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Stark R. The olfactory bulb: A neuroendocrine spotlight on feeding and metabolism. J Neuroendocrinol 2024; 36:e13382. [PMID: 38468186 DOI: 10.1111/jne.13382] [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: 11/23/2023] [Revised: 02/22/2024] [Accepted: 02/25/2024] [Indexed: 03/13/2024]
Abstract
Olfaction is the most ancient sense and is needed for food-seeking, danger protection, mating and survival. It is often the first sensory modality to perceive changes in the external environment, before sight, taste or sound. Odour molecules activate olfactory sensory neurons that reside on the olfactory epithelium in the nasal cavity, which transmits this odour-specific information to the olfactory bulb (OB), where it is relayed to higher brain regions involved in olfactory perception and behaviour. Besides odour processing, recent studies suggest that the OB extends its function into the regulation of food intake and energy balance. Furthermore, numerous hormone receptors associated with appetite and metabolism are expressed within the OB, suggesting a neuroendocrine role outside the hypothalamus. Olfactory cues are important to promote food preparatory behaviours and consumption, such as enhancing appetite and salivation. In addition, altered metabolism or energy state (fasting, satiety and overnutrition) can change olfactory processing and perception. Similarly, various animal models and human pathologies indicate a strong link between olfactory impairment and metabolic dysfunction. Therefore, understanding the nature of this reciprocal relationship is critical to understand how olfactory or metabolic disorders arise. This present review elaborates on the connection between olfaction, feeding behaviour and metabolism and will shed light on the neuroendocrine role of the OB as an interface between the external and internal environments. Elucidating the specific mechanisms by which olfactory signals are integrated and translated into metabolic responses holds promise for the development of targeted therapeutic strategies and interventions aimed at modulating appetite and promoting metabolic health.
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Affiliation(s)
- Romana Stark
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria, Australia
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Beltran-Casanueva R, Hernández-García A, Serrano-Castro PJ, Sánchez-Pérez JA, Barbancho-Fernández MA, García-Casares N, Fuxe K, Borroto-Escuela DO, Narváez M. Long-term enhancements in antidepressant efficacy and neurogenesis: Effects of intranasal co-administration of neuropeptide Y 1 receptor (NPY1R) and galanin receptor 2 (GALR2) agonists in the ventral hippocampus. FASEB J 2024; 38:e23595. [PMID: 38572811 DOI: 10.1096/fj.202400087r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 02/27/2024] [Accepted: 03/25/2024] [Indexed: 04/05/2024]
Abstract
This study evaluates the sustained antidepressant-like effects and neurogenic potential of a 3-day intranasal co-administration regimen of galanin receptor 2 (GALR2) agonist M1145 and neuropeptide Y Y1 receptor (NPY1R) agonist [Leu31, Pro34]NPY in the ventral hippocampus of adult rats, with outcomes analyzed 3 weeks post-treatment. Utilizing the forced swimming test (FST), we found that this co-administration significantly enhances antidepressant-like behaviors, an effect neutralized by the GALR2 antagonist M871, highlighting the synergistic potential of these neuropeptides in modulating mood-related behaviors. In situ proximity ligation assay (PLA) indicated a significant increase in GALR2/NPYY1R heteroreceptor complexes in the ventral hippocampal dentate gyrus, suggesting a molecular basis for the behavioral outcomes observed. Moreover, proliferating cell nuclear antigen (PCNA) immunolabeling revealed increased cell proliferation in the subgranular zone of the dentate gyrus, specifically in neuroblasts as evidenced by co-labeling with doublecortin (DCX), without affecting quiescent neural progenitors or astrocytes. The study also noted a significant uptick in the number of DCX-positive cells and alterations in dendritic morphology in the ventral hippocampus, indicative of enhanced neuronal differentiation and maturation. These morphological changes highlight the potential of these agonists to facilitate the functional integration of new neurons into existing neural circuits. By demonstrating the long-lasting effects of a brief, 3-day intranasal administration of GALR2 and NPY1R agonists, our findings contribute significantly to the understanding of neuropeptide-mediated neuroplasticity and herald novel therapeutic strategies for the treatment of depression and related mood disorders, emphasizing the therapeutic promise of targeting neurogenesis and neuronal maturation processes.
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Affiliation(s)
- Rasiel Beltran-Casanueva
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Edificio Lopez-Peñalver, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Aracelis Hernández-García
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Edificio Lopez-Peñalver, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Departamento de Docencia e Investigación, Universidad de Ciencias Médicas de Holguín, Hospital Pedíatrico Universitario Octavio de la Concepción de la Pedraja, Holguín, Cuba
| | - Pedro Jesús Serrano-Castro
- Instituto de Investigación Biomédica de Málaga, NeuronLab, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga, Unit of Neurology, Hospital Regional Universitario de Málaga, Málaga, Spain
- Vithas Málaga, Grupo Hospitalario Vithas, Málaga, Spain
| | - Jose Andrés Sánchez-Pérez
- Instituto de Investigación Biomédica de Málaga, NeuronLab, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga, Unit of Psychiatry, Hospital Universitario Virgen de la Victoria, Málaga, Spain
| | | | - Natalia García-Casares
- Instituto de Investigación Biomédica de Málaga, NeuronLab, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Dasiel O Borroto-Escuela
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Edificio Lopez-Peñalver, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Manuel Narváez
- Instituto de Investigación Biomédica de Málaga, NeuronLab, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga, Unit of Neurology, Hospital Regional Universitario de Málaga, Málaga, Spain
- Vithas Málaga, Grupo Hospitalario Vithas, Málaga, Spain
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Borroto-Escuela D, Serrano-Castro P, Sánchez-Pérez JA, Barbancho-Fernández MA, Fuxe K, Narváez M. Enhanced neuronal survival and BDNF elevation via long-term co-activation of galanin 2 (GALR2) and neuropeptide Y1 receptors (NPY1R): potential therapeutic targets for major depressive disorder. Expert Opin Ther Targets 2024; 28:295-308. [PMID: 38622072 DOI: 10.1080/14728222.2024.2342517] [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: 03/01/2024] [Accepted: 04/05/2024] [Indexed: 04/17/2024]
Abstract
BACKGROUND Major Depressive Disorder (MDD) is a prevalent and debilitating condition, necessitating novel therapeutic strategies due to the limited efficacy and adverse effects of current treatments. We explored how galanin receptor 2 (GALR2) and Neuropeptide Y1 Receptor (NPYY1R) agonists, working together, can boost brain cell growth and increase antidepressant-like effects in rats. This suggests new ways to treat Major Depressive Disorder (MDD). RESEARCH DESIGN AND METHODS In a controlled laboratory setting, adult naive Sprague-Dawley rats were administered directly into the brain's ventricles, a method known as intracerebroventricular (ICV) administration, with GALR2 agonist (M1145), NPYY1R agonist, both, or in combination with a GALR2 antagonist (M871). Main outcome measures included long-term neuronal survival, differentiation, and behavioral. RESULTS Co-administration of M1145 and NPYY1R agonist significantly enhanced neuronal survival and maturation in the ventral dentate gyrus, with a notable increase in Brain-Derived Neurotrophic Factor (BDNF) expression. This neurogenic effect was associated with an antidepressant-like effect, an outcome partially reversed by M871. CONCLUSIONS GALR2 and NPYY1R agonists jointly promote hippocampal neurogenesis and exert antidepressant-like effects in rats without adverse outcomes, highlighting their therapeutic potential for MDD. The study's reliance on an animal model and intracerebroventricular delivery warrants further clinical exploration to confirm these promising results.
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MESH Headings
- Animals
- Depressive Disorder, Major/drug therapy
- Depressive Disorder, Major/physiopathology
- Receptor, Galanin, Type 2/metabolism
- Rats, Sprague-Dawley
- Rats
- Brain-Derived Neurotrophic Factor/metabolism
- Male
- Receptors, Neuropeptide Y/metabolism
- Receptors, Neuropeptide Y/antagonists & inhibitors
- Neurons/drug effects
- Neurons/metabolism
- Cell Survival/drug effects
- Antidepressive Agents/pharmacology
- Antidepressive Agents/administration & dosage
- Disease Models, Animal
- Peptides
- Receptors, Neuropeptide
- Receptors, G-Protein-Coupled
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Affiliation(s)
- Dasiel Borroto-Escuela
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Edificio Lopez-Peñalver, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Pedro Serrano-Castro
- Instituto de Investigación Biomédica de Málaga, NeuronLab, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga, Unit of Neurology, Hospital Regional Universitario de Málaga, Málaga, Spain
- Vithas Málaga, Vithas Málaga, Grupo Hospitalario Vithas, Málaga, Spain
| | - Jose Andrés Sánchez-Pérez
- Instituto de Investigación Biomédica de Málaga, NeuronLab, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga, Unit of Psychiatry, Hospital Universitario Virgen de la Victoria, Málaga, Spain
| | | | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Manuel Narváez
- Instituto de Investigación Biomédica de Málaga, NeuronLab, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga, Unit of Neurology, Hospital Regional Universitario de Málaga, Málaga, Spain
- Vithas Málaga, Vithas Málaga, Grupo Hospitalario Vithas, Málaga, Spain
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Beltran-Casanueva R, Hernández-García A, de Amo García P, Blanco-Reina E, Serrano-Castro P, García-Casares N, Fuxe K, Borroto-Escuela DO, Narváez M. Neuropeptide Y receptor 1 and galanin receptor 2 (NPY1R-GALR2) interactions in the dentate gyrus and their relevance for neurogenesis and cognition. Front Cell Neurosci 2024; 18:1323986. [PMID: 38425430 PMCID: PMC10902914 DOI: 10.3389/fncel.2024.1323986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 01/24/2024] [Indexed: 03/02/2024] Open
Abstract
Introduction This study may unveil novel insights into the interactions between neuropeptide Y receptor 1 (NPY1R) and galanin receptor 2 (GALR2), in the dentate gyrus of the dorsal hippocampus, shedding light on their role in neurogenesis and cognitive functions. Existing literature highlights the potential of these interactions in enhancing learning and memory, yet detailed mechanisms remain underexplored. Methods Utilizing intracerebroventricular injections of GALR2 and NPY1R agonists in Sprague-Dawley male rats, we examined neurogenesis via markers PCNA and DCX, and memory consolidation through the object-in-place task over a three-week period. Results Significant increases in NPY1R-GALR2 co-localization and neuroblast proliferation were observed, alongside enhanced memory consolidation. These findings suggest a synergistic effect of NPY1R and GALR2 activation on cognitive functions. Discussion Our findings may foster the development of novel heterobivalent or multitargeting drugs, affecting NPY1R-GALR2 interaction, and suggest a future pharmacogical strategy for improving learning and memory found in many brain diseases. Further research is encouraged to explore these mechanisms in pathological models.
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Affiliation(s)
- Rasiel Beltran-Casanueva
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Facultad de Medicina, Edificio Lopez-Peñalver, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Spain
| | - Aracelis Hernández-García
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Facultad de Medicina, Edificio Lopez-Peñalver, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Spain
- Departamento de Docencia e Investigación, Universidad de Ciencias Médicas de Holguín, Hospital Pedíatrico Universitario Octavio de la Concepción de la Pedraja, Holguín, Cuba
| | - Paula de Amo García
- Facultad de Medicina, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Málaga, Spain
| | - Encarnación Blanco-Reina
- Facultad de Medicina, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Málaga, Spain
| | - Pedro Serrano-Castro
- Facultad de Medicina, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Málaga, Spain
- Grupo Hospitalario Vithas, Vithas Málaga, Málaga, Spain
- Unit of Neurology, Instituto de Investigación Biomédica de Málaga, Hospital Regional Universitario de Málaga, Málaga, Spain
| | - Natalia García-Casares
- Facultad de Medicina, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Málaga, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Dasiel O. Borroto-Escuela
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Facultad de Medicina, Edificio Lopez-Peñalver, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Spain
| | - Manuel Narváez
- Facultad de Medicina, Instituto de Investigación Biomédica de Málaga, Universidad de Málaga, Málaga, Spain
- Grupo Hospitalario Vithas, Vithas Málaga, Málaga, Spain
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Neuroanatomical characterization of the G protein-coupled receptor activity evoked by galanin-related ligands. J Chem Neuroanat 2023; 128:102226. [PMID: 36566994 DOI: 10.1016/j.jchemneu.2022.102226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/21/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022]
Abstract
Galanin neuropeptide is distributed throughout the mammalian nervous system modulating a plethora of diverse physiological functions, including nociception, cognition and neuroendocrine regulation. The regulation of the galaninergic system is an interesting approach for the treatment of different diseases associated to those systems. Nevertheless, the pharmacological selectivity and activities of some galanin receptor (GalR) ligands are still in discussion and seem to depend on the dose, the receptor subtype and the second messengers to which they are coupled at different brain areas. The activity of different GalR ligands on Gi/o proteins, was evaluated by the guanosine 5'-(γ-[35S]thio)triphosphate ([35S]GTPγS) autoradiography in vitro assay applied to rat brain tissue slices in the presence of galanin, M15, M35, M40, gal(2-11) or galnon. The enhancement of the [35S]GTPγS binding induced by the chimerical peptides M15, M35 and M40 was similar to that produced by Gal in those brain areas showing the highest stimulations, such as dorsal part of the olfactory nucleus and ventral subiculum. In contrast to these peptides, using gal(2-11) no effect was measured on Gi/o protein coupling in areas of the rat brain with high GalR1 density such as posterior hypothalamic nucleus and amygdala, indicating low selectivity for GalR1 receptors. The effects evoked by the non-peptide ligand, galnon, were different from those induced by galanin, behaving as agonist or antagonist depending on the brain area, but the stimulations were always blocked by M35. Thus, the activity of most used GalR ligands on Gi/o protein mediated signalling is complex and depends on the brain area. More selective and potent GalR ligands are necessary to develop new treatments aimed to modulate the galaninergic system.
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Díaz-Sánchez E, López-Salas A, Mirchandani-Duque M, Alvarez-Contino JE, Sánchez-Pérez JA, Fuxe K, Borroto-Escuela DO, García-Casares N, Narváez M. Decreased medial prefrontal cortex activity related to impaired novel object preference task performance following GALR2 and Y1R agonists intranasal infusion. Biomed Pharmacother 2023; 161:114433. [PMID: 36848750 DOI: 10.1016/j.biopha.2023.114433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/10/2023] [Accepted: 02/20/2023] [Indexed: 02/27/2023] Open
Abstract
Different brain regions' interactions have been implicated in relevant neurological diseases, such as major depressive disorder (MDD), anxiety disorders, age-dependent cognitive decline, Alzheimer's disease (AD) and addiction. We aim to explore the role of the medial prefrontal cortex (mPFC) in the Neuropeptide Y (NPY) and Galanin (GAL) interaction since we have demonstrated specific NPY and GAL interactions in brain areas related to these brain diseases. We performed GALR2 and Y1R agonists intranasal infusion and analyzed the mPFC activation through c-Fos expression. To assess the associated cellular mechanism we studied the formation of Y1R-GALR2 heteroreceptor complexes with in situ proximity ligation assay (PLA) and the expression of the brain-derived neurotrophic factor (BDNF). Moreover, the functional outcome of the NPY and GAL interaction on the mPFC was evaluated in the novel object preference task. We demonstrated that the intranasal administration of both agonists decrease the medial prefrontal cortex activation as shown with the c-Fos expression. These effects were mediated by the decreased formation of Y1R-GALR2 heteroreceptor complexes without affecting the BDNF expression. The functional outcome of this interaction was related to an impaired performance on the novel object preference task. Our data may suggest the translational development of new heterobivalent agonist pharmacophores acting on Y1R-GALR2 heterocomplexes in the medial prefrontal cortex for the novel therapy on neurodegenerative and psychiatric diseases. DATA SHARING AND DATA ACCESSIBILITY: The data that support the findings of this study are openly available in Institutional repository of the University of Malaga (RIUMA) and from the corresponding author upon reasonable request.
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Affiliation(s)
- Estela Díaz-Sánchez
- Laboratorio NeuronLab. Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Malaga 29071, Spain; Vithas Málaga. Grupo Hospitalario Vithas, Málaga, Spain.
| | - Alexander López-Salas
- Laboratorio NeuronLab. Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Malaga 29071, Spain.
| | - Marina Mirchandani-Duque
- Laboratorio NeuronLab. Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Malaga 29071, Spain.
| | - Jose Erik Alvarez-Contino
- Laboratorio NeuronLab. Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Malaga 29071, Spain.
| | - Jose Andrés Sánchez-Pérez
- Instituto de Investigación Biomédica de Málaga, Unit of Psychiatry, Hospital Universitario Virgen de la Victoria, Spain.
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institute, Stockholm 17177, Sweden.
| | - Dasiel O Borroto-Escuela
- Laboratorio NeuronLab. Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Malaga 29071, Spain; Department of Neuroscience, Karolinska Institute, Stockholm 17177, Sweden; Department of Biomolecular Science, Section of Physiology, University of Urbino, Urbino 61029, Italy.
| | - Natalia García-Casares
- Laboratorio NeuronLab. Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Malaga 29071, Spain.
| | - Manuel Narváez
- Laboratorio NeuronLab. Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Malaga 29071, Spain; Vithas Málaga. Grupo Hospitalario Vithas, Málaga, Spain; Department of Neuroscience, Karolinska Institute, Stockholm 17177, Sweden.
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Ganeyan A, Ganesh CB. Organization of the galaninergic neuronal system in the brain of the gecko Hemidactylus frenatus. Neuropeptides 2023; 97:102310. [PMID: 36459764 DOI: 10.1016/j.npep.2022.102310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/08/2022] [Accepted: 11/20/2022] [Indexed: 11/27/2022]
Abstract
Galanin (GAL) is a 29 amino acid peptide present in the central nervous system (CNS) as well as peripheral tissues in vertebrates. However, the brain distribution pattern of GAL is understudied in reptiles. The aim of this study was to determine the organization of galaninergic neuronal system in the brain of the gecko Hemidactylus frenatus, a tropical and sub-tropical lizard, using rabbit anti-galanin antibody. In the telencephalon, GAL-ir perikarya and fibres were found in the lateral septal nucleus, but only GAL-ir fibres were observed in the striatum, nucleus accumbens, anterior commissure, nucleus centralis amygdalae, dorsal and medial septal nuclei, nucleus of the diagonal band of Broca and in the optic chiasma. In the preoptic region, a cluster of GAL-ir cells and fibres was observed in the periventricular preoptic area and lateral preoptic area. GAL-ir perikarya and fibres were observed in hypothalamic areas such as the supraoptic nucleus, suprachiasmatic nucleus, paraventricular nucleus, periventricular nucleus of the hypothalamus, infundibular recess nucleus and in the median eminence, whereas GAL-ir fibres were present in the pars distalis of the pituitary gland. In the thalamus, GAL-ir fibres were observed in the dorsomedial, dorsolateral, and medial thalamic nuclei. GAL-ir fibres were also detected in mesencephalic areas such as the optic tectum, torus semicircularis, ventral tegmental area and substantia nigra, brain stem as well as the spinal cord. The organization of GAL-ir cells and fibres throughout the gecko brain suggests several neuroendocrine, neuromodulatory and behavioural functions for GAL in lizards. The study provides new insights into the evolutionarily conserved nature of GAL peptide in squamate reptiles and forms a valuable basis for future comparative studies.
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Affiliation(s)
- Ananya Ganeyan
- Neuroendocrinology Research Laboratory, Department of Studies in Zoology, Karnatak University, Dharwad 580 003, India
| | - C B Ganesh
- Neuroendocrinology Research Laboratory, Department of Studies in Zoology, Karnatak University, Dharwad 580 003, India.
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Sidorova MV, Palkeeva ME, Avdeev DV, Studneva IM, Serebryakova LI, Veselova OM, Dobrokhotov IV, Molokoedov AS, Pisarenko OI. Synthesis of the Antagonist of the GalR2 Galanin Receptor and Studies of Its Biological Activity in Ischemia and Reperfusion of the Rat Heart In Vivo. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2022. [DOI: 10.1134/s1068162022050223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Sánchez ML, Coveñas R. The Galaninergic System: A Target for Cancer Treatment. Cancers (Basel) 2022; 14:cancers14153755. [PMID: 35954419 PMCID: PMC9367524 DOI: 10.3390/cancers14153755] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 12/14/2022] Open
Abstract
Simple Summary Peptidergic systems play an important role in cancer progression. The galaninergic system (the peptide galanin and its receptors: galanin 1, 2 and 3) is involved in tumorigenesis, the invasion and migration of tumor cells and angiogenesis and it has been correlated with tumor stage/subtypes, metastasis and recurrence rate in many types of cancer. Galanin exerts a dual action in tumor cells: a proliferative or an antiproliferative effect depending on the galanin receptor involved in these mechanisms. Galanin receptors could be used in certain tumors as therapeutic targets and diagnostic markers for treatment, prognosis and surgical outcome. This review shows the importance of the galaninergic system in the development of tumors and suggests future promising clinical antitumor applications using galanin agonists or antagonists. Abstract The aim of this review is to show the involvement of the galaninergic system in neuroendocrine (phaeochromocytomas, insulinomas, neuroblastic tumors, pituitary tumors, small-cell lung cancer) and non-neuroendocrine (gastric cancer, colorectal cancer, head and neck squamous cell carcinoma, glioma) tumors. The galaninergic system is involved in tumorigenesis, invasion/migration of tumor cells and angiogenesis, and this system has been correlated with tumor size/stage/subtypes, metastasis and recurrence rate. In the galaninergic system, epigenetic mechanisms have been related with carcinogenesis and recurrence rate. Galanin (GAL) exerts both proliferative and antiproliferative actions in tumor cells. GAL receptors (GALRs) mediate different signal transduction pathways and actions, depending on the particular G protein involved and the tumor cell type. In general, the activation of GAL1R promoted an antiproliferative effect, whereas the activation of GAL2R induced antiproliferative or proliferative actions. GALRs could be used in certain tumors as therapeutic targets and diagnostic markers for treatment, prognosis and surgical outcome. The current data show the importance of the galaninergic system in the development of certain tumors and suggest future potential clinical antitumor applications using GAL agonists or antagonists.
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Affiliation(s)
- Manuel Lisardo Sánchez
- Laboratorio de Neuroanatomía de los Sistema Peptidérgicos (Lab. 14), Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, c/Pintor Fernando Gallego 1, 37007 Salamanca, Spain;
- Correspondence: ; Tel.: +34-923294400 (ext. 1856); Fax: +34-923294549
| | - Rafael Coveñas
- Laboratorio de Neuroanatomía de los Sistema Peptidérgicos (Lab. 14), Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, c/Pintor Fernando Gallego 1, 37007 Salamanca, Spain;
- Grupo GIR USAL: BMD (Bases Moleculares del Desarrollo), University of Salamanca, 37007 Salamanca, Spain
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A New Gal in Town: A Systematic Review of the Role of Galanin and Its Receptors in Experimental Pain. Cells 2022; 11:cells11050839. [PMID: 35269462 PMCID: PMC8909084 DOI: 10.3390/cells11050839] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 02/23/2022] [Accepted: 02/28/2022] [Indexed: 11/17/2022] Open
Abstract
Galanin is a neuropeptide expressed in a small percentage of sensory neurons of the dorsal root ganglia and the superficial lamina of the dorsal horn of the spinal cord. In this work, we systematically reviewed the literature regarding the role of galanin and its receptors in nociception at the spinal and supraspinal levels, as well as in chronic pain conditions. The literature search was performed in PubMed, Web of Science, Scopus, ScienceDirect, OVID, TRIP, and EMBASE using "Galanin" AND "pain" as keywords. Of the 1379 papers that were retrieved in the initial search, we included a total of 141 papers in this review. Using the ARRIVE guidelines, we verified that 89.1% of the works were of good or moderate quality. Galanin shows a differential role in pain, depending on the pain state, site of action, and concentration. Under normal settings, galanin can modulate nociceptive processing through both a pro- and anti-nociceptive action, in a dose-dependent manner. This peptide also plays a key role in chronic pain conditions and its antinociceptive action at both a spinal and supraspinal level is enhanced, reducing animals' hypersensitivity to both mechanical and thermal stimulation. Our results highlight galanin and its receptors as potential therapeutic targets in pain conditions.
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Foster SL, Galaj E, Karne SL, Ferré S, Weinshenker D. Cell-type specific expression and behavioral impact of galanin and GalR1 in the locus coeruleus during opioid withdrawal. Addict Biol 2021; 26:e13037. [PMID: 33768673 PMCID: PMC8376771 DOI: 10.1111/adb.13037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/15/2021] [Indexed: 12/14/2022]
Abstract
The neuropeptide galanin is reported to attenuate opioid withdrawal symptoms, potentially by reducing neuronal hyperactivity in the noradrenergic locus coeruleus (LC) via galanin receptor 1 (GalR1). We evaluated this mechanism by using RNAscope in situ hybridization to characterize GalR1 mRNA distribution in the dorsal pons and to compare galanin and GalR1 mRNA expression in tyrosine hydroxylase-positive (TH+) LC cells at baseline and following chronic morphine or precipitated withdrawal. We then used genetically altered mouse lines and pharmacology to test whether noradrenergic galanin (NE-Gal) modulates withdrawal symptoms. RNAscope revealed that, while GalR1 signal was evident in the dorsal pons, 80.7% of the signal was attributable to TH- neurons outside the LC. Galanin and TH mRNA were abundant in LC cells at baseline and were further increased by withdrawal, whereas low basal GalR1 mRNA expression was unaltered by chronic morphine or withdrawal. Naloxone-precipitated withdrawal symptoms in mice lacking NE-Gal (GalcKO-Dbh ) were largely similar to WT littermates, indicating that loss of NE-Gal does not exacerbate withdrawal. Complementary experiments using NE-Gal overexpressor mice (NE-Gal OX) and systemic administration of the galanin receptor agonist galnon revealed that increasing galanin signaling also failed to alter behavioral withdrawal, while suppressing noradrenergic transmission with the alpha-2 adrenergic receptor agonist clonidine attenuated multiple symptoms. These results indicate that galanin does not acutely attenuate precipitated opioid withdrawal via an LC-specific mechanism, which has important implications for the general role of galanin in regulation of somatic and affective opioid responses and LC activity.
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Affiliation(s)
- Stephanie L. Foster
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Ewa Galaj
- Addiction Biology Unit, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland, USA
| | - Saumya L. Karne
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Sergi Ferré
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - David Weinshenker
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA,Correspondence: David Weinshenker, PhD, Department of Human Genetics, 615 Michael St, Whitehead 301, Atlanta, GA 30322, , Fax: (404) 727-3949
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Shi H, Fang Y, Huang L, Gao L, Lenahan C, Okada T, Travis ZD, Xie S, Tang H, Lu Q, Liu R, Tang J, Cheng Y, Zhang JH. Activation of Galanin Receptor 1 with M617 Attenuates Neuronal Apoptosis via ERK/GSK-3β/TIP60 Pathway After Subarachnoid Hemorrhage in Rats. Neurotherapeutics 2021; 18:1905-1921. [PMID: 34086200 PMCID: PMC8609084 DOI: 10.1007/s13311-021-01066-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2021] [Indexed: 02/07/2023] Open
Abstract
Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular disease. Neuronal apoptosis plays an important pathological role in early brain injury after SAH. Galanin receptor 1 (GalR1) activation was recently shown to be anti-apoptotic in the setting of ischemic stroke. This study aimed to explore the anti-neuronal apoptosis effect of GalR1 activation after SAH, as well as the underlying mechanisms. GalR1 CRISPR and GalR1 selective agonist, M617, was administered, respectively. Extracellular-signal-regulated kinase (ERK) inhibitor (U0126) and glycogen synthase kinase 3-beta (GSK3-β) CRISPR were administered to investigate the involvement of the ERK/GSK3-β pathway in GalR1-mediated neuroprotection after SAH. Outcome assessments included neurobehavioral tests, western blot, and immunohistochemistry. The results showed that endogenous ligand galanin (Gal) and GalR1 were markedly increased in the ipsilateral brain hemisphere at 12 h and 24 h after SAH. GalR1 were expressed mainly in neurons, but expression was also observed in some astrocytes and microglia. GalR1 CRISPR knockdown exacerbated neurological deficits and neuronal apoptosis 24 h after SAH. Moreover, activation of GalR1 with M617 significantly improved short- and long-term neurological deficits but decreased neuronal apoptosis after SAH. Furthermore, GalR1 activation dysregulated the protein levels of phosphorylated ERK and GSK-3β, but downregulated the phosphorylated Tat-interactive protein 60 (TIP60) and cleaved caspase-3 at 24 h after SAH. GalR1 CRISPR, U0126, and GSK-3β CRISPR abolished the beneficial effects of GalR1 activation at 24 h after SAH in rats. Collectively, the present study demonstrated that activation of GalR1 using M617 attenuated neuronal apoptosis through the ERK/GSK-3β/TIP60 pathway after SAH in rats. GalR1 may serve as a promising therapeutic target for SAH patients.
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Affiliation(s)
- Hui Shi
- Department of Neurosurgery, Chongqing Medical University, Yongchuan Hospital, Yongchuan, Chongqing, China
| | - Yuanjian Fang
- Department of Neurosurgery, School of Medicine, The Second Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang, China
| | - Lei Huang
- Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Ling Gao
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Cameron Lenahan
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Takeshi Okada
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Zachary D Travis
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Shucai Xie
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Hong Tang
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Qin Lu
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Rui Liu
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Jiping Tang
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Yuan Cheng
- Department of Neurosurgery, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
| | - John H Zhang
- Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA.
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, USA.
- Department of Neurosurgery and Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA, USA.
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Involvement of Scratch2 in GalR1-mediated depression-like behaviors in the rat ventral periaqueductal gray. Proc Natl Acad Sci U S A 2021; 118:1922586118. [PMID: 34108238 DOI: 10.1073/pnas.1922586118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Galanin receptor1 (GalR1) transcript levels are elevated in the rat ventral periaqueductal gray (vPAG) after chronic mild stress (CMS) and are related to depression-like behavior. To explore the mechanisms underlying the elevated GalR1 expression, we carried out molecular biological experiments in vitro and in animal behavioral experiments in vivo. It was found that a restricted upstream region of the GalR1 gene, from -250 to -220, harbors an E-box and plays a negative role in the GalR1 promoter activity. The transcription factor Scratch2 bound to the E-box to down-regulate GalR1 promoter activity and lower expression levels of the GalR1 gene. The expression of Scratch2 was significantly decreased in the vPAG of CMS rats. Importantly, local knockdown of Scratch2 in the vPAG caused elevated expression of GalR1 in the same region, as well as depression-like behaviors. RNAscope analysis revealed that GalR1 mRNA is expressed together with Scratch2 in both GABA and glutamate neurons. Taking these data together, our study further supports the involvement of GalR1 in mood control and suggests a role for Scratch2 as a regulator of depression-like behavior by repressing the GalR1 gene in the vPAG.
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Ullrich D, Mac Gillavry DW. Mini-review: A possible role for galanin in post-traumatic stress disorder. Neurosci Lett 2021; 756:135980. [PMID: 34023414 DOI: 10.1016/j.neulet.2021.135980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 05/02/2021] [Accepted: 05/18/2021] [Indexed: 10/21/2022]
Abstract
Several neuroendocrine systems have been implicated in post-traumatic stress disorder, including the mesocortical and mesolimbic dopamine, the norepinephrine, the β-endorphin, the serotonin, and the oxytocin systems. The interaction between these different systems remains, however, largely unknown and a generally accepted unifying theory is thus far lacking. In this review, we suggest that galanergic suppression of dopaminergic neurons in the ventral tegmental may constitute the missing link in a post-traumatic feedback loop. In addition, we address the literature on the negative cross-antagonism in this brain region between the galanin 1 and μ-opioid receptors, which suggests that behavioural patterns which stimulate β-endorphin, a natural μ-opioid receptors ligand, secretion may provide novel avenues for the treatment and prevention of PTSD, as well as for recruitment, training, and leadership processes in high-stress/high-risk professions such as the military, first responders and the police.
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Affiliation(s)
- David Ullrich
- Department of Military Leadership, University of Defence, Brno, Czech Republic
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Borroto-Escuela DO, Pita-Rodriguez M, Fores-Pons R, Barbancho MA, Fuxe K, Narváez M. Galanin and neuropeptide Y interactions elicit antidepressant activity linked to neuronal precursor cells of the dentate gyrus in the ventral hippocampus. J Cell Physiol 2021; 236:3565-3578. [PMID: 33044017 DOI: 10.1002/jcp.30092] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 09/15/2020] [Accepted: 09/22/2020] [Indexed: 01/18/2023]
Abstract
A need for new antidepressants is necessary since traditional antidepressants have several flaws. Neuropeptide Y(NPY) Y1 receptor (NPYY1R) and galanin (GAL) receptor 2 (GALR2) interact in several regions of the limbic system, including the hippocampus. The current study assesses the antidepressant effects induced by GALR2 and NPYY1R coactivation, together with the evaluation of cell proliferation through 5-Bromo-2'-deoxyuridine expression within the dentate gyrus of the ventral hippocampus (vDG). We employed in situ proximity ligation assay to manifest GALR2/NPYY1R heteroreceptor complexes. Additionally, the expression pattern of GALR2 and the activation of the extracellular-regulated kinases (ERK) pathway after GALR2 and NPYY1R costimulation in cell cultures were examined. GALR2 and NPYY1R coactivation resulted in sustained antidepressant behaviors in the FST after 24 h, linked to increased cell proliferation in the vDG. Moreover, an increased density of GALR2/NPYY1R heteroreceptor complexes was observed in vDG, on doublecortin-expressing neuroblasts. Recruitment of the GALR2 expression to the plasma membrane was observed upon the coactivation of GALR2 and NPYY1R in cell cultures, presumably associated to the enhanced effects on the activation of ERK pathway. GALR2 may promote the GALR2/NPYY1R heteroreceptor complexes formation in the ventral hippocampus. It may induce a transformation of cell proliferation toward a neuronal lineage by enhancement of ERK pathway. Thus, it may give the mechanism for the antidepressant behavior observed. These results may provide the basis for the development of heterobivalent agonist pharmacophores, targeting GALR2/NPYY1R heteromers, especially in the neuronal precursor cells of the dentate gyrus in the ventral hippocampus for the novel treatment of depression.
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Affiliation(s)
- Dasiel O Borroto-Escuela
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
- Department of Biomolecular Science, Section of Physiology, University of Urbino, Urbino, Italy
- Grupo Bohío-Estudio, Observatorio Cubano de Neurociencias, Yaguajay, Cuba
| | - Mariana Pita-Rodriguez
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
- Departamento de Neurogenética, Instituto de Neurología y Neurocirugía, La Habana, Cuba
| | - Ramón Fores-Pons
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Miguel A Barbancho
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Manuel Narváez
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
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Patthy Á, Murai J, Hanics J, Pintér A, Zahola P, Hökfelt TGM, Harkany T, Alpár A. Neuropathology of the Brainstem to Mechanistically Understand and to Treat Alzheimer's Disease. J Clin Med 2021; 10:jcm10081555. [PMID: 33917176 PMCID: PMC8067882 DOI: 10.3390/jcm10081555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/01/2021] [Accepted: 04/05/2021] [Indexed: 12/18/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating neurodegenerative disorder as yet without effective therapy. Symptoms of this disorder typically reflect cortical malfunction with local neurohistopathology, which biased investigators to search for focal triggers and molecular mechanisms. Cortex, however, receives massive afferents from caudal brain structures, which do not only convey specific information but powerfully tune ensemble activity. Moreover, there is evidence that the start of AD is subcortical. The brainstem harbors monoamine systems, which establish a dense innervation in both allo- and neocortex. Monoaminergic synapses can co-release neuropeptides either by precisely terminating on cortical neurons or, when being “en passant”, can instigate local volume transmission. Especially due to its early damage, malfunction of the ascending monoaminergic system emerges as an early sign and possible trigger of AD. This review summarizes the involvement and cascaded impairment of brainstem monoaminergic neurons in AD and discusses cellular mechanisms that lead to their dysfunction. We highlight the significance and therapeutic challenges of transmitter co-release in ascending activating system, describe the role and changes of local connections and distant afferents of brainstem nuclei in AD, and summon the rapidly increasing diagnostic window during the last few years.
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Affiliation(s)
- Ágoston Patthy
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - János Murai
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - János Hanics
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
- SE NAP Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, H-1094 Budapest, Hungary
| | - Anna Pintér
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - Péter Zahola
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - Tomas G. M. Hökfelt
- Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, 17165 Stockholm, Sweden; (T.G.M.H.); (T.H.)
| | - Tibor Harkany
- Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, 17165 Stockholm, Sweden; (T.G.M.H.); (T.H.)
- Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, 1090 Vienna, Austria
| | - Alán Alpár
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
- SE NAP Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, H-1094 Budapest, Hungary
- Correspondence:
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Involvement of Neuropeptide Galanin Receptors 2 and 3 in Learning, Memory and Anxiety in Aging Mice. Molecules 2021; 26:molecules26071978. [PMID: 33915732 PMCID: PMC8037218 DOI: 10.3390/molecules26071978] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/22/2021] [Accepted: 03/24/2021] [Indexed: 01/19/2023] Open
Abstract
The neuropeptide galanin (GAL), which is expressed in limbic brain structures, has a strong impact on the regulation of mood and behavior. GAL exerts its effects via three G protein-coupled receptors (GAL1-3-R). Little is known about the effects of aging and loss of GAL-Rs on hippocampal-mediated processes connected to neurogenesis, such as learning, memory recall and anxiety, and cell proliferation and survival in the dorsal dentate gyrus (dDG) in mice. Our results demonstrate that loss of GAL3-R, but not GAL2-R, slowed learning and induced anxiety in older (12-14-month-old) mice. Lack of GAL2-R increased cell survival (BrdU incorporation) in the dDG of young mice. However, normal neurogenesis was observed in vitro using neural stem and precursor cells obtained from GAL2-R and GAL3-R knockouts upon GAL treatment. Interestingly, we found sub-strain differences between C57BL/6J and C57BL/6N mice, the latter showing faster learning, less anxiety and lower cell survival in the dDG. We conclude that GAL-R signaling is involved in cognitive functions and can modulate the survival of cells in the neurogenic niche, which might lead to new therapeutic applications. Furthermore, we observed that the mouse sub-strain had a profound impact on the behavioral parameters analyzed and should therefore be carefully considered in future studies.
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Zalecki M, Juranek J, Pidsudko Z, Mogielnicka-Brzozowska M, Kaleczyc J, Franke-Radowiecka A. Inferior vagal ganglion galaninergic response to gastric ulcers. PLoS One 2020; 15:e0242746. [PMID: 33227035 PMCID: PMC7682887 DOI: 10.1371/journal.pone.0242746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 11/06/2020] [Indexed: 01/17/2023] Open
Abstract
Galanin is a neuropeptide widely expressed in central and peripheral nerves and is known to be engaged in neuronal responses to pathological changes. Stomach ulcerations are one of the most common gastrointestinal disorders. Impaired stomach function in peptic ulcer disease suggests changes in autonomic nerve reflexes controlled by the inferior vagal ganglion, resulting in stomach dysfunction. In this paper, changes in the galaninergic response of inferior vagal neurons to gastric ulceration in a pig model of the disease were analyzed based on the authors' previous studies. The study was performed on 24 animals (12 control and 12 experimental). Gastric ulcers were induced by submucosal injections of 40% acetic acid solution into stomach submucosa and bilateral inferior vagal ganglia were collected one week afterwards. The number of galanin-immunoreactive perikarya in each ganglion was counted to determine fold-changes between both groups of animals and Q-PCR was applied to verify the changes in relative expression level of mRNA encoding both galanin and its receptor subtypes: GalR1, GalR2, GalR3. The results revealed a 2.72-fold increase in the number of galanin-immunoreactive perikarya compared with the controls. Q-PCR revealed that all studied genes were expressed in examined ganglia in both groups of animals. Statistical analysis revealed a 4.63-fold increase in galanin and a 1.45-fold increase in GalR3 mRNA as compared with the controls. No differences were observed between the groups for GalR1 or GalR2. The current study confirmed changes in the galaninergic inferior vagal ganglion response to stomach ulcerations and demonstrated, for the first time, the expression of mRNA encoding all galanin receptor subtypes in the porcine inferior vagal ganglia.
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Affiliation(s)
- Michal Zalecki
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
- * E-mail:
| | - Judyta Juranek
- Department of Human Physiology and Pathophysiology, School of Medicine, University of Warmia and Mazury, Olsztyn, Poland
| | - Zenon Pidsudko
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
| | - Marzena Mogielnicka-Brzozowska
- Department of Animal Biochemistry and Biotechnology, Faculty of Animal Bioengineering, University of Warmia and Mazury, Olsztyn, Poland
| | - Jerzy Kaleczyc
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
| | - Amelia Franke-Radowiecka
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
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Genders SG, Scheller KJ, Djouma E. Neuropeptide modulation of addiction: Focus on galanin. Neurosci Biobehav Rev 2020; 110:133-149. [DOI: 10.1016/j.neubiorev.2018.06.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/07/2018] [Accepted: 06/21/2018] [Indexed: 12/12/2022]
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Lyu C, Xia S, Lyu GW, Dun XP, Zheng K, Su J, Barde S, Xu ZQD, Hökfelt T, Shi TJS. A preliminary study on DRGs and spinal cord of a galanin receptor 2-EGFP transgenic mouse. Neuropeptides 2020; 79:102000. [PMID: 31864679 DOI: 10.1016/j.npep.2019.102000] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 12/12/2019] [Accepted: 12/12/2019] [Indexed: 01/31/2023]
Abstract
The neuropeptide galanin functions via three G-protein coupled receptors, Gal1-3-R. Both Gal1-R and 2-R are involved in pain signaling at the spinal level. Here a Gal2-R-EGFP transgenic (TG) mouse was generated and studied in pain tests and by characterizing Gal2-R expression in both sensory ganglia and spinal cord. After peripheral spared nerve injury, mechanical allodynia developed and was ipsilaterally similar between wild type (WT) and TG mice. A Gal2-R-EGFP-positive signal was primarily observed in small and medium-sized dorsal root ganglion (DRG) neurons and in spinal interneurons and processes. No significant difference in size distribution of DRG neuronal profiles was found between TG and WT mice. Both percentage and fluorescence intensity of Gal2-R-EGFP-positive neuronal profiles were overall significantly upregulated in ipsilateral DRGs as compared to contralateral DRGs. There was an ipsilateral reduction in substance P-positive and calcitonin gene-related peptide (CGRP)-positive neuronal profiles, and this reduction was more pronounced in TG as compared to WT mice. Moreover, Gal2-R-EGFP partly co-localized with three pain-related neuropeptides, CGRP, neuropeptide Y and galanin, both in intact and injured DRGs, and with galanin also in local neurons in the superficial dorsal horn. Taken together, the present results provide novel information on the localization and phenotype of DRG and spinal neurons expressing the second galanin receptor, Gal2-R, and on phenotypic changes following peripheral nerve injury. Gal2-R may also be involved in autoreceptor signaling.
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Affiliation(s)
- Chuang Lyu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150069, PR China.
| | - Sheng Xia
- Department of Neuroscience, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Gong-Wei Lyu
- Department of Neurology, 1st Hospital of Harbin Medical University, Harbin 150001, PR China
| | - Xin-Peng Dun
- Department of Neuroscience, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Kang Zheng
- Department of Neuroscience, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Jie Su
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Swapnali Barde
- Department of Neuroscience, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Zhi-Qing David Xu
- Department of Neuroscience, Karolinska Institutet, SE-171 77 Stockholm, Sweden; Department of Neurobiology, Capital Medical University, Beijing 100069, PR China
| | - Tomas Hökfelt
- Department of Neuroscience, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Tie-Jun Sten Shi
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway.
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Messanvi F, Perkins A, du Hoffmann J, Chudasama Y. Fronto-temporal galanin modulates impulse control. Psychopharmacology (Berl) 2020; 237:291-303. [PMID: 31705163 PMCID: PMC7024046 DOI: 10.1007/s00213-019-05365-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/12/2019] [Indexed: 12/11/2022]
Abstract
RATIONALE The neuropeptide galanin has been implicated in a wide range of pathological conditions in which frontal and temporal structures are compromised. It works through three subtypes of G-protein-coupled receptors. One of these, the galanin receptor 1 (Gal-R1) subtype, is densely expressed in the ventral hippocampus (vHC) and ventral prefrontal cortex (vPFC); two brain structures that have similar actions on behavioral control. We hypothesize that Gal-R1 contributes to cognitive-control mechanisms that require hippocampal-prefrontal cortical circuitry. OBJECTIVE To examine the effect of local vHC and vPFC infusions of M617, a Gal-R1 agonist, on inhibitory mechanisms of response control. METHODS Different cohorts of rats were implanted with bilateral guide cannulae targeting the vPFC or the vHC. Following infusion of the Gal-R1 agonist, we examined the animals' behavior using a touchscreen version of the 5-choice reaction time task (5-choice task). RESULTS The Gal-R1 agonist produced opposing behaviors in the vPFC and vHC, leading to disruption of impulse control when infused in the vPFC but high impulse control when infused into the vHC. This contrast between areas was accentuated when we added variability to the timing of the stimulus, which led to long decision times and reduced accuracy in the vPFC group but a general improvement in performance accuracy in the vHC group. CONCLUSIONS These results provide the first evidence of a selective mechanism of Gal-R1-mediated modulation of impulse control in prefrontal-hippocampal circuitry.
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Affiliation(s)
- F Messanvi
- Section on Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD, USA.
| | - A Perkins
- Section on Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD, USA
| | - J du Hoffmann
- Rodent Behavioral Core, National Institute of Mental Health, Bethesda, MD, USA
| | - Y Chudasama
- Section on Behavioral Neuroscience, National Institute of Mental Health, Bethesda, MD, USA
- Rodent Behavioral Core, National Institute of Mental Health, Bethesda, MD, USA
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Hooversmith JM, Bhatti DL, Holmes PV. Galanin administration into the prelimbic cortex impairs consolidation and expression of contextual fear conditioning. Behav Brain Res 2019; 375:112160. [DOI: 10.1016/j.bbr.2019.112160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 08/12/2019] [Accepted: 08/17/2019] [Indexed: 12/11/2022]
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Cellular Mechanisms for Antinociception Produced by Oxytocin and Orexins in the Rat Spinal Lamina II-Comparison with Those of Other Endogenous Pain Modulators. Pharmaceuticals (Basel) 2019; 12:ph12030136. [PMID: 31527474 PMCID: PMC6789548 DOI: 10.3390/ph12030136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 08/31/2019] [Accepted: 09/12/2019] [Indexed: 01/23/2023] Open
Abstract
Much evidence indicates that hypothalamus-derived neuropeptides, oxytocin, orexins A and B, inhibit nociceptive transmission in the rat spinal dorsal horn. In order to unveil cellular mechanisms for this antinociception, the effects of the neuropeptides on synaptic transmission were examined in spinal lamina II neurons that play a crucial role in antinociception produced by various analgesics by using the whole-cell patch-clamp technique and adult rat spinal cord slices. Oxytocin had no effect on glutamatergic excitatory transmission while producing a membrane depolarization, γ-aminobutyric acid (GABA)-ergic and glycinergic spontaneous inhibitory transmission enhancement. On the other hand, orexins A and B produced a membrane depolarization and/or a presynaptic spontaneous excitatory transmission enhancement. Like oxytocin, orexin A enhanced both GABAergic and glycinergic transmission, whereas orexin B facilitated glycinergic but not GABAergic transmission. These inhibitory transmission enhancements were due to action potential production. Oxytocin, orexins A and B activities were mediated by oxytocin, orexin-1 and orexin-2 receptors, respectively. This review article will mention cellular mechanisms for antinociception produced by oxytocin, orexins A and B, and discuss similarity and difference in antinociceptive mechanisms among the hypothalamic neuropeptides and other endogenous pain modulators (opioids, nociceptin, adenosine, adenosine 5’-triphosphate (ATP), noradrenaline, serotonin, dopamine, somatostatin, cannabinoids, galanin, substance P, bradykinin, neuropeptide Y and acetylcholine) exhibiting a change in membrane potential, excitatory or inhibitory transmission in the spinal lamina II neurons.
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Galanin Protects Rat Cortical Astrocyte from Oxidative Stress: Involvement of GalR2 and pERK1/2 Signal Pathway. Mediators Inflamm 2019; 2019:2716028. [PMID: 31249471 PMCID: PMC6556323 DOI: 10.1155/2019/2716028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 04/16/2019] [Indexed: 01/22/2023] Open
Abstract
The neuropeptide galanin and its receptors have been found to have protective effects on neurons. However, the role of galanin on astrocytes is still unclear. The present study is aimed at investigating the effects of galanin on the viability of cultured rat cortical astrocytes after oxidative stress induced by H2O2 and possible receptor and signaling mechanisms involved. Treatment of galanin had significant protective effects against H2O2-induced toxicity in the cultured cortical astrocytes. H2O2 induced an upregulation of phosphorylated extracellular signal-related kinase1/2 (pERK1/2) in astrocytes, which was suppressed by coapplication of galanin, suggesting an involvement of the pERK1/2 signal pathway in the protective effects of galanin. GalR2 has higher expression levels than GalR1 and GalR3 in the cultured cortical astrocytes, and GalR2 agonist AR-M1896 mimicked galanin effects on the astrocytes, implying that galanin protective effects mainly mediated by GalR2. Meanwhile, galanin had no effect on the A1-type transformation of rat cortical astrocytes. All those results suggest that galanin protects rat cortical astrocytes from oxidative stress by suppressing H2O2-induced upregulation of pERK1/2, mainly through GalR2.
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Hökfelt T, Barde S, Xu ZQD, Kuteeva E, Rüegg J, Le Maitre E, Risling M, Kehr J, Ihnatko R, Theodorsson E, Palkovits M, Deakin W, Bagdy G, Juhasz G, Prud’homme HJ, Mechawar N, Diaz-Heijtz R, Ögren SO. Neuropeptide and Small Transmitter Coexistence: Fundamental Studies and Relevance to Mental Illness. Front Neural Circuits 2018; 12:106. [PMID: 30627087 PMCID: PMC6309708 DOI: 10.3389/fncir.2018.00106] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 11/05/2018] [Indexed: 12/31/2022] Open
Abstract
Neuropeptides are auxiliary messenger molecules that always co-exist in nerve cells with one or more small molecule (classic) neurotransmitters. Neuropeptides act both as transmitters and trophic factors, and play a role particularly when the nervous system is challenged, as by injury, pain or stress. Here neuropeptides and coexistence in mammals are reviewed, but with special focus on the 29/30 amino acid galanin and its three receptors GalR1, -R2 and -R3. In particular, galanin's role as a co-transmitter in both rodent and human noradrenergic locus coeruleus (LC) neurons is addressed. Extensive experimental animal data strongly suggest a role for the galanin system in depression-like behavior. The translational potential of these results was tested by studying the galanin system in postmortem human brains, first in normal brains, and then in a comparison of five regions of brains obtained from depressed people who committed suicide, and from matched controls. The distribution of galanin and the four galanin system transcripts in the normal human brain was determined, and selective and parallel changes in levels of transcripts and DNA methylation for galanin and its three receptors were assessed in depressed patients who committed suicide: upregulation of transcripts, e.g., for galanin and GalR3 in LC, paralleled by a decrease in DNA methylation, suggesting involvement of epigenetic mechanisms. It is hypothesized that, when exposed to severe stress, the noradrenergic LC neurons fire in bursts and release galanin from their soma/dendrites. Galanin then acts on somato-dendritic, inhibitory galanin autoreceptors, opening potassium channels and inhibiting firing. The purpose of these autoreceptors is to act as a 'brake' to prevent overexcitation, a brake that is also part of resilience to stress that protects against depression. Depression then arises when the inhibition is too strong and long lasting - a maladaption, allostatic load, leading to depletion of NA levels in the forebrain. It is suggested that disinhibition by a galanin antagonist may have antidepressant activity by restoring forebrain NA levels. A role of galanin in depression is also supported by a recent candidate gene study, showing that variants in genes for galanin and its three receptors confer increased risk of depression and anxiety in people who experienced childhood adversity or recent negative life events. In summary, galanin, a neuropeptide coexisting in LC neurons, may participate in the mechanism underlying resilience against a serious and common disorder, MDD. Existing and further results may lead to an increased understanding of how this illness develops, which in turn could provide a basis for its treatment.
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Affiliation(s)
- Tomas Hökfelt
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Swapnali Barde
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Zhi-Qing David Xu
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Eugenia Kuteeva
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Joelle Rüegg
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- The Center for Molecular Medicine, Stockholm, Sweden
- Swedish Toxicology Sciences Research Center, Swetox, Södertälje, Sweden
| | - Erwan Le Maitre
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Mårten Risling
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Jan Kehr
- Pronexus Analytical AB, Solna, Sweden
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Robert Ihnatko
- Department of Clinical Chemistry, Linköping University, Linköping, Sweden
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Elvar Theodorsson
- Department of Clinical Chemistry, Linköping University, Linköping, Sweden
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Miklos Palkovits
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - William Deakin
- Neuroscience and Psychiatry Unit, University of Manchester, Manchester, United Kingdom
| | - Gyorgy Bagdy
- Department of Pharmacodynamics, Semmelweis University, Budapest, Hungary
- MTA-SE Neuropsychopharmacology and Neurochemistry Research Group, Hungarian Academy of Sciences, Semmelweis University, Budapest, Hungary
- NAP 2-SE New Antidepressant Target Research Group, Hungarian Brain Research Program, Semmelweis University, Budapest, Hungary
| | - Gabriella Juhasz
- Neuroscience and Psychiatry Unit, University of Manchester, Manchester, United Kingdom
- Department of Pharmacodynamics, Semmelweis University, Budapest, Hungary
- SE-NAP2 Genetic Brain Imaging Migraine Research Group, Hungarian Brain Research Program, Semmelweis University, Budapest, Hungary
| | | | - Naguib Mechawar
- Douglas Hospital Research Centre, Verdun, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | | | - Sven Ove Ögren
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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Activation of galanin receptor 1 inhibits locus coeruleus neurons via GIRK channels. Biochem Biophys Res Commun 2018; 503:79-85. [DOI: 10.1016/j.bbrc.2018.05.181] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 05/26/2018] [Indexed: 01/15/2023]
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Héricé C, Patel AA, Sakata S. Circuit mechanisms and computational models of REM sleep. Neurosci Res 2018; 140:77-92. [PMID: 30118737 PMCID: PMC6403104 DOI: 10.1016/j.neures.2018.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 07/03/2018] [Accepted: 07/10/2018] [Indexed: 01/31/2023]
Abstract
REM sleep was discovered in the 1950s. Many hypothalamic and brainstem areas have been found to contribute to REM sleep. An up-to-date picture of REM-sleep-regulating circuits is reviewed. A brief overview of computational models for REM sleep regulation is provided. Outstanding issues for future studies are discussed.
Rapid eye movement (REM) sleep or paradoxical sleep is an elusive behavioral state. Since its discovery in the 1950s, our knowledge of the neuroanatomy, neurotransmitters and neuropeptides underlying REM sleep regulation has continually evolved in parallel with the development of novel technologies. Although the pons was initially discovered to be responsible for REM sleep, it has since been revealed that many components in the hypothalamus, midbrain, pons, and medulla also contribute to REM sleep. In this review, we first provide an up-to-date overview of REM sleep-regulating circuits in the brainstem and hypothalamus by summarizing experimental evidence from neuroanatomical, neurophysiological and gain- and loss-of-function studies. Second, because quantitative approaches are essential for understanding the complexity of REM sleep-regulating circuits and because mathematical models have provided valuable insights into the dynamics underlying REM sleep genesis and maintenance, we summarize computational studies of the sleep-wake cycle, with an emphasis on REM sleep regulation. Finally, we discuss outstanding issues for future studies.
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Affiliation(s)
- Charlotte Héricé
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Amisha A Patel
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Shuzo Sakata
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK.
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The Expression of Galanin in the Parafacial Respiratory Group and its Effects on Respiration in Neonatal Rats. Neuroscience 2018; 384:1-13. [PMID: 29772344 DOI: 10.1016/j.neuroscience.2018.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 05/02/2018] [Accepted: 05/04/2018] [Indexed: 11/23/2022]
Abstract
The inhibitory peptide galanin is expressed within the retrotrapezoidal nucleus (RTN) - a key central chemoreceptor site that also contains the active expiratory oscillator. It was previously reported that microinjection of galanin into pre-Bötzinger complex - containing the inspiratory oscillator - exerts inhibitory effects on inspiratory motor output and respiratory rhythm. In neonatal rats, the present study aimed to investigate: (1) expression of galanin within the parafacial respiratory group (pFRG), which overlaps anatomically and functionally with the adult RTN, and; (2) effects of galanin on respiratory rhythm using the in vitro brainstem-spinal cord preparation. We showed that 14 ± 2% of Phox2b-immunoreactive (ir) neurons in the parafacial region were also galanin-ir. Galanin peptide expression was confirmed within 3/9 CO2-sensitive, Phox2b-ir Pre-Inspiratory neurons (Pre-I) recorded in parafacial region. Bath application of galanin (0.1-0.2 µM): (1) decreased the duration of membrane depolarization in both Pre-I and inspiratory pFRG neurons, and; (2) decreased the number of C4 bursts that were associated with each burst in Pre-I neurons within the pFRG. In preparations showing episodic breathing at baseline, the respiratory patterning reverted to the 'normal' pattern of single, uniformly rhythmic C4 bursts (n = 10). In preparations with normal respiratory patterning at baseline, slowing of C4 rhythm (n = 7) resulted although rhythmic bursting in recorded Pre-I neurons remained unperturbed (n = 6). This study therefore demonstrates that galanin is expressed within the pFRG of neonatal rats, including neurons that are intrinsically chemosensitive. Overall the peptide has an inhibitory effect on inspiratory motor output, as previously shown in adults.
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Merighi A. The histology, physiology, neurochemistry and circuitry of the substantia gelatinosa Rolandi (lamina II) in mammalian spinal cord. Prog Neurobiol 2018; 169:91-134. [PMID: 29981393 DOI: 10.1016/j.pneurobio.2018.06.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 06/07/2018] [Accepted: 06/30/2018] [Indexed: 02/06/2023]
Abstract
The substantia gelatinosa Rolandi (SGR) was first described about two centuries ago. In the following decades an enormous amount of information has permitted us to understand - at least in part - its role in the initial processing of pain and itch. Here, I will first provide a comprehensive picture of the histology, physiology, and neurochemistry of the normal SGR. Then, I will analytically discuss the SGR circuits that have been directly demonstrated or deductively envisaged in the course of the intensive research on this area of the spinal cord, with particular emphasis on the pathways connecting the primary afferent fibers and the intrinsic neurons. The perspective existence of neurochemically-defined sets of primary afferent neurons giving rise to these circuits will be also discussed, with the proposition that a cross-talk between different subsets of peptidergic fibers may be the structural and functional substrate of additional gating mechanisms in SGR. Finally, I highlight the role played by slow acting high molecular weight modulators in these gating mechanisms.
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Affiliation(s)
- Adalberto Merighi
- Department of Veterinary Sciences, University of Turin, Largo Paolo Braccini 2, I-10095 Grugliasco (TO), Italy.
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de Souza MM, Silote GP, Herbst LS, Funck VR, Joca SRL, Beijamini V. The antidepressant-like effect of galanin in the dorsal raphe nucleus of rats involves GAL 2 receptors. Neurosci Lett 2018; 681:26-30. [PMID: 29787787 DOI: 10.1016/j.neulet.2018.05.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/18/2018] [Indexed: 01/27/2023]
Abstract
Galanin is a neuropeptide distributed in human and rat brain regions that are involved with emotional regulation, such as the dorsal raphe nucleus (DRN). Galanin effects in the DRN are mediated by GAL1 and GAL2 receptors. Intracerebral infusion of a GAL2 (AR-M1896) or a GAL1 (M617) agonist induced either antidepressant or depressive-like effect, respectively, in rats exposed to the forced swimming test (FST). However, it is not clear if GAL1 and/or GAL2 receptors present in the DRN would be involved in such effects. Therefore, we investigated the effects induced by intra-DRN infusion of galanin (0.3 nmol), AR-M1896 (1 nmol, GAL2 agonist), or M617 (GAL1 agonist) in rats exposed to the FST. Galanin and AR-M1896 intra-DRN administration induced antidepressant-like effect in the FST. However, M617 did not induce any change in the FST. Neither M617 nor AR-M1896 changed the locomotor activity of rats in the open field test. Intra-DRN pre-treatment with M871 (1 nmol), a selective GAL2 antagonist, counteracted the antidepressant-like effect induced by galanin. These results suggest that galanin signaling through GAL2 receptors in the DRN produces triggers antidepressant-like effect.
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Affiliation(s)
- Mayara Machado de Souza
- Department of Pharmaceutical Sciences, Health Science Centre, Federal University of Espirito Santo, Vitoria, ES, 29043-900, Brazil
| | - Gabriela Pandini Silote
- Department of Physics and Chemistry, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil; Biochemistry and Pharmacology Postgraduate Program, Health Science Center, Federal University of Espirito Santo, Vitoria, ES, 29043-900, Brazil
| | - Leticia Santos Herbst
- Department of Pharmaceutical Sciences, Health Science Centre, Federal University of Espirito Santo, Vitoria, ES, 29043-900, Brazil
| | - Vinicius Rafael Funck
- Biochemistry and Pharmacology Postgraduate Program, Health Science Center, Federal University of Espirito Santo, Vitoria, ES, 29043-900, Brazil
| | - Samia Regiane Lourenço Joca
- Department of Physics and Chemistry, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil; Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark
| | - Vanessa Beijamini
- Department of Pharmaceutical Sciences, Health Science Centre, Federal University of Espirito Santo, Vitoria, ES, 29043-900, Brazil.
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Funck V, Fracalossi M, Vidigal A, Beijamini V. Dorsal hippocampal galanin modulates anxiety-like behaviours in rats. Brain Res 2018; 1687:74-81. [DOI: 10.1016/j.brainres.2018.02.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 02/08/2018] [Accepted: 02/22/2018] [Indexed: 01/22/2023]
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Li H, Wang T, Shi C, Yang Y, Li X, Wu Y, Xu ZQD. Inhibition of GALR1 in PFC Alleviates Depressive-Like Behaviors in Postpartum Depression Rat Model by Upregulating CREB-BNDF and 5-HT Levels. Front Psychiatry 2018; 9:588. [PMID: 30487761 PMCID: PMC6246688 DOI: 10.3389/fpsyt.2018.00588] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/25/2018] [Indexed: 01/12/2023] Open
Abstract
Estrogen (E2) withdrawal is a core pathology mechanism for postpartum depression (PPD). Galanin (GAL), an estrogen-inducible neuropeptide has also been reported to be associated with depression. However, it still remains unclear which GAL receptors (GALRs) are involved in PPD pathologic process. In the present study, we discovered that the expression of GALR1, rather than GALR2/3, was upregulated with a region-specific pattern in the prefrontal cortex (PFC) of E2 withdrawal induced PPD model rats. Meanwhile, c-fos was also upregulated only in PFC in the same animal model. Injection of GALR1-siRNA into the bilateral PFC ameliorated depressive-like behavior of PPD rats, suggesting that the upregulation of GALR1 in PFC is involved in PPD. Moreover, Western Blot and HPLC assays demonstrated that the downregulation of CREB-BDNF signaling and 5-HT levels in the PFC of PPD rats were reversed after GALR1-siRNA injection. These comprehensive results suggest that the knock down of GALR1 in PFC alleviates depressive-like behaviors and reverse downregulation of CREB-BDNF and 5-HT levels in PPD rat model. HIGHLIGHTS Expression level of GALR1 mRNA was significantly increased in PFC of estrogen withdraw-induced PPD rats. Injecting GALR1-siRNA into PFC alleviated depressive-like behavior and reversed the decrease of 5-HT level and CREB/BDNF signaling in PFC of PPD rats.
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Affiliation(s)
- Hui Li
- Department of Anatomy, Capital Medical University, Beijing, China
| | - Tong Wang
- Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Department of Neurobiology, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Cuige Shi
- Department of Cell Biology, National Research Institute of Family Planning, Beijing, China
| | - Yutao Yang
- Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Department of Neurobiology, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Xiaoxiao Li
- Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Department of Neurobiology, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Yan Wu
- Department of Anatomy, Capital Medical University, Beijing, China
| | - Zhi-Qing David Xu
- Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Department of Neurobiology, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
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Millón C, Flores-Burgess A, Narváez M, Borroto-Escuela DO, Gago B, Santín L, Castilla-Ortega E, Narváez JÁ, Fuxe K, Díaz-Cabiale Z. The neuropeptides Galanin and Galanin(1-15) in depression-like behaviours. Neuropeptides 2017; 64:39-45. [PMID: 28196617 DOI: 10.1016/j.npep.2017.01.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 01/24/2017] [Accepted: 01/24/2017] [Indexed: 12/11/2022]
Abstract
Galanin is a 29 amino acid neuropeptide widely distributed in neurons within the central nervous system. Galanin exerts its biological activities through three different G protein-receptors and participates in a number of functions, including mood regulation. Not only Galanin but also Galanin N-terminal fragments like Galanin(1-15) are active at the central level. In this work, we review the latest findings in studies on Galanin and Galanin(1-15) in depression-related behaviours. Our focus is on animal models for depression, and we pay some attention to research data obtained in human studies. Since Serotonin (5-HT), especially through 5-HT1A, and Galanin receptors interact at both pre-and postsynaptic level, the development of drugs targeting potential GAL1-GAL2-5-HT1A heteroreceptor complexes linked to the raphe-hippocampal 5-HT neurons may represent new treatment strategies in depression.
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Affiliation(s)
- Carmelo Millón
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain.
| | - Antonio Flores-Burgess
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Manuel Narváez
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | | | - Belén Gago
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Luis Santín
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Psicología, Departamento de Psicobiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Estela Castilla-Ortega
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Psicología, Departamento de Psicobiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - José Ángel Narváez
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Zaida Díaz-Cabiale
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Departamento de Fisiología, Campus de Teatinos s/n, 29071 Málaga, Spain
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Metcalf CS, Klein BD, McDougle DR, Zhang L, Kaufmann D, Bulaj G, White HS. Preclinical evaluation of intravenous NAX 810-2, a novel GalR2-preferring analog, for anticonvulsant efficacy and pharmacokinetics. Epilepsia 2017; 58:239-246. [PMID: 28098336 DOI: 10.1111/epi.13647] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2016] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Potential clinical utility of galanin or peptidic analogs has been hindered by poor metabolic stability, lack of brain penetration, and hyperglycemia due to galanin receptor subtype 1 (GalR1) activation. NAX 810-2, a galanin receptor subtype 2 (GalR2)-preferring galanin analog, possesses 15-fold greater affinity for GalR2 over GalR1 and protects against seizures in the mouse 6 Hz, corneal kindling, and Frings audiogenic seizure models. The purpose of these studies was to further evaluate the preclinical efficacy and pharmacokinetics of NAX 810-2 in mice. METHODS NAX 810-2 was administered by intravenous (i.v.; tail vein, bolus) injection to fully kindled (corneal kindling assay) or naive CF-1 mice (6 Hz assay and pharmacokinetic studies). Plasma NAX 810-2 levels were determined from trunk blood samples. NAX 810-2 was also added to human plasma at various concentrations for determination of plasma protein binding. RESULTS In the mouse corneal kindling model, NAX 810-2 dose-dependently blocked seizures following intravenous administration (median effective dose [ED50 ], 0.5 mg/kg). In the mouse 6 Hz (32 mA) seizure model, it was demonstrated that NAX 810-2 dose-dependently blocked seizures following bolus administration (0.375-1.5 mg/kg, i.v.; ED50 , 0.7 mg/kg), with a time-to-peak effect of 0.5 h posttreatment. Motor impairment was observed at 1.5 mg/kg, i.v., whereas one-half of this dose, 0.75 mg/kg, i.v., was maximally effective in the 6 Hz test. Plasma levels of NAX 810-2 show linear pharmacokinetics following intravenous administration and a half-life of 1.2 h. Functional agonist activity studies demonstrate that NAX 810-2 effectively activates GalR2 at therapeutic concentrations. SIGNIFICANCE These studies further suggest the potential utility of NAX 810-2 as a novel therapy for epilepsy.
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Affiliation(s)
- Cameron S Metcalf
- Department of Pharmacology & Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, U.S.A.,NeuroAdjuvants, Inc., Salt Lake City, Utah, U.S.A
| | - Brian D Klein
- Department of Pharmacology & Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, U.S.A.,NeuroAdjuvants, Inc., Salt Lake City, Utah, U.S.A
| | | | - Liuyin Zhang
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah, U.S.A
| | - Dan Kaufmann
- Department of Neurology, University of Utah Health Sciences Center, Salt Lake City, Utah, U.S.A
| | - Grzegorz Bulaj
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah, U.S.A
| | - H Steve White
- Department of Pharmacology & Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, U.S.A.,Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, U.S.A
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Alterations in the neuropeptide galanin system in major depressive disorder involve levels of transcripts, methylation, and peptide. Proc Natl Acad Sci U S A 2016; 113:E8472-E8481. [PMID: 27940914 DOI: 10.1073/pnas.1617824113] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Major depressive disorder (MDD) is a substantial burden to patients, families, and society, but many patients cannot be treated adequately. Rodent experiments suggest that the neuropeptide galanin (GAL) and its three G protein-coupled receptors, GAL1-3, are involved in mood regulation. To explore the translational potential of these results, we assessed the transcript levels (by quantitative PCR), DNA methylation status (by bisulfite pyrosequencing), and GAL peptide by RIA of the GAL system in postmortem brains from depressed persons who had committed suicide and controls. Transcripts for all four members were detected and showed marked regional variations, GAL and galanin receptor 1 (GALR1) being most abundant. Striking increases in GAL and GALR3 mRNA levels, especially in the noradrenergic locus coeruleus and the dorsal raphe nucleus, in parallel with decreased DNA methylation, were found in both male and female suicide subjects as compared with controls. In contrast, GAL and GALR3 transcript levels were decreased, GALR1 was increased, and DNA methylation was increased in the dorsolateral prefrontal cortex of male suicide subjects, however, there were no changes in the anterior cingulate cortex. Thus, GAL and its receptor GALR3 are differentially methylated and expressed in brains of MDD subjects in a region- and sex-specific manner. Such an epigenetic modification in GALR3, a hyperpolarizing receptor, might contribute to the dysregulation of noradrenergic and serotonergic neurons implicated in the pathogenesis of MDD. Thus, one may speculate that a GAL3 antagonist could have antidepressant properties by disinhibiting the firing of these neurons, resulting in increased release of noradrenaline and serotonin in forebrain areas involved in mood regulation.
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Webling K, Runesson J, Lang A, Saar I, Kofler B, Langel Ü. Ala 5-galanin (2-11) is a GAL 2R specific galanin analogue. Neuropeptides 2016; 60:75-82. [PMID: 27592409 DOI: 10.1016/j.npep.2016.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 08/11/2016] [Accepted: 08/22/2016] [Indexed: 12/18/2022]
Abstract
It is over 30years since the regulatory peptide galanin was discovered by Professor Mutt and co-workers. Galanin exerts its effects by binding to three galanin G-protein coupled receptors, namely GAL1R, GAL2R and GAL3R. Each galanin receptor has a different distribution in the central nervous system and the peripheral nervous system as well as distinctive signaling pathways, which implicates that the receptors are involved in different biological- and pathological effects. The delineation of the galaninergic system is however difficult due to a lack of stable, specific galanin receptor ligands. Herein, a new short GAL2R specific ligand, Ala5-galanin (2-11), is presented. The galanin (2-11) modified analogue Ala5-galanin (2-11) was tested in 125I-galanin competitive binding studies for the three galanin receptors and the G-protein coupled receptor signaling properties was tested by the ability to influence second-messenger molecules like inositol phosphate and cyclic adenosine monophosphate. In addition, two different label-free real-time assays, namely EnSpire® based on an optical biosensor and xCELLigence® based on an electric biosensor, were used for evaluating the signaling properties using cell lines with different levels of receptor expression. Ala5-galanin (2-11) was subsequently found to be a full agonist for GAL2R with more than 375-fold preference for GAL2R compared to both GAL1R and GAL3R. The single amino acid substitution of serine to alanine at position 5 in the short ligand galanin (2-11) resulted in a ligand subsequently unable to bind neither GAL3R nor GAL1R, even at concentrations as high as 0.1mM.
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Affiliation(s)
- Kristin Webling
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691 Stockholm, Sweden.
| | - Johan Runesson
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691 Stockholm, Sweden
| | - Andreas Lang
- Research Program for Receptorbiochemistry and Tumormetabolism, Laura Bassi Centre of Expertise THERAPEP, Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University, Müllner Hauptstr. 48, A-5020 Salzburg, Austria
| | - Indrek Saar
- Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
| | - Barbara Kofler
- Research Program for Receptorbiochemistry and Tumormetabolism, Laura Bassi Centre of Expertise THERAPEP, Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University, Müllner Hauptstr. 48, A-5020 Salzburg, Austria
| | - Ülo Langel
- Department of Neurochemistry, Stockholm University, Svante Arrheniusv. 16B, SE-10691 Stockholm, Sweden; Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
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Galanin subtype 1 and subtype 2 receptors mediate opposite anxiety-like effects in the rat dorsal raphe nucleus. Behav Brain Res 2016; 314:125-33. [DOI: 10.1016/j.bbr.2016.08.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 08/01/2016] [Accepted: 08/03/2016] [Indexed: 01/09/2023]
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Abstract
The posterior pituitary gland secretes oxytocin and vasopressin (the antidiuretic hormone) into the blood system. Oxytocin is required for normal delivery of the young and for delivery of milk to the young during lactation. Vasopressin increases water reabsorption in the kidney to maintain body fluid balance and causes vasoconstriction to increase blood pressure. Oxytocin and vasopressin secretion occurs from the axon terminals of magnocellular neurons whose cell bodies are principally found in the hypothalamic supraoptic nucleus and paraventricular nucleus. The physiological functions of oxytocin and vasopressin depend on their secretion, which is principally determined by the pattern of action potentials initiated at the cell bodies. Appropriate secretion of oxytocin and vasopressin to meet the challenges of changing physiological conditions relies mainly on integration of afferent information on reproductive, osmotic, and cardiovascular status with local regulation of magnocellular neurons by glia as well as intrinsic regulation by the magnocellular neurons themselves. This review focuses on the control of magnocellular neuron activity with a particular emphasis on their regulation by reproductive function, body fluid balance, and cardiovascular status. © 2016 American Physiological Society. Compr Physiol 6:1701-1741, 2016.
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Affiliation(s)
- Colin H Brown
- Brain Health Research Centre, Centre for Neuroendocrinology and Department of Physiology, University of Otago, Dunedin, New Zealand
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Wang P, Li H, Barde S, Zhang MD, Sun J, Wang T, Zhang P, Luo H, Wang Y, Yang Y, Wang C, Svenningsson P, Theodorsson E, Hökfelt TGM, Xu ZQD. Depression-like behavior in rat: Involvement of galanin receptor subtype 1 in the ventral periaqueductal gray. Proc Natl Acad Sci U S A 2016; 113:E4726-35. [PMID: 27457954 PMCID: PMC4987783 DOI: 10.1073/pnas.1609198113] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The neuropeptide galanin coexists in rat brain with serotonin in the dorsal raphe nucleus and with noradrenaline in the locus coeruleus (LC), and it has been suggested to be involved in depression. We studied rats exposed to chronic mild stress (CMS), a rodent model of depression. As expected, these rats showed several endophenotypes relevant to depression-like behavior compared with controls. All these endophenotypes were normalized after administration of a selective serotonin reuptake inhibitor. The transcripts for galanin and two of its receptors, galanin receptor 1 (GALR1) and GALR2, were analyzed with quantitative real-time PCR using laser capture microdissection in the following brain regions: the hippocampal formation, LC, and ventral periaqueductal gray (vPAG). Only Galr1 mRNA levels were significantly increased, and only in the latter region. After knocking down Galr1 in the vPAG with an siRNA technique, all parameters of the depressive behavioral phenotype were similar to controls. Thus, the depression-like behavior in rats exposed to CMS is likely related to an elevated expression of Galr1 in the vPAG, suggesting that a GALR1 antagonist could have antidepressant effects.
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Affiliation(s)
- Peng Wang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Hui Li
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Swapnali Barde
- Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Ming-Dong Zhang
- Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden; Division of Molecular Neurobiology, Department of Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Jing Sun
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Tong Wang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Pan Zhang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Hanjiang Luo
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Yongjun Wang
- Anding Hospital, Capital Medical University, Beijing 100088, China
| | - Yutao Yang
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China
| | - Chuanyue Wang
- Anding Hospital, Capital Medical University, Beijing 100088, China
| | - Per Svenningsson
- Center for Molecular Medicine, Department of Neurology and Clinical Neuroscience, Karolinska Institutet and Karolinska University Hospital, SE-17176 Stockholm, Sweden
| | - Elvar Theodorsson
- Department of Clinical Chemistry and Department of Clinical and Experimental Medicine, Linkoping University, SE-58183 Linkoping, Sweden
| | - Tomas G M Hökfelt
- Department of Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden;
| | - Zhi-Qing David Xu
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China;
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Local cholinergic-GABAergic circuitry within the basal forebrain is modulated by galanin. Brain Struct Funct 2016; 222:1385-1400. [PMID: 27496091 DOI: 10.1007/s00429-016-1283-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 07/26/2016] [Indexed: 02/07/2023]
Abstract
The basal forebrain (BF) is an important regulator of hippocampal and cortical activity. In Alzheimer's disease (AD), there is a significant loss and dysfunction of cholinergic neurons within the BF, and also a hypertrophy of fibers containing the neuropeptide galanin. Understanding how galanin interacts with BF circuitry is critical in determining what role galanin overexpression plays in the progression of AD. Here, we examined the location and function of galanin in the medial septum/diagonal band (MS/DBB) region of the BF. We show that galanin fibers are located throughout the MS/DBB and intermingled with both cholinergic and GABAergic neurons. Whole-cell patch clamp recordings from MS/DBB neurons in acute slices reveal that galanin decreases tetrodotoxin-sensitive spontaneous GABA release and dampens muscarinic receptor-mediated increases in GABA release in the MS/DBB. These effects are not blocked by pre-exposure to β-amyloid peptide (Aβ1-42). Optogenetic activation of cholinergic neurons in the MS/DBB increases GABA release back onto cholinergic neurons, forming a functional circuit within the MS/DBB. Galanin disrupts this cholinergic-GABAergic circuit by blocking the cholinergic-induced increase in GABA release. These data suggest that galanin works in the BF to reduce inhibitory input onto cholinergic neurons and to prevent cholinergic-induced increase in inhibitory tone. This disinhibition of cholinergic neurons could serve as a compensatory mechanism to counteract the loss of cholinergic signaling that occurs during the progression of AD.
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Kim E, Jeong I, Kim S, Kim HK, Lee DW, Kim B, Seong JY, Bae YK, Ryu JH, Park HC. Distribution of galanin receptor 2b neurons and interaction with galanin in the zebrafish central nervous system. Neurosci Lett 2016; 628:153-60. [DOI: 10.1016/j.neulet.2016.06.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 05/14/2016] [Accepted: 06/09/2016] [Indexed: 01/12/2023]
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Constantin S, Wray S. Galanin Activates G Protein Gated Inwardly Rectifying Potassium Channels and Suppresses Kisspeptin-10 Activation of GnRH Neurons. Endocrinology 2016; 157:3197-212. [PMID: 27359210 PMCID: PMC4967115 DOI: 10.1210/en.2016-1064] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 06/21/2016] [Indexed: 12/21/2022]
Abstract
GnRH neurons are regulated by hypothalamic kisspeptin neurons. Recently, galanin was identified in a subpopulation of kisspeptin neurons. Although the literature thoroughly describes kisspeptin activation of GnRH neurons, little is known about the effects of galanin on GnRH neurons. This study investigated whether galanin could alter kisspeptin signaling to GnRH neurons. GnRH cells maintained in explants, known to display spontaneous calcium oscillations, and a long-lasting calcium response to kisspeptin-10 (kp-10), were used. First, transcripts for galanin receptors (GalRs) were examined. Only GalR1 was found in GnRH neurons. A series of experiments was then performed to determine the action of galanin on kp-10 activated GnRH neurons. Applied after kp-10 activation, galanin 1-16 (Gal1-16) rapidly suppressed kp-10 activation. Applied with kp-10, Gal1-16 prevented kp-10 activation until its removal. To determine the mechanism by which galanin inhibited kp-10 activation of GnRH neurons, Gal1-16 and galanin were applied to spontaneously active GnRH neurons. Both inhibited GnRH neuronal activity, independent of GnRH neuronal inputs. This inhibition was mimicked by a GalR1 agonist but not by GalR2 or GalR2/3 agonists. Although Gal1-16 inhibition relied on Gi/o signaling, it was independent of cAMP levels but sensitive to blockers of G protein-coupled inwardly rectifying potassium channels. A newly developed bioassay for GnRH detection showed Gal1-16 decreased the kp-10-evoked GnRH secretion below detection threshold. Together, this study shows that galanin is a potent regulator of GnRH neurons, possibly acting as a physiological break to kisspeptin excitation.
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Affiliation(s)
- Stephanie Constantin
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke/National Institutes of Health, Bethesda, Maryland 20892-3703
| | - Susan Wray
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke/National Institutes of Health, Bethesda, Maryland 20892-3703
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Characterization of the Rat GAL2R Promoter: Positive Role of ETS-1 in Regulation of the Rat GAL2R Gene in PC12 Cells. Mol Neurobiol 2016; 54:4421-4431. [PMID: 27349435 DOI: 10.1007/s12035-016-9986-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 06/14/2016] [Indexed: 10/21/2022]
Abstract
Galanin receptor 2 (GAL2R) is a G protein-coupled receptor for the neuropeptide galanin that regulates many important physiological functions and pathological processes. To investigate the molecular mechanism governing GAL2R gene transcription, the rat GAL2R promoter was isolated and analyzed. We found that the region from -320 to -300 of the GAL2R promoter contains two putative ETS-1 elements and plays an important role in regulating GAL2R promoter activity. We also showed that transcription factor ETS-1 bound to this region in vitro and in vivo. Overexpression of ETS-1 significantly increased GAL2R promoter activity and transcription of the GAL2R gene, whereas knockdown of ETS-1 produced the opposite effects. In addition, we showed that ETS-1 recruited co-activator p300 to the GAL2R promoter. These data indicate a role for ETS-1 in the control of the GAL2R gene expression and provide a basis for understanding the transcriptional regulation of the GAL2R gene.
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Petschner P, Juhasz G, Tamasi V, Adori C, Tothfalusi L, Hökfelt T, Bagdy G. Chronic venlafaxine treatment fails to alter the levels of galanin system transcripts in normal rats. Neuropeptides 2016; 57:65-70. [PMID: 26891823 DOI: 10.1016/j.npep.2016.01.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 01/22/2016] [Accepted: 01/31/2016] [Indexed: 11/16/2022]
Abstract
It is widely accepted that efficacy and speed of current antidepressants' therapeutic effect are far from optimal. Thus, there is a need for the development of antidepressants with new mechanisms of action. The neuropeptide galanin and its receptors (GalR1, GalR2 and GalR3) are among the promising targets. However, it is not clear whether or not the galanin system is involved in the antidepressant effect exerted by the currently much used inhibitors of the reuptake of serotonin and/or noradrenaline. To answer this question we administered the selective serotonin and noradrenaline reuptake inhibitor (SNRI) venlafaxine (40mg/kg/day via osmotic minipumps) to normal rats and examined the levels of the transcripts for galanin and GalR1-3 after a 3-week venlafaxine treatment in the dorsal raphe, hippocampus and frontal cortex. These areas are known to be involved in the effects of antidepressants and in depression itself. Venlafaxine failed to alter the expression of any of the galanin system genes in these areas. Our results show that one of the most efficient, currently used SNRIs does not alter transcript levels of galanin or its three receptors in normal rats. These findings suggest that the pro- and antidepressive-like effects of galanin reported in animal experiments may employ a novel mechanism(s).
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Affiliation(s)
- Peter Petschner
- Department of Pharmacodynamics, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary; MTA-SE Neuropsychopharmacology & Neurochemistry Research Group, H-1089, Nagyvarad ter 4., Budapest, Hungary
| | - Gabriella Juhasz
- Department of Pharmacodynamics, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary; MTA-SE Neuropsychopharmacology & Neurochemistry Research Group, H-1089, Nagyvarad ter 4., Budapest, Hungary; MTA-SE-NAP B Genetic Brain Imaging Migraine Research Group, Hungarian Academy of Sciences, Semmelweis University, Hungary
| | - Viola Tamasi
- Department of Genetics-, Cell and Immunobiology, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary
| | - Csaba Adori
- Department of Pharmacodynamics, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary; Retzius Laboratory, Department of Neuroscience, Karolinska Institutet, Retzius väg 8, 17177, Stockholm, Sweden
| | - Laszlo Tothfalusi
- Department of Pharmacodynamics, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary
| | - Tomas Hökfelt
- Retzius Laboratory, Department of Neuroscience, Karolinska Institutet, Retzius väg 8, 17177, Stockholm, Sweden
| | - Gyorgy Bagdy
- Department of Pharmacodynamics, Semmelweis University, H-1089, Nagyvarad ter 4., Budapest, Hungary; MTA-SE Neuropsychopharmacology & Neurochemistry Research Group, H-1089, Nagyvarad ter 4., Budapest, Hungary.
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Abstract
Since the neuropeptide galanin’s discovery in 1983, information has accumulated that implicates it in a wide range of functions, including pain sensation, stress responses, appetite regulation, and learning and memory. This article reviews the evidence for specific functions of galanin in cognitive processes. Consistencies as well as gaps in the literature are organized around basic questions of methodology and theory. This review shows that although regularities are evident in the observed behavioral effects of galanin across several methods for measuring learning and memory, generalization from these findings is tempered with concerns about confounds and a restricted range of testing conditions. Furthermore, it is revealed that many noncognitive behavioral constructs that are relevant for assessing potential roles for galanin in cognition have not been thoroughly examined. The review concludes by laying out how future theory and experimental work can overcome these concerns and confidently define the nature of the association of galanin with particular cognitive constructs.
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Galanin (1-15) enhances the antidepressant effects of the 5-HT1A receptor agonist 8-OH-DPAT: involvement of the raphe-hippocampal 5-HT neuron system. Brain Struct Funct 2016; 221:4491-4504. [PMID: 26792005 DOI: 10.1007/s00429-015-1180-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 12/23/2015] [Indexed: 10/22/2022]
Abstract
Galanin N-terminal fragment (1-15) [GAL(1-15)] is associated with depression-related and anxiogenic-like effects in rats. In this study, we analyzed the ability of GAL(1-15) to modulate 5-HT1A receptors (5-HT1AR), a key receptor in depression. GAL(1-15) enhanced the antidepressant effects induced by the 5-HT1AR agonist 8-OH-DPAT in the forced swimming test. These effects were stronger than the ones induced by Galanin (GAL). This action involved interactions at receptor level since GAL(1-15) affected the binding characteristics and the mRNA levels of 5-HT1AR in the dorsal hippocampus and dorsal raphe. The involvement of the GALR2 was demonstrated with the GALR2 antagonist M871. Proximity ligation assay experiments indicated that 5-HT1AR are in close proximity with GALR1 and GALR2 in both regions and in raphe RN33B cells. The current results indicate that GAL(1-15) enhances the antidepressant effects induced by 8-OH-DPAT acting on 5-HT1AR operating as postjunctional or as autoreceptors. These results may give the basis for the development of drugs targeting potential GALR1-GALR2-5-HT1AR heteroreceptor complexes linked to the raphe-hippocampal 5-HT neurons for the treatment of depression.
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Soares FRC, Silote GP, Almeida-Santos AF, Aguiar DC, Schenberg LC, Beijamini V. Galanin microinjection into the dorsal periaqueductal gray matter produces paradigm-dependent anxiolytic effects. Brain Res Bull 2016; 121:42-7. [PMID: 26751815 DOI: 10.1016/j.brainresbull.2015.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 12/09/2015] [Accepted: 12/28/2015] [Indexed: 01/07/2023]
Abstract
Galanin is a peptide that is present in the central nervous system in mammals, including rodents and humans. The actions of galanin are mediated by three types of metabotropic receptors: GAL1, GAL2, and GAL3. GAL1 and GAL3 increase K(+) efflux, and GAL2 increases intracellular Ca(2+) levels. The distribution of galanin and its receptors suggests its involvement in fear and/or anxiety. The periaqueductal gray matter (PAG) is a key mediator of defensive behaviors that is both targeted by galaninergic projections and supplied with GAL1 receptors and, less markedly, GAL2 receptors. We examined the effects of galanin microinjections in the dorsal PAG (dPAG) on the performance of rats in different models of anxiety. Male Wistar rats (n=7-12) were implanted with guide cannulae in the dPAG. They received microinjections of either galanin (0.3, 1.0, and 3.0 nmol) or vehicle and were tested in the Vogel conflict test (VCT), elevated plus maze (EPM), and elevated T-maze (ETM). Rats that were tested in the ETM were further evaluated for exploratory activity in the open field test (OFT). Galanin microinjections had no effects on anxiety-like behavior in the EPM or VCT or exploratory activity in the EPM or OFT. In the ETM, however, microinjections of 3 nmol galanin impaired learned anxiety (i.e., avoidance of the open arms) without changing unconditioned fear (i.e., escape from the open arms). The present data suggest that galanin transmission in the dPAG inhibits the acquisition of anxiety-like responses in the ETM.
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Affiliation(s)
- F R C Soares
- Biochemistry and Pharmacology Postgraduate Program, Health Science Center, Federal University of Espirito Santo, Vitoria, ES 29043-900, Brazil
| | - G P Silote
- Biochemistry and Pharmacology Postgraduate Program, Health Science Center, Federal University of Espirito Santo, Vitoria, ES 29043-900, Brazil
| | - A F Almeida-Santos
- Department of Pharmacology, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - D C Aguiar
- Department of Pharmacology, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - L C Schenberg
- Biochemistry and Pharmacology Postgraduate Program, Health Science Center, Federal University of Espirito Santo, Vitoria, ES 29043-900, Brazil
| | - V Beijamini
- Biochemistry and Pharmacology Postgraduate Program, Health Science Center, Federal University of Espirito Santo, Vitoria, ES 29043-900, Brazil.
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Narváez M, Borroto-Escuela DO, Millón C, Gago B, Flores-Burgess A, Santín L, Fuxe K, Narváez JA, Díaz-Cabiale Z. Galanin receptor 2-neuropeptide Y Y1 receptor interactions in the dentate gyrus are related with antidepressant-like effects. Brain Struct Funct 2015; 221:4129-4139. [DOI: 10.1007/s00429-015-1153-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/19/2015] [Indexed: 11/30/2022]
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Weinshenker D, Holmes PV. Regulation of neurological and neuropsychiatric phenotypes by locus coeruleus-derived galanin. Brain Res 2015; 1641:320-37. [PMID: 26607256 DOI: 10.1016/j.brainres.2015.11.025] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 10/27/2015] [Accepted: 11/12/2015] [Indexed: 12/28/2022]
Abstract
Decades of research confirm that noradrenergic locus coeruleus (LC) neurons are essential for arousal, attention, motivation, and stress responses. While most studies on LC transmission focused unsurprisingly on norepinephrine (NE), adrenergic signaling cannot account for all the consequences of LC activation. Galanin coexists with NE in the vast majority of LC neurons, yet the precise function of this neuropeptide has proved to be surprisingly elusive given our solid understanding of the LC system. To elucidate the contribution of galanin to LC physiology, here we briefly summarize the nature of stimuli that drive LC activity from a neuroanatomical perspective. We go on to describe the LC pathways in which galanin most likely exerts its effects on behavior, with a focus on addiction, depression, epilepsy, stress, and Alzheimer׳s disease. We propose a model in which LC-derived galanin has two distinct functions: as a neuromodulator, primarily acting via the galanin 1 receptor (GAL1), and as a trophic factor, primarily acting via galanin receptor 2 (GAL2). Finally, we discuss how the recent advances in neuropeptide detection, optogenetics and chemical genetics, and galanin receptor pharmacology can be harnessed to identify the roles of LC-derived galanin definitively. This article is part of a Special Issue entitled SI: Noradrenergic System.
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Affiliation(s)
- David Weinshenker
- Department of Human Genetics, Emory University School of Medicine, 615 Michael St., Whitehead 301, Atlanta, GA 30322, USA.
| | - Philip V Holmes
- Neuroscience Program, Biomedical and Health Sciences Institute and Psychology Department, University of Georgia, Athens, GA 30602, USA.
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50
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Adori C, Barde S, Bogdanovic N, Uhlén M, Reinscheid RR, Kovacs GG, Hökfelt T. Neuropeptide S- and Neuropeptide S receptor-expressing neuron populations in the human pons. Front Neuroanat 2015; 9:126. [PMID: 26441556 PMCID: PMC4585187 DOI: 10.3389/fnana.2015.00126] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 09/07/2015] [Indexed: 01/26/2023] Open
Abstract
Neuropeptide S (NPS) is a regulatory peptide with potent pharmacological effects. In rodents, NPS is expressed in a few pontine cell clusters. Its receptor (NPSR1) is, however, widely distributed in the brain. The anxiolytic and arousal-promoting effects of NPS make the NPS–NPSR1 system an interesting potential drug target in mood-related disorders. However, so far possible disease-related mechanisms involving NPS have only been studied in rodents. To validate the relevance of these animal studies for i.a. drug development, we have explored the distribution of NPS-expressing neurons in the human pons using in situ hybridization and stereological methods and we compared the distribution of NPS mRNA expressing neurons in the human and rat brain. The calculation revealed a total number of 22,317 ± 2411 NPS mRNA-positive neurons in human, bilaterally. The majority of cells (84%) were located in the parabrachial area in human: in the extension of the medial and lateral parabrachial nuclei, in the Kölliker-Fuse nucleus and around the adjacent lateral lemniscus. In human, in sharp contrast to the rodents, only very few NPS-positive cells (5%) were found close to the locus coeruleus. In addition, we identified a smaller cell cluster (11% of all NPS cells) in the pontine central gray matter both in human and rat, which has not been described previously even in rodents. We also examined the distribution of NPSR1 mRNA-expressing neurons in the human pons. These cells were mainly located in the rostral laterodorsal tegmental nucleus, the cuneiform nucleus, the microcellular tegmental nucleus region and in the periaqueductal gray. Our results show that both NPS and NPSR1 in the human pons are preferentially localized in regions of importance for integration of visceral autonomic information and emotional behavior. The reported interspecies differences must, however, be considered when looking for targets for new pharmacotherapeutical interventions.
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Affiliation(s)
- Csaba Adori
- Department of Neuroscience, Karolinska Institutet Stockholm, Sweden
| | - Swapnali Barde
- Department of Neuroscience, Karolinska Institutet Stockholm, Sweden
| | - Nenad Bogdanovic
- Geriatric Department, Institute for Clinical Medicine, Oslo University Oslo, Norway
| | - Mathias Uhlén
- Science for Life Laboratory, Department of Neuroscience, Karolinska Institutet Stockholm, Sweden ; Science for Life Laboratory, Albanova University Center, Royal Institute of Technology Stockholm, Sweden
| | - Rainer R Reinscheid
- Department of Pharmaceutical Sciences, University of California, Irvine Irvine, CA, USA ; Department of Pharmacology, University of California, Irvine Irvine, CA, USA ; Department of Molecular Biology and Biochemistry, University of California, Irvine Irvine, CA, USA
| | - Gabor G Kovacs
- Institute of Neurology, Medical University of Vienna Vienna, Austria
| | - Tomas Hökfelt
- Department of Neuroscience, Karolinska Institutet Stockholm, Sweden
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