1
|
Viskaitis P, Tesmer AL, Liu Z, Karnani MM, Arnold M, Donegan D, Bracey E, Grujic N, Patriarchi T, Peleg-Raibstein D, Burdakov D. Orexin neurons track temporal features of blood glucose in behaving mice. Nat Neurosci 2024; 27:1299-1308. [PMID: 38773350 PMCID: PMC11239495 DOI: 10.1038/s41593-024-01648-w] [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: 02/17/2023] [Accepted: 04/10/2024] [Indexed: 05/23/2024]
Abstract
Does the brain track how fast our blood glucose is changing? Knowing such a rate of change would enable the prediction of an upcoming state and a timelier response to this new state. Hypothalamic arousal-orchestrating hypocretin/orexin neurons (HONs) have been proposed to be glucose sensors, yet whether they track glucose concentration (proportional tracking) or rate of change (derivative tracking) is unknown. Using simultaneous recordings of HONs and blood glucose in behaving male mice, we found that maximal HON responses occur in considerable temporal anticipation (minutes) of glucose peaks due to derivative tracking. Analysis of >900 individual HONs revealed glucose tracking in most HONs (98%), with derivative and proportional trackers working in parallel, and many (65%) HONs multiplexed glucose and locomotion information. Finally, we found that HON activity is important for glucose-evoked locomotor suppression. These findings reveal a temporal dimension of brain glucose sensing and link neurobiological and algorithmic views of blood glucose perception in the brain's arousal orchestrators.
Collapse
Affiliation(s)
- Paulius Viskaitis
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zurich, Switzerland
| | - Alexander L Tesmer
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zurich, Switzerland
| | - Ziyu Liu
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zurich, Switzerland
- Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Mahesh M Karnani
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zurich, Switzerland
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Myrtha Arnold
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zurich, Switzerland
| | - Dane Donegan
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zurich, Switzerland
| | - Eva Bracey
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zurich, Switzerland
| | - Nikola Grujic
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zurich, Switzerland
| | - Tommaso Patriarchi
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Daria Peleg-Raibstein
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zurich, Switzerland
| | - Denis Burdakov
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zurich, Switzerland.
| |
Collapse
|
2
|
Grujic N, Polania R, Burdakov D. Neurobehavioral meaning of pupil size. Neuron 2024:S0896-6273(24)00406-9. [PMID: 38925124 DOI: 10.1016/j.neuron.2024.05.029] [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: 11/24/2023] [Revised: 03/22/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024]
Abstract
Pupil size is a widely used metric of brain state. It is one of the few signals originating from the brain that can be readily monitored with low-cost devices in basic science, clinical, and home settings. It is, therefore, important to investigate and generate well-defined theories related to specific interpretations of this metric. What exactly does it tell us about the brain? Pupils constrict in response to light and dilate during darkness, but the brain also controls pupil size irrespective of luminosity. Pupil size fluctuations resulting from ongoing "brain states" are used as a metric of arousal, but what is pupil-linked arousal and how should it be interpreted in neural, cognitive, and computational terms? Here, we discuss some recent findings related to these issues. We identify open questions and propose how to answer them through a combination of well-defined tasks, neurocomputational models, and neurophysiological probing of the interconnected loops of causes and consequences of pupil size.
Collapse
Affiliation(s)
- Nikola Grujic
- Neurobehavioural Dynamics Lab, ETH Zürich, Department of Health Sciences and Technology, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland.
| | - Rafael Polania
- Decision Neuroscience Lab, ETH Zürich, Department of Health Sciences and Technology, Winterthurstrasse 190, 8057 Zürich, Switzerland
| | - Denis Burdakov
- Neurobehavioural Dynamics Lab, ETH Zürich, Department of Health Sciences and Technology, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland.
| |
Collapse
|
3
|
Li J, Yan Y, Fu Y, Chen Z, Yang Y, Li Y, Pan J, Li F, Zha C, Miao K, Ben L, Saleemi MK, Zhu Y, Ye H, Yang L, Wang W. ACE2 mediates tryptophan alleviation on diarrhea by repairing intestine barrier involved mTOR pathway. Cell Mol Biol Lett 2024; 29:90. [PMID: 38877403 PMCID: PMC11179371 DOI: 10.1186/s11658-024-00603-8] [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: 11/01/2023] [Accepted: 05/24/2024] [Indexed: 06/16/2024] Open
Abstract
The membrane-delimited receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), angiotensin-converting enzyme 2 (ACE2), which is expressed in the intestine, collaborates with broad neutral amino acid transporter 1 (B0AT1). Tryptophan (Trp) is transported into intestinal epithelial cells by ACE2 and B0AT1. However, whether ACE2 and its binding protein B0AT1 are involved in Trp-mediated alleviation of intestinal injury is largely unknown. Here, we used weaned piglets and IPEC-J2 cells as models and found that ACE2/B0AT1 alleviated lipopolysaccharide (LPS)-induced diarrhea and promoted intestinal barrier recovery via transport of Trp. The levels of the aryl hydrocarbon receptor (AhR) and mechanistic target of rapamycin (mTOR) pathways were altered by ACE2. Dietary Trp supplementation in LPS-treated weaned piglets revealed that Trp alleviated diarrhea by promoting ACE2/B0AT1 expression, and examination of intestinal morphology revealed that the damage to the intestinal barrier was repaired. Our study demonstrated that ACE2 accompanied by B0AT1 mediated the alleviation of diarrhea by Trp through intestinal barrier repair via the mTOR pathway.
Collapse
Affiliation(s)
- Jinze Li
- State Key Laboratory of Swine and Poultry Breeding Industry and Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China
| | - Yingli Yan
- State Key Laboratory of Swine and Poultry Breeding Industry and Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China
| | - Yang Fu
- State Key Laboratory of Swine and Poultry Breeding Industry and Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China
| | - Zhe Chen
- State Key Laboratory of Swine and Poultry Breeding Industry and Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China
| | - Yongjie Yang
- State Key Laboratory of Swine and Poultry Breeding Industry and Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China
| | - Yu Li
- State Key Laboratory of Swine and Poultry Breeding Industry and Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China
| | - Jie Pan
- Zhuhai Tianjiao Technology Co., LTD, Zhuhai, 519000, China
| | - Feiwu Li
- Hunan New Wellful Co., LTD, Changsha, 410005, China
| | - Cuifang Zha
- State Key Laboratory of Swine and Poultry Breeding Industry and Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China
| | - Kai Miao
- Cancer Center, Faculty of Health Sciences, University of Macau, Macau, 999078, China
| | - Lukuyu Ben
- International Livestock Research Institute, Nairobi, 00100, Kenya
| | | | - Yongwen Zhu
- State Key Laboratory of Swine and Poultry Breeding Industry and Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China
| | - Hui Ye
- State Key Laboratory of Swine and Poultry Breeding Industry and Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China
| | - Lin Yang
- State Key Laboratory of Swine and Poultry Breeding Industry and Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China.
| | - Wence Wang
- State Key Laboratory of Swine and Poultry Breeding Industry and Guangdong Provincial Key Laboratory of Animal Nutrition and Regulation, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China.
| |
Collapse
|
4
|
Concetti C, Viskaitis P, Grujic N, Duss SN, Privitera M, Bohacek J, Peleg-Raibstein D, Burdakov D. Exploratory Rearing Is Governed by Hypothalamic Melanin-Concentrating Hormone Neurons According to Locus Ceruleus. J Neurosci 2024; 44:e0015242024. [PMID: 38575343 PMCID: PMC11112542 DOI: 10.1523/jneurosci.0015-24.2024] [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: 01/03/2024] [Revised: 03/20/2024] [Accepted: 03/25/2024] [Indexed: 04/06/2024] Open
Abstract
Information seeking, such as standing on tiptoes to look around in humans, is observed across animals and helps survival. Its rodent analog-unsupported rearing on hind legs-was a classic model in deciphering neural signals of cognition and is of intense renewed interest in preclinical modeling of neuropsychiatric states. Neural signals and circuits controlling this dedicated decision to seek information remain largely unknown. While studying subsecond timing of spontaneous behavioral acts and activity of melanin-concentrating hormone (MCH) neurons (MNs) in behaving male and female mice, we observed large MN activity spikes that aligned to unsupported rears. Complementary causal, loss and gain of function, analyses revealed specific control of rear frequency and duration by MNs and MCHR1 receptors. Activity in a key stress center of the brain-the locus ceruleus noradrenaline cells-rapidly inhibited MNs and required functional MCH receptors for its endogenous modulation of rearing. By defining a neural module that both tracks and controls rearing, these findings may facilitate further insights into biology of information seeking.
Collapse
Affiliation(s)
- Cristina Concetti
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Paulius Viskaitis
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Nikola Grujic
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Sian N Duss
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Mattia Privitera
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Johannes Bohacek
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Daria Peleg-Raibstein
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Denis Burdakov
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| |
Collapse
|
5
|
Harada M, Capdevila LS, Wilhelm M, Burdakov D, Patriarchi T. Stimulation of VTA dopamine inputs to LH upregulates orexin neuronal activity in a DRD2-dependent manner. eLife 2024; 12:RP90158. [PMID: 38567902 PMCID: PMC10990487 DOI: 10.7554/elife.90158] [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] [Indexed: 04/05/2024] Open
Abstract
Dopamine and orexins (hypocretins) play important roles in regulating reward-seeking behaviors. It is known that hypothalamic orexinergic neurons project to dopamine neurons in the ventral tegmental area (VTA), where they can stimulate dopaminergic neuronal activity. Although there are reciprocal connections between dopaminergic and orexinergic systems, whether and how dopamine regulates the activity of orexin neurons is currently not known. Here we implemented an opto-Pavlovian task in which mice learn to associate a sensory cue with optogenetic dopamine neuron stimulation to investigate the relationship between dopamine release and orexin neuron activity in the lateral hypothalamus (LH). We found that dopamine release can be evoked in LH upon optogenetic stimulation of VTA dopamine neurons and is also naturally evoked by cue presentation after opto-Pavlovian learning. Furthermore, orexin neuron activity could also be upregulated by local stimulation of dopaminergic terminals in the LH in a way that is partially dependent on dopamine D2 receptors (DRD2). Our results reveal previously unknown orexinergic coding of reward expectation and unveil an orexin-regulatory axis mediated by local dopamine inputs in the LH.
Collapse
Affiliation(s)
- Masaya Harada
- Institute of Pharmacology and Toxicology, University of ZürichZürichSwitzerland
| | | | - Maria Wilhelm
- Institute of Pharmacology and Toxicology, University of ZürichZürichSwitzerland
| | - Denis Burdakov
- Neuroscience Center Zürich, University and ETH ZürichZürichSwitzerland
- Department of Health Sciences and Technology, ETH ZürichZürichSwitzerland
| | - Tommaso Patriarchi
- Institute of Pharmacology and Toxicology, University of ZürichZürichSwitzerland
- Neuroscience Center Zürich, University and ETH ZürichZürichSwitzerland
| |
Collapse
|
6
|
Choi PP, Wang Q, Brenner LA, Li AJ, Ritter RC, Appleyard SM. Lesion of NPY Receptor-expressing Neurons in Perifornical Lateral Hypothalamus Attenuates Glucoprivic Feeding. Endocrinology 2024; 165:bqae021. [PMID: 38368624 PMCID: PMC11043786 DOI: 10.1210/endocr/bqae021] [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: 06/07/2023] [Revised: 01/19/2024] [Accepted: 02/15/2024] [Indexed: 02/20/2024]
Abstract
Glucoprivic feeding is one of several counterregulatory responses (CRRs) that facilitates restoration of euglycemia following acute glucose deficit (glucoprivation). Our previous work established that glucoprivic feeding requires ventrolateral medullary (VLM) catecholamine (CA) neurons that coexpress neuropeptide Y (NPY). However, the connections by which VLM CA/NPY neurons trigger increased feeding are uncertain. We have previously shown that glucoprivation, induced by an anti-glycolygic agent 2-deoxy-D-glucose (2DG), activates perifornical lateral hypothalamus (PeFLH) neurons and that expression of NPY in the VLM CA/NPY neurons is required for glucoprivic feeding. We therefore hypothesized that glucoprivic feeding and possibly other CRRs require NPY-sensitive PeFLH neurons. To test this, we used the ribosomal toxin conjugate NPY-saporin (NPY-SAP) to selectively lesion NPY receptor-expressing neurons in the PeFLH of male rats. We found that NPY-SAP destroyed a significant number of PeFLH neurons, including those expressing orexin, but not those expressing melanin-concentrating hormone. The PeFLH NPY-SAP lesions attenuated 2DG-induced feeding but did not affect 2DG-induced increase in locomotor activity, sympathoadrenal hyperglycemia, or corticosterone release. The 2DG-induced feeding response was also significantly attenuated in NPY-SAP-treated female rats. Interestingly, PeFLH NPY-SAP lesioned male rats had reduced body weights and decreased dark cycle feeding, but this effect was not seen in female rats. We conclude that a NPY projection to the PeFLH is necessary for glucoprivic feeding, but not locomotor activity, hyperglycemia, or corticosterone release, in both male and female rats.
Collapse
Affiliation(s)
- Pique P Choi
- Neuroscience Program, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Qing Wang
- Neuroscience Program, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Lynne A Brenner
- Neuroscience Program, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Ai-Jun Li
- Neuroscience Program, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Robert C Ritter
- Neuroscience Program, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Suzanne M Appleyard
- Neuroscience Program, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| |
Collapse
|
7
|
Ispoglou T, McCullough D, Windle A, Nair S, Cox N, White H, Burke D, Kanatas A, Prokopidis K. Addressing cancer anorexia-cachexia in older patients: Potential therapeutic strategies and molecular pathways. Clin Nutr 2024; 43:552-566. [PMID: 38237369 DOI: 10.1016/j.clnu.2024.01.009] [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: 11/03/2022] [Revised: 01/04/2024] [Accepted: 01/10/2024] [Indexed: 02/03/2024]
Abstract
Cancer cachexia (CC) syndrome, a feature of cancer-associated muscle wasting, is particularly pronounced in older patients, and is characterised by decreased energy intake and upregulated skeletal muscle catabolic pathways. To address CC, appetite stimulants, anabolic drugs, cytokine mediators, essential amino acid supplementation, nutritional counselling, cognitive behavioural therapy, and enteral nutrition have been utilised. However, pharmacological treatments that have also shown promising results, such as megestrol acetate, anamorelin, thalidomide, and delta-9-tetrahydrocannabinol, have been associated with gastrointestinal and cardiovascular complications. Emerging evidence on the efficacy of probiotics in modulating gut microbiota also presents a promising adjunct to traditional therapies, potentially enhancing nutritional absorption and systemic inflammation control. Additionally, low-dose olanzapine has demonstrated improved appetite and weight management in older patients undergoing chemotherapy, offering a potential refinement to current therapeutic approaches. This review aims to elucidate the molecular mechanisms underpinning CC, with a particular focus on the role of anorexia in exacerbating muscle wasting, and to propose pharmacological and non-pharmacological strategies to mitigate this syndrome, particularly emphasising the needs of an older demographic. Future research targeting CC should focus on refining appetite-stimulating drugs with fewer side-effects, specifically catering to the needs of older patients, and investigating nutritional factors that can either enhance appetite or minimise suppression of appetite in individuals with CC, especially within this vulnerable group.
Collapse
Affiliation(s)
| | | | - Angela Windle
- Department of Nursing and Midwifery, School of Human and Health Sciences, University of Huddersfield, Huddersfield, UK; School of Medicine, University of Leeds, Leeds, UK
| | | | - Natalie Cox
- Academic Geriatric Medicine, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Helen White
- School of Health, Leeds Beckett University, Leeds, UK
| | - Dermot Burke
- School of Medicine, University of Leeds, Leeds, UK
| | | | - Konstantinos Prokopidis
- Department of Musculoskeletal and Ageing Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK; Liverpool Centre for Cardiovascular Science, University of Liverpool, Liverpool, UK
| |
Collapse
|
8
|
Teegala SB, Sarkar P, Siegel DM, Sheng Z, Hao L, Bello NT, De Lecea L, Beck KD, Routh VH. Lateral hypothalamus hypocretin/orexin glucose-inhibited neurons promote food seeking after calorie restriction. Mol Metab 2023; 76:101788. [PMID: 37536499 PMCID: PMC10448466 DOI: 10.1016/j.molmet.2023.101788] [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: 05/31/2023] [Revised: 07/05/2023] [Accepted: 07/31/2023] [Indexed: 08/05/2023] Open
Abstract
OBJECTIVE The present study tests the hypothesis that changes in the glucose sensitivity of lateral hypothalamus (LH) hypocretin/orexin glucose-inhibited (GI) neurons following weight loss leads to glutamate plasticity on ventral tegmental area (VTA) dopamine neurons and drives food seeking behavior. METHODS C57BL/6J mice were calorie restricted to a 15% body weight loss and maintained at that body weight for 1 week. The glucose sensitivity of LH hypocretin/orexin GI and VTA dopamine neurons was measured using whole cell patch clamp recordings in brain slices. Food seeking behavior was assessed using conditioned place preference (CPP). RESULTS 1-week maintenance of calorie restricted 15% body weight loss reduced glucose inhibition of hypocretin/orexin GI neurons resulting in increased neuronal activation with reduced glycemia. The effect of decreased glucose on hypocretin/orexin GI neuronal activation was blocked by pertussis toxin (inhibitor of G-protein coupled receptor subunit Gαi/o) and Rp-cAMP (inhibitor of protein kinase A, PKA). This suggests that glucose sensitivity is mediated by the Gαi/o-adenylyl cyclase-cAMP-PKA signaling pathway. The excitatory effect of the hunger hormone, ghrelin, on hcrt/ox neurons was also blocked by Rp-cAMP suggesting that hormonal signals of metabolic status may converge on the glucose sensing pathway. Food restriction and weight loss increased glutamate synaptic strength (indexed by increased AMPA/NMDA receptor current ratio) on VTA dopamine neurons and the motivation to seek food (indexed by CPP). Chemogenetic inhibition of hypocretin/orexin neurons during caloric restriction and weight loss prevented these changes in glutamate plasticity and food seeking behavior. CONCLUSIONS We hypothesize that this change in the glucose sensitivity of hypocretin/orexin GI neurons may drive, in part, food seeking behavior following caloric restriction.
Collapse
Affiliation(s)
- Suraj B Teegala
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Pallabi Sarkar
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Dashiel M Siegel
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Zhenyu Sheng
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Lihong Hao
- Department of Animal Science, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Nicholas T Bello
- Department of Animal Science, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Luis De Lecea
- Department of Psychiatry and Behavioral Sciences. Wu Tsai Neuroscience Institute. 1201 Welch Rd. Stanford, CA 94305, USA
| | - Kevin D Beck
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA; Neurobehavioral Research Laboratory, Research Service, Veterans Affairs New Jersey Health Care System, East Orange, NJ, USA
| | - Vanessa H Routh
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA.
| |
Collapse
|
9
|
Peleg-Raibstein D, Viskaitis P, Burdakov D. Eat, seek, rest? An orexin/hypocretin perspective. J Neuroendocrinol 2023; 35:e13259. [PMID: 36994677 DOI: 10.1111/jne.13259] [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: 12/21/2022] [Revised: 03/06/2023] [Accepted: 03/10/2023] [Indexed: 03/19/2023]
Abstract
Seeking and ingesting nutrients is an essential cycle of life in all species. In classical neuropsychology these two behaviours are viewed as fundamentally distinct from each other, and known as appetitive and consummatory, respectively. Appetitive behaviour is highly flexible and diverse, but typically involves increased locomotion and spatial exploration. Consummatory behaviour, in contrast, typically requires reduced locomotion. Another long-standing concept is "rest and digest", a hypolocomotive response to calorie intake, thought to facilitate digestion and storage of energy after eating. Here, we note that the classical seek➔ingest➔rest behavioural sequence is not evolutionarily advantageous for all ingested nutrients. Our limited stomach capacity should be invested wisely, rather than spent on the first available nutrient. This is because nutrients are not simply calories: some nutrients are more essential for survival than others. Thus, a key choice that needs to be made soon after ingestion: to eat more and rest, or to terminate eating and search for better food. We offer a perspective on recent work suggesting how nutrient-specific neural responses shape this choice. Specifically, the hypothalamic hypocretin/orexin neurons (HONs) - cells that promote hyperlocomotive explorative behaviours - are rapidly and differentially modulated by different ingested macronutrients. Dietary non-essential (but not essential) amino acids activate HONs, while glucose depresses HONs. This nutrient-specific HON modulation engages distinct reflex arcs, seek➔ingest➔seek and seek➔ingest➔rest, respectively. We propose that these nutri-neural reflexes evolved to facilitate optimal nutrition despite the limitations of our body.
Collapse
Affiliation(s)
- Daria Peleg-Raibstein
- ETH Zürich, Department of Health Sciences and Technology, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland
| | - Paulius Viskaitis
- ETH Zürich, Department of Health Sciences and Technology, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland
| | - Denis Burdakov
- ETH Zürich, Department of Health Sciences and Technology, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland
| |
Collapse
|
10
|
Maruyama T, Ueta Y. Internal and external modulation factors of the orexin system (REVIEW). Peptides 2023; 165:171009. [PMID: 37054895 DOI: 10.1016/j.peptides.2023.171009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 04/10/2023] [Accepted: 04/11/2023] [Indexed: 04/15/2023]
Abstract
Orexin-A and -B (identical to hypocretin-1 and -2) are neuropeptides synthesized in the lateral hypothalamus and perifornical area, and orexin neurons project their axon terminals broadly throughout the entire central nervous system (CNS). The activity of orexins is mediated by two specific G protein-coupled receptors (GPCRs), termed orexin type1 receptor (OX1R) and orexin type2 receptor (OX2R). The orexin system plays a relevant role in various physiological functions, including arousal, feeding, reward, and thermogenesis, and is key to human health. Orexin neurons receive various signals related to environmental, physiological, and emotional stimuli. Previous studies have reported that several neurotransmitters and neuromodulators influence the activation or inhibition of orexin neuron activity. In this review, we summarize the modulating factors of orexin neurons in the sleep/wake rhythm and feeding behavior, particularly in the context of the modulation of appetite, body fluids, and circadian signaling. We also describe the effects of life activity, behavior, and diet on the orexin system. Some studies have observed phenomena that have been verified in animal experiments, revealing the detailed mechanism and neural pathway, while their applications to humans is expected in future research.
Collapse
Affiliation(s)
- Takashi Maruyama
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Japan.
| | - Yoichi Ueta
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Japan
| |
Collapse
|
11
|
Aklan I, Sayar-Atasoy N, Deng F, Kim H, Yavuz Y, Rysted J, Laule C, Davis D, Li Y, Atasoy D. Dorsal raphe serotonergic neurons suppress feeding through redundant forebrain circuits. Mol Metab 2023; 69:101676. [PMID: 36682413 PMCID: PMC9923194 DOI: 10.1016/j.molmet.2023.101676] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 12/04/2022] [Accepted: 01/13/2023] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVE Serotonin (5HT) is a well-known anorexigenic molecule, and 5HT neurons of dorsal raphe nucleus (DRN) have been implicated in suppression of feeding; however, the downstream circuitry is poorly understood. Here we explored major projections of DRN5HT neurons for their capacity to modulate feeding. METHODS We used optogenetics to selectively activate DRN5HT axonal projections in hypothalamic and extrahypothalamic areas and monitored food intake. We next used fiber photometry to image the activity dynamics of DRN5HT axons and 5HT levels in projection areas in response feeding and metabolic hormones. Finally, we used electrophysiology to determine how DRN5HT axons affect downstream neuron activity. RESULTS We found that selective activation of DRN5HT axons in (DRN5HT → LH) and (DRN5HT → BNST) suppresses feeding whereas activating medial hypothalamic projections has no effect. Using in vivo imaging, we found that food access and satiety hormones activate DRN5HT projections to LH where they also rapidly increase extracellular 5HT levels. Optogenetic mapping revealed that DRN5HT → LHvGAT and DRN5HT → LHvGlut2 connections are primarily inhibitory and excitatory respectively. Further, in addition to its direct action on LH neurons, we found that 5HT suppresses GABA release from presynaptic terminals arriving from AgRP neurons. CONCLUSIONS These findings define functionally redundant forebrain circuits through which DRN5HT neurons suppress feeding and reveal that these projections can be modulated by metabolic hormones.
Collapse
Affiliation(s)
- Iltan Aklan
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Nilufer Sayar-Atasoy
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Fei Deng
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China
| | - Hyojin Kim
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Yavuz Yavuz
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA,Department of Physiology, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Jacob Rysted
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Connor Laule
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Debbie Davis
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China
| | - Deniz Atasoy
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Fraternal Order of Eagles Diabetes Research Center (FOEDRC), Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
| |
Collapse
|
12
|
Mogavero MP, Silvani A, Lanza G, DelRosso LM, Ferini-Strambi L, Ferri R. Targeting Orexin Receptors for the Treatment of Insomnia: From Physiological Mechanisms to Current Clinical Evidence and Recommendations. Nat Sci Sleep 2023; 15:17-38. [PMID: 36713640 PMCID: PMC9879039 DOI: 10.2147/nss.s201994] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/08/2023] [Indexed: 01/23/2023] Open
Abstract
After a detailed description of orexins and their roles in sleep and other medical disorders, we discuss here the current clinical evidence on the effects of dual (DORAs) or selective (SORAs) orexin receptor antagonists on insomnia with the aim to provide recommendations for their further assessment in a context of personalized and precision medicine. In the last decade, many trials have been conducted with orexin receptor antagonists, which represent an innovative and valid therapeutic option based on the multiple mechanisms of action of orexins on different biological circuits, both centrally and peripherally, and their role in a wide range of medical conditions which are often associated with insomnia. A very interesting aspect of this new category of drugs is that they have limited abuse liability and their discontinuation does not seem associated with significant rebound effects. Further studies on the efficacy of DORAs are required, especially on children and adolescents and in particular conditions, such as menopause. Which DORA is most suitable for each patient, based on comorbidities and/or concomitant treatments, should be the focus of further careful research. On the contrary, studies on SORAs, some of which seem to be appropriate also in insomnia in patients with psychiatric diseases, are still at an early stage and, therefore, do not allow to draw definite conclusions.
Collapse
Affiliation(s)
- Maria P Mogavero
- Vita-Salute San Raffaele University, Milan, Italy.,Sleep Disorders Center, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Alessandro Silvani
- PRISM Lab, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Giuseppe Lanza
- Sleep Research Centre, Oasi Research Institute - IRCCS, Troina, Italy.,Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
| | - Lourdes M DelRosso
- Pulmonary and Sleep Medicine, University of California San Francisco-Fresno, Fresno, CA, USA
| | - Luigi Ferini-Strambi
- Vita-Salute San Raffaele University, Milan, Italy.,Sleep Disorders Center, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Raffaele Ferri
- Sleep Research Centre, Oasi Research Institute - IRCCS, Troina, Italy
| |
Collapse
|
13
|
Wu Q, Gao ZJ, Yu X, Wang P. Dietary regulation in health and disease. Signal Transduct Target Ther 2022; 7:252. [PMID: 35871218 PMCID: PMC9308782 DOI: 10.1038/s41392-022-01104-w] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/21/2022] [Accepted: 07/04/2022] [Indexed: 02/08/2023] Open
Abstract
Nutriments have been deemed to impact all physiopathologic processes. Recent evidences in molecular medicine and clinical trials have demonstrated that adequate nutrition treatments are the golden criterion for extending healthspan and delaying ageing in various species such as yeast, drosophila, rodent, primate and human. It emerges to develop the precision-nutrition therapeutics to slow age-related biological processes and treat diverse diseases. However, the nutritive advantages frequently diversify among individuals as well as organs and tissues, which brings challenges in this field. In this review, we summarize the different forms of dietary interventions extensively prescribed for healthspan improvement and disease treatment in pre-clinical or clinical. We discuss the nutrient-mediated mechanisms including metabolic regulators, nutritive metabolism pathways, epigenetic mechanisms and circadian clocks. Comparably, we describe diet-responsive effectors by which dietary interventions influence the endocrinic, immunological, microbial and neural states responsible for improving health and preventing multiple diseases in humans. Furthermore, we expatiate diverse patterns of dietotheroapies, including different fasting, calorie-restricted diet, ketogenic diet, high-fibre diet, plants-based diet, protein restriction diet or diet with specific reduction in amino acids or microelements, potentially affecting the health and morbid states. Altogether, we emphasize the profound nutritional therapy, and highlight the crosstalk among explored mechanisms and critical factors to develop individualized therapeutic approaches and predictors.
Collapse
Affiliation(s)
- Qi Wu
- Tongji University Cancer Center, Shanghai Tenth People's Hospital of Tongji University, School of Medicine, Tongji University, Shanghai, 200092, China
| | - Zhi-Jie Gao
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, P. R. China
| | - Xin Yu
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, P. R. China
| | - Ping Wang
- Tongji University Cancer Center, Shanghai Tenth People's Hospital of Tongji University, School of Medicine, Tongji University, Shanghai, 200092, China.
| |
Collapse
|
14
|
Mice eat less and explore more after intake of certain amino acids. Nature 2022. [DOI: 10.1038/d41586-022-00830-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
15
|
Lin S, Du Y, Xia Y, Xie Y, Xiao L, Wang G. Advances in optogenetic studies of depressive-like behaviors and underlying neural circuit mechanisms. Front Psychiatry 2022; 13:950910. [PMID: 36159933 PMCID: PMC9492959 DOI: 10.3389/fpsyt.2022.950910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUNDS The neural circuit mechanisms underlying depression remain unclear. Recently optogenetics has gradually gained recognition as a novel technique to regulate the activity of neurons with light stimulation. Scientists are now transferring their focus to the function of brain regions and neural circuits in the pathogenic progress of depression. Deciphering the circuitry mechanism of depressive-like behaviors may help us better understand the symptomatology of depression. However, few studies have summarized current progress on optogenetic researches into the neural circuit mechanisms of depressive-like behaviors. AIMS This review aimed to introduce fundamental characteristics and methodologies of optogenetics, as well as how this technique achieves specific neuronal control with spatial and temporal accuracy. We mainly summarized recent progress in neural circuit discoveries in depressive-like behaviors using optogenetics and exhibited the potential of optogenetics as a tool to investigate the mechanism and possible optimization underlying antidepressant treatment such as ketamine and deep brain stimulation. METHODS A systematic review of the literature published in English mainly from 2010 to the present in databases was performed. The selected literature is then categorized and summarized according to their neural circuits and depressive-like behaviors. CONCLUSIONS Many important discoveries have been made utilizing optogenetics. These findings support optogenetics as a powerful and potential tool for studying depression. And our comprehension to the etiology of depression and other psychiatric disorders will also be more thorough with this rapidly developing technique in the near future.
Collapse
Affiliation(s)
- Shanshan Lin
- Department of Psychiatry, Renmin Hospital of Wuhan University, Wuhan, China.,Institute of Neuropsychiatry, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yiwei Du
- Department of Psychiatry, Renmin Hospital of Wuhan University, Wuhan, China.,Institute of Neuropsychiatry, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yujie Xia
- Department of Psychiatry, Renmin Hospital of Wuhan University, Wuhan, China.,Institute of Neuropsychiatry, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yumeng Xie
- Department of Psychiatry, Renmin Hospital of Wuhan University, Wuhan, China.,Institute of Neuropsychiatry, Renmin Hospital of Wuhan University, Wuhan, China
| | - Ling Xiao
- Department of Psychiatry, Renmin Hospital of Wuhan University, Wuhan, China.,Institute of Neuropsychiatry, Renmin Hospital of Wuhan University, Wuhan, China
| | - Gaohua Wang
- Department of Psychiatry, Renmin Hospital of Wuhan University, Wuhan, China.,Institute of Neuropsychiatry, Renmin Hospital of Wuhan University, Wuhan, China
| |
Collapse
|