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Sandoval-Caballero C, Jara J, Luarte L, Jiménez Y, Teske JA, Perez-Leighton C. Control of motivation for sucrose in the paraventricular hypothalamic nucleus by dynorphin peptides and the kappa opioid receptor. Appetite 2024; 200:107504. [PMID: 38768926 DOI: 10.1016/j.appet.2024.107504] [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: 12/12/2023] [Revised: 03/14/2024] [Accepted: 05/17/2024] [Indexed: 05/22/2024]
Abstract
The dynorphin peptides are the endogenous ligands for the kappa opioid receptor (KOR) and regulate food intake. Administration of dynorphin-A1-13 (DYN) in the paraventricular hypothalamic nucleus (PVN) increases palatable food intake, and this effect is blocked by co-administration of the orexin-A neuropeptide, which is co-released with DYN in PVN from neurons located in the lateral hypothalamus. While PVN administration of DYN increases palatable food intake, whether it increases food-seeking behaviors has yet to be examined. We tested the effects of DYN and norBNI (a KOR antagonist) on the seeking and consumption of sucrose using a progressive ratio (PR) and demand curve (DC) tasks. In PVN, DYN did not alter the sucrose breaking point (BP) in the PR task nor the elasticity or intensity of demand for sucrose in the DC task. Still, DYN reduced the delay in obtaining sucrose and increased licks during sucrose intake in the PR task, irrespective of the co-administration of orexin-A. In PVN, norBNI increased the delay in obtaining sucrose and reduced licks during sucrose intake in the PR task while increasing elasticity without altering intensity of demand in the DC task. However, subcutaneous norBNI reduced the BP for sucrose and increased the delay in obtaining sucrose in the PR task while reducing the elasticity of demand. Together, these data show different effects of systemic and PVN blockade of KOR on food-seeking, consummatory behaviors, and incentive motivation for sucrose and suggest that KOR activity in PVN is necessary but not sufficient to drive seeking behaviors for palatable food.
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Affiliation(s)
- C Sandoval-Caballero
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - J Jara
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - L Luarte
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Y Jiménez
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - J A Teske
- School of Nutritional Sciences and Wellness, University of Arizona, Tucson, Arizona, USA
| | - C Perez-Leighton
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
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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.
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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
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Jörimann M, Maliković J, Wolfer DP, Pryce CR, Endo T, Benner S, Amrein I. Bank Voles Show More Impulsivity in IntelliCage Learning Tasks than Wood Mice. Neuroscience 2023; 510:157-170. [PMID: 36403688 DOI: 10.1016/j.neuroscience.2022.11.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/02/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022]
Abstract
Impulsivity is a personality trait of healthy individuals, but in extreme forms common in mental disorders. Previous behavioral testing of wild-caught bank voles and wood mice suggested impulsiveness in bank voles. Here, we compared behavioral performance of bank voles and wood mice in tests for response control in the IntelliCage. In the reaction time task, a test similar to the five-choice serial-reaction time task (5CSRTT), bank voles made more premature responses. Impulsivity in the reaction time task was associated with smaller medial habenular nucleus in bank voles. Additional tests revealed reduced behavioral flexibility in the self-paced flexibility task in bank voles, but equal spatial and reversal learning in the chaining/reversal task in both species. Expression of immediate early gene Arc after behavioral testing was low in medial prefrontal cortex, but high in hypothalamic supraoptic and paraventricular nucleus in bank voles. Wood mice showed the opposite pattern. Numbers of Arc-positive cells in the dorsal hippocampus were higher in bank voles than wood mice. Due to continuous behavioral testing (24/7), associations between behavioral performance and Arc were rare. Corticosterone measurements at the end of experiments suggested that IntelliCage testing did not elicit a stress response in these wild rodents. In summary, habenular size differences and altered activation of brain areas after testing might indicate differently balanced activations of cortico-limbic and cortico-hypothalamic circuits in bank voles compared to wood mice. Behavioral performance of bank voles suggest that these rodents could be a natural animal model for investigating impulsive and perseverative behaviors.
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Affiliation(s)
- Marielle Jörimann
- Institute of Anatomy, Division Functional Neuroanatomy, University Zurich, Switzerland
| | - Jovana Maliković
- Institute of Anatomy, Division Functional Neuroanatomy, University Zurich, Switzerland
| | - David P Wolfer
- Institute of Anatomy, Division Functional Neuroanatomy, University Zurich, Switzerland; Department of Health Sciences and Technology, ETH, Zürich, Switzerland
| | - Christopher R Pryce
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital and University of Zurich, Switzerland
| | | | - Seico Benner
- Hamamatsu University School of Medicine, Department of Psychiatry, Hamamatsu, Japan; Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan
| | - Irmgard Amrein
- Institute of Anatomy, Division Functional Neuroanatomy, University Zurich, Switzerland; Department of Health Sciences and Technology, ETH, Zürich, Switzerland.
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Stephan D, Taege N, Dore R, Folberth J, Jöhren O, Schwaninger M, Lehnert H, Schulz C. Knockdown of Endogenous Nucb2/Nesfatin-1 in the PVN Leads to Obese-Like Phenotype and Abolishes the Metformin- and Stress-Induced Thermogenic Response in Rats. Horm Metab Res 2022; 54:768-779. [PMID: 36195118 DOI: 10.1055/a-1926-7280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Nesfatin-1, the cleavage product of nucleobindin-2, is an anorexigenic peptide and major regulator of energy homeostasis. Beyond reducing food intake and increasing energy expenditure, it is also involved in regulating the stress response. Interaction of nucleobindin-2/nesfatin-1 and glucose homeostasis has been observed and recent findings suggest a link between the action of the antidiabetic drug metformin and the nesfatinergic system. Hence, this study aimed to clarify the role of nucleobindin-2/nesfatin-1 in the paraventricular nucleus of the hypothalamus in energy homeostasis as well as its involvement in stress- and metformin-mediated changes in energy expenditure. Knockdown of nucleobindin-2/nesfatin-1 in male Wistar rats led to significantly increased food intake, body weight, and reduced energy expenditure compared to controls. Nucleobindin-2/nesfatin-1 knockdown animals developed an obese-like phenotype represented by significantly increased fat mass and overall increase of circulating lipids. Concomitantly, expression of nucleobindin-2 and melanocortin receptor type 3 and 4 mRNA in the paraventricular nucleus was decreased indicating successful knockdown and impairment at the level of the melanocortin system. Additionally, stress induced activation of interscapular brown adipose tissue was significantly decreased in nucleobindin-2/nesfatin-1 knockdown animals and accompanied by lower adrenal weight. Finally, intracerebroventricular administration of metformin significantly increased energy expenditure in controls and this effect was absent in nucleobindin-2/nesfatin-1 knockdown animals. Overall, we clarified the crucial role of nucleobindin-2/nesfatin-1 in the paraventricular nucleus of the hypothalamus in the regulation of energy homeostasis. The nesfatinergic system was further identified as important mediator in stress- and metformin-induced thermogenesis.
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Affiliation(s)
- Daniel Stephan
- Department of Internal Medicine I, University of Lübeck, Lübeck, Germany
- Department of Oral- and Maxillofacial Surgery, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Natalie Taege
- Department of Internal Medicine I, University of Lübeck, Lübeck, Germany
- Institute of Human Genetics, Section Epigenetics & Metabolism, University of Lübeck, Lübeck, Germany
| | - Riccardo Dore
- Department of Internal Medicine I, University of Lübeck, Lübeck, Germany
- Institute of Endocrinology and Diabetes, University of Lübeck, Lübeck, Germany
- Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Julica Folberth
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
- Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Olaf Jöhren
- Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Hendrik Lehnert
- Department of Internal Medicine I, University of Lübeck, Lübeck, Germany
- Rektorat, Paris Lodron Universität Salzburg, Salzburg, Austria
| | - Carla Schulz
- Department of Internal Medicine I, University of Lübeck, Lübeck, Germany
- Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
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Cho JH, Kim K, Cho HC, Lee J, Kim EK. Silencing of hypothalamic FGF11 prevents diet-induced obesity. Mol Brain 2022; 15:75. [PMID: 36064426 PMCID: PMC9447329 DOI: 10.1186/s13041-022-00962-3] [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: 07/05/2022] [Accepted: 08/21/2022] [Indexed: 11/18/2022] Open
Abstract
Fibroblast growth factor 11 (FGF11) is a member of the intracellular fibroblast growth factor family. Here, we report the central role of FGF11 in the regulation of metabolism. Lentiviral injection of Fgf11 shRNA into the arcuate nucleus of the mouse hypothalamus decreased weight gain and fat mass, increased brown adipose tissue thermogenesis, and improved glucose and insulin intolerances under high-fat diet conditions. Fgf11 was expressed in the NPY–expressing neurons, and Fgf11 knockdown considerably decreased Npy expression and projection, leading to increased expression of tyrosine hydroxylase in the paraventricular nucleus. Mechanistically, FGF11 regulated Npy gene expression through the glycogen synthase kinase 3–cAMP response element-binding protein pathway. Our study defines the physiological significance of hypothalamic FGF11 in the regulation of metabolism in response to overnutrition such as high-fat diet.
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Affiliation(s)
- Jae Hyun Cho
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, 333, Techno Jungang-Daero, Hyeonpung-Myeon, Daegu, Dalseonggun, 42988, South Korea
| | - Kyungchan Kim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, 333, Techno Jungang-Daero, Hyeonpung-Myeon, Daegu, Dalseonggun, 42988, South Korea
| | - Han Chae Cho
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, 333, Techno Jungang-Daero, Hyeonpung-Myeon, Daegu, Dalseonggun, 42988, South Korea
| | - Jaemeun Lee
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, 333, Techno Jungang-Daero, Hyeonpung-Myeon, Daegu, Dalseonggun, 42988, South Korea
| | - Eun-Kyoung Kim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, 333, Techno Jungang-Daero, Hyeonpung-Myeon, Daegu, Dalseonggun, 42988, South Korea. .,Neurometabolomics Research Center, Daegu Gyeongbuk Institute of Science and Technology, 333, Techno Jungang-Daero, Hyeonpung-Myeon, Daegu, Dalseonggun, 42988, South Korea.
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6
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Zheng DJ, Okobi DE, Shu R, Agrawal R, Smith SK, Long MA, Phelps SM. Mapping the vocal circuitry of Alston's singing mouse with pseudorabies virus. J Comp Neurol 2022; 530:2075-2099. [PMID: 35385140 DOI: 10.1002/cne.25321] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 02/06/2022] [Accepted: 03/07/2022] [Indexed: 11/11/2022]
Abstract
Vocalizations are often elaborate, rhythmically structured behaviors. Vocal motor patterns require close coordination of neural circuits governing the muscles of the larynx, jaw, and respiratory system. In the elaborate vocalization of Alston's singing mouse (Scotinomys teguina) each note of its rapid, frequency-modulated trill is accompanied by equally rapid modulation of breath and gape. To elucidate the neural circuitry underlying this behavior, we introduced the polysynaptic retrograde neuronal tracer pseudorabies virus (PRV) into the cricothyroid and digastricus muscles, which control frequency modulation and jaw opening, respectively. Each virus singly labels ipsilateral motoneurons (nucleus ambiguus for cricothyroid, and motor trigeminal nucleus for digastricus). We find that the two isogenic viruses heavily and bilaterally colabel neurons in the gigantocellular reticular formation, a putative central pattern generator. The viruses also show strong colabeling in compartments of the midbrain including the ventrolateral periaqueductal gray and the parabrachial nucleus, two structures strongly implicated in vocalizations. In the forebrain, regions important to social cognition and energy balance both exhibit extensive colabeling. This includes the paraventricular and arcuate nuclei of the hypothalamus, the lateral hypothalamus, preoptic area, extended amygdala, central amygdala, and the bed nucleus of the stria terminalis. Finally, we find doubly labeled neurons in M1 motor cortex previously described as laryngeal, as well as in the prelimbic cortex, which indicate these cortical regions play a role in vocal production. The progress of both viruses is broadly consistent with vertebrate-general patterns of vocal circuitry, as well as with circuit models derived from primate literature.
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Affiliation(s)
- Da-Jiang Zheng
- Department of Integrative Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Daniel E Okobi
- Department of Neurology, University of California Los Angeles, Los Angeles, California, USA
| | - Ryan Shu
- Department of Integrative Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Rania Agrawal
- Department of Integrative Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Samantha K Smith
- Department of Integrative Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Michael A Long
- NYU Neuroscience Institute and Department of Otolaryngology, Langone Medical Center, New York University, New York City, New York, USA
| | - Steven M Phelps
- Department of Integrative Biology, The University of Texas at Austin, Austin, Texas, USA
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7
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Smulders TV. Telencephalic regulation of the HPA axis in birds. Neurobiol Stress 2021; 15:100351. [PMID: 34189191 PMCID: PMC8220096 DOI: 10.1016/j.ynstr.2021.100351] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/26/2021] [Accepted: 06/03/2021] [Indexed: 12/21/2022] Open
Abstract
The hypothalamo-pituitary-adrenal (HPA) axis is one of the major output systems of the vertebrate stress response. It controls the release of cortisol or corticosterone from the adrenal gland. These hormones regulate a range of processes throughout the brain and body, with the main function of mobilizing energy reserves to improve coping with a stressful situation. This axis is regulated in response to both physical (e.g., osmotic) and psychological (e.g., social) stressors. In mammals, the telencephalon plays an important role in the regulation of the HPA axis response in particular to psychological stressors, with the amygdala and part of prefrontal cortex stimulating the stress response, and the hippocampus and another part of prefrontal cortex inhibiting the response to return it to baseline. Birds also mount HPA axis responses to psychological stressors, but much less is known about the telencephalic areas that control this response. This review summarizes which telencephalic areas in birds are connected to the HPA axis and are known to respond to stressful situations. The conclusion is that the telencephalic control of the HPA axis is probably an ancient system that dates from before the split between sauropsid and synapsid reptiles, but more research is needed into the functional relationships between the brain areas reviewed in birds if we want to understand the level of this conservation.
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Affiliation(s)
- Tom V. Smulders
- Centre for Behaviour & Evolution, Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
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Lamy GB, Cafarchio EM, do Vale B, Antonio BB, Venancio DP, de Souza JS, Maciel RM, Giannocco G, Aronsson P, Sato MA. Lateral Preoptic Area Neurons Activated by Angiotensin-(1-7) Increase Intravesical Pressure: A Novel Feature in Central Micturition Control. Front Physiol 2021; 12:682711. [PMID: 34322035 PMCID: PMC8311566 DOI: 10.3389/fphys.2021.682711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/14/2021] [Indexed: 11/23/2022] Open
Abstract
Central micturition control and urine storage involve a multisynaptic neuronal circuit for the efferent control of the urinary bladder. Electrical stimulation of the lateral preoptic area (LPA) at the level of the decussation of the anterior commissure in cats evokes relaxation of the bladder, whereas ventral stimulation of LPA evokes vigorous contraction. Endogenous Angiotensin-(1–7) [(Ang-(1–7)] synthesis depends on ACE-2, and its actions on binding to Mas receptors, which were found in LPA neurons. We aimed to investigate the Ang-(1–7) actions into the LPA on intravesical pressure (IP) and cardiovascular parameters. The gene and protein expressions of Mas receptors and ACE-2 were also evaluated in the LPA. Angiotensin-(1–7) (5 nmol/μL) or A-779 (Mas receptor antagonist, 50 nmol/μL) was injected into the LPA in anesthetized female Wistar rats; and the IP, mean arterial pressure (MAP), heart rate (HR), and renal conductance (RC) were recorded for 30 min. Unilateral injection of Ang-(1–7) into the LPA increased IP (187.46 ± 37.23%) with peak response at ∼23–25-min post-injection and yielded no changes in MAP, HR, and RC. Unilateral or bilateral injections of A-779 into the LPA decreased IP (−15.88 ± 2.76 and −27.30 ± 3.40%, respectively) and elicited no changes in MAP, HR, and RC. The genes and the protein expression of Mas receptors and ACE-2 were found in the LPA. Therefore, the LPA is an important part of the circuit involved in the urinary bladder control, in which the Ang-(1–7) synthetized into the LPA activates Mas receptors for increasing the IP independent on changes in RC and cardiovascular parameters.
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Affiliation(s)
- Gustavo B Lamy
- Department of Morphology and Physiology, Faculdade de Medicina do ABC, Centro Universitario FMABC, Santo Andre, Brazil
| | - Eduardo M Cafarchio
- Department of Morphology and Physiology, Faculdade de Medicina do ABC, Centro Universitario FMABC, Santo Andre, Brazil
| | - Bárbara do Vale
- Department of Morphology and Physiology, Faculdade de Medicina do ABC, Centro Universitario FMABC, Santo Andre, Brazil
| | - Bruno B Antonio
- Department of Morphology and Physiology, Faculdade de Medicina do ABC, Centro Universitario FMABC, Santo Andre, Brazil
| | - Daniel P Venancio
- Department of Morphology and Physiology, Faculdade de Medicina do ABC, Centro Universitario FMABC, Santo Andre, Brazil
| | - Janaina S de Souza
- Department of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Rui M Maciel
- Department of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Gisele Giannocco
- Department of Medicine, Federal University of São Paulo, São Paulo, Brazil.,Department of Biological Sciences, Federal University of São Paulo, Diadema, Brazil
| | - Patrik Aronsson
- Department of Pharmacology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Monica A Sato
- Department of Morphology and Physiology, Faculdade de Medicina do ABC, Centro Universitario FMABC, Santo Andre, Brazil
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9
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Witchey SK, Fuchs J, Patisaul HB. Perinatal bisphenol A (BPA) exposure alters brain oxytocin receptor (OTR) expression in a sex- and region- specific manner: A CLARITY-BPA consortium follow-up study. Neurotoxicology 2019; 74:139-148. [PMID: 31251963 PMCID: PMC6750986 DOI: 10.1016/j.neuro.2019.06.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 06/17/2019] [Accepted: 06/24/2019] [Indexed: 12/15/2022]
Abstract
Bisphenol A (BPA) is a well-characterized endocrine disrupting chemical (EDC) used in plastics, epoxy resins and other products. Neurodevelopmental effects of BPA exposure are a major concern with multiple rodent and human studies showing that early life BPA exposure may impact the developing brain and sexually dimorphic behaviors. The CLARITY-BPA (Consortium Linking Academic and Regulatory Insights on BPA Toxicity) program was established to assess multiple endpoints, including neural, across a wide dose range. Studies from our lab as part of (and prior to) CLARITY-BPA have shown that BPA disrupts estrogen receptor expression in the developing brain, and some evidence of oxytocin (OT) and oxytocin receptor (OTR) disruption in the hypothalamus and amygdala. While BPA disruption of steroid hormone function is well documented, less is known about its capacity to alter nonapeptide signals. In this CLARITY-BPA follow up study, we used remaining juvenile rat tissues to test the hypothesis that developmental BPA exposure affects OTR expression across the brain. Perinatal BPA exposure (2.5, 25, or 2500 μg/kg body weight (bw)/day) spanned gestation and lactation with dams gavaged from gestational day 6 until birth and then the offspring gavaged directly through weaning. Ethinyl estradiol (0.5 μg/kg bw/day) was used as a reference estrogen. Animals of both sexes were sacrificed as juveniles and OTR expression assessed by receptor binding. Our results demonstrate prenatal exposure to BPA can eliminate sex differences in OTR expression in three hypothalamic regions, and that male OTR expression may be more susceptible. Our data also identify a sub-region of the BNST with sexually dimorphic OTR expression not previously reported in juvenile rats that is also susceptible to BPA.
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Affiliation(s)
- Shannah K Witchey
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, United States
| | - Joelle Fuchs
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, United States
| | - Heather B Patisaul
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, United States; Center for Human Health and the Environment, NC State University, Raleigh, NC, 27695, United States.
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10
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Iwen KA, Oelkrug R, Brabant G. Effects of thyroid hormones on thermogenesis and energy partitioning. J Mol Endocrinol 2018; 60:R157-R170. [PMID: 29434028 DOI: 10.1530/jme-17-0319] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 02/06/2018] [Indexed: 01/08/2023]
Abstract
Thyroid hormones (TH) are of central importance for thermogenesis, energy homeostasis and metabolism. Here, we will discuss these aspects by focussing on the physiological aspects of TH-dependent regulation in response to cold exposure and fasting, which will be compared to alterations in primary hyperthyroidism and hypothyroidism. In particular, we will summarise current knowledge on regional thyroid hormone status in the central nervous system (CNS) and in peripheral cells. In contrast to hyperthyroidism and hypothyroidism, where parallel changes are observed, local alterations in the CNS differ to peripheral compartments when induced by cold exposure or fasting. Cold exposure is associated with low hypothalamic TH concentrations but increased TH levels in the periphery. Fasting results in a reversed TH pattern. Primary hypothyroidism and hyperthyroidism disrupt these fine-tuned adaptive mechanisms and both, the hypothalamus and the periphery, will have the same TH status. These important mechanisms need to be considered when discussing thyroid hormone replacement and other therapeutical interventions to modulate TH status.
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Affiliation(s)
- K Alexander Iwen
- Medizinische Klinik IExperimentelle und Klinische Endokrinologie, Universität zu Lübeck, Lübeck, Germany
- Department of Molecular EndocrinologyCenter of Brain, Behavior and Metabolism, Universität zu Lübeck, Lübeck, Germany
| | - Rebecca Oelkrug
- Department of Molecular EndocrinologyCenter of Brain, Behavior and Metabolism, Universität zu Lübeck, Lübeck, Germany
| | - Georg Brabant
- Medizinische Klinik IExperimentelle und Klinische Endokrinologie, Universität zu Lübeck, Lübeck, Germany
- Department of EndocrinologyThe Christie Manchester Academic Health Science Centre, Manchester, UK
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Hao H, Luan X, Guo F, Sun X, Gong Y, Xu L. Lateral hypothalamic area orexin-A influence the firing activity of gastric distension-sensitive neurons and gastric motility in rats. Neuropeptides 2016; 57:45-52. [PMID: 26919916 DOI: 10.1016/j.npep.2016.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 02/05/2016] [Accepted: 02/14/2016] [Indexed: 12/13/2022]
Abstract
The orexins system consists of two G-protein coupled receptors (the orexin-1 and the orexin-2 receptor) and two neuropeptides, orexin-A and orexin-B. Orexin-A is an excitatory neuropeptide that regulates arousal, wakefulness and appetite. Recent studies have shown that orexin-A may promote gastric motility. We aim to explore the effects of orexin-A on the gastric -distension (GD) sensitive neurons and gastric motility in the lateral hypothalamic area (LHA), and the possible regulation by the paraventricular nucleus (PVN). Extracellular single unit discharges were recorded and the gastric motility was monitored by administration of orexin-A into the LHA and electrical stimulation of the PVN. There were GD neurons in the LHA, and administration of orexin-A to the LHA could increase the firing rate of both GD-excitatory (GD-E) and GD-inhibited (GD-I) neurons. The gastric motility was significantly enhanced by injection of orexin-A into the LHA with a dose dependent manner, which could be completely abolished by pre-treatment with orexin-A receptor antagonist SB334867. Electrical stimulation of the PVN could significantly increase the firing rate of GD neurons responsive to orexin-A in the LHA as well as promote gastric motility of rats. However, those effects could be partly blocked by pre-treatment with SB334867 in the LHA. It is suggested that orexin-A plays an important role in promoting gastric motility via LHA. The PVN may be involved in regulation of LHA on gastric motility.
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Affiliation(s)
- Heling Hao
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, Shandong 266021, PR China
| | - Xiao Luan
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, Shandong 266021, PR China
| | - Feifei Guo
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, Shandong 266021, PR China
| | - Xiangrong Sun
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, Shandong 266021, PR China
| | - Yanling Gong
- Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, Shandong, PR China
| | - Luo Xu
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, Shandong 266021, PR China.
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12
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Sokolowski K, Esumi S, Hirata T, Kamal Y, Tran T, Lam A, Oboti L, Brighthaupt SC, Zaghlula M, Martinez J, Ghimbovschi S, Knoblach S, Pierani A, Tamamaki N, Shah NM, Jones KS, Corbin JG. Specification of select hypothalamic circuits and innate behaviors by the embryonic patterning gene dbx1. Neuron 2015; 86:403-16. [PMID: 25864637 DOI: 10.1016/j.neuron.2015.03.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 12/29/2014] [Accepted: 03/03/2015] [Indexed: 12/30/2022]
Abstract
The hypothalamus integrates information required for the production of a variety of innate behaviors such as feeding, mating, aggression, and predator avoidance. Despite an extensive knowledge of hypothalamic function, how embryonic genetic programs specify circuits that regulate these behaviors remains unknown. Here, we find that in the hypothalamus the developmentally regulated homeodomain-containing transcription factor Dbx1 is required for the generation of specific subclasses of neurons within the lateral hypothalamic area/zona incerta (LH) and the arcuate (Arc) nucleus. Consistent with this specific developmental role, Dbx1 hypothalamic-specific conditional-knockout mice display attenuated responses to predator odor and feeding stressors but do not display deficits in other innate behaviors such as mating or conspecific aggression. Thus, activity of a single developmentally regulated gene, Dbx1, is a shared requirement for the specification of hypothalamic nuclei governing a subset of innate behaviors. VIDEO ABSTRACT.
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Affiliation(s)
- Katie Sokolowski
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Shigeyuki Esumi
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA; Graduate School of Medical Sciences, Kumamoto University, 2-39-1 Kurokami, Chuo Ward, Kumamoto, Kumamoto Prefecture 860-0862, Japan
| | - Tsutomu Hirata
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Yasman Kamal
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Tuyen Tran
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Andrew Lam
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Livio Oboti
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Sherri-Chanelle Brighthaupt
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Manar Zaghlula
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Jennifer Martinez
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Svetlana Ghimbovschi
- Center for Genetic Medicine, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Susan Knoblach
- Center for Genetic Medicine, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Alessandra Pierani
- Institut Jacques Monod, Universite Paris Diderot, 15 rue Hélène Brion, 75013 Paris, France
| | - Nobuaki Tamamaki
- Graduate School of Medical Sciences, Kumamoto University, 2-39-1 Kurokami, Chuo Ward, Kumamoto, Kumamoto Prefecture 860-0862, Japan
| | - Nirao M Shah
- Department of Anatomy, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Kevin S Jones
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA; Department of Biology, Howard University, 415 College Street NW, Washington, DC 20059, USA
| | - Joshua G Corbin
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA.
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Guo FF, Xu L, Gao SL, Sun XR, Li ZL, Gong YL. The effects of nesfatin-1 in the paraventricular nucleus on gastric motility and its potential regulation by the lateral hypothalamic area in rats. J Neurochem 2014; 132:266-75. [PMID: 25328037 DOI: 10.1111/jnc.12973] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 08/19/2014] [Accepted: 10/10/2014] [Indexed: 12/11/2022]
Abstract
The current study investigated the effects of nesfatin-1 in the hypothalamic paraventricular nucleus (PVN) on gastric motility and the regulation of the lateral hypothalamic area (LHA). Using single unit recordings in the PVN, we show that nesfatin-1 inhibited the majority of the gastric distention (GD)-excitatory neurons and excited more than half of the GD-inhibitory (GD-I) neurons in the PVN, which were weakened by oxytocin receptor antagonist H4928. Gastric motility experiments showed that administration of nesfatin-1 in the PVN decreased gastric motility, which was also partly prevented by H4928. The nesfatin-1 concentration producing a half-maximal response (EC50) in the PVN was lower than the value in the dorsomedial hypothalamic nucleus, while nesfatin-1 in the reuniens thalamic nucleus had no effect on gastric motility. Retrograde tracing and immunofluorescent staining showed that nucleobindin-2/nesfatin-1 and fluorogold double-labeled neurons were observed in the LHA. Electrical LHA stimulation changed the firing rate of GD-responsive neurons in the PVN. Pre-administration of an anti- nucleobindin-2/nesfatin-1 antibody in the PVN strengthened gastric motility and decreased the discharging of the GD-I neurons induced by electrical stimulation of the LHA. These results demonstrate that nesfatin-1 in the PVN could serve as an inhibitory factor to inhibit gastric motility, which might be regulated by the LHA.
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Affiliation(s)
- Fei-fei Guo
- Department of Pathophysiology, Medical College of Qingdao University, Qingdao, China
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14
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Martelli D, Luppi M, Cerri M, Tupone D, Mastrotto M, Perez E, Zamboni G, Amici R. The direct cooling of the preoptic-hypothalamic area elicits the release of thyroid stimulating hormone during wakefulness but not during REM sleep. PLoS One 2014; 9:e87793. [PMID: 24498374 PMCID: PMC3911997 DOI: 10.1371/journal.pone.0087793] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 01/01/2014] [Indexed: 12/03/2022] Open
Abstract
Thermoregulatory responses to temperature changes are not operant during REM sleep (REMS), but fully operant in non-REM sleep and wakefulness. The specificity of the relationship between REMS and the impairment of thermoregulation was tested by eliciting the reflex release of Thyrotropin Releasing Hormone (TRH), which is integrated at hypothalamic level. By inducing the sequential secretion of Thyroid Stimulating Hormone (TSH) and Thyroid Hormone, TRH intervenes in the regulation of obligatory and non-shivering thermogenesis. Experiments were performed on male albino rats implanted with epidural electrodes for EEG recording and 2 silver-copper wire thermodes, bilaterally placed in the preoptic-hypothalamic area (POA) and connected to small thermoelectric heat pumps driven by a low-voltage high current DC power supply. In preliminary experiments, a thermistor was added in order to measure hypothalamic temperature. The activation of TRH hypophysiotropic neurons by the thermode cooling of POA was indirectly assessed, in conditions in which thermoregulation was either fully operant (wakefulness) or not operant (REMS), by a radioimmunoassay determination of plasmatic levels of TSH. Different POA cooling were performed for 120 s or 40 s at current intensities of 80 mA and 125 mA, respectively. At both current intensities, POA cooling elicited, with respect to control values (no cooling current), a significant increase in plasmatic TSH levels in wakefulness, but not during REMS. These results confirm the inactivation of POA thermal sensitivity during REMS and show, for the first time, that this inactivation concerns also the fundamental endocrine control of non-shivering thermogenesis.
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Affiliation(s)
- Davide Martelli
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum - University of Bologna, Bologna, Italy
- Systems Neurophysiology Division, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Marco Luppi
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Matteo Cerri
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Domenico Tupone
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum - University of Bologna, Bologna, Italy
- Department of Neurological Surgery, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Marco Mastrotto
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum - University of Bologna, Bologna, Italy
- Department of Cellular and Molecular Physiology and Center for Neurodegeneration and Repair, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Emanuele Perez
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Giovanni Zamboni
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum - University of Bologna, Bologna, Italy
- * E-mail:
| | - Roberto Amici
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum - University of Bologna, Bologna, Italy
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Gyengesi E, Paxinos G, Andrews ZB. Oxidative Stress in the Hypothalamus: the Importance of Calcium Signaling and Mitochondrial ROS in Body Weight Regulation. Curr Neuropharmacol 2013; 10:344-53. [PMID: 23730258 PMCID: PMC3520044 DOI: 10.2174/157015912804143496] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 07/12/2012] [Accepted: 08/02/2012] [Indexed: 12/25/2022] Open
Abstract
A considerable amount of evidence shows that reactive oxygen species (ROS) in the mammalian brain are directly responsible for cell and tissue function and dysfunction. Excessive reactive oxygen species contribute to various conditions including inflammation, diabetes mellitus, neurodegenerative diseases, tumor formation, and mental disorders such as depression. Increased intracellular calcium levels have toxic roles leading to cell death. However, the exact connection between reactive oxygen production and high calcium stress is not yet fully understood. In this review, we focus on the role of reactive oxygen species and calcium stress in hypothalamic arcuate neurons controlling feeding. We revisit the role of NPY and POMC neurons in the regulation of appetite and energy homeostasis, and consider how ROS and intracellular calcium levels affect these neurons. These novel insights give a new direction to research on hypothalamic mechanisms regulating energy homeostasis and may offer novel treatment strategies for obesity and type-2 diabetes.
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Affiliation(s)
- Erika Gyengesi
- Neuroscience Research Australia, Barker Street, Randwick, New South Wales, Australia
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16
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Abstract
Research into the control of energy balance has tended to focus on discrete brain regions, such as the brainstem, medulla, arcuate nucleus of the hypothalamus, and neocortex. Recently, a larger picture has begun to emerge in which the coordinated communication between these areas is proving to be critical to appropriate regulation of metabolism. By serving as a center for such communication, the paraventricular nucleus of the hypothalamus (PVH) is perhaps the most important brain nucleus regulating the physiological response to energetic challenges. Here we review recent advances in the understanding of the circuitry and function of the PVH.
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Affiliation(s)
- Jennifer W. Hill
- Department of Physiology and Pharmacology, Center for Diabetes and Endocrine Research, University of Toledo Medical Center, Obstetrics-Gynecology, University of Toledo, USA
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Chen P, Lin D, Giesler J, Li C. Identification of urocortin 3 afferent projection to the ventromedial nucleus of the hypothalamus in rat brain. J Comp Neurol 2011; 519:2023-42. [PMID: 21452217 DOI: 10.1002/cne.22620] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Urocortin 3 (Ucn 3) is a corticotrophin-releasing factor related neuropeptide highly expressed in the brain. Ucn 3 nerve fibers heavily innervate the hypothalamic ventromedial nucleus (VMH), and Ucn 3 injection into the VMH suppresses feeding. Currently, the origin of the Ucn 3 afferent input into the VMH is unknown. In the present study, anatomical tracing shows that the major Ucn 3 afferent input to the VMH resides in the anterior parvicellular part of the paraventricular nucleus of the hypothalamus (PVHap) and the adjacent posterior part of the bed nucleus of stria terminalis (pBNST). VMH also receives moderate Ucn 3 input from the medial amygdala. Ucn 3 neurons located immediately caudal to the PVHap/pBNST in the rostral perifornical hypothalamic area (rPFH) provide only minimal input. The paucity of rPFH-VMH Ucn 3 projection is consistent with the finding that only Ucn 3 neurons in the rPFH co-expressed enkephalin (Enk), and Ucn 3/Enk double-labeled nerve fibers and terminals were observed predominately in the lateral septum (LS), whereas only a few double-labeled fibers were found in other brain areas including the VMH. Furthermore, retrograde tracing demonstrates that Ucn 3 neurons in the rPFH project to the LS. In conclusion, the present study determines that the major Ucn 3 afferent into the VMH originates from the PVHap/pBNST. Moreover, anatomical heterogeneity is observed in the hypothalamic Ucn 3 neuron population as the rostral part (PVHap/pBNST) of the population projects to the VMH and the caudal part (rPFH) co-localizes with Enk and provides major afferent input to the LS.
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Affiliation(s)
- Peilin Chen
- Department of Pharmacology, University of Virginia Health System, Charlottesville, Virginia 22908, USA
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18
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Identification of neuronal subpopulations that project from hypothalamus to both liver and adipose tissue polysynaptically. Proc Natl Acad Sci U S A 2010; 107:7024-9. [PMID: 20351287 DOI: 10.1073/pnas.1002790107] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The autonomic nervous system regulates fuel availability and energy storage in the liver, adipose tissue, and other organs; however, the molecular components of this neural circuit are poorly understood. We sought to identify neural populations that project from the CNS indirectly through multisynaptic pathways to liver and epididymal white fat in mice using pseudorabies virus strains expressing different reporters together with BAC transgenesis and immunohistochemistry. Neurons common to both circuits were identified in subpopulations of the paraventricular nucleus of the hypothalamus (PVH) by double labeling with markers expressed in viruses injected in both sites. The lateral hypothalamus and arcuate nucleus of the hypothalamus and brainstem regions (nucleus of the solitary tract and A5 region) also project to both tissues but are labeled at later times. Connections from these same sites to the PVH were evident after direct injection of virus into the PVH, suggesting that these regions lie upstream of the PVH in a common pathway to liver and adipose tissue (two metabolically active organs). These common populations of brainstem and hypothalamic neurons express neuropeptide Y and proopiomelanocortin in the arcuate nucleus, melanin-concentrating hormone, and orexin in the lateral hypothalamus and in the corticotrophin-releasing hormone and oxytocin in the PVH. The delineation of this circuitry will facilitate a functional analysis of the possible role of these potential command-like neurons to modulate autonomic outflow and coordinate metabolic responses in liver and adipose tissue.
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19
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Marques de Souza L, Franci CR. GABAergic mediation of stress-induced secretion of corticosterone and oxytocin, but not prolactin, by the hypothalamic paraventricular nucleus. Life Sci 2008; 83:686-92. [PMID: 18840449 DOI: 10.1016/j.lfs.2008.09.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2007] [Revised: 08/17/2008] [Accepted: 09/13/2008] [Indexed: 10/21/2022]
Abstract
The hypothalamus-pituitary-adrenal axis (HPA) participates in mediating the response to stressful stimuli. Within the HPA, neurons in the medial parvocellular region of paraventricular nucleus (PVN) of the hypothalamus integrate excitatory and inhibitory signals triggering secretion of corticotropin-releasing hormone (CRH), the main secretagogue of adrenocorticotropic hormone (ACTH). Stressful situations alter CRH secretion as well as other hormones, including prolactin and oxytocin. Most inputs to the PVN are of local origin, half of which are GABAergic neurons, and both GABA-A and GABA-B receptors are present in the PVN. The objective of the present study was to investigate the role of GABA-A and GABA-B receptors in the PVN's control of stress-induced corticosterone, oxytocin and prolactin secretion. Rats were microinjected with saline or different doses (0.5, 5 and 50 pmol) of GABA-A (bicuculine) or GABA-B (phaclofen) antagonists in the PVN. Ten minutes later, they were subjected to a stressor (ether inhalation) and blood samples were collected 30 min before and 10, 30, 60, 90 and 120 min after the stressful stimulus to measure hormone levels by radioimmunoassay. Our results indicate that GABA acts in the PVN to inhibit stress-induced corticosterone secretion via both its receptor subtypes, especially GABA-B. In contrast, GABA in the PVN stimulates oxytocin secretion through GABA-B receptors and does not alter prolactin secretion.
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Affiliation(s)
- Leandro Marques de Souza
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, 14049-900 Ribeirão Preto SP, Brazil
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20
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Williamson M, Viau V. Androgen receptor expressing neurons that project to the paraventricular nucleus of the hypothalamus in the male rat. J Comp Neurol 2007; 503:717-40. [PMID: 17570493 DOI: 10.1002/cne.21411] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Androgen receptors are distributed throughout the central nervous system and are contained by a variety of nuclei that are known to project to or regulate the paraventricular nucleus (PVN) of the hypothalamus, the final common pathway by which the brain regulates the hypothalamic-pituitary-adrenal (HPA) response to homeostatic threat. Here we characterized androgen receptor staining within cells identified as projecting to the PVN in male rats bearing iontophoretic or crystalline injections of the retrograde tracer FluoroGold aimed at the caudal two-thirds of the nucleus, where corticotropin-releasing hormone-expressing neurons are amassed. Androgen receptor (AR) and FluoroGold (FG) double labeling was revealed throughout the limbic forebrain, including scattered numbers of cells within the anterior and posterior subdivisions of the bed nuclei of the stria terminalis; the medial zone of the hypothalamus, including large numbers of AR-FG-positive cells within the anteroventral periventricular and medial preoptic cell groups. Strong and consistent colabeling was also revealed throughout the hindbrain, predominantly within the periaqueductal gray and the lateral parabrachial nucleus, and within various medullary cell groups identified as catecholaminergic, predominantly C1 and A1 neurons of the ventral medulla. These connectional data predict that androgens can act on a large assortment of multimodal inputs to the PVN, including those involved with the processing of various types of sensory and limbic information, and provide an anatomical framework for understanding how gonadal status could contribute to individual differences in HPA function.
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Affiliation(s)
- Martin Williamson
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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Watts AG, Sanchez-Watts G. Rapid and preferential activation of Fos protein in hypocretin/orexin neurons following the reversal of dehydration-anorexia. J Comp Neurol 2007; 502:768-82. [PMID: 17436292 DOI: 10.1002/cne.21316] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Dehydration (DE)-anorexia is stimulated by chronic consumption of hypertonic saline. Spontaneous nocturnal food intake is markedly reduced with this treatment but is rapidly reversed upon the return of drinking water. Here we examined the neurons in the lateral hypothalamic area (LHA) of chronically dehydrated rats for their peptidergic phenotype, colocalization, and activation profiles following the rapid reversal of anorexia. To do this, we used double-labeling combinations of Fos immunocytochemistry and radioisotopic- and digoxigenin-labeled in situ hybridization. We found that lateral hypothalamic corticotropin-releasing hormone (CRH) neurons show extensive coexpression with neurotensin mRNA, but they are distinct from hypocretin/orexin and melanin-concentrating hormone (MCH) neurons. Chronic dehydration increases Fos-ir in large numbers of neurons in dorsal regions of the LHA. Some of these LHA neurons also show increased CRH, but not hypocretin/orexin or MCH gene expression, as dehydration-anorexia develops. Furthermore, the behavioral sequence of eating and increased activity exhibited by DE animals in the minutes following water drinking is accompanied by a further increase in the number of Fos-ir nuclei in the LHA. Increased Fos activation occurs in a significant number of LHA hypocretin/orexin neurons, but not CRH or MCH neurons, in the LHA. Together these data implicate CRH but not hypocretin/orexin or MCH neurons in the LHA in the motor events associated with dehydration. However, when water is returned, contributions to the network controlling responses evidently come from hypocretin/orexin, but not CRH or MCH, neurons in the LHA.
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Affiliation(s)
- Alan G Watts
- The Neuroscience Research Institute and the Department of Biological Sciences, USC College, University of Southern California, Los Angeles, California 90089-2520, USA.
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22
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DAS MAHASWETA, VIHLEN CHRISTOPHERS, LEGRADI GABOR. Hypothalamic and brainstem sources of pituitary adenylate cyclase-activating polypeptide nerve fibers innervating the hypothalamic paraventricular nucleus in the rat. J Comp Neurol 2007; 500:761-76. [PMID: 17154257 PMCID: PMC1934940 DOI: 10.1002/cne.21212] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The hypothalamic paraventricular nucleus (PVN) coordinates major neuroendocrine and behavioral mechanisms, particularly responses to homeostatic challenges. Parvocellular and magnocellular PVN neurons are richly innervated by pituitary adenylate cyclase-activating polypeptide (PACAP) axons. Our recent functional observations have also suggested that PACAP may be an excitatory neuropeptide at the level of the PVN. Nevertheless, the exact localization of PACAP-producing neurons that project to the PVN is not understood. The present study examined the specific contribution of various brain areas sending PACAP innervation to the rat PVN by using iontophoretic microinjections of the retrograde neuroanatomical tracer cholera toxin B subunit (CTb). Retrograde transport was evaluated from hypothalamic and brainstem sections by using multiple labeling immunofluorescence for CTb and PACAP. PACAP-containing cell groups were found to be retrogradely labeled from the PVN in the median preoptic nucleus; preoptic and lateral hypothalamic areas; arcuate, dorsomedial, ventromedial, and supramammillary nuclei; ventrolateral midbrain periaqueductal gray; rostral and midlevel ventrolateral medulla, including the C1 catecholamine cell group; nucleus of the solitary tract; and dorsal motor nucleus of vagus. Minor PACAP projections with scattered double-labeled neurons originated from the parabrachial nucleus, pericoeruleus area, and caudal regions of the nucleus of the solitary tract and ventrolateral medulla. These observations indicate a multisite origin of PACAP innervation to the PVN and provide a strong chemical neuroanatomical foundation for interaction between PACAP and its potential target neurons in the PVN, such as parvocellular CRH neurons, controlling physiologic responses to stressful challenges and other neuroendocrine or preautonomic PVN neurons.
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Affiliation(s)
| | | | - GABOR LEGRADI
- *Correspondence to: Gabor Legradi, MD, Department of Pathology and Cell Biology, College of Medicine University of South Florida, 12901 Bruce B. Downs Blvd., MDC6, Tampa, FL 33612-4799. E-mail:
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Kiss A, Søderman A, Bundzikova J, Pirnik Z, Mikkelsen JD. Zolpidem, a selective GABAA receptor α1 subunit agonist, induces comparable Fos expression in oxytocinergic neurons of the hypothalamic paraventricular and accessory but not supraoptic nuclei in the rat. Brain Res Bull 2006; 71:200-7. [PMID: 17113947 DOI: 10.1016/j.brainresbull.2006.09.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2006] [Revised: 09/02/2006] [Accepted: 09/07/2006] [Indexed: 10/24/2022]
Abstract
Functional activation of oxytocinergic (OXY) cells in the hypothalamic paraventricular (PVN), supraoptic (SON), and accessory (ACC) nuclei was investigated in response to acute treatment with Zolpidem (a GABA(A) receptor agonist with selectivity for alpha(1) subunits) utilizing dual Fos/OXY immunohistochemistry. Zolpidem was administered intraperitoneally in dose 10 mg/kg of BW and 60 min later the animals were sacrificed by transcardial perfusion with fixative. The Fos/OXY co-labelings were analyzed on 40 microm thick serial coronal sections using computerized light microscopy. Zolpidem elicited a concordant Fos/OXY staining in all four PVN sub-areas investigated, including the anterior (15.71+/-2.35%), middle (14.52+/-2.53%), dorsal (13.34+/-2.61%), and periventricular (18.21+/-4.75%) ones, however, had no significant stimulatory effect on OXY cells in the SON. In response to Zolpidem, statistically significant activations were also seen in certain groups of accessory structures including the circular nucleus (13.99+/-3.43%), small clusters of accessory neurons (10.55+/-1.94%), and the lateral hypothalamic perivascular nucleus (9.42+/-2.74%). Between the naive and vehicle controls, the dual Fos/OXY labelings did not elicit any significant differences. Our data provide insight into the topographic patterns of brain activity within the clusters of magnocellular OXY cells in the hypothalamus associated with stimulation of GABA(A) benzodiazepine receptors and for the first time illustrate the triggering contemporaneousness within the cells of the principal and accessory magnocellular nuclei in response to Zolpidem treatment. The present study provides a comparative background that may help in the further understanding of a possible extend of Zolpidem effect on the brain.
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Affiliation(s)
- Alexander Kiss
- Laboratory of Functional Neuromorphology, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska Street 3, 833 06 Bratislava, Slovakia.
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Koylu EO, Balkan B, Kuhar MJ, Pogun S. Cocaine and amphetamine regulated transcript (CART) and the stress response. Peptides 2006; 27:1956-69. [PMID: 16822586 DOI: 10.1016/j.peptides.2006.03.032] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Accepted: 03/25/2006] [Indexed: 01/24/2023]
Abstract
CART is expressed abundantly in the hypothalamic paraventricular nucleus and locus coeruleus, major corticotropin releasing factor (CRF) and noradrenaline sources, respectively. There is a bidirectional relation between CART and hypothalamo-pituitary-adrenal axis activity. CART stimulates CRF, adrenocorticotropic hormone and glucocorticoid secretion, whereas CRF and glucocorticoids increase the transcriptional activity of the CART gene; adrenalectomy declines CART expression in the hypothalamus. Stress exposure modulates CART expression in hypothalamus and amygdala in rat brain in a region and sex specific manner. CART may be a mediator peptide in the interaction between stress, drug abuse, and feeding. The review discusses the established role of CART as it relates to the stress response.
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Affiliation(s)
- Ersin O Koylu
- Ege University Center for Brain Research, Department of Physiology, Bornova, 35100 Izmir, Turkey.
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Mikkelsen JD, Søderman A, Kiss A, Mirza N. Effects of benzodiazepines receptor agonists on the hypothalamic–pituitary–adrenocortical axis. Eur J Pharmacol 2005; 519:223-30. [PMID: 16125698 DOI: 10.1016/j.ejphar.2005.06.049] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Revised: 06/23/2005] [Accepted: 06/30/2005] [Indexed: 11/20/2022]
Abstract
Previous studies have demonstrated that classical benzodiazepines decrease hypothalamic-pituitary-adrenocortical cortex (HPA) axis activity. Paradoxically, high doses of benzodiazepines also stimulate basal circulating corticosterone levels in some conditions. Because benzodiazepine agonists display little selectivity to any of the alpha subtypes of the gamma-amino butyric acid (GABA)(A) receptor to which they bind, we propose that the unequivocal results are due to an alpha subtype-dependent modulation of the hypothalamic-pituitary-adrenocortical cortex axis output. To test this, basal hormonal output and induction of Fos in the hypothalamic paraventricular nucleus were measured after administration of various benzodiazepine ligands in mice. Zolpidem, a selective alpha1 subtype agonist, produced a very strong increase in plasma adrenocorticotropic hormone and corticosterone whereas the inverse agonist FG7142 induced a small rise in plasma corticosterone. More surprisingly, the non-selective full agonists diazepam and zopiclone induced a lower increase in circulating corticosterone than after zolpidem. In contrast, the alpha(2,3,5)-selective benzodiazepine agonist and alpha1 antagonist L-838,417 had no effect on corticosterone levels. Strong induction of Fos in the paraventricular nucleus was found in response to zolpidem, diazepam, and zopiclone, but not after L-838,417. Finally, pre-administration of L-838,417 prior to zolpidem strongly inhibited the effect of zolpidem on corticosterone. Likewise, the non-selective agonists diazepam and zopiclone at a dose that alone had no effect on corticosterone also inhibited the effect of zolpidem. Taken together, these results suggest that benzodiazepine ligands modulate the hypothalamic-pituitary-adrenocortical cortex axis through partly opposite mechanisms; and that the net effect is dependent on the composition of the GABA(A) receptor subunits to which they bind.
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Affiliation(s)
- Jens D Mikkelsen
- Department of Functional Neuroanatomy and Biomarkers, NeuroSearch A/S, Pederstrupvej 93, 2750 Ballerup, Denmark.
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Fenoglio KA, Brunson KL, Avishai-Eliner S, Chen Y, Baram TZ. Region-specific onset of handling-induced changes in corticotropin-releasing factor and glucocorticoid receptor expression. Endocrinology 2004; 145:2702-6. [PMID: 15044366 PMCID: PMC3088480 DOI: 10.1210/en.2004-0111] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Early-life experience including maternal care profoundly influences hormonal stress responses during adulthood. Daily handling on postnatal day (P) 2-9, eliciting augmented maternal care upon returning pups to their cage, permanently modifies the expression of the stress neuromodulators corticotropin-releasing factor (CRF) and glucocorticoid receptor (GR). We have previously demonstrated reduced hypothalamic CRF expression already at the end of the handling period, followed by enhanced hippocampal GR mRNA levels (by P45). However, the initial site(s) and time of onset of these enduring changes have remained unclear. Therefore, we used semiquantitative in situ hybridization to delineate the spatiotemporal evolution of CRF and GR expression throughout stress-regulatory brain regions in handled (compared with undisturbed) pups. Enhanced CRF mRNA expression was apparent in the amygdaloid central nucleus (ACe) of handled pups already by P6. By P9, the augmented CRF mRNA levels persisted in ACe, accompanied by increased peptide expression in the bed nucleus of the stria terminalis and reduced expression in the paraventricular nucleus. The earliest change in GR consisted of reduced expression in the ACe of handled pups on P9, a time point when hippocampal GR expression was not yet affected. Thus, altered gene expression in ACe, bed nucleus of the stria terminalis as well as paraventricular nucleus may contribute to the molecular cascade by which handling (and increased maternal care) influences the stress response long term.
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Affiliation(s)
- Kristina A Fenoglio
- 19182 Jamboree Boulevard, University of California, Irvine, Med Sci I Room B160, Irvine, California 92697-4475, USA
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Steininger TL, Kilduff TS, Behan M, Benca RM, Landry CF. Comparison of hypocretin/orexin and melanin-concentrating hormone neurons and axonal projections in the embryonic and postnatal rat brain. J Chem Neuroanat 2004; 27:165-81. [PMID: 15183202 DOI: 10.1016/j.jchemneu.2004.02.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2003] [Accepted: 02/13/2004] [Indexed: 11/15/2022]
Abstract
Hypocretin/orexin (H/O) and melanin-concentrating hormone (MCH) are peptide neuromodulators found in separate populations of neurons located within the lateral and perifornical hypothalamic regions. H/O has been linked to sleep-wakefulness regulation and to the sleep disorder narcolepsy, and both systems have been implicated in energy homeostasis, including the regulation of food intake. In the present study we compared the development of H/O and MCH-expressing neuronal populations with in situ hybridization and immunohistochemistry on adjacent sections in the embryonic and postnatal rat brain. We found that MCH mRNA and protein were present in developing neurons of the hypothalamus by embryonic day 16 (E16), whereas H/O mRNA and protein were not detected until E18. We also identified previously undescribed populations of MCH-immunoreactive cells in the lateral septum, paraventricular hypothalamic nucleus, lateral zona incerta, and ventral lateral geniculate nucleus that may play a specific role in the development of these regions. MCH immunoreactive axonal processes were also evident earlier than H/O stained fibers and at the time H/O immunoreactive processes were first identified in the hypothalamus at E20, extensive MCH axonal fiber systems were already present in many brain regions. Interestingly, however, the density of axonal fibers immunoreactive for H/O in the locus coeruleus reached peak levels at the same developmental age (P21) as MCH immunoreactive axons in the diagonal band of Broca (DBB). The peak of axon density coincided with the developmental stage at which adult patterns of feeding and sleep-waking activity become established. The present results demonstrate developmental differences and similarities between the MCH and H/O systems that may relate to their respective roles in feeding and sleep regulation.
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Affiliation(s)
- Teresa L Steininger
- Molecular Neurobiology Laboratory, SRI International, Menlo Park, CA 94025, USA
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Hay-Schmidt A, Vrang N, Larsen PJ, Mikkelsen JD. Projections from the raphe nuclei to the suprachiasmatic nucleus of the rat. J Chem Neuroanat 2003; 25:293-310. [PMID: 12842274 DOI: 10.1016/s0891-0618(03)00042-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The presence of serotonergic afferents in the hypothalamic suprachiasmatic nucleus (SCN) is well documented and several functional roles of serotonin (5-HT) in circadian function are well established. However, there is some controversy about the precise location of the serotonergic neurones from where this input arises. Discrete injection of the tracer Cholera toxin, subunit B, (ChB) was centred in the rat SCN, and a few retrograde labelled neurones were distributed in the dorsal and median raphe nuclei (MnR) and in the rostral part of the raphe magnus (RMg), but no neurones were found in the raphe pallidus or raphe obscurus. In addition, a group of neurones was consistently found in the medial part of the pontine supra lemniscal nucleus but not including the serotonergic B(9) region. A combination of retrograde tracing with Fluoro-Gold together with 5-HT-immunolabelling, showed few double-labelled neurones in the dorsal, MnR and B(9). However, the majority of projecting neurones were not co-storing 5-HT immunoreactivity. Phaseolus vulgaris-leucoagglutinin (PHA-L) injections in the dorsal raphe resulted in faint labelling, whereas the MnR gave rise to several labelled fibres in the SCN. Individual delicate PHA-L nerve fibres were found in all compartments of the SCN both in terms of rostrocaudal, ventromedial and dorsomedial extent, without any sign of a topographical organisation of the MnR input to the SCN. PHA-L injections into RMg gave rise to labelling of a few processes within the SCN. In conclusion, the main serotonergic input to the rat SCN originates from a few neurones in the MnR.
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Affiliation(s)
- Anders Hay-Schmidt
- Department of Medical Anatomy, The Panum Institute, 18.2, University of Copenhagen, Blegdamsvej 3, DK-2200 N, Copenhagen, Denmark.
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Satoh S, Matsumura H, Nakajima T, Nakahama KI, Kanbayashi T, Nishino S, Yoneda H, Shigeyoshi Y. Inhibition of rostral basal forebrain neurons promotes wakefulness and induces FOS in orexin neurons. Eur J Neurosci 2003; 17:1635-45. [PMID: 12752381 DOI: 10.1046/j.1460-9568.2003.02577.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The present study examined whether the activities of the rostral basal forebrain neurons alter the activities of the orexin (also known as hypocretin) neurons in the tuberal part of the hypothalamus in rats. We performed microdialysis perfusion of the ventromedial portion of the rostral basal forebrain with the GABAA receptor agonist muscimol to inhibit focally the neuronal activities in the rostral basal forebrain. Then, we monitored sleep/wake behaviour and investigated the pattern of activities of orexin neurons by examining the expression of FOS as an indicator of cellular activation. Bilateral perfusion with muscimol (5, 15, and 50 micro m) produced a dose-dependent decrease in the amount of sleep. This perfusion with muscimol at 50 micro m produced FOS-like immunoreactivity in 37% of the orexin neurons located in the tuberal part of the hypothalamus, whereas the FOS-like immunoreactivity was sparse in orexin neurons of the sleeping control rats (P = 0.001 by Mann-Whitney U-test). Unilateral perfusion with muscimol (50 micro m) also suppressed sleep. In this case, FOS-like immunoreactivity was seen in 40% of the orexin neurons on the side ipsilateral to the perfusion site but only in 10% of orexin neurons on the contralateral side (P = 0.018 by Wilcoxon signed rank test). These functional data suggested that a sleep-generating element in the ventromedial part of the rostral basal forebrain provides an inhibitory influence on the activities of the orexin neurons in the tuberal part of the hypothalamus.
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Affiliation(s)
- Shinsuke Satoh
- Second Department of Anatomy and Neurobiology, Kinki University School of Medicine, Osaka-Sayama, Osaka 589-8511, Japan.
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Nomura M, McKenna E, Korach KS, Pfaff DW, Ogawa S. Estrogen receptor-beta regulates transcript levels for oxytocin and arginine vasopressin in the hypothalamic paraventricular nucleus of male mice. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2002; 109:84-94. [PMID: 12531518 DOI: 10.1016/s0169-328x(02)00525-9] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Estrogen receptor (ER)-beta, unlike ER-alpha, is localized in the hypothalamic paraventricular nucleus (PVN) which also contains neuropeptide synthesizing neurons, such as oxytocin (OT), arginine vasopressin (AVP) and corticotropin-releasing hormone (CRH). Although it is known that some ER-beta containing neurons co-express OT and AVP, but not CRH, in the PVN, it is not yet determined whether ER-beta activation may indeed play a role in estrogenic regulation on syntheses of these neuropeptides. In the present study, we tested this hypothesis by comparing the effects of estrogen on the levels of OT, AVP and CRH messenger RNA (mRNA) between ER-beta knockout (betaERKO) and wild type (WT) control male mice. Mice were gonadectomized and implanted with either a pellet containing estradiol benzoate (2.5-5.0 microg/day) or a placebo pellet for 21 days. In situ hybridization histochemistry revealed that estrogen treatment resulted in a significant increase in OT transcripts (151.6+/-6.0%) and a decrease in AVP transcripts (77.8+/-5.2%) in the PVN of WT mice, compared to the placebo control group. This estrogenic regulation of OT and AVP mRNA levels in the PVN was completely abolished in betaERKO mice. Similar genotype differences in the effects of estrogen on the numbers of OT- and AVP-containing cells were found in immunocytochemical studies performed in a separate set of mice. On the other hand, the expression of CRH mRNA in the PVN was not affected by estrogen treatment in either WT or betaERKO mice. Furthermore, estrogen did not cause any changes in the levels of OT or AVP mRNA, regardless of genotype, in the supraoptic nucleus where, unlike in rats, ER-beta containing neurons are rarely found in mice. Finally, estrogen significantly increased OT mRNA levels in both betaERKO and WT in the medial preoptic area, which contains both ER-alpha and ER-beta. These results suggest that ER-beta activation may play a critical role in estrogenic regulation of OT and AVP gene expression in the PVN.
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Affiliation(s)
- Masayoshi Nomura
- Laboratory of Neurobiology and Behavior, The Rockefeller University, Box 275, 1230 York Avenue, New York, NY 10021, USA
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Abstract
Drinking and eating are critically important motivated behaviors whose expression is usually tightly linked; under conditions of spontaneous intake, disruption of one usually disturbs the other. This characteristic is exemplified by dehydration-induced anorexia in which increasing plasma osmolality leads to a centrally generated reduction in food intake, which is then rapidly reversed as water is again made available. This review discusses, at a systems level, how the brain is organized to generate these behaviors and how dehydration affects the expression of neuropeptides in sets of anatomically defined forebrain circuits that contribute to the integration of motor outputs. These findings are then used to consider how altered neuropeptidergic signaling operates within motor drive networks and how these changes may impact the way neuroendocrine, autonomic, and behavioral motor systems respond to this fundamental homeostatic challenge.
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Affiliation(s)
- A G Watts
- The Neuroscience Program and the Department of Biological Sciences, University of Southern California, Los Angeles, California 90089-2520, USA.
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Feldman S, Weidenfeld J. Electrical stimulation of the dorsal hippocampus caused a long lasting inhibition of ACTH and adrenocortical responses to photic stimuli in freely moving rats. Brain Res 2001; 911:22-6. [PMID: 11489440 DOI: 10.1016/s0006-8993(01)02538-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The effect of a single train of electrical hippocampal stimulation on ACTH and corticosterone (CS) responses to subsequent photic stimulation was studied in freely moving male rats. The hippocampal stimulation inhibited the stress-induced rise [corrected] in serum CS levels up to 150 h when compared to sham stimulated animals. This effect did not exist at 300 h following stimulation. This sustained hippocampal inhibitory effect on the adrenocortical response, which was not reported previously, was partially abolished by section of the dorsal fornix. The present data demonstrate that dorsal hippocampal stimulation has a long lasting inhibitory effect on pituitary adrenocortical secretion following neural stimuli and this is partially mediated by the dorsal fornix.
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Affiliation(s)
- S Feldman
- Department of Neurology, The Agnes Ginges Center for Neurogenetics, Hadassah University Hospital and Hebrew University-Hadassah Medical School, P.O. Box 12000, Jerusalem, Israel
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Watts AG. Understanding the neural control of ingestive behaviors: helping to separate cause from effect with dehydration-associated anorexia. Horm Behav 2000; 37:261-83. [PMID: 10860672 DOI: 10.1006/hbeh.2000.1581] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Eating and drinking are motivated behaviors that are made up of coordinated sets of neuroendocrine, autonomic, and behavioral motor events. Although the spinal cord, hindbrain, and hypothalamus contain the motor neurons and circuitry sufficient to maintain the reflex parts of these motor events, inputs from the telencephalon are required to furnish the behavioral components with a motivated (goal-directed) character. Each of these motor events derives from the complex interaction of a variety of sensory inputs with groups of neural networks whose components are distributed throughout the brain and collectively support motor expression and coordination. At a first approximation based on a variety of data, these networks can be divided into three groups: networks that stimulate, those that inhibit, and those that disinhibit motor functions. A fourth contributor is the circadian timing signal that originates in the hypothalamic suprachiasmatic nucleus and provides the temporal anchor for the expression of all behaviors. This article discusses the nature of these networks using neuroanatomical (tract-tracing and neuropeptide in situ hybridization), endocrine, and behavioral evidence from a variety of experimental models. A persistent problem when studying the control of food intake from a neural systems perspective has been the difficulty in separating those neuronal changes that result in hunger from those that are as a consequence of eating. To address this problem, dehydration-associated anorexia is presented as a particularly useful experimental model because it can be used to distinguish between neural mechanisms underlying anorexia and those changes that occur as a consequence of anorexia. The article concludes by highlighting the potential role of neuropeptidergic action in the operation of these networks, using forebrain neuropeptidergic innervation of the parabrachial nucleus as an example.
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Affiliation(s)
- A G Watts
- The Neuroscience Program and the Department of Biological Sciences, University of Southern California, Los Angeles, California 90089-2520, USA.
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Campeau S, Watson Jr. SJ. Connections of some auditory-responsive posterior thalamic nuclei putatively involved in activation of the hypothalamo-pituitary-adrenocortical axis in response to audiogenic stress in rats: An anterograde and retrograde tract tracing study combined with fos expression. J Comp Neurol 2000. [DOI: 10.1002/1096-9861(20000731)423:3<474::aid-cne10>3.0.co;2-s] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Distinct patterns of neuropeptide gene expression in the lateral hypothalamic area and arcuate nucleus are associated with dehydration-induced anorexia. J Neurosci 1999. [PMID: 10407047 DOI: 10.1523/jneurosci.19-14-06111.1999] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We have investigated the hormonal and hypothalamic neuropeptidergic substrates of dehydration-associated anorexia. In situ hybridization and hormone analyses of anorexic and paired food-restricted rats revealed two distinct profiles. First, both groups had the characteristic gene expression and endocrine signatures usually associated with starvation: increased neuropeptide Y and decreased proopiomelanocortin and neurotensin mRNAs in the arcuate nucleus (ARH); increased circulating glucocorticoid but reduced leptin and insulin. Dehydrated animals are strongly anorexic despite these attributes, showing that the output of leptin- and insulin-sensitive ARH neurons that ordinarily stimulate eating must be inhibited. The second pattern occurred only in anorexic animals and had two components: (1) reduced corticotropin-releasing hormone (CRH) mRNA in the neuroendocrine paraventricular nucleus (PVH) and (2) increased CRH and neurotensin mRNAs in the lateral hypothalamic (LHA) and retrochiasmatic areas. However, neither corticosterone nor suppressed PVH CRH gene expression is required for anorexia after dehydration because PVH CRH mRNA in dehydrated adrenalectomized animals is unchanged from euhydrated adrenalectomized controls. We also showed that LHA CRH mRNA was strongly correlated with the intensity of anorexia, increased LHA CRH gene expression preceded the onset of anorexia, and dehydrated adrenalectomized animals (which also develop anorexia) had elevated LHA CRH gene expression with a distribution pattern similar to intact animals. Finally, we identified specific efferents from the CRH-containing region of the LHA to the PVH, thereby providing a neuroanatomical framework for the integration by the PVH of neuropeptidergic signals from the ARH and the LHA. Together, these observations suggest that CRH and neurotensin neurons in the LHA constitute a novel anatomical substrate for their well known anorexic effects.
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Levin BE, Dunn-Meynell AA, Routh VH. Brain glucose sensing and body energy homeostasis: role in obesity and diabetes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:R1223-31. [PMID: 10233011 DOI: 10.1152/ajpregu.1999.276.5.r1223] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The brain has evolved mechanisms for sensing and regulating glucose metabolism. It receives neural inputs from glucosensors in the periphery but also contains neurons that directly sense changes in glucose levels by using glucose as a signal to alter their firing rate. Glucose-responsive (GR) neurons increase and glucose-sensitive (GS) decrease their firing rate when brain glucose levels rise. GR neurons use an ATP-sensitive K+ channel to regulate their firing. The mechanism regulating GS firing is less certain. Both GR and GS neurons respond to, and participate in, the changes in food intake, sympathoadrenal activity, and energy expenditure produced by extremes of hyper- and hypoglycemia. It is less certain that they respond to the small swings in plasma glucose required for the more physiological regulation of energy homeostasis. Both obesity and diabetes are associated with several alterations in brain glucose sensing. In rats with diet-induced obesity and hyperinsulinemia, GR neurons are hyporesponsive to glucose. Insulin-dependent diabetic rats also have abnormalities of GR neurons and neurotransmitter systems potentially involved in glucose sensing. Thus the challenge for the future is to define the role of brain glucose sensing in the physiological regulation of energy balance and in the pathophysiology of obesity and diabetes.
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Affiliation(s)
- B E Levin
- Neurology Service, Veterans Affairs Medical Center, East Orange 07018, USA.
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Van Koughnet K, Smirnova O, Hyman SE, Borsook D. Proenkephalin transgene regulation in the paraventricular nucleus of the hypothalamus by lipopolysaccharide and interleukin-1? J Comp Neurol 1999. [DOI: 10.1002/(sici)1096-9861(19990308)405:2<199::aid-cne5>3.0.co;2-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
The novel neuropeptides called hypocretins (orexins) have recently been identified as being localized exclusively in cell bodies in a subregion of the tuberal part of the hypothalamus. The structure of the hypocretins, their accumulation in vesicles of axon terminals, and their excitatory effect on cultured hypothalamic neurons suggest that the hypocretins function in intercellular communication. To characterize these peptides further and to help understand what physiological functions they may serve, we undertook an immunohistochemical study to examine the distribution of preprohypocretin-immunoreactive neurons and fibers in the rat brain. Preprohypocretin-positive neurons were found in the perifornical nucleus and in the dorsal and lateral hypothalamic areas. These cells were distinct from those that express melanin-concentrating hormone. Although they represent a restricted group of cells, their projections were widely distributed in the brain. We observed labeled fibers throughout the hypothalamus. The densest extrahypothalamic projection was found in the locus coeruleus. Fibers were also seen in the septal nuclei, the bed nucleus of the stria terminalis, the paraventricular and reuniens nuclei of the thalamus, the zona incerta, the subthalamic nucleus, the central gray, the substantia nigra, the raphe nuclei, the parabrachial area, the medullary reticular formation, and the nucleus of the solitary tract. Less prominent projections were found in cortical regions, central and anterior amygdaloid nuclei, and the olfactory bulb. These results suggest that hypocretins are likely to have a role in physiological functions in addition to food intake such as regulation of blood pressure, the neuroendocrine system, body temperature, and the sleep-waking cycle.
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Hübschle T, McKinley MJ, Oldfield BJ. Efferent connections of the lamina terminalis, the preoptic area and the insular cortex to submandibular and sublingual gland of the rat traced with pseudorabies virus. Brain Res 1998; 806:219-31. [PMID: 9739143 DOI: 10.1016/s0006-8993(98)00765-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Neurones situated in the lamina terminalis (organum vasculosum of the lamina terminalis, median preoptic nucleus and subfornical organ) as well as within medial and lateral parts of the preoptic area and in the insular cortex become transneuronally labelled following pseudorabies virus injections into the submandibular or the sublingual gland. These neurones are efferently connected to a chain of central neurones directed to secretory or vascular tissue of the submandibular or the sublingual gland. By varying the postinoculation time a stepwise infection of different forebrain nuclei was registered, with the hypothalamic paraventricular nucleus and the lateral hypothalamic area being the first forebrain structures labelled. Such early infected neurones within these hypothalamic nuclei are in all likelihood third order neurones regulating salivary secretion and might have functioned as relays transmitting virus to other forebrain structures. The above mentioned forebrain areas together with several other hypothalamic nuclei as well as the bed nucleus of the stria terminalis, the central nucleus of the amygdala and the substantia innominata, seem to be the widespread anatomical basis for the central regulation of salivary gland function.
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Affiliation(s)
- T Hübschle
- The Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria 3052, Australia.
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40
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Kelly AB, Watts AG. The region of the pontine parabrachial nucleus is a major target of dehydration-sensitive CRH neurons in the rat lateral hypothalamic area. J Comp Neurol 1998; 394:48-63. [PMID: 9550142 DOI: 10.1002/(sici)1096-9861(19980427)394:1<48::aid-cne5>3.0.co;2-h] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Neurons in a restricted part of the lateral hypothalamic area (LHA) show increased expression of corticotropin-releasing hormone (CRH) mRNA as a consequence of cellular dehydration. In the present study, we have investigated the organization of their efferent projections by using anterograde and retrograde tracing techniques. Additionally, we have compared the distribution of CRH mRNA-containing neurons after cellular dehydration and intraventricular (i.c.v.) colchicine injections. Our results show that cellular dehydration activates a more restricted neuronal population than does i.c.v. colchicine. Iontophoretic injections of Phaseolus vulgaris leucoagglutinin (PHAL) were placed in the LHA of animals drinking hypertonic saline and their proximity to activated CRH neurons determined by in situ hybridization for CRH mRNA. Although labelled fibers from these injections were seen throughout the brain, the region of the parabrachial nucleus and nucleus of the solitary tract (NTS) were most conspicuous in also having CRH immunoreactive fibers. Injections of Fluoro-Gold placed in these two structures were used to confirm these findings in dehydrated animals. Significant numbers of neurons containing both Fluoro-Gold and CRH mRNA were seen in the lateral hypothalamus after injections in the lateral and medial parts of the parabrachial nucleus; far fewer were seen after injections in the NTS. These results strongly suggest that the CRH neurons in the LHA activated by cellular dehydration provide an input to the region of the parabrachial nucleus. The altered biochemical composition of this pathway may well be able to modify sensory and motor patterns both during and after dehydration.
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Affiliation(s)
- A B Kelly
- Department of Biological Sciences, University of Southern California, Los Angeles 90089, USA
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41
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Champagne D, Beaulieu J, Drolet G. CRFergic innervation of the paraventricular nucleus of the rat hypothalamus: a tract-tracing study. J Neuroendocrinol 1998; 10:119-31. [PMID: 9535058 DOI: 10.1046/j.1365-2826.1998.00179.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
It has been reported that corticotropin-releasing factor (CRF) may regulate its own biosynthesis in the paraventricular nucleus of the hypothalamus (PVH). Whether this CRF autoregulation is mediated by local circuitry or from extra-PVH CRF neuronal fibers terminating on CRF perikarya within the PVH is unknown. In the present study, we sought to determine the origin(s) of this CRF innervation using retrograde transport of wheat germ-conjugated-gold particles (WGA-apoHRP-Au) combined with immunohistochemistry for CRF. The rats also received colchicine (100 microg, icv) 5-7 days after tracer injection and were perfused 24 h later. Results of retrograde labeling with pressure injections of WGA-apoHRP-Au centered to PVH and subsequent immunohistochemical staining for CRF demonstrated numerous retrogradely labeled CRF neurons in the perifornical hypothalamic nucleus (PeF), the dorsolateral hypothalamic area (DA) (medial and lateral portions) and the dorsomedial nucleus of the hypothalamus (DMH). Smaller groups of CRF-ir neurons that were retrogradely labeled were found in the bed nuclei of the stria terminalis (BnST), the Barrington's nucleus (Bar) and the dorsal raphé (DR). These CRFergic pathways to the PVH may represent an anatomical substrate underlying the function of the stress-integrative PVH neurons in the autonomic, behavioral and neuroendocrine regulation during the stress response, including CRF autoregulation.
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Affiliation(s)
- D Champagne
- Centre Hospitalier Universitaire de Québec, Unité de Recherche en Neuroscience, Canada
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42
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Larsen PJ, Enquist LW, Card JP. Characterization of the multisynaptic neuronal control of the rat pineal gland using viral transneuronal tracing. Eur J Neurosci 1998; 10:128-45. [PMID: 9753120 DOI: 10.1046/j.1460-9568.1998.00003.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Knowledge of the polysynaptic pathway conveying photic information to the pineal gland is based upon studies employing lesions, knife cuts and classical tracers. In the present investigation we used viral transneuronal tracing to re-examine the organization of this circuitry. This was accomplished by injecting a neurotropic alpha herpesvirus (pseudorabies virus) into the gland and localizing viral antigen in infected neurones at various postinoculation intervals. This approach is based upon the demonstrated ability of this virus to invade axon terminals, replicate in neurones and pass retrogradely through a multisynaptic circuit. Immunohistochemical localization of viral antigen revealed the progressive appearance of infected neurones in the superior cervical ganglion (SCG), intermediolateral nucleus of the upper thoracic spinal cord (IML), parvicellular subdivisions of the hypothalamic paraventricular nucleus (PVN), and the suprachiasmatic nucleus (SCN). Other infected cell groups known to project to the IML also became infected. Infection of the PVN reproducibly involved neurones in the dorsal, medial and lateral parvicellular subdivisions and preceded the appearance of infected neurones in the SCN and other regions of hypothalamus. Topographic analysis of virus infected neurones within the SCN revealed differential infection of SCN subdivisions that suggested topography in the projection of the SCN to the PVN. Removal of the SCG eliminated infection within the aforementioned circuitry and revealed a parasympathetic innervation from the sphenopalatine ganglion. The data provide further detail on the cellular identity and synaptology of neural circuitry controlling the rhythmic secretion of melatonin by the rat pineal gland.
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Affiliation(s)
- P J Larsen
- Department of Anatomy, University of Copenhagen, Denmark.
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43
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Ling C, Jhaveri S, Schneider GE. Target- as well as source-derived factors direct the morphogenesis of anomalous retino-thalamic projections. J Comp Neurol 1997; 388:454-66. [PMID: 9368853 DOI: 10.1002/(sici)1096-9861(19971124)388:3<454::aid-cne8>3.0.co;2-#] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Neonatal tectal lesions in hamsters result in the elimination of a major central target of retinal axons, massively denervate the lateral posterior nucleus of the thalamus (LP), and lead to a marked increase of the retino-LP projection. In such animals, retino-LP axons show all of the normally-occurring terminal types. In addition, large clusters of varicosities, whose tubular configuration resembles the major type of tecto-LP terminals observed in normal animals, are also noted if the tectal lesion is made on the day after birth (P1). If, however, the neonatal lesion occurs on P5 rather than on P1, terminals resembling normal tecto-LP endings are rarely observed; rather, the distribution and morphology of retino-LP terminals bear a greater resemblance to those seen in normal hamsters, but the size and complexity of the terminals, particularly those that form string-like arrangements, is significantly increased. Our findings suggest that the altered morphology of some abnormally induced retino-LP terminals may be orchestrated by target-associated signals. However, there are age-related limitations on the degree to which afferent systems can vary their terminal morphology; these restrictions may derive from the target, or may be a function of intrinsic changes within the cells of origin of the afferent fibers.
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Affiliation(s)
- C Ling
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139, USA
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44
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Mikkelsen JD, Hay-Schmidt A, Larsen PJ. Central innervation of the rat ependyma and subcommissural organ with special reference to ascending serotoninergic projections from the raphe nuclei. J Comp Neurol 1997. [DOI: 10.1002/(sici)1096-9861(19970811)384:4<556::aid-cne5>3.0.co;2-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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45
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Abstract
Local inhibitory synaptic inputs to neurons of the rat hypothalamic paraventricular nucleus (PVN) were studied by using glutamate microstimulation and conventional intracellular and whole-cell patch-clamp recording in coronal, horizontal, and parasagittal slices of rat hypothalamus. PVN cells were classified as magnocellular or parvocellular neurons on the basis of electrophysiological and post hoc immunohistochemical analyses; GABA-producing neurons were localized with in situ hybridization. Glutamate microstimulation of different sites around the PVN evoked volleys of postsynaptic potentials in 43% of the PVN neurons tested. Some responses to stimulation at each site were blocked by bicuculline, suggesting that they were mediated by the activation of presynaptic GABA neurons. In the coronal plane, presynaptic inhibitory sites were located lateral to the PVN and ventral to the fornix, corresponding to the lateral hypothalamic area and the posterior bed nucleus of the stria terminalis (BNST). In the horizontal plane, presynaptic inhibitory sites were found rostral, lateral, and caudal to the nucleus, corresponding to parts of the anterior hypothalamic area, the posterior BNST, the medial preoptic area, and the dorsomedial hypothalamus. In the parasagittal plane, presynaptic inhibitory neurons were revealed at sites rostral and caudal to the nucleus, corresponding to the medial preoptic area and the dorsomedial hypothalamus, and in a site dorsal to the optic chiasm that included the suprachiasmatic nucleus. These presynaptic sites each contained GABA-producing neurons based on in situ hybridization with a glutamic acid decarboxylase riboprobe and together formed a three-dimensional ring around the PVN. Unexpectedly, both magnocellular and parvocellular neurons received inhibitory synaptic inputs from common sites.
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46
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Cullinan WE, Helmreich DL, Watson SJ. Fos expression in forebrain afferents to the hypothalamic paraventricular nucleus following swim stress. J Comp Neurol 1996; 368:88-99. [PMID: 8725295 DOI: 10.1002/(sici)1096-9861(19960422)368:1<88::aid-cne6>3.0.co;2-g] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The paraventricular nucleus of the hypothalamus (PVN) serves as the origin of the final common pathway in the secretion of glucocorticoid hormones in response to stress. Various stress-related inputs converge upon the cells of the medial parvocellular division of the PVN. These neurons, which synthesize and release corticotropin-releasing hormone, arginine vasopressin, and other secretagogues, are responsible for a cascade of events which culminates in the adrenocorticotropin-induced release of corticosteroids from the adrenal cortex. Previous data have suggested complex afferent regulation of PVN neurons, although the neuronal pathways by which the effects of stress are mediated remain to be fully disclosed. The present experiment sought to identify forebrain areas potentially involved in afferent regulation of the PVN in response to an acute stressor. Discrete injections of the retrograde tracer Fluoro-gold were delivered to the PVN, and rats were subsequently subjected to an acute swim stress. Brains were processed immunocytochemically for the simultaneous detection of the tracer and Fos, the protein product of the immediate early gene c-fos, utilized as a marker for neuronal activation. The majority of Fluoro-gold/Fos labeled neurons were detected in the parastrial nucleus, the medial preoptic area, the anterior hypothalamic area, the dorsomedial hypothalamic nucleus and adjacent posterior hypothalamic area, and, to a lesser extent, the supramammillary nucleus. These findings are discussed in relation to neural pathways mediating activation and inhibition of the hypothalamic-pituitary-adrenocortical axis.
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Affiliation(s)
- W E Cullinan
- Mental Health Research Institute, University of Michigan, Ann Arbor 48109-0720, USA
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47
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Nieuwenhuys R. The greater limbic system, the emotional motor system and the brain. PROGRESS IN BRAIN RESEARCH 1996; 107:551-80. [PMID: 8782542 DOI: 10.1016/s0079-6123(08)61887-7] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- R Nieuwenhuys
- Department of Anatomy and Embryology, University of Nijmegen, The Netherlands
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48
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Abstract
The major afferent projections of the suprachiasmatic nuclei originate in the retina and the intergeniculate leaflet of the lateral geniculate nucleus and are important in the entrainment of endogenous circadian rhythms. A characteristic feature of the suprachiasmatic nucleus and the intergeniculate leaflet of the thalamus is that they are bilaterally innervated from the retina. However, parts of the olivary and posterior pretectal nuclei have been shown to be bilaterally innervated from the retina as well. We therefore aimed to explore whether these two nuclei, in the rat, were anatomically related to the suprachiasmatic nucleus. The anterograde neuronal tract-tracer, Phaseolus vulgaris-leucoagglutinin, was injected iontophoretically into different pretectal nuclei. Pretectal injections centered only in the medial part of the pretectum, i.e. involving the olivary and posterior pretectal nuclei, gave rise to a substantial bilateral innervation of the suprachiasmatic nucleus. From the site of injection, Phaseolus vulgaris-leucoagglutinin-immunoreactive nerve fibers coursed laterally and rostrally into the optic tract, and within the optic tract and chiasm, under the diencephalon to penetrate dorsally into the suprachiasmatic nucleus. Varicose Phaseolus vulgaris-leucoagglutinin-labeled nerve fibers were found exclusively in the ventrolateral part of the suprachiasmatic nucleus, mostly on the ipsilateral side. To determine the precise location of the projecting neurons, the retrograde tracer Cholera toxin, subunit B, was iontophoretically injected into the suprachiasmatic nucleus. The presence of of labeled neurons scattered in both the posterior and olivary pretectal nuclei was observed.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J D Mikkelsen
- Institute of Medical Anatomy B, University of Copenhagen, Denmark
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