenic threats to study fear, however, accumulating evidence suggests a primary role of homeostatic perturbations and interoception in regulating emotional behaviors. Heightened reactivity to interoceptive threat carbon dioxide (CO2) inhalation associates with increased risk for developing PD and PTSD, however, contributory mechanisms and molecular targets are not well understood. Previous studies from our group suggested a potential role of interleukin 1 receptor (IL-1R1) signaling within BBB-devoid sensory circumventricular organ, the subfornical organ (SFO) in CO2-evoked fear. However, the necessity of SFO-IL-1R1 in regulating CO2-associated spontaneous fear as well as, long-term fear potentiation relevant to PD/PTSD has not been investigated. The current study tested male mice with SFO-targeted microinfusion of the IL-1R1 antagonist (IL-1RA) or vehicle in a recently developed CO2-startle-fear conditioning-extinction paradigm. Consistent with our hypothesis, SFO IL-1RA treatment elicited significant attenuation of freezing and increased rearing during CO2 inhalation suggesting SFO-IL1R1 regulation of spontaneous fear to CO2. Intriguingly, SFO IL-1RA treatment normalized CO2-associated potentiation of conditioned fear and impaired extinction a week later suggesting modulation of long-term fear by SFO-IL-1R1 signaling. Post behavior FosB mapping revealed recruitment of prefrontal cortex-amygdala-periaqueductal gray (PAG) areas in SFO-IL-1RA mediated effects. Additionally, we localized cellular IL-1R1 expression within the SFO to blood vessel endothelial cells and observed CO2-induced alterations in IL-1β/IL-1R1 expression in peripheral mononuclear cells and SFO. Lastly, CO2-evoked microglial activation was attenuated in SFO-IL-1RA treated mice. These observations suggest a peripheral monocyte-endothelial-microglia interplay in SFO-IL-1R1 modulation of CO2-associated spontaneous fear and delayed fear memory. Collectively, our data highlight a novel, "bottom-up" neuroimmune mechanism that integrates interoceptive and exteroceptive threat processing of relevance to fear-related pathologies.
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41
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Hunter RW, Dhaun N, Bailey MA. The impact of excessive salt intake on human health. Nat Rev Nephrol 2022; 18:321-335. [DOI: 10.1038/s41581-021-00533-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2021] [Indexed: 12/19/2022]
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42
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NODA M, MATSUDA T. Central regulation of body fluid homeostasis. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2022; 98:283-324. [PMID: 35908954 PMCID: PMC9363595 DOI: 10.2183/pjab.98.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Extracellular fluids, including blood, lymphatic fluid, and cerebrospinal fluid, are collectively called body fluids. The Na+ concentration ([Na+]) in body fluids is maintained at 135-145 mM and is broadly conserved among terrestrial animals. Homeostatic osmoregulation by Na+ is vital for life because severe hyper- or hypotonicity elicits irreversible organ damage and lethal neurological trauma. To achieve "body fluid homeostasis" or "Na homeostasis", the brain continuously monitors [Na+] in body fluids and controls water/salt intake and water/salt excretion by the kidneys. These physiological functions are primarily regulated based on information on [Na+] and relevant circulating hormones, such as angiotensin II, aldosterone, and vasopressin. In this review, we discuss sensing mechanisms for [Na+] and hormones in the brain that control water/salt intake behaviors, together with the responsible sensors (receptors) and relevant neural pathways. We also describe mechanisms in the brain by which [Na+] increases in body fluids activate the sympathetic neural activity leading to hypertension.
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Affiliation(s)
- Masaharu NODA
- Homeostatic Mechanism Research Unit, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan
- Correspondence should be addressed to: Homeostatic Mechanism Research Unit, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama, Kanagawa 226-8503, Japan (e-mail: )
| | - Takashi MATSUDA
- Homeostatic Mechanism Research Unit, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan
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Park S, Sohn JW. Protocol for sodium depletion and measurement of sodium appetite in mice. STAR Protoc 2021; 2:101026. [PMID: 34950894 PMCID: PMC8671748 DOI: 10.1016/j.xpro.2021.101026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Sodium appetite is a state that motivates animals to consume normally unappetizing concentrations of sodium. Here we describe a protocol to induce sodium appetite in mice by furosemide-induced diuresis and measure sodium intake using volumetric drinking tubes. This protocol induces sodium appetite rapidly and can be used to assess the effect of various treatments on sodium appetite. This protocol does not require electronic equipment and can be implemented easily. For complete details on the use and execution of this protocol, please refer to Park et al. (2020). Protocol describes easy and affordable approaches to study sodium appetite in mice Sodium appetite is induced by sodium-losing diuretics and sodium-deficient diet Sodium appetite is assessed by two-bottle assay using volumetric drinking tubes Protocol can be used to assess effects of various treatments on sodium appetite
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Affiliation(s)
- Seahyung Park
- Department of Biological Sciences, Korea Advanced Institution of Science and Technology, 34141 Daejeon, Korea
| | - Jong-Woo Sohn
- Department of Biological Sciences, Korea Advanced Institution of Science and Technology, 34141 Daejeon, Korea
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Yang Z, Wang T, Oka Y. Predicting changes in osmolality. eLife 2021; 10:74551. [PMID: 34792465 PMCID: PMC8601660 DOI: 10.7554/elife.74551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Two neural circuits control the release of vasopressin in response to eating and drinking before there are any detectable changes in blood water levels.
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Affiliation(s)
- Zhe Yang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Tongtong Wang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Yuki Oka
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
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Khan MS, Spann RA, Münzberg H, Yu S, Albaugh VL, He Y, Berthoud HR, Morrison CD. Protein Appetite at the Interface between Nutrient Sensing and Physiological Homeostasis. Nutrients 2021; 13:4103. [PMID: 34836357 PMCID: PMC8620426 DOI: 10.3390/nu13114103] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/04/2021] [Accepted: 11/11/2021] [Indexed: 12/19/2022] Open
Abstract
Feeding behavior is guided by multiple competing physiological needs, as animals must sense their internal nutritional state and then identify and consume foods that meet nutritional needs. Dietary protein intake is necessary to provide essential amino acids and represents a specific, distinct nutritional need. Consistent with this importance, there is a relatively strong body of literature indicating that protein intake is defended, such that animals sense the restriction of protein and adaptively alter feeding behavior to increase protein intake. Here, we argue that this matching of food consumption with physiological need requires at least two concurrent mechanisms: the first being the detection of internal nutritional need (a protein need state) and the second being the discrimination between foods with differing nutritional compositions. In this review, we outline various mechanisms that could mediate the sensing of need state and the discrimination between protein-rich and protein-poor foods. Finally, we briefly describe how the interaction of these mechanisms might allow an animal to self-select between a complex array of foods to meet nutritional needs and adaptively respond to changes in either the external environment or internal physiological state.
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Affiliation(s)
| | | | | | | | | | | | | | - Christopher D. Morrison
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA; (M.S.K.); (R.A.S.); (H.M.); (S.Y.); (V.L.A.); (Y.H.); (H.-R.B.)
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Signal Transduction of Mineralocorticoid and Angiotensin II Receptors in the Central Control of Sodium Appetite: A Narrative Review. Int J Mol Sci 2021; 22:ijms222111735. [PMID: 34769164 PMCID: PMC8584094 DOI: 10.3390/ijms222111735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/16/2021] [Accepted: 10/25/2021] [Indexed: 11/17/2022] Open
Abstract
Sodium appetite is an innate behavior occurring in response to sodium depletion that induces homeostatic responses such as the secretion of the mineralocorticoid hormone aldosterone from the zona glomerulosa of the adrenal cortex and the stimulation of the peptide hormone angiotensin II (ANG II). The synergistic action of these hormones signals to the brain the sodium appetite that represents the increased palatability for salt intake. This narrative review summarizes the main data dealing with the role of mineralocorticoid and ANG II receptors in the central control of sodium appetite. Appropriate keywords and MeSH terms were identified and searched in PubMed. References to original articles and reviews were examined, selected, and discussed. Several brain areas control sodium appetite, including the nucleus of the solitary tract, which contains aldosterone-sensitive HSD2 neurons, and the organum vasculosum lamina terminalis (OVLT) that contains ANG II-sensitive neurons. Furthermore, sodium appetite is under the control of signaling proteins such as mitogen-activated protein kinase (MAPK) and inositol 1,4,5-thriphosphate (IP3). ANG II stimulates salt intake via MAPK, while combined ANG II and aldosterone action induce sodium intake via the IP3 signaling pathway. Finally, aldosterone and ANG II stimulate OVLT neurons and suppress oxytocin secretion inhibiting the neuronal activity of the paraventricular nucleus, thus disinhibiting the OVLT activity to aldosterone and ANG II stimulation.
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Hellas JA, Andrew RD. Neuronal Swelling: A Non-osmotic Consequence of Spreading Depolarization. Neurocrit Care 2021; 35:112-134. [PMID: 34498208 PMCID: PMC8536653 DOI: 10.1007/s12028-021-01326-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 08/04/2021] [Indexed: 01/22/2023]
Abstract
An acute reduction in plasma osmolality causes rapid uptake of water by astrocytes but not by neurons, whereas both cell types swell as a consequence of lost blood flow (ischemia). Either hypoosmolality or ischemia can displace the brain downwards, potentially causing death. However, these disorders are fundamentally different at the cellular level. Astrocytes osmotically swell or shrink because they express functional water channels (aquaporins), whereas neurons lack functional aquaporins and thus maintain their volume. Yet both neurons and astrocytes immediately swell when blood flow to the brain is compromised (cytotoxic edema) as following stroke onset, sudden cardiac arrest, or traumatic brain injury. In each situation, neuronal swelling is the direct result of spreading depolarization (SD) generated when the ATP-dependent sodium/potassium ATPase (the Na+/K+ pump) is compromised. The simple, and incorrect, textbook explanation for neuronal swelling is that increased Na+ influx passively draws Cl- into the cell, with water following by osmosis via some unknown conduit. We first review the strong evidence that mammalian neurons resist volume change during acute osmotic stress. We then contrast this with their dramatic swelling during ischemia. Counter-intuitively, recent research argues that ischemic swelling of neurons is non-osmotic, involving ion/water cotransporters as well as at least one known amino acid water pump. While incompletely understood, these mechanisms argue against the dogma that neuronal swelling involves water uptake driven by an osmotic gradient with aquaporins as the conduit. Promoting clinical recovery from neuronal cytotoxic edema evoked by spreading depolarizations requires a far better understanding of molecular water pumps and ion/water cotransporters that act to rebalance water shifts during brain ischemia.
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Affiliation(s)
- Julia A Hellas
- Center for Neuroscience Studies, Queen's University, Kingston, ON, K7L 3N6, Canada.
| | - R David Andrew
- Center for Neuroscience Studies, Queen's University, Kingston, ON, K7L 3N6, Canada
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Kim A, Madara JC, Wu C, Andermann ML, Lowell BB. Neural basis for regulation of vasopressin secretion by anticipated disturbances in osmolality. eLife 2021; 10:66609. [PMID: 34585668 PMCID: PMC8601670 DOI: 10.7554/elife.66609] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 09/28/2021] [Indexed: 12/01/2022] Open
Abstract
Water balance, tracked by extracellular osmolality, is regulated by feedback and feedforward mechanisms. Feedback regulation is reactive, occurring as deviations in osmolality are detected. Feedforward or presystemic regulation is proactive, occurring when disturbances in osmolality are anticipated. Vasopressin (AVP) is a key hormone regulating water balance and is released during hyperosmolality to limit renal water excretion. AVP neurons are under feedback and feedforward regulation. Not only do they respond to disturbances in blood osmolality, but they are also rapidly suppressed and stimulated, respectively, by drinking and eating, which will ultimately decrease and increase osmolality. Here, we demonstrate that AVP neuron activity is regulated by multiple anatomically and functionally distinct neural circuits. Notably, presystemic regulation during drinking and eating are mediated by non-overlapping circuits that involve the lamina terminalis and hypothalamic arcuate nucleus, respectively. These findings reveal neural mechanisms that support differential regulation of AVP release by diverse behavioral and physiological stimuli. Fine-tuning the amount of water present in the body at any given time is a tight balancing act. The hormone vasopressin helps to ensure that organisms do not get too dehydrated by allowing water in the urine to be reabsorbed into the bloodstream. A group of vasopressin neurons in the brain trigger the release of the hormone if water levels get too low (as reflected by an increase in osmolality, the level of substances dissolved in a unit of blood). However, these cells also receive additional information that allows them to predict and respond to upcoming changes in water levels. For example, drinking water while dehydrated ‘switches off’ the neurons, even before osmolality is restored in the blood to normal levels. Eating, on the other hand, rapidly activates vasopressin neurons before the food is digested and blood osmolality increases as a result. How vasopressin neurons receive this ‘anticipatory’ information remains unclear. Kim et al. explored this question in mice by inhibiting different sets of brain cells one by one, and then examining whether the neurons could still exhibit anticipatory responses. This revealed a remarkable division of labor in the neural circuits that regulate vasopressin neurons: two completely different sets of neurons from distinct areas of the brain are dedicated to relaying anticipatory information about either water or food intake. These findings help to understand how healthy levels of water can be maintained in the body. Overall, they give a glimpse into the neural mechanisms that underlie anticipatory forms of regulation, which can also take place when hunger or thirst neurons ‘foresee’ that food or water will be consumed.
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Affiliation(s)
- Angela Kim
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, United States.,Program in Neuroscience, Harvard Medical School, Boston, United States
| | - Joseph C Madara
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, United States
| | - Chen Wu
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, United States
| | - Mark L Andermann
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, United States.,Program in Neuroscience, Harvard Medical School, Boston, United States
| | - Bradford B Lowell
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, United States.,Program in Neuroscience, Harvard Medical School, Boston, United States
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Jeong JK, Dow SA, Young CN. Sensory Circumventricular Organs, Neuroendocrine Control, and Metabolic Regulation. Metabolites 2021; 11:metabo11080494. [PMID: 34436435 PMCID: PMC8402088 DOI: 10.3390/metabo11080494] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/13/2021] [Accepted: 07/27/2021] [Indexed: 11/16/2022] Open
Abstract
The central nervous system is critical in metabolic regulation, and accumulating evidence points to a distributed network of brain regions involved in energy homeostasis. This is accomplished, in part, by integrating peripheral and central metabolic information and subsequently modulating neuroendocrine outputs through the paraventricular and supraoptic nucleus of the hypothalamus. However, these hypothalamic nuclei are generally protected by a blood-brain-barrier limiting their ability to directly sense circulating metabolic signals—pointing to possible involvement of upstream brain nuclei. In this regard, sensory circumventricular organs (CVOs), brain sites traditionally recognized in thirst/fluid and cardiovascular regulation, are emerging as potential sites through which circulating metabolic substances influence neuroendocrine control. The sensory CVOs, including the subfornical organ, organum vasculosum of the lamina terminalis, and area postrema, are located outside the blood-brain-barrier, possess cellular machinery to sense the metabolic interior milieu, and establish complex neural networks to hypothalamic neuroendocrine nuclei. Here, evidence for a potential role of sensory CVO-hypothalamic neuroendocrine networks in energy homeostasis is presented.
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Affiliation(s)
| | | | - Colin N. Young
- Correspondence: ; Tel.: +1-202-994-9575; Fax: +1-202-994-287
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Fry WM, Ferguson AV. The subfornical organ and organum vasculosum of the lamina terminalis: Critical roles in cardiovascular regulation and the control of fluid balance. HANDBOOK OF CLINICAL NEUROLOGY 2021; 180:203-215. [PMID: 34225930 DOI: 10.1016/b978-0-12-820107-7.00013-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In this chapter, we review the extensive literature describing the roles of the subfornical organ (SFO), the organum vasculosum of the terminalis (OVLT), and the median preoptic nucleus (MnPO), comprising the lamina terminalis, in cardiovascular regulation and the control of fluid balance. We present this information in the context of both historical and technological developments which can effectively be overlaid upon each other. We describe intrinsic anatomy and connectivity and then discuss early work which described how circulating angiotensin II acts at the SFO to stimulate drinking and increase blood pressure. Extensive studies using direct administration and lesion approaches to highlight the roles of all regions of the lamina terminalis are then discussed. At the cellular level we describe c-Fos and electrophysiological work, which has highlighted an extensive group of circulating hormones which appear to influence the activity of specific neurons in the SFO, OVLT, and MnPO. We highlight optogenetic studies that have begun to unravel the complexities of circuitries underlying physiological outcomes, especially those related to different components of drinking. Finally, we describe the somewhat limited human literature supporting conclusions that these structures play similar and potentially important roles in human physiology.
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Affiliation(s)
- W Mark Fry
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Alastair V Ferguson
- Department of Biomedical and Molecular Sciences and Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada.
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