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Jacq A, Becquet D, Guillen S, Boyer B, Bello-Goutierrez MM, Franc JL, François-Bellan AM. Identification of RNAs Engaged in Direct RNA-RNA Interaction with a Long Non-Coding RNA. J Vis Exp 2021. [PMID: 34309599 DOI: 10.3791/62475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The growing role attributed nowadays to long non-coding RNAs (lncRNA) in physiology and pathophysiology makes it crucial to characterize their interactome by identifying their molecular partners, DNA, proteins and/or RNAs. The latter can interact with lncRNA through networks involving proteins, but they can also be engaged in direct RNA/RNA interactions. We, therefore, developed an easy-to-use RNA pull-down procedure that allowed identification of RNAs engaged in direct RNA/RNA interaction with a lncRNA using psoralen, a molecule that cross-links only RNA/RNA interactions. Bioinformatics modeling of the lncRNA secondary structure allowed the selection of several specific antisense DNA oligonucleotide probes with a strong affinity for regions displaying a low probability of internal base pairing. Since the specific probes that were designed targeted accessible regions throughout the length of the lncRNA, the RNA-interaction zones could be delineated in the sequence of the lncRNA. When coupled with a high throughput RNA sequencing, this protocol can be used for the whole direct RNA interactome studies of a lncRNA of interest.
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Affiliation(s)
- Audrey Jacq
- Faculté des Sciences Médicales et Paramédicales, Aix Marseille Univ, CNRS, INP
| | - Denis Becquet
- Faculté des Sciences Médicales et Paramédicales, Aix Marseille Univ, CNRS, INP
| | - Séverine Guillen
- Faculté des Sciences Médicales et Paramédicales, Aix Marseille Univ, CNRS, INP
| | - Bénédicte Boyer
- Faculté des Sciences Médicales et Paramédicales, Aix Marseille Univ, CNRS, INP
| | | | - Jean-Louis Franc
- Faculté des Sciences Médicales et Paramédicales, Aix Marseille Univ, CNRS, INP;
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Jacq A, Becquet D, Bello-Goutierrez MM, Boyer B, Guillen S, Franc JL, François-Bellan AM. Genome-wide screening of circadian and non-circadian impact of Neat1 genetic deletion. Comput Struct Biotechnol J 2021; 19:2121-2132. [PMID: 33995907 PMCID: PMC8085668 DOI: 10.1016/j.csbj.2021.04.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 04/07/2021] [Accepted: 04/07/2021] [Indexed: 12/25/2022] Open
Abstract
Neat1 deletion affects numerous circadian and non-circadian genes. Neat1 deletion causes loss, modification or acquisition of gene circadian pattern. Paraspeckles contribute significantly to the circadian transcriptome.
The functions of the long non-coding RNA, Nuclear enriched abundant transcript 1 (Neat1), are poorly understood. Neat1 is required for the formation of paraspeckles, but its respective paraspeckle-dependent or independent functions are unknown. Several studies including ours reported that Neat1 is involved in the regulation of circadian rhythms. We characterized the impact of Neat1 genetic deletion in a rat pituitary cell line. The mRNAs whose circadian expression pattern or expression level is regulated by Neat1 were identified after high-throughput RNA sequencing of the circadian transcriptome of wild-type cells compared to cells in which Neat1 was deleted by CRISPR/Cas9. The numerous RNAs affected by Neat1 deletion were found to be circadian or non-circadian, targets or non-targets of paraspeckles, and to be associated with many key biological processes showing that Neat1, in interaction with the circadian system or independently, could play crucial roles in key physiological functions through diverse mechanisms.
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Jacq A, Becquet D, Guillen S, Boyer B, Bello-Goutierrez MM, Franc JL, François-Bellan AM. Direct RNA-RNA interaction between Neat1 and RNA targets, as a mechanism for RNAs paraspeckle retention. RNA Biol 2021; 18:2016-2027. [PMID: 33573434 DOI: 10.1080/15476286.2021.1889253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Paraspeckles are nuclear ribonucleic complex formed of a long non-coding RNA, nuclear-enriched abundant transcript one (Neat1) and associated RNA-binding proteins (RBP) whose cellular known functions are to sequester in the nucleus both proteins and RNAs. However, how RNAs are bound to paraspeckles is largely unknown. It is highly likely that binding of RNAs may occur via interactions with RBPs and accordingly, two structures present in the 3'UTR of some RNAs have been shown to allow their association to paraspeckles via protein binding. However, Neat1 could also be involved in the targeting of RNAs through direct RNA-RNA interactions. Using an RNA pull-down procedure adapted to select only RNAs engaged in direct RNA-RNA interactions and followed by RNA-seq we showed that in a rat pituitary cell line, GH4C1 cells, 1791 RNAs were associated with paraspeckles by direct interaction with Neat1. Neat1 was actually found able to bind more than 30% of the total transcripts targeted by the paraspeckles, we have identified in this cell line in a previous study. Furthermore, given the biological processes in which direct RNAs targets of Neat1 were involved as determined by gene ontology analysis, it was proposed that Neat1 played a major role in paraspeckle functions such as circadian rhythms, mRNA processing, RNA splicing and regulation of cell cycle. Finally, we provided evidence that direct RNA targets of Neat1 were preferentially bound to the 5' end of Neat1 demonstrating that they are located in the shell region of paraspeckles.
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Affiliation(s)
- Audrey Jacq
- Aix-Marseille Univ, CNRS, INP, Marseille, France
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Torres M, Becquet D, Guillen S, Boyer B, Moreno M, Blanchard MP, Franc JL, François-Bellan AM. RNA Pull-down Procedure to Identify RNA Targets of a Long Non-coding RNA. J Vis Exp 2018. [PMID: 29708552 PMCID: PMC5933463 DOI: 10.3791/57379] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Long non-coding RNA (lncRNA), which are sequences of more than 200 nucleotides without a defined reading frame, belong to the regulatory non-coding RNA's family. Although their biological functions remain largely unknown, the number of these lncRNAs has steadily increased and it is now estimated that humans may have more than 10,000 such transcripts. Some of these are known to be involved in important regulatory pathways of gene expression which take place at the transcriptional level, but also at different steps of RNA co- and post-transcriptional maturation. In the latter cases, RNAs that are targeted by the lncRNA have to be identified. That's the reason why it is useful to develop a method enabling the identification of RNAs associated directly or indirectly with a lncRNA of interest. This protocol, which was inspired by previously published protocols allowing the isolation of a lncRNA together with its associated chromatin sequences, was adapted to permit the isolation of associated RNAs. We determined that two steps are critical for the efficiency of this protocol. The first is the design of specific anti-sense DNA oligonucleotide probes able to hybridize to the lncRNA of interest. To this end, the lncRNA secondary structure was predicted by bioinformatics and anti-sense oligonucleotide probes were designed with a strong affinity for regions that display a low probability of internal base pairing. The second crucial step of the procedure relies on the fixative conditions of the tissue or cultured cells that have to preserve the network between all molecular partners. Coupled with high throughput RNA sequencing, this RNA pull-down protocol can provide the whole RNA interactome of a lncRNA of interest.
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Affiliation(s)
- Manon Torres
- CNRS, CRN2M-UMR7286, Faculté de Médecine Nord, Aix-Marseille Université
| | - Denis Becquet
- CNRS, CRN2M-UMR7286, Faculté de Médecine Nord, Aix-Marseille Université
| | - Séverine Guillen
- CNRS, CRN2M-UMR7286, Faculté de Médecine Nord, Aix-Marseille Université
| | - Bénédicte Boyer
- CNRS, CRN2M-UMR7286, Faculté de Médecine Nord, Aix-Marseille Université
| | - Mathias Moreno
- CNRS, CRN2M-UMR7286, Faculté de Médecine Nord, Aix-Marseille Université
| | | | - Jean-Louis Franc
- CNRS, CRN2M-UMR7286, Faculté de Médecine Nord, Aix-Marseille Université
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Torres M, Becquet D, Franc JL, François-Bellan AM. Circadian processes in the RNA life cycle. Wiley Interdiscip Rev RNA 2018; 9:e1467. [PMID: 29424086 DOI: 10.1002/wrna.1467] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 11/24/2017] [Accepted: 12/18/2017] [Indexed: 12/11/2022]
Abstract
The circadian clock drives daily rhythms of multiple physiological processes, allowing organisms to anticipate and adjust to periodic changes in environmental conditions. These physiological rhythms are associated with robust oscillations in the expression of at least 30% of expressed genes. While the ability for the endogenous timekeeping system to generate a 24-hr cycle is a cell-autonomous mechanism based on negative autoregulatory feedback loops of transcription and translation involving core-clock genes and their protein products, it is now increasingly evident that additional mechanisms also govern the circadian oscillations of clock-controlled genes. Such mechanisms can take place post-transcriptionally during the course of the RNA life cycle. It has been shown that many steps during RNA processing are regulated in a circadian manner, thus contributing to circadian gene expression. These steps include mRNA capping, alternative splicing, changes in splicing efficiency, and changes in RNA stability controlled by the tail length of polyadenylation or the use of alternative polyadenylation sites. RNA transport can also follow a circadian pattern, with a circadian nuclear retention driven by rhythmic expression within the nucleus of particular bodies (the paraspeckles) and circadian export to the cytoplasm driven by rhythmic proteins acting like cargo. Finally, RNA degradation may also follow a circadian pattern through the rhythmic involvement of miRNAs. In this review, we summarize the current knowledge of the post-transcriptional circadian mechanisms known to play a prominent role in shaping circadian gene expression in mammals. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA Processing > RNA Editing and Modification RNA Export and Localization > Nuclear Export/Import.
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Affiliation(s)
- Manon Torres
- CNRS, CRN2M-UMR7286, Faculté de Médecine Nord, Aix-Marseille Université, Marseille, France
| | - Denis Becquet
- CNRS, CRN2M-UMR7286, Faculté de Médecine Nord, Aix-Marseille Université, Marseille, France
| | - Jean-Louis Franc
- CNRS, CRN2M-UMR7286, Faculté de Médecine Nord, Aix-Marseille Université, Marseille, France
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Torres M, Becquet D, Blanchard MP, Guillen S, Boyer B, Moreno M, Franc JL, François-Bellan AM. Paraspeckles as rhythmic nuclear mRNA anchorages responsible for circadian gene expression. Nucleus 2017; 8:249-254. [PMID: 28060565 DOI: 10.1080/19491034.2016.1277304] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Circadian clocks regulate rhythmic gene expression levels by means of mRNA oscillations that are mainly driven by post-transcriptional regulation. We identified a new post-transcriptional mechanism, which involves nuclear bodies called paraspeckles. Major components of paraspeckles including the long noncoding RNA Neat1, which is the structural component, and its major protein partners, as well as the number of paraspeckles, follow a circadian pattern in pituitary cells. Paraspeckles are known to retain within the nucleus RNAs containing inverted repeats of Alu sequences. We showed that a reporter gene in which these RNA duplex elements were inserted in the 3'-UTR region displayed a circadian expression. Moreover, circadian endogenous mRNA associated with paraspeckles lost their circadian pattern when paraspeckles were disrupted. This work not only highlights a new paraspeckle-based post-transcriptional mechanism involved in circadian gene expression but also provides the list of all mRNA associated with paraspeckles in the nucleus of pituitary cells.
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Affiliation(s)
- Manon Torres
- a Aix Marseille Université, CNRS, CRN2M-UMR7286, Faculté de Médecine Nord , Marseille , France
| | - Denis Becquet
- a Aix Marseille Université, CNRS, CRN2M-UMR7286, Faculté de Médecine Nord , Marseille , France
| | - Marie-Pierre Blanchard
- a Aix Marseille Université, CNRS, CRN2M-UMR7286, Faculté de Médecine Nord , Marseille , France
| | - Séverine Guillen
- a Aix Marseille Université, CNRS, CRN2M-UMR7286, Faculté de Médecine Nord , Marseille , France
| | - Bénédicte Boyer
- a Aix Marseille Université, CNRS, CRN2M-UMR7286, Faculté de Médecine Nord , Marseille , France
| | - Mathias Moreno
- a Aix Marseille Université, CNRS, CRN2M-UMR7286, Faculté de Médecine Nord , Marseille , France
| | - Jean-Louis Franc
- a Aix Marseille Université, CNRS, CRN2M-UMR7286, Faculté de Médecine Nord , Marseille , France
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Torres M, Becquet D, Blanchard MP, Guillen S, Boyer B, Moreno M, Franc JL, François-Bellan AM. Circadian RNA expression elicited by 3'-UTR IRAlu-paraspeckle associated elements. eLife 2016; 5. [PMID: 27441387 PMCID: PMC4987140 DOI: 10.7554/elife.14837] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 07/20/2016] [Indexed: 12/31/2022] Open
Abstract
Paraspeckles are nuclear bodies form around the long non-coding RNA, Neat1, and RNA-binding proteins. While their role is not fully understood, they are believed to control gene expression at a post-transcriptional level by means of the nuclear retention of mRNA containing in their 3’-UTR inverted repeats of Alu sequences (IRAlu). In this study, we found that, in pituitary cells, all components of paraspeckles including four major proteins and Neat1 displayed a circadian expression pattern. Furthermore the insertion of IRAlu at the 3’-UTR of the EGFP cDNA led to a rhythmic circadian nuclear retention of the egfp mRNA that was lost when paraspeckles were disrupted whereas insertion of a single antisense Alu had only a weak effect. Using real-time video-microscopy, these IRAlu were further shown to drive a circadian expression of EGFP protein. This study shows that paraspeckles, thanks to their circadian expression, control circadian gene expression at a post-transcriptional level. DOI:http://dx.doi.org/10.7554/eLife.14837.001 Many biological features of animals, including body temperature and hormone levels, follow daily rhythms that repeat every 24 hours. These so-called circadian rhythms are driven by an internal body clock and are essential for the organism to adapt to the daily cycle of light and dark. Circadian rhythms also take place inside individual cells – for example, the amount of a given protein in a cell often rises and falls over each 24-hour period. To generate these daily fluctuations, the processes used to make proteins based on the instructions encoded within a gene must be carefully controlled. Genes are first copied or ‘transcribed' into intermediate molecules called messenger RNAs (mRNAs). These mRNA molecules must then travel out of the cell’s nucleus before they can be de-coded to produce proteins. This means that daily fluctuations in mRNA and protein levels could occur because the rate at which the DNA is transcribed fluctuates or because controlling the steps that occur after transcription. However it is not clear how much these post-transcriptional steps contribute to circadian rhythms inside cells. Recently, structures called paraspeckles were seen inside the nucleus. These structures are made from a long RNA molecule that does not code for a protein, and a number of proteins that can bind mRNA molecules. Paraspeckles are thought to prevent certain mRNAs from leaving the nucleus and therefore stop them from being decoded to make proteins. Torres et al. have now investigated whether paraspeckles may play a role in circadian rhythms. Torres et al. looked at the long non-coding RNA and several proteins that are known to be components of paraspeckles in cells taken from the pituitary glands of rats using a variety of techniques. These cells were chosen because they were known to have a working circadian clock. The analysis showed that the levels of these components, as well as the number of paraspeckles within the nucleus, changed over the course of a daily cycle. Torres et al. then confirmed that mRNAs containing a sequence that is known to recruit mRNAs to paraspeckes (the IRAlu sequence) could be also retained in the nucleus or released with a circadian rhythm. This pattern was lost when the paraspeckles were disrupted. These findings suggest that daily fluctuations in protein levels can be post-transcriptionally controlled by paraspeckles rhythmically retaining mRNAs in the nucleus. Future studies could explore whether it may be possible to control circadian rhythms by targeting the paraspeckles, which could help to improve conditions where the internal body clock goes wrong. DOI:http://dx.doi.org/10.7554/eLife.14837.002
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Affiliation(s)
- Manon Torres
- Faculté de Médecine Nord, Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| | - Denis Becquet
- Faculté de Médecine Nord, Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| | - Marie-Pierre Blanchard
- Faculté de Médecine Nord, Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| | - Séverine Guillen
- Faculté de Médecine Nord, Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| | - Bénédicte Boyer
- Faculté de Médecine Nord, Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| | - Mathias Moreno
- Faculté de Médecine Nord, Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| | - Jean-Louis Franc
- Faculté de Médecine Nord, Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
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Sage D, Ganem J, Guillaumond F, Laforge-Anglade G, François-Bellan AM, Bosler O, Becquet D. Influence of the Corticosterone Rhythm on Photic Entrainment of Locomotor Activity in Rats. J Biol Rhythms 2016; 19:144-56. [PMID: 15038854 DOI: 10.1177/0748730403261894] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The question of involvement of glucocorticoid hormones as temporal signals for the synchronization of the timekeeping system was addressed in rats with different corticosterone status. The authors showed that adrenalectomy had no effects on the synchronization of wheel-running activity rhythms to a steady-state LD 12:12 cycle, regardless of whether it was compensated for by a corticosterone replacement therapy that either reinstated constant plasma concentrations of the hormone or mimicked its natural rhythm. However, after a 12-h phase shift (daylight reversal), the lack of circulating corticosterone induced a significant shortening of the resynchronization rate (less than 3 days vs. 7 days). Normalization required restoration of a rhythmic corticosterone secretion that was synchronized to the new photoperiod. Under constant darkness, the corticosterone rhythm did not show any synchronizing effect, providing evidence that it participates in entrainment of the locomotor activity rhythm through modulation of light effects. It is proposed that, under stable lighting conditions, circulating glucocorticoids contribute to stabilizing activity rhythms by reinforcing resistance of the circadian timing system to variations of the photoperiod. Experimental evidence that serotonergic neurons are involved in relaying their modulatory effects to the clock is also presented.
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Affiliation(s)
- Dominique Sage
- Interactions Fonctionnelles en Neuroendocrinologie, Institut Fédératif de Recherche Jean-Roche, Faculté de Médecine, Université de la Méditerranée, Marseille, France
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Bosler O, Girardet C, Franc JL, Becquet D, François-Bellan AM. Structural plasticity of the circadian timing system. An overview from flies to mammals. Front Neuroendocrinol 2015; 38:50-64. [PMID: 25703789 DOI: 10.1016/j.yfrne.2015.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 12/22/2022]
Abstract
The circadian timing system orchestrates daily variations in physiology and behavior through coordination of multioscillatory cell networks that are highly plastic in responding to environmental changes. Over the last decade, it has become clear that this plasticity involves structural changes and that the changes may be observed not only in central brain regions where the master clock cells reside but also in clock-controlled structures. This review considers experimental data in invertebrate and vertebrate model systems, mainly flies and mammals, illustrating various forms of structural circadian plasticity from cellular to circuit-based levels. It highlights the importance of these plastic events in the functional adaptation of the clock to the changing environment.
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Affiliation(s)
- Olivier Bosler
- Aix-Marseille Université, CNRS, CRN2M, UMR 7286, Faculté de médecine, secteur nord, Boulevard Pierre Dramard, CS 80011, F-13344 Marseille cedex 15, France.
| | - Clémence Girardet
- Aix-Marseille Université, CNRS, CRN2M, UMR 7286, Faculté de médecine, secteur nord, Boulevard Pierre Dramard, CS 80011, F-13344 Marseille cedex 15, France.
| | - Jean-Louis Franc
- Aix-Marseille Université, CNRS, CRN2M, UMR 7286, Faculté de médecine, secteur nord, Boulevard Pierre Dramard, CS 80011, F-13344 Marseille cedex 15, France
| | - Denis Becquet
- Aix-Marseille Université, CNRS, CRN2M, UMR 7286, Faculté de médecine, secteur nord, Boulevard Pierre Dramard, CS 80011, F-13344 Marseille cedex 15, France
| | - Anne-Marie François-Bellan
- Aix-Marseille Université, CNRS, CRN2M, UMR 7286, Faculté de médecine, secteur nord, Boulevard Pierre Dramard, CS 80011, F-13344 Marseille cedex 15, France
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Becquet D, Boyer B, Rasolonjanahary R, Brue T, Guillen S, Moreno M, Franc JL, François-Bellan AM. Evidence for an internal and functional circadian clock in rat pituitary cells. Mol Cell Endocrinol 2014; 382:888-98. [PMID: 24239982 DOI: 10.1016/j.mce.2013.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 10/14/2013] [Accepted: 11/06/2013] [Indexed: 12/26/2022]
Abstract
In primary cultures of rat pituitary cells and in a pituitary sommatolactotroph cell line (GH4C1), endogenous core-clock- as well as hormone-genes such as prolactin displayed a rhythmic expression pattern, fitted by a sinusoidal equation in which the period value was close to the circadian one. This is consistent with the presence of a functional circadian oscillator in pituitary cells whose importance was ascertained in GH4C1 cell lines stably expressing a dominant negative mutant of BMAL1. In these cells, both endogenous core-clock- and prolactin-genes no more displayed a circadian pattern. Some genes we recently identified as mouse pituitary BMAL1-regulated genes in a DNA-microarray study, lost their circadian pattern in these cells, suggesting that BMAL1 controlled these genes locally in the pituitary. The intra-pituitary circadian oscillator could then play a role in the physiology of the gland that would not be seen anymore as a structure only driven by hypothalamic rhythmic control.
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Affiliation(s)
- Denis Becquet
- CRN2M, CNRS UMR 7286, Aix-Marseille Université, Marseille, France
| | - Bénédicte Boyer
- CRN2M, CNRS UMR 7286, Aix-Marseille Université, Marseille, France
| | | | - Thierry Brue
- CRN2M, CNRS UMR 7286, Aix-Marseille Université, Marseille, France
| | - Séverine Guillen
- CRN2M, CNRS UMR 7286, Aix-Marseille Université, Marseille, France
| | - Mathias Moreno
- CRN2M, CNRS UMR 7286, Aix-Marseille Université, Marseille, France
| | - Jean-Louis Franc
- CRN2M, CNRS UMR 7286, Aix-Marseille Université, Marseille, France
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Girardet C, Lebrun B, Cabirol-Pol MJ, Tardivel C, François-Bellan AM, Becquet D, Bosler O. Brain-derived neurotrophic factor/TrkB signaling regulates daily astroglial plasticity in the suprachiasmatic nucleus: electron-microscopic evidence in mouse. Glia 2013; 61:1172-7. [PMID: 23640807 DOI: 10.1002/glia.22509] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 03/20/2013] [Indexed: 11/07/2022]
Abstract
Synchronization of circadian rhythms to the 24-h light/dark (L/D) cycle is associated with daily rearrangements of the neuronal-glial network of the suprachiasmatic nucleus of the hypothalamus (SCN), the central master clock orchestrating biological functions in mammals. These anatomical plastic events involve neurons synthesizing vasoactive intestinal peptide (VIP), known as major integrators of photic signals in the retinorecipient region of the SCN. Using an analog-sensitive kinase allele murine model (TrkB(F616A) ), we presently show that the pharmacological blockade of the tropomyosin-related kinase receptor type B (TrkB), the high-affinity receptor of brain-derived neurotrophic factor (BDNF), abolished day/night changes in the dendrite enwrapping of VIP neurons by astrocytic processes (glial coverage), used as an index of SCN plasticity on electron-microscopic sections. Therefore, the BDNF/TrkB signaling pathway exerts a permissive role on the ultrastructural rearrangements that occur in SCN under L/D alternance, an action that could be a critical determinant of the well-established role played by BDNF in the photic regulation of the SCN. In contrast, the extent of glial coverage of non-VIP neighboring dendrites was not different at daytime and nighttime in TrkB(F616A) mice submitted to TrkB inactivation or not receiving any pharmacological treatment. These data not only show that BDNF regulates SCN structural plasticity across the 24-h cycle but also reinforce the view that the daily changes in SCN architecture subserve the light synchronization process.
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Affiliation(s)
- Clémence Girardet
- Aix Marseille Université, CNRS, CRN2M UMR7286, Faculté de Médecine, 13344 cedex 15, Marseille, France
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Guillaumond F, Becquet D, Boyer B, Bosler O, Delaunay F, Franc JL, François-Bellan AM. DNA microarray analysis and functional profile of pituitary transcriptome under core-clock protein BMAL1 control. Chronobiol Int 2012; 29:103-30. [PMID: 22324551 DOI: 10.3109/07420528.2011.645707] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Although it is known to contain five cell types that synthesize and release hormones with a circadian pattern, the pituitary gland is poorly characterized as a circadian oscillator. By a differential microarray analysis, 252 genes were found to be differentially expressed in pituitaries from Bmal1(-/-) knockout versus wild-type mice. By integrative analyses of the data set with the Annotation, Visualization, and Integrated Discovery (DAVID) Bioinformatics Resources annotation analysis system, pituitary genes with altered expression in Bmal1(-/-) mice were dispatched among functional categories. Clusters of genes related to signaling and rhythmic processes as well as transcription regulators, in general, were found enriched in the data set, as were pathways such as circadian rhythm, transforming growth factor β (TGFβ) signaling, valine, leucine, and isoleucine degradation, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. Gene Ontology term overrepresentation analyses revealed significant enrichment for genes involved in 10 key biological processes. To determine whether genes with altered expression in Bmal1(-/-) mice were actually circadian genes, we further characterized in the mouse pituitary gland the daily pattern of some of these genes, including core-clock genes. Core-clock genes and genes selected from three identified overrepresented biological processes, namely, hormone metabolic process, regulation of transcription from RNA polymerase II promoter, and cell adhesion, displayed a rhythmic pattern. Given the enrichment in genes dedicated to cell adhesion and their daily changes in the pituitary, it is hypothesized that cell-cell interactions could be involved in the transmission of information between endocrine cells, allowing rhythmic hormone outputs to be controlled in a temporally precise manner.
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Affiliation(s)
- F Guillaumond
- Aix-Marseille University , INSERM-U624, Marseille, France
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Guillaumond F, Boyer B, Becquet D, Guillen S, Kuhn L, Garin J, Belghazi M, Bosler O, Franc J, François‐Bellan A. Chromatin remodeling as a mechanism for circadian prolactin transcription: rhythmic NONO and SFPQ recruitment to HLTF. FASEB J 2011; 25:2740-56. [DOI: 10.1096/fj.10-178616] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Fabienne Guillaumond
- Institut des Sciences Moleculaires de Marseille (ISM2)UMR6263 Université Aix‐Marseille IIIMarseilleFrance
| | - Benedicte Boyer
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille (CRN2M)Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 6231Université Aix‐Marseille II, IIIMarseilleFrance
| | - Denis Becquet
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille (CRN2M)Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 6231Université Aix‐Marseille II, IIIMarseilleFrance
| | - Severine Guillen
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille (CRN2M)Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 6231Université Aix‐Marseille II, IIIMarseilleFrance
| | - Lauriane Kuhn
- Plateforme Étude de la Dynamique des Protéomes (EDyP)‐ServiceGrenobleFrance
| | - Jerome Garin
- Centre d'Analyse Protéomique de MarseilleInstitut Fédératif de Recherche (IFR) Jean‐RocheMarseilleFrance
| | - Maya Belghazi
- Plateforme Protéomique de l'Esplanade Institut de Biologie Moléculaire et Cellulaire (IBMC)StrasbourgFrance
| | - Olivier Bosler
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille (CRN2M)Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 6231Université Aix‐Marseille II, IIIMarseilleFrance
| | - Jean‐Louis Franc
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille (CRN2M)Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 6231Université Aix‐Marseille II, IIIMarseilleFrance
| | - Anne‐Marie François‐Bellan
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille (CRN2M)Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 6231Université Aix‐Marseille II, IIIMarseilleFrance
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Girardet C, Becquet D, Blanchard MP, François-Bellan AM, Bosler O. Neuroglial and synaptic rearrangements associated with photic entrainment of the circadian clock in the suprachiasmatic nucleus. Eur J Neurosci 2011. [DOI: 10.1111/j.1460-9568.2011.07712.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Girardet C, Becquet D, Blanchard MP, François-Bellan AM, Bosler O. Neuroglial and synaptic rearrangements associated with photic entrainment of the circadian clock in the suprachiasmatic nucleus. Eur J Neurosci 2010; 32:2133-42. [DOI: 10.1111/j.1460-9568.2010.07520.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Girardet C, Blanchard MP, Ferracci G, Lévêque C, Moreno M, François-Bellan AM, Becquet D, Bosler O. Daily changes in synaptic innervation of VIP neurons in the rat suprachiasmatic nucleus: contribution of glutamatergic afferents. Eur J Neurosci 2010; 31:359-70. [PMID: 20074215 DOI: 10.1111/j.1460-9568.2009.07071.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The daily temporal organization of rhythmic functions in mammals, which requires synchronization of the circadian clock to the 24-h light-dark cycle, is believed to involve adjustments of the mutual phasing of the cellular oscillators that comprise the time-keeper within the suprachiasmatic nucleus of the hypothalamus (SCN). Following from a previous study showing that the SCN undergoes day/night rearrangements of its neuronal-glial network that may be crucial for intercellular phasing, we investigated the contribution of glutamatergic synapses, known to play major roles in SCN functioning, to such rhythmic plastic events. Neither expression levels of the vesicular glutamate transporters nor numbers of glutamatergic terminals showed nycthemeral variations in the SCN. However, using quantitative imaging after combined immunolabelling, the density of synapses on neurons expressing vasoactive intestinal peptide, known as targets of the retinal input, increased during the day and both glutamatergic and non-glutamatergic synapses contributed to the increase (+36%). This was not the case for synapses made on vasopressin-containing neurons, the other major source of SCN efferents in the non-retinorecipient region. Together with electron microscope observations showing no differences in the morphometric features of glutamatergic terminals during the day and night, these data show that the light synchronization process in the SCN involves a selective remodelling of synapses at sites of photic integration. They provide a further illustration of how the adult brain may rapidly and reversibly adapt its synaptic architecture to functional needs.
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Affiliation(s)
- Clémence Girardet
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille (CRN2M), CNRS-UMR 6231, Université de la Méditerranée, Faculté de Médecine Nord, Marseille, France
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Bosler O, Girardet C, Sage-Ciocca D, Jacomy H, François-Bellan AM, Becquet D. Mécanismes de plasticité structurale associés à la synchronisation photique de l'horloge circadienne au sein du noyau suprachiasmatique. ACTA ACUST UNITED AC 2009; 203:49-63. [DOI: 10.1051/jbio:2009004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Becquet D, Girardet C, Guillaumond F, François-Bellan AM, Bosler O. Ultrastructural plasticity in the rat suprachiasmatic nucleus. Possible involvement in clock entrainment. Glia 2008; 56:294-305. [PMID: 18080293 DOI: 10.1002/glia.20613] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Circadian rhythms in mammals are synchronized to the light (L)/dark (D) cycle through messages relaying in the master clock, the suprachiasmatic nucleus of the hypothalamus (SCN). Here, we provide evidence that the SCN undergoes rhythmic ultrastructural rearrangements over the 24-h cycle characterized by day/night changes of the glial, axon terminal, and/or somato-dendritic coverage of neurons expressing arginine vasopressin (AVP) or vasoactive intestinal peptide (VIP), the two main sources of SCN efferents. At nighttime, we noted an increase in the glial coverage of the dendrites of the VIP neurons (+29%) that was concomitant with a decrease in the mean coverage of the somata (-36%) and dendrites (-43%) of these neurons by axon terminals. Conversely, glial coverage of the dendrites of AVP neurons decreased (-19%) with parallel increase in the extent of somatal (+96%) and dendritic (+52%) membrane appositions involving these neurons. These plastic events were concomitant with daily fluctuations in quantitative expression of glial fibrillary acidic protein (GFAP), which were then used as an index of structural plasticity. The GFAP rhythm appeared to be strictly dependent on light entrainment, indicating that structural reorganization of the SCN may subserve synchronization of the clock to the L/D cycle. Other results presented reinforced this view while showing that circulating glucocorticoid hormones, which are known to modulate photic entrainment, were required to maintain amplitude of the GFAP rhythm to normal values.
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Affiliation(s)
- Denis Becquet
- CNRS-UMR 6544, IFR Jean-Roche, Faculté de médecine, Université de la Méditerranée, Marseille, France
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Guillaumond F, Becquet D, Blanchard MP, Attia J, Moreno M, Bosler O, François-Bellan AM. Nocturnal expression of phosphorylated-ERK1/2 in gastrin-releasing peptide neurons of the rat suprachiasmatic nucleus. J Neurochem 2007; 101:1224-35. [PMID: 17250649 DOI: 10.1111/j.1471-4159.2006.04416.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Extracellular regulated kinase (ERK) signalling is believed to play roles in various aspects of circadian clock mechanisms. In this study, we show in rat that the nuclear versus cytoplasmic intracellular distribution of the phosphorylated forms of ERK1/2 (P-ERK1/2) in the central clock, namely the suprachiasmatic nucleus (SCN), is proportionally constant across the light/dark cycle while the spatial distribution and neurochemical phenotype of cells expressing these activated forms are time-regulated according to a daily rhythm and light-regulated. P-ERK1/2 was exclusively found in neuronal elements. At daytime, it was detected throughout the dorsoventral extent of the SCN, partly within neurons synthesizing either arginine-vasopressin or vasoactive intestinal peptide (VIP). At night time, it was segregated in the ventrolateral aspect of the nucleus, within a cluster of cells 45% of which were gastrin-releasing peptide (GRP) neurons with or without co-localization with VIP. After a light pulse at night, expression of P-ERK1/2 increased in GRP neurons but also appeared in a population of neurons that stained for VIP only. These data show that the GRP neurons are closely associated with ERK1/2 activation at night and point to the importance of ERK1/2 signalling not only in intra-SCN transmission of photic information but also in maintenance of neuronal rhythms in the SCN.
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Guillaumond F, Giraudet F, Becquet D, Sage D, Laforge-Anglade G, Bosler O, François-Bellan AM. Vitamin A is a necessary factor for sympathetic-independent rhythmic activation of mitogen-activated protein kinase in the rat pineal gland. Eur J Neurosci 2005; 21:798-802. [PMID: 15733098 DOI: 10.1111/j.1460-9568.2005.03901.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The circadian clock in the suprachiasmatic nucleus (SCN) controls day-to-day physiology and behavior by sending timing messages to multiple peripheral oscillators. In the pineal gland, a major SCN target, circadian events are believed to be driven exclusively by the rhythmic release of norepinephrine from superior cervical ganglia (SCG) neurons relaying clock messages through a polysynaptic pathway. Here we show in rat an SCN-driven daily rhythm of pineal MAPK activation that is not dependent on the SCG and whose maintenance requires vitamin A as a blood-borne factor. This finding challenges the dogma that SCG-released norepinephrine is an exclusive mediator of SCN-pineal communication and allows the assumption that humoral mechanisms are involved in pineal integration of temporal messages.
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Affiliation(s)
- F Guillaumond
- EA Laboratoire d'Interactions Fonctionnelles Neuroendocriniennes
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Abstract
The main known function of the pineal gland in mammals is the temporal synchronization of physiological rhythms to seasonal changes of day length (photoperiod). In rat, the transcription factor activating protein-1 (AP-1) displays a circadian rhythm in its DNA binding in the pineal gland, which results from the rhythmic expression of Fra-2. We postulated that, if AP-1 is an important component of pineal gland functioning, then variations in photoperiodic conditions should lead to an adaptation of the AP-1 binding rhythm. Here we show that AP-1 binding patterns adapt to variations in lighting conditions, in the same way as the rhythm of arylalkylamine-N-acetyltransferase (AA-NAT) activity. This adaptation appeared to result from photoperiodic adaptation of the rhythmic fra-2 gene expression and was reflected by an adapted delay between the onset of night and the acrophase of the nocturnal peak. We further showed that photoperiodic adaptation of both the AP-1 binding and AA-NAT activity rhythms resulted from adapted changes in adrenergic inducibility of both variables at night onset. We finally provided evidence that AP-1 shared with the CREM gene encoding the transcriptional repressor protein inducible cAMP early repressor (ICER) the ability to be hypersensitive or subsensitive to adrenergic stimuli, depending on prior photoperiod.
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Affiliation(s)
- F Guillaumond
- Institut Fédératif Jean-Roche, Faculté de Médecine Nord, Université de la Méditerranée, Boulevard Pierre Dramard, 13916 Marseille cedex 20, France
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Abstract
It has been shown previously that the CRH-induced POMC gene transcription in the corticotroph cell line AtT-20 involves an increase in AP-1 DNA binding activity that remained elevated for at least 24 h, while induction of c-fos was transient. We showed here that there were dramatic changes in protein components of AP-1 including an initial recruitment of the transcriptional activators c-Fos and Jun-B then of Fra-2 and Jun-D. Changes in AP-1 composition were concomitant with a decrease in POMC mRNA. Moreover, the presence of Fra-2/Jun-D dimers suppressed the CRH-induction of c-fos mRNA expression as well as c-Fos/Jun-B recruitment in AP-1 complexes, suggesting the existence of autoregulatory loops of AP-1 composition that involve complex interactions between the different members of the Jun and Fos families. It is concluded that CRH stimulation of corticotroph cells involves successive recruitment of activators and repressors, possibly contributing to prevent over expression of POMC.
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Affiliation(s)
- D Becquet
- Interactions Fonctionnelles en Neuroendocrinologie, INSERM U 501 Faculté de Médecine Nord, Bd P. Dramard 13916 cedex 20, Marseille, France.
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François-Bellan AM, Guillaumond F, Bosler O, Becquet D. Is light-regulated AP-1 binding in the rat suprachiasmatic nucleus gated by the circadian clock? Brain Res Mol Brain Res 2000; 85:161-70. [PMID: 11146118 DOI: 10.1016/s0169-328x(00)00258-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In mammals, photic entrainment of circadian rhythms likely involves light- and clock-dependent expression of immediate early genes, including fos-like and jun-like genes, in the rat suprachiasmatic nucleus. Using an electrophoretic mobility shift assay, we evaluated whether the photic regulation of DNA-binding activity and composition of activating protein-1 (AP-1) complexes in the suprachiasmatic nucleus is also dependent on circadian phase. Phase-dependent light inducibility in the expression of fra-2 and c-fos genes and in immunoreactive Fra-2 and c-Fos protein expression was also evaluated, by in situ hybridization and immunocytochemistry. Light's effects on AP-1 DNA-binding differed both qualitatively and quantitatively according to the circadian phase at which light was applied. This phase dependence accounted for by both compartmentalization of proteins involved in constitutive AP-1 complexes within the nucleus or cytoplasm and control of the extent to which the expression of specific complexes was induced. It was then shown that the mechanisms by which the circadian clock gates the photic induction of AP-1 components differed according to the nature of the protein.
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Affiliation(s)
- A M François-Bellan
- INSERM U-501, Institut Fédératif Jean-Roche, Faculté de Médecine Nord, Université de la Méditerranée, Bd. Pierre Dramard, 13916 Marseille cedex 20, France.
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Guillaumond F, Sage D, Deprez P, Bosler O, Becquet D, François-Bellan AM. Circadian binding activity of AP-1, a regulator of the arylalkylamine N-acetyltransferase gene in the rat pineal gland, depends on circadian Fra-2, c-Jun, and Jun-D expression and is regulated by the clock's zeitgebers. J Neurochem 2000; 75:1398-407. [PMID: 10987819 DOI: 10.1046/j.1471-4159.2000.0751398.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The daily rhythm in circulating melatonin is driven by a circadian rhythm in the expression of the arylalkylamine N:-acetyltransferase gene in the rat pineal gland. Turning off expression of this gene at the end of night is believed to involve inhibitory transcription factors, among which Fos-related antigen 2 (Fra-2) appears as a good candidate. Circadian rhythms in the expression of three proteins of activating protein-1 (AP-1) complexes, namely, Fra-2, c-Jun, and Jun-D, are shown here to account for circadian variations in AP-1 binding activity. Quantitative variations in the Fra-2 component over the circadian cycle were associated with qualitative variations in protein isoforms. Destruction of the suprachiasmatic nucleus resulted in decreased nocturnal AP-1 activity, showing that AP-1 circadian rhythm is driven by this nucleus. Exposure to light during subjective night and administration of a serotonin 5-HT(1A)/5-HT(7) receptor agonist during subjective day, respectively, induced a 50% decrease and a 50% increase in both AP-1 and Fra-2 expression. These effects were impaired by suprachiasmatic nucleus lesions. These data show that pineal AP-1 binding activity, which results from Fra-2 expression, can be modulated by light and serotonin through the suprachiasmatic nucleus according to a "phase dependence" that is characteristic of the rhythm of clock sensitivity to both zeitgebers.
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Affiliation(s)
- F Guillaumond
- INSERM U501, Institut Fédératif Jean-Roche, Faculté de Médecine Nord, Université de la Méditerranée, Marseille, France
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Crevon L, Alla P, Colle B, Becquet D, Picot S, Flechaire A. À propos de quatre observations de myélite bilharzienne. Rev Med Interne 1999. [DOI: 10.1016/s0248-8663(99)80215-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Héry F, Boulenguez P, Sémont A, Héry M, Becquet D, Faudon M, Deprez P, Fache MP. Identification and role of serotonin 5-HT1A and 5-HT1B receptors in primary cultures of rat embryonic rostral raphe nucleus neurons. J Neurochem 1999; 72:1791-801. [PMID: 10217255 DOI: 10.1046/j.1471-4159.1999.0721791.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Autoregulatory mechanisms affecting serotonin [5-hydroxytryptamine (5-HT)] release and synthesis during the early period of development were investigated in dissociated cell cultures raised from embryonic rostral rat rhombencephalon. The presence of 5-HT1A and 5-HT1B receptors in serotoninergic neurons was assessed using binding assays. The involvement of 5-HT1A and 5-HT1B receptors in the control of the synthesis and release of [3H]5-HT was studied using biochemical approaches with several serotoninergic receptor ligands. A mean decrease of 30% in [3H]5-HT synthesis and release was observed in the presence of 5-HT (10(-8) M), the 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), the 5HT1B/1A agonist 5-methoxy-3-(1,2,5,6-tetrahydro-4-pyridinyl)-1H-indole (RU 24969), the 5-HT1B agonist 3-(1,2,5,6-tetrahydropyrid-4-yl)pyrrolo[3,2-b]pyrid-5-one (CP-93,129), and the 5-HT(1D/1B) agonist sumatriptan. Inhibition of 5-HT synthesis and release induced by 8-OH-DPAT was blocked by chiral N-tert-butyl-3-[1-[1-(2-methoxy)phenyl]piperazinyl]-1-phenylpropionam ide dihydrochloride quaternary-hydrate (WAY 100135) (10(7) M) or methyl 4-[4-[4-(1,1,3-trioxo-2H-1,2-benzoisothiazol-2-yl)butyl]-1-p iperazinyl]-1Hindole-2-carboxylate (SDZ 216-525) (10(-7)M), and that of CP-93,129 was blocked by methiothepin (10(-7) M). Paradoxically, extracellular levels of [3H]5-HT increased in the presence of 8-OH-DPAT and RU 24969 at 10(-6) M. 5-HT uptake experiments showed that these two agonists interacted with the 5-HT transporter. 5-HT1 binding sites (620 fmol/mg of protein) and 5-HT1A (482 fmol/mg of protein) and 5-HT1B (127 fmol/mg of protein) receptors were detected in 12-day in vitro cell cultures. Experiments carried out with tetrodotoxin suggested that 5-HT1A receptors are located on nerve cell bodies, whereas 5-HT1B receptors are located on the nerve terminals. We concluded that autoregulatory mechanisms involving 5-HT1A and 5-HT1B autoreceptors are functionally mature in cells from rostral raphe nuclei during the early period of development.
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Affiliation(s)
- F Héry
- Laboratoire de Neuroendocrinologie Expérimentale, INSERM U.501, Institut Fédératif Jean Roche, Université de la Méditerranée, UER de Médecine Nord, Marseille, France
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Abstract
Expression of immediate early genes, including fos-like and jun-like genes, in the suprachiasmatic nucleus is believed to be part of the mechanism for photic entrainment of circadian rhythms to the environmental light/dark cycle. However, the effects of a light stimulus on activating protein-1 (AP-1) complexes in the suprachiasmatic nucleus remain unclear. The photic regulation of AP-1 DNA-binding activity and composition in the rat suprachiasmatic nucleus was evaluated by using an electrophoretic mobility shift assay. A light pulse given during subjective night induced an increase in AP-1 binding activity when either nuclear or whole-cell extracts from suprachiasmatic nuclei were used. Under constant dark conditions, proteins that are predominant components of AP-1 complexes are Fra-2 and Jun-D. Under light stimulation, c-Fos and Jun-B consistently increased, as expected, but this was also the case for Fra-2, Jun-D, and c-Jun, although to a lesser extent. An immunocytochemical study of the Fra-2 expression pattern demonstrated the presence of the protein in the ventrolateral as well as in the dorsomedial subdivisions of the suprachiasmatic nucleus. Light regulation of Fra-2 immunoreactivity, however, appeared to be restricted to the ventrolateral subdivision. It is concluded that light may be acting both by increasing constitutive AP-1 complexes and by inducing the expression of specific complexes.
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Affiliation(s)
- A M François-Bellan
- Laboratoire des Interactions Fonctionnelles en Neuroendocrinologie, INSERM U501, Institut Fédératif Jean-Roche, Faculté de Médecine Nord, Marseille, France
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Manrique C, Bosler O, Becquet D, Héry F, Faudon M, François-Bellan AM. Post-lesion up-regulation of 5-HT1B binding sites in the suprachiasmatic nucleus may be reversed after spontaneous or graft-induced serotonin reinnervation. Brain Res 1998; 788:332-6. [PMID: 9555084 DOI: 10.1016/s0006-8993(98)00043-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have previously reported that selective axotomy of serotoninergic neurons produced by an intraventricular injection of 5, 7-dihydroxytryptamine is followed by an increase in 5-HT1B binding sites in the suprachiasmatic nucleus of the hypothalamus. This post-lesion up-regulation is shown here to be spontaneously reversed after long-term survival in spite of an incomplete reinnervation of the nucleus. Recovery may be accelerated by fetal raphe transplants that produce more rapid reinnervation.
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Affiliation(s)
- C Manrique
- Laboratoire de Neuroendocrinologie Expérimentale, INSERM U297, Institut Fédératif Jean Roche, Faculté de Médecine Nord, Boulevard Pierre Dramard, 13916 Marseille Cedex 20, France
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Héry M, François-Bellan AM, Héry F, Deprez P, Becquet D. Serotonin directly stimulates luteinizing hormone-releasing hormone release from GT1 cells via 5-HT7 receptors. Endocrine 1997; 7:261-5. [PMID: 9549053 DOI: 10.1007/bf02778149] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Luteinizing hormone-releasing hormone (LHRH release, which serves as the primary drive to the hypothalamic-pituitary gonadal axis, is controlled by many neuromediators. Serotonin has been implicated in this regulation. However, it is unclear whether the central effect of serotonin on LHRH secretion is exerted directly on LHRH neurosecretory neurons or indirectly via multisynaptic pathways. The present studies were undertaken in order to examine whether LHRH secretion from immortalized LHRH cell lines is directly regulated by serotonin and, if so, to identify the receptor subtype involved. 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a 5-HT1A/7 receptor agonist, stimulated LHRH release from GT1-1 cells. This effect was blocked by ritanserin, a 5-HT2/7 receptor antagonist, but not by SDZ-216-525, a 5-HT1A antagonist. Basal LHRH release was not affected by the 5-HT2 agonist DOI. Reverse transcription and polymerase chain reaction technique (RT-PCR) was used in order to identify 5-HT1A and 5-HT7 receptor mRNA in immortalized LHRH cell lines. GT1-1 cells express mRNA for the 5-HT7, but not the 5-HT1A receptor subtypes. These results demonstrate a direct stimulatory effect of serotonin on LHRH release via 5-HT7 receptor.
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Affiliation(s)
- M Héry
- Laboratoire de Neuroendocrinologie Expérimentale, INSERM U297, Faculté de Médecine Nord, Institut Fédératif Jean Roche, Marseille, France.
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Gerin C, Becquet D, Privat A. Direct evidence for the link between monoaminergic descending pathways and motor activity. I. A study with microdialysis probes implanted in the ventral funiculus of the spinal cord. Brain Res 1995; 704:191-201. [PMID: 8788914 DOI: 10.1016/0006-8993(95)01111-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Monoaminergic projections to the spinal cord are involved in the modulation of motor, autonomic, and sensory functions. More specifically, the increase of electrical activity of serotonergic neurons in raphe obscurus has been correlated with locomotion in treadmill-trained cats [Jacobs, B.L. and Fornal, C., Trends Neurosci., 9 (1993) 346-352]. In order to test the direct correlation between locomotion and the release of monoamines, microdialysis probes were permanently implanted for 45 days into the ventral funiculus of the spinal cord (white matter) of adult rats. Eight days after implantation, these rats were subjected to an endurant exercise on a treadmill, and dialysis sessions were organized in such a way that microdialysate samples of 15 min duration were collected during pre-, per- and post-exercise periods. Measurements of serotonin, 5-hydroxyindoleacetic acid, dopamine and 3-methoxy-4-hydroxyphenylethylglycol concentration in the extracellular space showed significant increases during locomotion when compared with both pre- and post-exercise values. Histological analysis shows that serotonergic axons were present close to the dialysis probe. These results demonstrate that the implantation of a microdialysis probe in the ventral funiculus, close to a potential target of monoaminergic projections, is a suitable technique for the collection of neuromediators released during spontaneous running.
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Affiliation(s)
- C Gerin
- INSERM U-336, Université Montpellier 2, France
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31
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Héry M, Becquet D, François-Bellan AM, Deprez P, Fache MP, Héry F. Stimulatory effects of 5HT1A receptor agonists on luteinizing hormone-releasing hormone release from cultured fetal rat hypothalamic cells: interactions with progesterone. Neuroendocrinology 1995; 61:11-8. [PMID: 7731493 DOI: 10.1159/000126828] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Previous works have suggested an interactive stimulatory effect of progesterone (P) and serotonin (5-HT) on luteinizing hormone release. The purpose of the present study was to determine whether 5-HT via 5-HT1A receptors interacts with P in the process of luteinizing hormone-releasing hormone (LHRH) release. Using fetal hypothalamic neurons in primary cell cultures the first goal of this study was to determine the effects of 5-HT1A receptor agonists on LHRH secretion. 8-Hydroxy-2 (di-n-propylamino) tetralin (8-OH-DPAT) or ipsapirone (10(-5) M) significantly stimulated LHRH release. Pharmacological studies have allowed to rule out the possible involvement of alpha 2- or beta-adrenoreceptors, or 5-HT uptake sites, in the stimulatory effect of 8-OH-DPAT on LHRH release, thus demonstrating the specific involvement of 5-HT1A receptors in the stimulation of LHRH release. The second goal was to test the ability of P to stimulate LHRH release from fetal hypothalamic neurons. P (10(-6) M) applied for 30 or 120 min significantly stimulated LHRH secretion. The maintenance of the stimulation of LHRH release by P after a cycloheximide treatment or by an impermeable analog of P, P-3-BSA, has suggested a nongenomic effect of P on LHRH release. The effects of a pretreatment of cells by P on 8-OH-DPAT-induced LHRH release were tested. While 10(-7) M P alone did not stimulate LHRH release, this concentration of steroid potentiated the LHRH response to 10(-5) M 8-OH-DPAT. These findings led to the conclusion that P acting at the level of the plasma membrane potentiates the stimulatory effect of 5-HT1A receptor agonists on LHRH release.
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Affiliation(s)
- M Héry
- Laboratoire de Neuroendocrinologie Expérimentale, INSERM U-297, Institut Fédératif, Jean Roche, Faculté de Médecine Nord, Marseille, France
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Manrique C, François-Bellan AM, Segu L, Becquet D, Héry M, Faudon M, Héry F. Impairment of serotoninergic transmission is followed by adaptive changes in 5HT1B binding sites in the rat suprachiasmatic nucleus. Brain Res 1994; 663:93-100. [PMID: 7531598 DOI: 10.1016/0006-8993(94)90466-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Serotonin1B (5-HT1B) receptor binding in the suprachiasmatic nucleus (SCN) following impairment of serotoninergic transmission was studied by quantitative autoradiography. Serotonin (5-HT) denervation with 5,7-dihydroxytryptamine (5,7-DHT) caused a significant increase in the density of 5-HT1B receptors in both the ventral (62%) and dorsal (53%) parts of the SCN as early as 3 days after axotomy. The magnitude of this increase did not differ 3, 15 or 21 days post-lesion. An up-regulation of 5-HT1B receptors with similar magnitude was obtained in the two parts of the SCN after inhibition of 5-HT synthesis by chronic parachlorophenylalanine treatment. In this case, up-regulation was shown to be reversible after restoration of 5-HT synthesis with L-5-hydroxytryptophan. These results indicate that 5-HT1B receptor density in the SCN was inversely correlated with 5-HT levels. These plastic properties exhibited by 5-HT1B receptors in the SCN are discussed in relation to the mode of 5-HT transmission and possible localization of the receptors onto the main chemically defined cell populations of the nucleus.
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Affiliation(s)
- C Manrique
- Laboratoire de Neuroendocrinologie Expérimentale, INSERM U297, Institut Fédératif Jean Roche, Faculté de Médecine Nord, Marseille, France
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33
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Becquet D, Héry M, Deprez P, Faudon M, Fache MP, Giraud P, Héry F. N-methyl-D-aspartic acid/glycine interactions on the control of 5-hydroxytryptamine release in raphe primary cultures. J Neurochem 1993; 61:1692-7. [PMID: 7901329 DOI: 10.1111/j.1471-4159.1993.tb09805.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Glutamic acid and glycine were quantified in cells and medium of cultured rostral rhombencephalic neurons derived from fetal rats. In the presence of 1 mM Mg2+, NMDA (50 microM) significantly stimulated (by 69%) release of newly synthesized 5-[3H]hydroxytryptamine ([3H]5-HT). D-2-Amino-5-phosphonopentanoate (AP-5; 50 microM) blocked the stimulatory effect of NMDA. AP-5 by itself inhibited [3H]5-HT release (by 25%), suggesting a tonic control of 5-HT by glutamate. In the absence of Mg2+, basal [3H]5-HT release was 60% higher as compared with release with Mg2+. AP-5 blocked the increased [3H]5-HT release observed without Mg2+, suggesting that this effect was due to the stimulation of NMDA receptors by endogenous glutamate. Glycine (100 microM) inhibited [3H]5-HT release in the absence of Mg2+. Strychnine (50 microM) blocked the inhibitory effect of glycine, indicating an action through strychnine-sensitive inhibitory glycine receptors. The [3H]5-HT release stimulated by NMDA was unaffected by glycine. In contrast, when tested in the presence of strychnine, glycine increased NMDA-evoked [3H]5-HT release (by 22%), and this effect was prevented by a selective antagonist of the NMDA-associated glycine receptor, 7-chlorokynurenate (100 microM). 7-Chlorokynurenate by itself induced a drastic decrease in [3H]5-HT release, indicating that under basal conditions these sites were stimulated by endogenous glycine. These results indicate that NMDA stimulated [3H]5-HT release in both the presence or absence of Mg2+. Use of selective antagonists allowed differentiation of a strychnine-sensitive glycine response (inhibition of [3H]5-HT release) from a 7-chlorokynurenate-sensitive response (potentiation of NMDA-evoked [3H]5-HT release).
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Affiliation(s)
- D Becquet
- Laboratoire de Neuroendocrinologie Expérimentale, INSERM U. 297, UER Faculté de Médecine-Nord, Marseille, France
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Becquet D, Hery M, Francois-Bellan AM, Giraud P, Deprez P, Faudon M, Fache MP, Hery F. Glutamate, GABA, glycine and taurine modulate serotonin synthesis and release in rostral and caudal rhombencephalic raphe cells in primary cultures. Neurochem Int 1993; 23:269-83. [PMID: 7693110 DOI: 10.1016/0197-0186(93)90118-o] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Control of serotonin release and synthesis by amino acid neurotransmitters was investigated in rat rostral and caudal rhombencephalic raphe cells in primary cultures respectively. Endogenous amounts of taurine, glycine, GABA and glutamate were measured in both types of cultures. These amino acids were spontaneously released to the incubating medium. Exogenous taurine (10(-4) M) inhibited release and synthesis of newly formed [3H]serotonin [3H]5-HT from [3H]-tryptophan only in rostral raphe cells. Glycine (10(-3) M) decreased [3H]5-HT release in both types of cells, synthesis being diminished only in rostral raphe cells. Glycine inhibitory effect was totally blocked by strychnine (5 x 10(-5) M). GABA (10(-4) M) reduced [3H]5-HT metabolism in rostral as well as caudal raphe cells. This effect was totally antagonized in caudal and partially in rostral raphe cells by bicuculline (5 x 10(-5) M) a GABAA receptor antagonist. Baclofen (5 x 10(-5) M), a GABAB receptor agonist, induced a decrease of 5-HT release in rostral raphe cells. These observations suggest that monoamine release was entirely mediated by GABAA receptors in caudal raphe cells although GABAA and GABAB receptors were involved in control of 5-HT metabolism in rostral raphe cells. L-glutamate (10(-4) M) stimulated 5-HT metabolism in both types of cells, effect totally blocked by PK26124 (10(-6) M). N-methyl-D-aspartate (10(-4) M) enhanced 5-HT metabolism and the induced-effect was antagonized by the selective N-methyl-D-aspartate receptor antagonist D,L-2 amino-5-phosphonovaleric acid. Quisqualate (10(-5) M) stimulated [3H]5-HT release only in caudal raphe cells. This effect was mimicked by (RS)-a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, a quisqualate "ionotropic" receptor agonist, this increase being blocked by 6,7-dinitroquinoxaline 2,3-dione. These observations suggest that the glutamate stimulating-induced effect on serotonin metabolism is entirely mediated by N-methyl-D-aspartate receptor-type in rostral raphe cells and that quisqualate "ionotropic" receptors are also involved in caudal raphe cells. Taken together these results show that [3H]5-HT metabolism is controlled by taurine, glycine, GABA and glutamate in rhombencephalic raphe cells in primary cultures. However, some difference in amino acid receptor-types involved in the control of serotonin metabolism are observed according to the rostral or caudal origin of raphe cells.
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Affiliation(s)
- D Becquet
- Inserm U 297, Faculté de Médecine Nord, Marseille, France
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Joanny P, Peyre G, Steinberg J, Guillaume V, Pesce G, Becquet D, Oliver C. Effect of diabetes on in vivo and in vitro hypothalamic somatostatin release. Neuroendocrinology 1992; 55:485-91. [PMID: 1350065 DOI: 10.1159/000126161] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In order to better understand the mechanisms underlying the reduction in growth hormone (GH) secretion in diabetic rats, we studied hypothalamic somatostatin secretion both in vivo (into hypophysial portal blood) and in vitro (from hypothalamic fragments) 5, 9 and 30 days after induction of diabetes. Experimental diabetes was induced by an intraperitoneal injection of streptozotocin (STZ) at a dose of 65 mg/kg. Basal plasma GH was significantly reduced in diabetic rats at all stages. Somatostatin levels in hypophysial portal blood was unaffected in 5-day STZ-diabetic rats and significantly increased 9 days after STZ administration. Chronic insulin replacement therapy in diabetic animals partly normalized somatostatin levels as well as plasma GH and glucose levels. A good correlation was observed between in vivo and in vitro experiments. Indeed, somatostatin release from hypothalamic fragments did not change 5 days after STZ-induced diabetes and significantly increased 9 and 30 days after STZ administration. The in vitro increase in hypothalamic somatostatin secretion was observed in 10 as well as in 33 mM glucose concentration in the incubation medium. In the same experiment, the in vitro hypothalamic corticotropin-releasing factor secretion was lowered 5 and 9 days after diabetes induction. We conclude that hypothalamic somatostatin release increases in diabetic rats. These changes may contribute to the reduction in GH secretion in these animals. However, since these changes occur after the onset of plasma GH decrease, a factor(s) other(s) than somatostatin may play a causal role in the reduction in GH secretion.
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Affiliation(s)
- P Joanny
- Laboratoire de Neuroendocrinologie, Expérimentale, INSERM U 297, Faculté de Médecine Nord, Marseille, France
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Abstract
The inter-renal (adrenal) gland of amphibians is composed of chromaffin and steroidogenic cells which can interact through a paracrine mode of communication. We have previously shown that serotonin is present in secretory granules of frog adrenochromaffin cells; concurrently, we have demonstrated that serotonin is a potent stimulator of corticosterone and aldosterone secretion by adrenocortical cells. The aim of the present study was to determine the origin of the amine contained in frog chromaffin cells. Using 3H-labelled tryptophan as a precursor, we observed the formation of substantial amounts of serotonin and its metabolite 5-hydroxyindoleacetic acid by frog inter-renal slices. Newly synthesized serotonin was secreted into the incubation medium and the release process was enhanced by depolarizing concentrations of KCl. Fluoxetine, and inhibitor of serotonin uptake, caused an increase of 3H-labelled serotonin in the incubation medium, suggesting that the indoleamine was taken up again by adrenal chromaffin cells. The capacity of the frog inter-renal gland to synthesize serotonin was also demonstrated by incubating inter-renal slices with non-labelled tryptophan or 5-hydroxytryptophan. In these conditions, we observed that the rate of synthesis was higher when 5-hydroxytryptophan was used as a a precursor, rather than tryptophan. Taken together, these results indicate that chromaffin cells, which have the capacity for synthesizing and releasing serotonin, behave like authentic serotonergic paraneurons. As far as is known, these data provide the first evidence for the occurrence of tryptophan-5-hydroxylase activity within the adrenal gland.
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Affiliation(s)
- C Delarue
- European Institute for Peptide Research, Laboratory of Molecular Endocrinology, CNRS URA 650, UA INSERM, University of Rouen, Mont-Saint-Aignan, France
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Boudouresque F, Chautard T, Jezová D, Becquet D, Guillaume V, Héry F, Giraud P, Grino M, Oliver C. Excitatory amino acids and adenopituitary hormone secretion in mammals, with special reference to development. Endocr Regul 1991; 25:44-52. [PMID: 1683588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- F Boudouresque
- Laboratoire de Neuroendocrinologie Expérimentale, INSERM U 297, Faculté de Médecine, Marseille, France
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Grino M, Boudouresque F, Chautard T, Becquet D, Guillaume V, Strbák V, Oliver C. Developmental aspects of the hypothalamic-pituitary-adrenal axis in the rat. Endocr Regul 1991; 25:36-43. [PMID: 1958831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- M Grino
- Laboratoire de Neuroendocrinologie Expérimentale, INSERM U 297, Faculté de Médecine, Marseille, France
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Becquet D, Héry F, Héry M, Drian MJ, Faudon M, König N. Population-specific modulation of 5-HT expression in cultures of embryonic rat rhombencephalon. J Neurosci Res 1991; 29:42-50. [PMID: 1886167 DOI: 10.1002/jnr.490290105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This study aimed at analyzing the regulation of in vitro serotonin expression by neurons taken from different regions of the embryonic rat rhombencephalon. We studied the influence of co-culture with alarplate tissue using immunocytochemical and biochemical methods. Computer-assisted densitometry was used to estimate the co-culture effects on the serotonin content of the cell bodies. The more dynamic aspects of serotonin expression, such as synthesis and release, were studied by measuring (3H)serotonin newly synthesized from (3H)tryptophan. The density of the immunostaining was significantly decreased in B1,B2 cells by co-culture with both caudal and rostral alar-plate tissue. For B4-B9 cells, only co-culture with rostral alar-plate tissue produced a significant decrease. The de novo synthesis of serotonin was significantly decreased in B1,B2 neurons co-cultured with caudal alar-plate tissue only. Once again, the B4-B9 cells proved to be less influenced by the experimental conditions, as co-culture with both types of alar-plate tissue produced no significant effect. We concluded that the in vitro expression of serotonin can be modulated by environmental factors, but the relative influence of these factors is very different in rostral versus caudal serotonin expressing cell populations.
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Affiliation(s)
- D Becquet
- Laboratoire de Neurobiologie du Developpement, INSERM U 336, Institut de Biologie, Montpellier, France
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Giraud P, Kowalski C, Barthel F, Becquet D, Renard M, Grino M, Boudouresque F, Loeffler JP. Striatal proenkephalin turnover and gene transcription are regulated by cyclic AMP and protein kinase C-related pathways. Neuroscience 1991; 43:67-79. [PMID: 1656316 DOI: 10.1016/0306-4522(91)90418-n] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Preproenkephalin metabolism, in the rat, was studied in primary striatal neurons maintained in a chemically defined medium. Acute treatment (30 min) with forskolin (10(-5) M) or phorbol 12 myristate 13 acetate (10(-7) M) resulted, respectively, in a two- and seven-fold increase in methionine-enkephalin secretion. Chronic treatment with forskolin or phorbol 12 myristate 13 acetate (24 h) induced a 100% increase in methionine-enkephalin content (forskolin) and on the other hand a 50% decrease in methionine-enkephalin (phorbol 12 myristate 13 acetate). Both treatments increased preproenkephalin mRNA levels in a time-dependent manner, this augmentation being observable after 180 min by Northern blot analysis and in situ hybridization. These data indicate that under chronic stimulation, with either forskolin or phorbol 12 myristate 13 acetate, proenkephalin turnover is accelerated. However, after stimulation with phorbol 12 myristate 13 acetate, the more potent methionine-enkephalin secretagogue, increased peptide synthesis is not sufficient to replenish methionine-enkephalin intracellular stores. Preproenkephalin gene transcription was analysed by introducing the preproenkephalin gene promoter fused to the bacterial acetyl chloramphenicol transferase reporter gene into primary neurons. Chronic stimulation (48 h) by forskolin (10(-5) M) or phorbol 12 myristate 13 acetate (10(-7) M) of striatal neurons transfected with this fusion gene increased chloramphenicol acetyltransferase activity six-fold and the two effects were additive. These data suggest that the cyclic AMP and the protein kinase C pathways directly activate preproenkephalin gene transcription.
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Affiliation(s)
- P Giraud
- Laboratoire de Neuroendocrinologie Expérimentale, INSERM U297 affilée au CRNS, Faculté de Médecine Nord, France
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Abstract
The TRH secretory responsiveness of the pancreatic islet cell clusters from newborn rat in organ culture was studied. Basal TRH secretion was stable over a 9-day period. The response to various secretagogues was tested on day 4. TRH secretion was stimulated by high potassium-induced depolarization and also through both cAMP and protein kinase-C dependent pathways. Like insulin, TRH release was stimulated by glucose and arginine and inhibited by somatostatin. These data suggest the existence of a common mechanism for TRH and insulin secretion by the pancreatic beta-cells.
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Affiliation(s)
- A Dutour
- Laboratoire de Neuroendocrinologie Expérimentale, INSERM U 297, Faculté de Médecine Nord Bd P. Dramard, Marseille, France
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Becquet D, Faudon M, Hery F. In vivo evidence for an inhibitory glutamatergic control of serotonin release in the cat caudate nucleus: involvement of GABA neurons. Brain Res 1990; 519:82-8. [PMID: 1975768 DOI: 10.1016/0006-8993(90)90063-h] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The local effect of L-glutamic acid (5 x 10(-5) M) on the release of [3H]serotonin continuously synthesized from [3H]tryptophan was examined in the caudate nucleus of 'encéphale isolé' unanaesthetized cats implanted with push-pull cannula. L-Glutamic acid (5 x 10(-5) M) decreased [3H]serotonin release from nerve terminals of the dorsalis raphe-striatal serotonergic neurons. The effect was antagonized by 2-amino-6-trifluoromethoxybenzothiazole (PK 26124) (10(-6) M), an antagonist of glutamatergic transmission. This effect was mimicked by N-methoxy-D-aspartic acid NMDA (5 x 10(-5) M) and prevented by DL-2-phosphono-valeric acid (APV) (5 x 10(-6) M), indicating that L-glutamic acid decreased serotonin release via a N-methoxy-D-aspartate type receptor. The superfusion of serotonergic nerve terminals in the caudate nucleus with tetrodotoxin prevented the inhibitory L-glutamic acid-induced effect on serotonin release. Furthermore, L-glutamic acid-induced inhibition of [3H]serotonin release was antagonized by bicuculline (5 x 10(-5) M). These data suggest that the glutamatergic receptors involved were not located directly on serotonin nerve terminals. The inhibitory control exerted by L-glutamic acid on serotonergic transmission could involve gamma-aminobutyric acid interneurons. Since no reduction of spontaneous [3H]serotonin release was observed in the presence of bicuculline, GABAergic neurons appeared to exert a phasic influence on serotonin release. Indirect inhibitory presynaptic control on serotonin release mediated by corticostriatal glutamatergic fibers is discussed in light of previous findings.
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Affiliation(s)
- D Becquet
- Laboratoire de Neuroendocrinologie Expérimentale, Faculté de Médecine Nord, I.N.S.E.R.M. U.297, Marseille, France
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Becquet D, Francois-Bellan AM, Boudouresque F, Faudon M, Hery F, Guillaume V, Hery M. Serotonin synthesis from tryptophan by hypothalamic cells in serum-free medium culture. Brain Res Dev Brain Res 1990; 54:142-6. [PMID: 1694745 DOI: 10.1016/0165-3806(90)90075-a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The hypothalamus of both adult and fetal rats contains a population of cells which can exhibit some features of serotoninergic (5-HT) neurons under certain circumstances. However, their neuronal serotoninergic nature is still controversial. In fact the presence of tryptophan hydroxylase activity has not yet been clearly established. This study attempted to verify whether [3H]5-HT can be synthesized from [3H]tryptophan ([3H]TRP) in hypothalamic cell cultures from 16-day-old fetuses. Data showed that [3H]5-HT was synthesized from [3H]TRP and the amounts of [3H]5-HT increased linearly as a function of time for 60 min. Pargyline markedly increased the quantities of [3H]5-HT and decreased those of [3H]5-hydroxyindole acetic acid. [3H]5-HT synthesis was inhibited by p-chlorophenylalanine, while alpha-methyl-p-tyrosine had no effect. The present biochemical study shows the presence of an intrinsic 5-HT neuronal system in the hypothalamus of the fetal rat.
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Affiliation(s)
- D Becquet
- Faculté de Médecine Nord, Laboratoire de Neuroendocrinologie Expérimentale, INSERM U 297, Marseille, France
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Becquet D, Faudon M, Hery F. The role of serotonin release and autoreceptors in the dorsalis raphe nucleus in the control of serotonin release in the cat caudate nucleus. Neuroscience 1990; 39:639-47. [PMID: 2097518 DOI: 10.1016/0306-4522(90)90248-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Using a push-pull cannula technique and an isotopic method for estimating [3H]serotonin continuously synthesized from [3H]tryptophan, the effects of changes in the release of serotonin in the dorsalis raphe nucleus on in vivo release of [3H]serotonin in the cat caudate nucleus were investigated. The increase in the release of serotonin in the dorsalis raphe nucleus caused by local application of parachlorophenylethylamine (10(-6) M) reduced striatal [3H]serotonin release. This inhibition in serotonin release in the striatum was blocked by the prior and continuous local superfusion of the dorsal raphe with methiothepin (10(-6) M), a serotonin autoreceptor antagonist. GABA (5 x 10(-5) M) applied to the dorsalis raphe reduced both local and striatal release of [3H]serotonin. However, picrotoxin (10(-5) M), a GABA A receptor antagonist applied locally in the dorsalis raphe nucleus increased [3H]serotonin release while decreasing striatal [3H]serotonin release. This decrease in serotonin release in the striatum was again blocked by continuous superfusion of the raphe with methiothepin. Furthermore, superfusion of serotonergic cell bodies of the dorsalis raphe nucleus with methiothepin alone never altered local release or striatal release of [3H]serotonin. These data strongly suggest that the release of serotonin from the cell body in the dorsalis raphe nucleus phasically controls release of the amine at the axonal nerve ending through serotonergic autoreceptors located on serotonergic nerve cell bodies in the dorsalis raphe nucleus. The origin of the serotonin released in the dorsalis raphe nucleus and the possibility that this type of regulation could be related to changes in nerve impulse conduction of the serotonergic raphe-striatal system are discussed.
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Affiliation(s)
- D Becquet
- Laboratoire de Neuroendocrinologie Expérimentale, Faculté de Médecine Nord, INSERM U 297 and CNRS, Marseille, France
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Oliver C, Jezová D, Grino M, Guillaume V, Boudouresque F, Conte-Devolx B, Pesce G, Dutour A, Becquet D. Differences in the effects of acute and chronic administration of dexfenfluramine on cortisol and prolactin secretion. Adv Exp Med Biol 1990; 274:427-43. [PMID: 2173365 DOI: 10.1007/978-1-4684-5799-5_27] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- C Oliver
- Laboratoire de Neuroendocrinologie Expérimentale, INSERM U 297, Faculté de Médecine Nord, Marseille, France
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Becquet D, Faudon M, Hery F. Effect of thalamic parafascicularis nucleus stimulation in regulation of serotoninergic transmission in the cat caudate nucleus: involvement of autoreceptors in the dorsalis raphe nucleus. Neuroscience 1989; 33:293-300. [PMID: 2622527 DOI: 10.1016/0306-4522(89)90209-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The mechanisms involved in parafascicularis nucleus control on serotoninergic neurons projecting into the caudate nucleus were investigated in "encéphale-isole" cats. The effects of unilateral stimulation of the parafascicularis nucleus on the release of newly synthesized [3H]serotonin were simultaneously determined in the ipsilateral caudate nucleus and the dorsalis raphe nucleus using push-pull cannulae. The actions of various pharmacological treatments performed either in the caudate nucleus or in the dorsalis raphe nucleus were also examined. The electrical or chemical stimulation of the parafascicularis nucleus induced a decrease in striatal [3H]serotonin release and an increase in [3H]serotonin release in the dorsalis raphe nucleus. The blockade of cholinergic (mecamylamine) and glutamatergic (PK 26124) transmissions at the striatal level did not modify the thalamic stimulation-induced effect on serotonin release in the caudate nucleus or in the dorsalis raphe nucleus. However, a decrease induced by parafascicularis nucleus stimulation in serotonin release in the caudate nucleus could not be observed when the autoreceptors present on serotoninergic nerve cell bodies localized in the dorsalis raphe nucleus were blocked by a methiothepin perfusion within the nucleus. These results indicate that the parafascicularis nucleus controls striatal serotonin transmission by inducing changes in the nerve activity of serotoninergic neurons in the dorsalis raphe nucleus via somatodendritic serotonin release and autoreceptors.
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Affiliation(s)
- D Becquet
- Laboratoire de Neuroendocrinologie Experimentale, Faculté de Médecine Nord, INSERM U 297, Marseille, France
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Héry F, Becquet D, Faudon M. [Regulation of serotoninergic transmission in the basal ganglia]. Encephale 1989; 15 Spec No:127-32. [PMID: 2545432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- F Héry
- Laboratoire de Neuroendocrinologie Expérimentale INSERM Unité 297, UER de Médecine Nord, Marseille
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Becquet D, Faudon M, Hery F. In vivo evidence for acetylcholine control of serotonin release in the cat caudate nucleus: influence of halothane anaesthesia. Neuroscience 1988; 27:819-26. [PMID: 3252174 DOI: 10.1016/0306-4522(88)90185-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Using a push-pull cannula technique and an isotopic method for the estimation of [3H]serotonin continuously synthesized from [3H]tryptophan, the effects of acetylcholine were investigated on the in vivo release of [3H]serotonin in the cat basal ganglia and the dorsal raphe nucleus. The unilateral striatal application of acetylcholine (5 x 10(-5) M) reduced local release of [3H]serotonin. This effect was mimicked by nicotine (5 x 10(-5) M) and prevented by mecamylamine (10(-6) M. Oxotremorine (5 x 10(-5) M) had no effect on the local release of [3H]serotonin. All these treatments failed to modify [3H]serotonin release in the ipsilateral substantia nigra or in the dorsal raphe nucleus. The superfusion of serotonergic nerve terminals of the caudate nucleus with tetrodotoxin prevented the inhibitory acetylcholine-induced effect on serotonin release. Furthermore, bicuculline (5 x 10(-5) M) in the caudate nucleus blocked the effect of nicotine, while gamma-aminobutyric acid (10(-5) M) induced a decrease in local release of [3H]serotonin. These data strongly suggest that the inhibitory control exerted by acetylcholine on serotonergic transmission could involve gamma-aminobutyric acid interneurons. Acetylcholine-induced changes in [3H]serotonin release were only observed in non-anaesthetized "encéphale isolé" cats and not in halothane-anaesthetized animals. The possibility that such a regulation could be presynaptic (direct or through other neurotransmitters) or related to a change in the activity of the serotonergic raphe-striatal neuronal system is discussed.
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Becquet D, Faudon M, Hery F. Effects of thalamic lesion on the bilateral regulation of serotoninergic transmission in rat basal ganglia. J Neural Transm (Vienna) 1988; 74:117-28. [PMID: 2466948 DOI: 10.1007/bf01245145] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Unilateral kainic acid lesion of the rat centromedian-parafascicular complex (CM-PF) of the thalamus induced a decrease in the 5-hydroxyindole acetic acid/5-hydroxytryptamine ratio both in ipsi and contralateral striatum and substantia nigra, and an increase in both ipsi and contralateral frontal cerebral cortex. No change in apparent serotonin turnover was detected in anterior raphe nuclei. Serotonin synthesis, estimated by measuring 5-hydroxytryptophan accumulation after injection of a decarboxylase inhibitor, was not affected by the CM-PF lesion. The possible pathways involved in the control of serotonin transmission by CM-PF are discussed.
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Affiliation(s)
- D Becquet
- Departement de Neuropharmacologie INSERM U 6, Marseille, France
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