1
|
Migliaro M, Ruiz-Contreras AE, Herrera-Solís A, Méndez-Díaz M, Prospéro-García OE. Endocannabinoid system and aggression across animal species. Neurosci Biobehav Rev 2023; 153:105375. [PMID: 37643683 DOI: 10.1016/j.neubiorev.2023.105375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 08/14/2023] [Accepted: 08/23/2023] [Indexed: 08/31/2023]
Abstract
This narrative review article summarizes the current state of knowledge regarding the relationship between the endocannabinoid system (ECS) and aggression across multiple vertebrate species. Experimental evidence indicates that acute administration of phytocannabinoids, synthetic cannabinoids, and the pharmacological enhancement of endocannabinoid signaling decreases aggressive behavior in several animal models. However, research on the chronic effects of cannabinoids on animal aggression has yielded inconsistent findings, indicating a need for further investigation. Cannabinoid receptors, particularly cannabinoid receptor type 1, appear to be an important part of the endogenous mechanism involved in the dampening of aggressive behavior. Overall, this review underscores the importance of the ECS in regulating aggressive behavior and provides a foundation for future research in this area.
Collapse
Affiliation(s)
- Martin Migliaro
- Grupo de Neurociencias: Laboratorio de Cannabinoides, Departamento de Fisiología, Facultad de Medicina, UNAM, Mexico.
| | - Alejandra E Ruiz-Contreras
- Grupo de Neurociencias: Laboratorio de Neurogenómica Cognitiva, Unidad de Investigación en Psicobiología y Neurociencias, Coordinación de Psicobiología y Neurociencias, Facultad de Psicología, UNAM, Mexico
| | - Andrea Herrera-Solís
- Grupo de Neurociencias: Laboratorio de Efectos Terapéuticos de los Cannabinoides, Hospital General Dr. Manuel Gea González, Secretaría de Salud, Mexico
| | - Mónica Méndez-Díaz
- Grupo de Neurociencias: Laboratorio de Cannabinoides, Departamento de Fisiología, Facultad de Medicina, UNAM, Mexico
| | - Oscar E Prospéro-García
- Grupo de Neurociencias: Laboratorio de Cannabinoides, Departamento de Fisiología, Facultad de Medicina, UNAM, Mexico
| |
Collapse
|
2
|
Maksimoski AN, Stevenson SA, Polzin BJ, Zhao C, Luebke EM, Riters LV. The motivation to flock correlates with vocal-social behaviors and dopamine-related gene expression in male European starlings. Horm Behav 2023; 153:105374. [PMID: 37271085 PMCID: PMC10330916 DOI: 10.1016/j.yhbeh.2023.105374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 04/12/2023] [Accepted: 05/13/2023] [Indexed: 06/06/2023]
Abstract
It is proposed that songbird flocks are partly reinforced by positive social interactions, however not all flock mate interactions are positive. The combination of both positive and negative social interactions with flock mates may play a role in the motivation for birds to flock. The nucleus accumbens (NAc), medial preoptic area (POM), and ventral tegmental area (VTA) are implicated in vocal-social behaviors in flocks, including singing. Dopamine (DA) within these regions modifies motivated, reward-directed behaviors. Here, we begin to test the hypothesis that individual social interactions and DA within these regions are involved in the motivation to flock. Vocal-social behaviors were recorded in eighteen male European starlings in mixed-sex flocks in fall, when starlings are highly social and form large flocks. Males were then singly removed from their flock and the motivation to flock was quantified as the amount of time spent attempting to join a flock following separation. We used quantitative real-time polymerase chain reaction to measure expression of DA-related genes in the NAc, POM, and VTA. Birds producing high levels of vocal behaviors were more highly motivated to flock and had higher tyrosine hydroxylase (the rate-limiting enzyme in DA synthesis) expression in the NAc and VTA. Birds that received high levels of agonistic behaviors were less motivated to flock and had higher DA receptor subtype 1 expression in the POM. Overall, our findings suggest that interplay between social experience and DA activity in NAc, POM, and VTA plays a key role in social motivation in flocking songbirds.
Collapse
Affiliation(s)
- Alyse N Maksimoski
- Department of Integrative Biology, University of Wisconsin-Madison, 430 Lincoln Dr, Madison, WI 53706, United States of America.
| | - Sharon A Stevenson
- Department of Integrative Biology, University of Wisconsin-Madison, 430 Lincoln Dr, Madison, WI 53706, United States of America
| | - Brandon J Polzin
- Department of Integrative Biology, University of Wisconsin-Madison, 430 Lincoln Dr, Madison, WI 53706, United States of America
| | - Changjiu Zhao
- Department of Integrative Biology, University of Wisconsin-Madison, 430 Lincoln Dr, Madison, WI 53706, United States of America
| | - Elsa M Luebke
- Department of Integrative Biology, University of Wisconsin-Madison, 430 Lincoln Dr, Madison, WI 53706, United States of America
| | - Lauren V Riters
- Department of Integrative Biology, University of Wisconsin-Madison, 430 Lincoln Dr, Madison, WI 53706, United States of America
| |
Collapse
|
3
|
Luo Y, Zhao P, Dou M, Mao J, Zhang G, Su Y, Wang Q, Wang Q, Wang Y, Sun R, Liu T, Gong M, Gao Y, Yin X, Song L, Shi H. Exogenous microbiota-derived metabolite trimethylamine N-oxide treatment alters social behaviors: Involvement of hippocampal metabolic adaptation. Neuropharmacology 2021; 191:108563. [PMID: 33887311 DOI: 10.1016/j.neuropharm.2021.108563] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/01/2021] [Accepted: 04/03/2021] [Indexed: 02/06/2023]
Abstract
Increasing evidence indicates that gut microbiota and its metabolites can influence the brain function and the related behaviors. Trimethylamine N-oxide (TMAO), an indirect metabolite of gut microbiota, has been linked to aging, cognitive impairment, and many brain disorders. However, the potential effects of TMAO on social behaviors remain elusive. The present study investigated the effects of early life systemic TMAO exposure and intra-hippocampal TMAO infusion during adulthood on social behaviors in mice. We also analyzed the effects of intra-hippocampus infusion of TMAO during adulthood on levels of metabolites. The results showed that both systemic TMAO exposure in the post-weaning period and intra-hippocampal TMAO infusion during adulthood decreased social rank and reduced sexual preference in adult mice. Data from LC-MS metabolomics analysis showed that intra-hippocampal TMAO infusion induced a total 207 differential metabolites, which belongs to several metabolic or signaling pathways, especially FoxO signaling pathway and retrograde endocannabinoid signaling pathway. These data suggest that TMAO may affect social behaviors by regulating metabolites in the hippocampus, which may provide a new insight into the role of gut microbiota in regulating social behaviors.
Collapse
Affiliation(s)
- Yixiao Luo
- Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Changsha, 410081, China; Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China
| | - Penghui Zhao
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China
| | - Mengxiao Dou
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China
| | - Jiawen Mao
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China
| | - Ge Zhang
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China
| | - Yujiao Su
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China
| | - Qingqun Wang
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China
| | - Qian Wang
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China
| | - Yurun Wang
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China
| | - Ruoxuan Sun
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China
| | - Tingxuan Liu
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China
| | - Miao Gong
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, 050017, China
| | - Yuan Gao
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, 050017, China; Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medicinal University, Shijiazhuang, 050017, China
| | - Xi Yin
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China; Department of Functional Region of Diagnosis, Fourth Hospital of Hebei Medical University, Shijiazhuang, 050011, China.
| | - Li Song
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, 050017, China; Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medicinal University, Shijiazhuang, 050017, China.
| | - Haishui Shi
- Neuroscience Research Center, Institute of Medical and Health Science of HeBMU, Hebei Medical University, Shijiazhuang, 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, 050017, China; Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medicinal University, Shijiazhuang, 050017, China; Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology. Chinese Academy of Medical Sciences, Shijiazhuang, 050017, China.
| |
Collapse
|
4
|
Simmons TC, Freeman SM, Lackey NS, Dreyer BK, Manoli DS, Bales KL. Cannabinoid receptor Type 1 densities reflect social organization in Microtus. J Comp Neurol 2021; 529:1004-1017. [PMID: 33460115 DOI: 10.1002/cne.24996] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 07/02/2020] [Accepted: 07/18/2020] [Indexed: 01/09/2023]
Abstract
Across many species, endocannabinoids play an important role in regulating social play, reward, and anxiety. These processes are mediated through at least two distinct cannabinoid receptors (CB), CB1 and CB2. CB1 expression is found in appreciable densities across regions of the brain that integrate memory with socio-spatial information; many of these regions have been directly linked to the neurobiology of pair bonding in monogamous species. Using receptor autoradiography, we provide the first distributional map of CB1 within the brains of closely related monogamous prairie voles and promiscuous meadow voles, and compare receptor densities across sexes and species in limbic regions. We observe CB1-specific signal using [3H] CP-55,940 and [3H] SR141716A, though the latter exhibited a lower signal to noise ratio. We confirmed the presence of CB2 in prairie vole spleen tissue using [3H] CP-55,940. However, we found no evidence of CB2 in the brain using either [3H] CP-55,940 or [3H] A-836,339. The overall distribution of putative CB1 in the brain was similar across vole species and followed the pattern of CB1 expression observed in other species-high intensity binding within the telencephalon, moderate binding within the diencephalon, and mild binding within the mesencephalon and metencephalon (aside from the cerebellar cortex). However, we found profound differences in CB1 densities across species, with prairie voles having higher CB1 binding in regions implicated in social attachment and spatial memory (e.g., periaqueductal gray, hippocampus). These findings suggest that CB1 densities, but not distribution, correlate with the social systems of vole species.
Collapse
Affiliation(s)
- Trenton C Simmons
- Department of Psychology, University of California, Davis, California, USA
| | - Sara M Freeman
- Department of Psychology, University of California, Davis, California, USA.,Department of Biology, Utah State University, Logan, Utah, USA
| | - Nicholas S Lackey
- Department of Psychology, University of California, Davis, California, USA
| | - Brooke K Dreyer
- Department of Psychology, University of California, Davis, California, USA
| | - Devanand S Manoli
- Center for Integrative Neuroscience, University of California, San Francisco, California, USA
| | - Karen L Bales
- Department of Psychology, University of California, Davis, California, USA
| |
Collapse
|
5
|
Aamodt CM, Farias-Virgens M, White SA. Birdsong as a window into language origins and evolutionary neuroscience. Philos Trans R Soc Lond B Biol Sci 2019; 375:20190060. [PMID: 31735151 DOI: 10.1098/rstb.2019.0060] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Humans and songbirds share the key trait of vocal learning, manifested in speech and song, respectively. Striking analogies between these behaviours include that both are acquired during developmental critical periods when the brain's ability for vocal learning peaks. Both behaviours show similarities in the overall architecture of their underlying brain areas, characterized by cortico-striato-thalamic loops and direct projections from cortical neurons onto brainstem motor neurons that control the vocal organs. These neural analogies extend to the molecular level, with certain song control regions sharing convergent transcriptional profiles with speech-related regions in the human brain. This evolutionary convergence offers an unprecedented opportunity to decipher the shared neurogenetic underpinnings of vocal learning. A key strength of the songbird model is that it allows for the delineation of activity-dependent transcriptional changes in the brain that are driven by learned vocal behaviour. To capitalize on this advantage, we used previously published datasets from our laboratory that correlate gene co-expression networks to features of learned vocalization within and after critical period closure to probe the functional relevance of genes implicated in language. We interrogate specific genes and cellular processes through converging lines of evidence: human-specific evolutionary changes, intelligence-related phenotypes and relevance to vocal learning gene co-expression in songbirds. This article is part of the theme issue 'What can animal communication teach us about human language?'
Collapse
Affiliation(s)
- Caitlin M Aamodt
- Neuroscience Interdepartmental Program, University of California Los Angeles, CA 90095-7239, USA
| | - Madza Farias-Virgens
- Molecular, Cellular and Integrative Physiology Interdepartmental Program, University of California Los Angeles, CA 90095-7239, USA
| | - Stephanie A White
- Neuroscience Interdepartmental Program, University of California Los Angeles, CA 90095-7239, USA.,Molecular, Cellular and Integrative Physiology Interdepartmental Program, University of California Los Angeles, CA 90095-7239, USA.,Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA 90095-7239, USA
| |
Collapse
|
6
|
Hahn AH, Spool JA, Angyal CS, Stevenson SA, Riters LV. Conditioned place preferences induced by hearing song outside the breeding season relate to neural dopamine D 1 and cannabinoid CB 1 receptor gene expression in female European starlings (Sturnus vulgaris). Behav Brain Res 2019; 371:111970. [PMID: 31128162 DOI: 10.1016/j.bbr.2019.111970] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 05/21/2019] [Accepted: 05/21/2019] [Indexed: 01/04/2023]
Abstract
The affective state induced by sensory stimuli changes to adaptively modify behaviors that are critical for survival and reproduction. In European starlings, during the spring breeding season, male courtship song is rewarding to females, but only to those that possess resources that are necessary for reproduction (i.e., nesting sites). In fall, starling song is non-sexual and proposed to maintain flocks. This suggests that in fall it may be adaptive for females to be rewarded by fall rather than spring, courtship song. We used a conditioned place preference (CPP) test to evaluate song-induced affective state in fall condition females and quantitative real-time PCR to measure expression of genes that modulate affective state (CB1 endocannabinoid and D1 dopamine receptors) in brain regions that were previously implicated in song-induced reward (i.e., the medial preoptic nucleus (mPOA) and ventromedial hypothalamus (VMH)). Fall condition females developed an aversion to a place that had been paired with playback of both male fall and courtship song, indicating that in general male song induces a negative affective state outside the breeding season. Song-induced aversion was stronger in birds conditioned towards an initial place preference. For mPOA, CB1 receptor expression correlated positively with fall and spring song-induced CPP. D1 receptor expression correlated negatively with fall (but not spring) song-induced CPP, and the ratio of CB1 to D1 receptor expression correlated positively with fall (but not spring) song-induced CPP. These correlations suggest that interactions between D1 and CB1 receptors in mPOA may play a role in modifying affective responses to song.
Collapse
Affiliation(s)
- Allison H Hahn
- Department of Integrative Biology, 428 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Jeremy A Spool
- Department of Integrative Biology, 428 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Caroline S Angyal
- Department of Integrative Biology, 428 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Sharon A Stevenson
- Department of Integrative Biology, 428 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Lauren V Riters
- Department of Integrative Biology, 428 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| |
Collapse
|
7
|
Messina S, Eens M, Casasole G, AbdElgawad H, Asard H, Pinxten R, Costantini D. Experimental inhibition of a key cellular antioxidant affects vocal communication. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12825] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Simone Messina
- Behavioural Ecology & Ecophysiology Group Department of Biology University of Antwerp Universiteitsplein 1 2610 Wilrijk Belgium
| | - Marcel Eens
- Behavioural Ecology & Ecophysiology Group Department of Biology University of Antwerp Universiteitsplein 1 2610 Wilrijk Belgium
| | - Giulia Casasole
- Behavioural Ecology & Ecophysiology Group Department of Biology University of Antwerp Universiteitsplein 1 2610 Wilrijk Belgium
| | - Hamada AbdElgawad
- Integrated Molecular Plant Physiology Research Department of Biology University of Antwerp Antwerp Belgium
- Department of Botany Faculty of Science University of Beni‐Suef Beni‐Suef62511 Egypt
| | - Han Asard
- Integrated Molecular Plant Physiology Research Department of Biology University of Antwerp Antwerp Belgium
| | - Rianne Pinxten
- Behavioural Ecology & Ecophysiology Group Department of Biology University of Antwerp Universiteitsplein 1 2610 Wilrijk Belgium
- Faculty of Social Sciences Antwerp School of Education University of Antwerp Antwerp Belgium
| | - David Costantini
- Behavioural Ecology & Ecophysiology Group Department of Biology University of Antwerp Universiteitsplein 1 2610 Wilrijk Belgium
- UMR 7221 Muséum National d'Histoire Naturelle 7 rue Cuvier 75231 Paris Cedex 05 France
| |
Collapse
|
8
|
Hahn AH, Merullo DP, Spool JA, Angyal CS, Stevenson SA, Riters LV. Song-associated reward correlates with endocannabinoid-related gene expression in male European starlings (Sturnus vulgaris). Neuroscience 2017; 346:255-266. [PMID: 28147243 DOI: 10.1016/j.neuroscience.2017.01.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/16/2017] [Accepted: 01/17/2017] [Indexed: 01/08/2023]
Abstract
Vocal communication is required for successful social interactions in numerous species. During the breeding season, songbirds produce songs that are reinforced by behavioral consequences (e.g., copulation). However, some songbirds also produce songs not obviously directed at other individuals. The consequences maintaining or reinforcing these songs are less obvious and the neural mechanisms associated with undirected communication are not well-understood. Previous studies indicate that undirected singing is intrinsically rewarding and mediated by opioid or dopaminergic systems; however, endocannabinoids are also involved in regulating reward and singing behavior. We used a conditioned place preference paradigm to examine song-associated reward in European starlings and quantitative real-time PCR to measure expression of endocannabinoid-related neural markers (CB1, FABP7, FABP5, FAAH, DAGLα), in brain regions involved in social behavior, reward and motivation (ventral tegmental area [VTA], periaqueductal gray [PAG], and medial preoptic nucleus [POM]), and a song control region (Area X). Our results indicate that starlings producing high rates of song developed a conditioned place preference, suggesting that undirected song is associated with a positive affective state. We found a significant positive relationship between song-associated reward and CB1 receptors in VTA and a significant negative relationship between song-associated reward and CB1 in PAG. There was a significant positive relationship between reward and the cannabinoid transporter FABP7 in POM and a significant negative relationship between reward and FABP7 in PAG. In Area X, FABP5 and DAGLα correlated positively with singing. These results suggest a role for endocannabinoid signaling in vocal production and reward associated with undirected communication.
Collapse
Affiliation(s)
- Allison H Hahn
- Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Devin P Merullo
- Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Jeremy A Spool
- Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Caroline S Angyal
- Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Sharon A Stevenson
- Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Lauren V Riters
- Department of Zoology, 426 Birge Hall, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, WI 53706, USA
| |
Collapse
|
9
|
Riters LV, Cordes MA, Stevenson SA. Prodynorphin and kappa opioid receptor mRNA expression in the brain relates to social status and behavior in male European starlings. Behav Brain Res 2016; 320:37-47. [PMID: 27913257 DOI: 10.1016/j.bbr.2016.11.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 11/21/2016] [Accepted: 11/28/2016] [Indexed: 12/18/2022]
Abstract
Numerous animal species display behavioral changes in response to changes in social status or territory possession. For example, in male European starlings only males that acquire nesting sites display high rates of sexual and agonistic behavior. Past studies show that mu and delta opioid receptors regulate behaviors associated with social ascension or defeat. Opioids also act at kappa receptors, with dynorphin binding with the highest affinity; however, the role of these opioids in social behavior has not been well studied. We observed flocks of male starlings during the breeding season and ran quantitative real-time polymerase chain reaction (qPCR) to measure expression of kappa opioid receptors (OPRK1) and prodynorphin (PDYN) in brain regions involved in social behavior and motivation (ventral tegmental area [VTA], medial preoptic nucleus [mPOA]) and vocal behavior (Area X). Males with nesting territories displayed more sexual/agonistic behavior than males without nesting territories. They also had lower OPRK1 expression in VTA and mPOA. OPRK1 expression in VTA correlated negatively with sexual/agonistic behaviors, consistent with past studies showing kappa receptors in VTA to inhibit sociosexual behaviors. PDYN in mPOA correlated negatively with a measure of nesting behavior that may also reflect sexual motivation. PDYN in Area X related positively to song. Distinct patterns of OPRK1 and PDYN expression in VTA, mPOA, and Area X related to gonad volume, suggesting that breeding condition may modify (or be modified by) OPRK1 and PDYN expression. Studies are now needed to further characterize the role of OPRK1 and PDYN in status-appropriate social behaviors.
Collapse
Affiliation(s)
- Lauren V Riters
- Department of Zoology, 428 Birge Hall, 430 Lincoln Drive, University of Wisconsin, Madison, WI 53706, USA.
| | - Melissa A Cordes
- Department of Zoology, 428 Birge Hall, 430 Lincoln Drive, University of Wisconsin, Madison, WI 53706, USA
| | - Sharon A Stevenson
- Department of Zoology, 428 Birge Hall, 430 Lincoln Drive, University of Wisconsin, Madison, WI 53706, USA
| |
Collapse
|