1
|
Ducroq S, Duplus E, Penalva-Mousset L, Trivelloni F, L’honoré A, Chabat-Courrède C, Nemazanyy I, Grange-Messent V, Petropoulos I, Mhaouty-Kodja S. Behavior, Neural Structure, and Metabolism in Adult Male Mice Exposed to Environmentally Relevant Doses of Di(2-ethylhexyl) Phthalate Alone or in a Phthalate Mixture. ENVIRONMENTAL HEALTH PERSPECTIVES 2023; 131:77008. [PMID: 37458746 PMCID: PMC10351581 DOI: 10.1289/ehp11514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/12/2023] [Accepted: 06/23/2023] [Indexed: 07/20/2023]
Abstract
BACKGROUND We have previously shown that chronic exposure of adult male mice to low doses of di(2-ethylhexyl) phthalate (DEHP) altered male sexual behavior and induced down-regulation of the androgen receptor (AR) in the neural circuitry controlling this behavior. OBJECTIVES The cellular mechanisms induced by chronic exposure of adult male mice to low doses of DEHP alone or in an environmental phthalate mixture were studied. METHODS Two-month-old C57BL/6J males were exposed orally for 8 wk to DEHP alone (0, 5, or 50μg/kg/d) or to DEHP (50μg/kg/d) in a phthalate mixture. Behavior, dendritic density per 50-μm length, pre-/postsynaptic markers, synapse ultrastructure, and bioenergetic activity were analyzed. RESULTS Mice exposed to DEHP either alone or in a phthalate mixture differed in mating, emission of ultrasonic vocalizations, and the ability to attract receptive females in urinary preference tests from control mice. Analyses in the medial preoptic area, the key hypothalamic region involved in male sexual behavior, showed lower dendritic spine density and protein levels of glutamate receptors and differences in other postsynaptic components and presynaptic markers between the treated groups. Ultrastructural observation of dendritic synapses by electron microscopy showed comparable morphology between the treated groups. Metabolic analyses highlighted differences in hypothalamic metabolites of males exposed to DEHP alone or in a phthalate mixture compared to control mice. These differences included lower tryptophan and higher NAD+ levels, respectively, a precursor and end product of the kynurenine pathway of tryptophan metabolism. The protein amounts of the xenobiotic aryl hydrocarbon receptor, one of the targets of this metabolic pathway and known negative regulator of the AR, were higher in the medial preoptic area of exposed male mice. DISCUSSION Differences in behavior of male mice exposed to environmental doses of phthalates were associated with differences in neural structure and metabolism, with possibly a key role of the kynurenine pathway of tryptophan metabolism in the effects mediated by these substances. https://doi.org/10.1289/EHP11514.
Collapse
Affiliation(s)
- Suzanne Ducroq
- Sorbonne Université, CNRS UMR 8246, Inserm U1130, Neuroscience Paris Seine – Institut de Biologie Paris Seine, 75005 Paris, France
| | - Eric Duplus
- Sorbonne Université, CNRS UMR 8256, Inserm ERL1164, Biological Adaptation and Ageing – Institut de Biologie Paris-Seine, 75005 Paris, France
| | - Lucille Penalva-Mousset
- Sorbonne Université, CNRS UMR 8256, Inserm ERL1164, Biological Adaptation and Ageing – Institut de Biologie Paris-Seine, 75005 Paris, France
| | - Francesca Trivelloni
- Sorbonne Université, CNRS UMR 8246, Inserm U1130, Neuroscience Paris Seine – Institut de Biologie Paris Seine, 75005 Paris, France
| | - Aurore L’honoré
- Sorbonne Université, CNRS UMR 8256, Inserm ERL1164, Biological Adaptation and Ageing – Institut de Biologie Paris-Seine, 75005 Paris, France
| | - Caroline Chabat-Courrède
- Sorbonne Université, CNRS UMR 8256, Inserm ERL1164, Biological Adaptation and Ageing – Institut de Biologie Paris-Seine, 75005 Paris, France
| | - Ivan Nemazanyy
- Platform for Metabolic Analyses, Structure Fédérative de Recherche Necker, Inserm US24/CNRS UMS 3633, Paris 75015, France
| | - Valérie Grange-Messent
- Sorbonne Université, CNRS UMR 8246, Inserm U1130, Neuroscience Paris Seine – Institut de Biologie Paris Seine, 75005 Paris, France
| | - Isabelle Petropoulos
- Sorbonne Université, CNRS UMR 8256, Inserm ERL1164, Biological Adaptation and Ageing – Institut de Biologie Paris-Seine, 75005 Paris, France
| | - Sakina Mhaouty-Kodja
- Sorbonne Université, CNRS UMR 8246, Inserm U1130, Neuroscience Paris Seine – Institut de Biologie Paris Seine, 75005 Paris, France
| |
Collapse
|
2
|
Jean A, Mhaouty-Kodja S, Hardin-Pouzet H. Hypothalamic cellular and molecular plasticity linked to sexual experience in male rats and mice. Front Neuroendocrinol 2021; 63:100949. [PMID: 34687674 DOI: 10.1016/j.yfrne.2021.100949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/22/2021] [Accepted: 10/18/2021] [Indexed: 10/20/2022]
Abstract
Male sexual behavior is subject to learning, resulting in increased efficiency of experienced males compared to naive ones. The improvement in behavioral parameters is underpinned by cellular and molecular changes in the neural circuit controlling sexual behavior, particularly in the hypothalamic medial preoptic area. This review provides an update on the mechanisms related to the sexual experience in male rodents, emphasizing the differences between rats and mice.
Collapse
Affiliation(s)
- Arnaud Jean
- Sorbonne Université - Faculté de Sciences et Ingénierie, Neuroplasticité des Comportements de la Reproduction, Neurosciences Paris Seine, UM119 - CNRS UMR 8246 - INSERM UMRS 1130, 7 quai Saint Bernard, 75 005 Paris, France
| | - Sakina Mhaouty-Kodja
- Sorbonne Université - Faculté de Sciences et Ingénierie, Neuroplasticité des Comportements de la Reproduction, Neurosciences Paris Seine, UM119 - CNRS UMR 8246 - INSERM UMRS 1130, 7 quai Saint Bernard, 75 005 Paris, France
| | - Hélène Hardin-Pouzet
- Sorbonne Université - Faculté de Sciences et Ingénierie, Neuroplasticité des Comportements de la Reproduction, Neurosciences Paris Seine, UM119 - CNRS UMR 8246 - INSERM UMRS 1130, 7 quai Saint Bernard, 75 005 Paris, France.
| |
Collapse
|
3
|
Huijgens PT, Snoeren EMS, Meisel RL, Mermelstein PG. Effects of gonadectomy and dihydrotestosterone on neuronal plasticity in motivation and reward related brain regions in the male rat. J Neuroendocrinol 2021; 33:e12918. [PMID: 33340384 DOI: 10.1111/jne.12918] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/25/2020] [Accepted: 11/02/2020] [Indexed: 12/22/2022]
Abstract
Gonadal hormones affect neuronal morphology to ultimately regulate behaviour. In female rats, oestradiol mediates spine plasticity in hypothalamic and limbic brain structures, contributing to long-lasting effects on motivated behaviour. Parallel effects of androgens in male rats have not been extensively studied. Here, we investigated the effect of both castration and androgen replacement on spine plasticity in the nucleus accumbens shell and core (NAcSh and NAcC), caudate putamen (CPu), medial amygdala (MeA) and medial preoptic nucleus (MPN). Intact and castrated (gonadectomy [GDX]) male rats were treated with dihydrotestosterone (DHT, 1.5 mg) or vehicle (oil) in three experimental groups: intact-oil, GDX-oil and GDX-DHT. Spine density and morphology, measured 24 hours after injection, were determined through three-dimensional reconstruction of confocal z-stacks of DiI-labelled dendritic segments. We found that GDX decreased spine density in the MPN, which was rescued by DHT treatment. DHT also increased spine density in the MeA in GDX animals compared to intact oil-treated animals. By contrast, DHT decreased spine density in the NAcSh compared to GDX males. No effect on spine density was observed in the NAcC or CPu. Spine length and spine head diameter were unaffected by GDX and DHT in the investigated brain regions. In addition, immunohistochemistry revealed that DHT treatment of GDX animals rapidly increased the number of cell bodies in the NAcSh positive for phosphorylated cAMP response-element binding protein, a downstream messenger of the androgen receptor. These findings indicate that androgen signalling plays a role in the regulation of spine plasticity within neurocircuits involved in motivated behaviours.
Collapse
Affiliation(s)
- Patty T Huijgens
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
- Department of Psychology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Eelke M S Snoeren
- Department of Psychology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Robert L Meisel
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Paul G Mermelstein
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
5
|
Jean A, Bonnet P, Liere P, Mhaouty-Kodja S, Hardin-Pouzet H. Revisiting medial preoptic area plasticity induced in male mice by sexual experience. Sci Rep 2017; 7:17846. [PMID: 29259324 PMCID: PMC5736590 DOI: 10.1038/s41598-017-18248-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/07/2017] [Indexed: 01/25/2023] Open
Abstract
Sexual experience in male rodents, induced by a first exposure to a receptive female, improves efficiency of following copulations. In mice, the mechanisms supporting this improvement are poorly understood. We characterized molecular modifications of the mouse hypothalamic medial preoptic area (mPOA), the main integrative structure for male sexual behaviour, after a single mating event. This paradigm induced long-lasting behavioural improvements and mPOA morphological changes, evidenced by dendritic spine maturation and an increase in the acetylated and tri-methylated forms of histone H3. Ejaculation affected testosterone, progesterone and corticosterone levels in both naive and experienced mice, but sexual experience did not modify basal plasma or hypothalamic levels of steroids. In contrast to studies carried out in rats, no changes were observed, either in the nitrergic system, or in sex steroid receptor levels. However, levels of glutamate- and calcium-associated proteins, including PSD-95, calbindin and the GluN1 subunit of the NMDA receptor, were increased in sexually experienced male mice. The Iba-1 microglial marker was up-regulated in these animals suggesting multicellular interactions induced within the mPOA by sexual experience. In conclusion, plasticity mechanisms induced by sexual experience differ between rat and mouse, even if in both cases they converge to potentiation of the mPOA network.
Collapse
Affiliation(s)
- Arnaud Jean
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris - Seine; Institut de Biologie Paris Seine, 75005, Paris, France
| | - Pauline Bonnet
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris - Seine; Institut de Biologie Paris Seine, 75005, Paris, France
| | - Philippe Liere
- U1195 INSERM and Université Paris Sud and Université Paris-Saclay, 80 rue du Général Leclerc, 94276, Le Kremlin-Bicêtre, France
| | - Sakina Mhaouty-Kodja
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris - Seine; Institut de Biologie Paris Seine, 75005, Paris, France
| | - Helene Hardin-Pouzet
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Neuroscience Paris - Seine; Institut de Biologie Paris Seine, 75005, Paris, France.
| |
Collapse
|