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Melanin-concentrating hormone does not modulate serotonin release in primary cultures of fetal raphe nucleus neurons.
- Source :
-
Neuropeptides [Neuropeptides] 2019 Apr; Vol. 74, pp. 70-81. Date of Electronic Publication: 2019 Jan 03. - Publication Year :
- 2019
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Abstract
- Melanin-concentrating hormone (MCH) is a neuropeptide present in neurons located in the hypothalamus that densely innervate serotonergic cells in the dorsal raphe nucleus (DRN). MCH administration into the DRN induces a depressive-like effect through a serotonergic mechanism. To further understand the interaction between MCH and serotonin, we used primary cultured serotonergic neurons to evaluate the effect of MCH on serotonergic release and metabolism by HPLC-ED measurement of serotonin (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) levels. We confirmed the presence of serotonergic neurons in the E14 rat rhombencephalon by immunohistochemistry and showed for the first time evidence of MCHergic fibers reaching the area. Cultures obtained from rhombencephalic tissue presented 2.2 ± 0.7% of serotonergic and 48.9 ± 5.4% of GABAergic neurons. Despite the low concentration of serotonergic neurons, we were able to measure basal cellular and extracellular levels of 5-HT and 5-HIAA without the addition of any serotonergic-enhancer drug. As expected, 5-HT release was calcium-dependent and induced by depolarization. 5-HT extracellular levels were significantly increased by incubation with serotonin reuptake inhibitors (citalopram and nortriptyline) and a monoamine-oxidase inhibitor (clorgyline), and were not significantly modified by a 5-HT1A autoreceptor agonist (8-OHDPAT). Even though serotonergic cells responded as expected to these pharmacological treatments, MCH did not induce significant modifications of 5-HT and 5-HIAA extracellular levels in the cultures. Despite this unexpected result, we consider that assessment of 5-HT and 5-HIAA levels in primary serotonergic cultures may be an adequate approach to study the effect of other drugs and modulators on serotonin release, uptake and turnover.<br /> (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Subjects :
- Animals
GABAergic Neurons cytology
Hypothalamic Hormones administration & dosage
Hypothalamus cytology
Melanins administration & dosage
Neural Pathways cytology
Neural Pathways metabolism
Neurons cytology
Neurons drug effects
Pituitary Hormones administration & dosage
Primary Cell Culture
Raphe Nuclei cytology
Raphe Nuclei drug effects
Rats, Sprague-Dawley
Receptor, Serotonin, 5-HT1A metabolism
Hypothalamic Hormones metabolism
Hypothalamus metabolism
Melanins metabolism
Neurons metabolism
Pituitary Hormones metabolism
Raphe Nuclei metabolism
Serotonin metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1532-2785
- Volume :
- 74
- Database :
- MEDLINE
- Journal :
- Neuropeptides
- Publication Type :
- Academic Journal
- Accession number :
- 30642579
- Full Text :
- https://doi.org/10.1016/j.npep.2018.12.005