1
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Ramos EN, Jiron GM, Danoff JS, Anderson Z, Carter CS, Perkeybile AM, Connelly JJ, Erisir A. The central oxytocinergic system of the prairie vole. Brain Struct Funct 2024; 229:1737-1756. [PMID: 39042140 PMCID: PMC11374920 DOI: 10.1007/s00429-024-02832-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 07/06/2024] [Indexed: 07/24/2024]
Abstract
Oxytocin (OXT) is a peptide hormone and a neuropeptide that regulates various peripheral physiological processes and modulates behavioral responses in the central nervous system. While the humoral release occurs from the axons arriving at the median eminence, the neuropeptide is also released from oxytocinergic cell axons in various brain structures that contain its receptor, and from their dendrites in hypothalamic nuclei and potentially into the cerebrospinal fluid (CSF). Understanding oxytocin's complex functions requires the knowledge on patterns of oxytocinergic projections in relationship to its receptor (OXTR). This study provides the first comprehensive examination of the oxytocinergic system in the prairie vole (Microtus ochrogaster), an animal exhibiting social behaviors that mirror human social behaviors linked to oxytocinergic functioning. Using light and electron microscopy, we characterized the neuroanatomy of the oxytocinergic system in this species. OXT+ cell bodies were found primarily in the hypothalamus, and axons were densest in subcortical regions. Examination of the OXT+ fibers and their relationship to oxytocin receptor transcripts (Oxtr) revealed that except for some subcortical structures, the presence of axons was not correlated with the amount of Oxtr across the brain. Of particular interest, the cerebral cortex that had high expression of Oxtr transcripts contained little to no fibers. Electron microscopy is used to quantify dense cored vesicles (DCV) in OXT+ axons and to identify potential axonal release sites. The ependymal cells that line the ventricles were frequently permissive of DCV-containing OXT+ dendrites reaching the third ventricle. Our results highlight a mechanism in which oxytocin is released directly into the ventricles and circulates throughout the ventricular system, may serve as the primary source for oxytocin that binds to OXTR in the cerebral cortex.
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Affiliation(s)
- E N Ramos
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - G M Jiron
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - J S Danoff
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - Z Anderson
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - C S Carter
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - A M Perkeybile
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - J J Connelly
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - A Erisir
- Department of Psychology, University of Virginia, Charlottesville, VA, USA.
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2
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Johnson MC, Zweig JA, Zhang Y, Nunez L, Ryabinina OP, Hibert M, Ryabinin AE. Effects of oxytocin receptor agonism on acquisition and expression of pair bonding in male prairie voles. Transl Psychiatry 2024; 14:286. [PMID: 39009600 PMCID: PMC11251033 DOI: 10.1038/s41398-024-02993-x] [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: 01/05/2024] [Revised: 06/24/2024] [Accepted: 06/27/2024] [Indexed: 07/17/2024] Open
Abstract
There is much interest in targeting the activity in the oxytocin system to regulate social bonding. However, studies with exogenous administration of oxytocin face the caveats of its low stability, poor brain permeability and insufficient receptor specificity. The use of a small-molecule oxytocin receptor-specific agonist could overcome these caveats. Prior to testing the potential effects of a brain-penetrant oxytocin receptor agonist in clinical settings, it is important to assess how such an agonist would affect social bonds in animal models. The facultatively monogamous prairie voles (Microtus ochrogaster), capable of forming long-term social attachments between adult individuals, are an ideal rodent model for such testing. Therefore, in a series of experiments we investigated the effects of the recently developed oxytocin receptor-specific agonist LIT-001 on the acquisition and expression of partner preference, a well-established model of pair bonding, in prairie voles. LIT-001 (10 mg/kg, intraperitoneal), as expected, facilitated the acquisition of partner preference when administered prior to a 4hr cohabitation. In contrast, while animals injected with vehicle after the 4hr cohabitation exhibited significant partner preference, animals that were injected with LIT-001 did not show such partner preference. This result suggests that OXTR activation during expression of pair bonding can inhibit partner preference. The difference in effects of LIT-001 on acquisition versus expression was not due to basal differences in partner preference between the experiments, as LIT-001 had no significant effects on expression of partner preference if administered following a shorter (2hr-long) cohabitation. Instead, this difference agrees with the hypothesis that the activation of oxytocin receptors acts as a signal of presence of a social partner. Our results indicate that the effects of pharmacological activation of oxytocin receptors crucially depend on the phase of social attachments.
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Affiliation(s)
- Michael C Johnson
- Department of Behavioral Neuroscience, School of Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Jonathan A Zweig
- Department of Behavioral Neuroscience, School of Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Yangmiao Zhang
- Department of Behavioral Neuroscience, School of Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Louis Nunez
- Department of Behavioral Neuroscience, School of Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Olga P Ryabinina
- Department of Behavioral Neuroscience, School of Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Marcel Hibert
- Laboratoire d'Innovation Thérapeutique, Faculté de Pharmacie, UMR7200 CNRS/Université de Strasbourg, Strasbourg, IL, France
| | - Andrey E Ryabinin
- Department of Behavioral Neuroscience, School of Medicine, Oregon Health & Science University, Portland, OR, USA.
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3
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Gaidica M, Zhang M, Dantzer B. A Wireless Wearable Ecosystem for Social Network Analysis in Free-living Animals. IEEE SENSORS LETTERS 2024; 8:6006804. [PMID: 38948074 PMCID: PMC11210449 DOI: 10.1109/lsens.2024.3406328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Studying animal social systems requires understanding variations in contact and interaction, influenced by factors like environmental conditions, resource availability, and predation risk. Traditional observational methods have limitations, but advancements in sensor technologies and data analytics provide new opportunities. We developed a wireless wearable sensor system, "Juxta," with features such as modular battery packs and a smartphone app for data collection. A pilot study on free-living prairie voles (Microtus ochrogaster), a species with complex social behavior, demonstrated Juxta's potential for studying social networks and behavior. We propose a framework for merging temporal, spatial, and event-driven data, which can help explore complex social dynamics across species and environments.
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Affiliation(s)
- Matt Gaidica
- Department of Psychology, University of Michigan, Ann Arbor, MI, USA
| | - Mengxiao Zhang
- Department of Psychology, University of Michigan, Ann Arbor, MI, USA
- School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA
| | - Ben Dantzer
- Department of Psychology, University of Michigan, Ann Arbor, MI, USA
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
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4
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Ryabinin A, Johnson M, Zweig J, Zhang Y, Nunez L, Ryabinina O, Hibert M. Effects of Oxytocin Receptor Agonism on Acquisition and Expression of Pair Bonding in Male Prairie Voles. RESEARCH SQUARE 2024:rs.3.rs-4351761. [PMID: 38798348 PMCID: PMC11118693 DOI: 10.21203/rs.3.rs-4351761/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
There is much interest in targeting the activity in the oxytocin system to regulate social bonding. However, studies with exogenous administration of oxytocin face the caveats of its low stability, poor brain permeability and insufficient receptor specificity. The use of a small-molecule oxytocin receptor-specific agonist could overcome these caveats. Prior to testing the potential effects of a brain-penetrant oxytocin receptor agonist in clinical settings, it is important to assess how such an agonist would affect social bonds in animal models. The facultatively monogamous prairie voles (Microtus ochrogaster), capable of forming long-term social attachments between adult individuals, are an ideal rodent model for such testing. Therefore, in a series of experiments we investigated the effects of the recently developed oxytocin receptor-specific agonist LIT-001 on the acquisition and expression of partner preference, a well-established model of pair bonding, in prairie voles. LIT-001 (10 mg/kg, intraperitoneal), as expected, facilitated the acquisition of partner preference when administered prior to a 4-hour cohabitation. In contrast, while animals injected with vehicle after the 4-hour cohabitation exhibited significant partner preference, animals that were injected with LIT-001 did not show such partner preference. This result suggests that OXTR activation during expression of pair bonding can inhibit partner preference. The difference in effects of LIT-001 on acquisition versus expression was not due to basal differences in partner preference between the experiments, as LIT-001 had no significant effects on expression of partner preference if administered following a shorter (2 hour-long) cohabitation. Instead, this difference agrees with the hypothesis that the activation of oxytocin receptors acts as a signal of presence of a social partner. Our results indicate that the effects of pharmacological activation of oxytocin receptors crucially depend on the phase of social attachments.
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5
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Kenkel WM, Ahmed S, Partie M, Rogers K. Delivery by cesarean section leads to heavier adult bodyweight in prairie voles (Microtus ochrogaster). Horm Behav 2024; 160:105499. [PMID: 38350334 PMCID: PMC10961198 DOI: 10.1016/j.yhbeh.2024.105499] [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: 09/12/2023] [Revised: 11/20/2023] [Accepted: 01/29/2024] [Indexed: 02/15/2024]
Abstract
Delivery by cesarean section now makes up 32.1 % of all births in the United States. Meta-analyses have estimated that delivery by cesarean section is associated with a > 50 % increased risk for childhood obesity by 5 years of age. While this association is independent of maternal obesity, breastfeeding, and heritable factors, studies in humans have been unable to test for a causal role of cesarean delivery in this regard. Here, we set out to use an animal model to experimentally test whether delivery by cesarean section would increase offspring weight in adulthood. Delivery by cesarean section may exert neurodevelopmental consequences by impacting hormones that are important at birth as well as during metabolic regulation in later life, such as oxytocin and vasopressin. The prairie vole (Microtus ochrogaster) has long been studied to investigate the roles of oxytocin and vasopressin in brain development and social behavior. Here, we establish that prairie voles tolerate a range of ambient temperatures, including conventional 22° housing, which makes them translationally appropriate for studies of diet-induced obesity. We also studied vole offspring for their growth, sucrose preference, home cage locomotor activity, and food consumption after birth by either cesarean section or vaginal delivery. At sacrifice, we collected measures of weight, length, and adipose tissue to analyze body composition in adulthood. Voles delivered by cesarean section had consistently greater bodyweights than those born vaginally, despite having lower food consumption and greater locomotive activity. Cesarean-delivered animals were also longer, though this did not explain their greater body weights. While cesarean delivery had no effect on vasopressin, it resulted in less oxytocin immunoreactivity within the hypothalamus in adulthood. These results support the case that cesarean section delivery plays a causal role in increasing offspring body weight, potentially by affecting the oxytocin system.
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Affiliation(s)
- William M Kenkel
- Department of Psychological and Brain Sciences, University of Delaware, United States of America.
| | - Sabreen Ahmed
- Department of Psychological and Brain Sciences, University of Delaware, United States of America
| | - Miranda Partie
- Department of Psychological and Brain Sciences, University of Delaware, United States of America
| | - Katelyn Rogers
- Department of Psychological and Brain Sciences, University of Delaware, United States of America
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6
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Drzewiecki CM, Fox AS. Understanding the heterogeneity of anxiety using a translational neuroscience approach. COGNITIVE, AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2024; 24:228-245. [PMID: 38356013 PMCID: PMC11039504 DOI: 10.3758/s13415-024-01162-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/14/2024] [Indexed: 02/16/2024]
Abstract
Anxiety disorders affect millions of people worldwide and present a challenge in neuroscience research because of their substantial heterogeneity in clinical presentation. While a great deal of progress has been made in understanding the neurobiology of fear and anxiety, these insights have not led to effective treatments. Understanding the relationship between phenotypic heterogeneity and the underlying biology is a critical first step in solving this problem. We show translation, reverse translation, and computational modeling can contribute to a refined, cross-species understanding of fear and anxiety as well as anxiety disorders. More specifically, we outline how animal models can be leveraged to develop testable hypotheses in humans by using targeted, cross-species approaches and ethologically informed behavioral paradigms. We discuss reverse translational approaches that can guide and prioritize animal research in nontraditional research species. Finally, we advocate for the use of computational models to harmonize cross-species and cross-methodology research into anxiety. Together, this translational neuroscience approach will help to bridge the widening gap between how we currently conceptualize and diagnose anxiety disorders, as well as aid in the discovery of better treatments for these conditions.
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Affiliation(s)
- Carly M Drzewiecki
- California National Primate Research Center, University of California, Davis, CA, USA.
| | - Andrew S Fox
- California National Primate Research Center, University of California, Davis, CA, USA.
- Department of Psychology, University of California, Davis, CA, USA.
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7
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Gustison ML, Muñoz-Castañeda R, Osten P, Phelps SM. Sexual coordination in a whole-brain map of prairie vole pair bonding. eLife 2024; 12:RP87029. [PMID: 38381037 PMCID: PMC10942618 DOI: 10.7554/elife.87029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024] Open
Abstract
Sexual bonds are central to the social lives of many species, including humans, and monogamous prairie voles have become the predominant model for investigating such attachments. We developed an automated whole-brain mapping pipeline to identify brain circuits underlying pair-bonding behavior. We identified bonding-related c-Fos induction in 68 brain regions clustered in seven major brain-wide neuronal circuits. These circuits include known regulators of bonding, such as the bed nucleus of the stria terminalis, paraventricular hypothalamus, ventral pallidum, and prefrontal cortex. They also include brain regions previously unknown to shape bonding, such as ventromedial hypothalamus, medial preoptic area, and the medial amygdala, but that play essential roles in bonding-relevant processes, such as sexual behavior, social reward, and territorial aggression. Contrary to some hypotheses, we found that circuits active during mating and bonding were largely sexually monomorphic. Moreover, c-Fos induction across regions was strikingly consistent between members of a pair, with activity best predicted by rates of ejaculation. A novel cluster of regions centered in the amygdala remained coordinated after bonds had formed, suggesting novel substrates for bond maintenance. Our tools and results provide an unprecedented resource for elucidating the networks that translate sexual experience into an enduring bond.
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Affiliation(s)
- Morgan L Gustison
- Department of Integrative Biology, The University of Texas at AustinAustinUnited States
- Department of Psychology, Western UniversityLondonCanada
| | - Rodrigo Muñoz-Castañeda
- Cold Spring Harbor LaboratoryCold Spring HarborUnited States
- Appel Alzheimer's Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell MedicineNew YorkUnited States
| | - Pavel Osten
- Cold Spring Harbor LaboratoryCold Spring HarborUnited States
| | - Steven M Phelps
- Department of Integrative Biology, The University of Texas at AustinAustinUnited States
- Institute for Neuroscience, The University of Texas at AustinAustinUnited States
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8
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Pierce AF, Protter DSW, Watanabe YL, Chapel GD, Cameron RT, Donaldson ZR. Nucleus accumbens dopamine release reflects the selective nature of pair bonds. Curr Biol 2024; 34:519-530.e5. [PMID: 38218185 PMCID: PMC10978070 DOI: 10.1016/j.cub.2023.12.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 10/06/2023] [Accepted: 12/13/2023] [Indexed: 01/15/2024]
Abstract
In monogamous species, prosocial behaviors directed toward partners are dramatically different from those directed toward unknown individuals and potential threats. Dopamine release in the nucleus accumbens has a well-established role in social reward and motivation, but how this mechanism may be engaged to drive the highly divergent social behaviors directed at a partner or unfamiliar conspecific remains unknown. Using monogamous prairie voles, we first employed receptor pharmacology in partner preference and social operant tasks to show that dopamine is critical for the appetitive drive for social interaction but not for low-effort, unconditioned consummatory behaviors. We then leveraged the subsecond temporal resolution of the fluorescent biosensor, GRABDA, to ask whether differential dopamine release might distinguish between partner and novel social access and interaction. We found that partner seeking, anticipation, and interaction resulted in more accumbal dopamine release than the same events directed toward a novel vole. Further, partner-associated dopamine release decreased after prolonged partner separation. Our results are consistent with a model in which dopamine signaling plays a prominent role in the appetitive aspects of social interactions. Within this framework, differences in partner- and novel-associated dopamine release reflect the selective nature of pair bonds and may drive the partner- and novel-directed social behaviors that reinforce and cement bonds over time. This provides a potential mechanism by which highly conserved reward systems can enable selective, species-appropriate social behaviors.
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Affiliation(s)
- Anne F Pierce
- Department of Psychology & Neuroscience, University of Colorado Boulder, 1945 Colorado Ave, Boulder, CO 80309, USA.
| | - David S W Protter
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, 1945 Colorado Ave, Boulder, CO 80309, USA
| | - Yurika L Watanabe
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, 1945 Colorado Ave, Boulder, CO 80309, USA
| | - Gabriel D Chapel
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, 1945 Colorado Ave, Boulder, CO 80309, USA
| | - Ryan T Cameron
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, 1945 Colorado Ave, Boulder, CO 80309, USA
| | - Zoe R Donaldson
- Department of Psychology & Neuroscience, University of Colorado Boulder, 1945 Colorado Ave, Boulder, CO 80309, USA; Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, 1945 Colorado Ave, Boulder, CO 80309, USA.
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9
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Marinello WP, Gillera SEA, Han Y, Richardson JR, St Armour G, Horman BM, Patisaul HB. Gestational exposure to FireMaster® 550 (FM 550) disrupts the placenta-brain axis in a socially monogamous rodent species, the prairie vole (Microtus ochrogaster). Mol Cell Endocrinol 2023; 576:112041. [PMID: 37562579 PMCID: PMC10795011 DOI: 10.1016/j.mce.2023.112041] [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: 06/07/2023] [Revised: 07/26/2023] [Accepted: 08/06/2023] [Indexed: 08/12/2023]
Abstract
Gestational flame retardant (FR) exposure has been linked to heightened risk of neurodevelopmental disorders, but the mechanisms remain largely unknown. Historically, toxicologists have relied on traditional, inbred rodent models, yet those do not always best model human vulnerability or biological systems, especially social systems. Here we used prairie voles (Microtus ochrogaster), a monogamous and bi-parental rodent, leveraged for decades to decipher the underpinnings of social behaviors, to examine the impact of fetal FR exposure on gene targets in the mid-gestational placenta and fetal brain. We previously established gestational exposure to the commercial mixture Firemaster 550 (FM 550) impairs sociality, particularly in males. FM 550 exposure disrupted placental monoamine production, particularly serotonin, and genes required for axon guidance and cellular respiration in the fetal brains. Effects were dose and sex specific. These data provide insights on the mechanisms by which FRs impair neurodevelopment and later in life social behaviors.
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Affiliation(s)
- William P Marinello
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA
| | | | - Yoonhee Han
- Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA
| | - Jason R Richardson
- Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA
| | - Genevieve St Armour
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA
| | - Brian M Horman
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA
| | - Heather B Patisaul
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA; Center for Human Health and the Environment, NC State University, Raleigh, NC, 27695, USA.
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10
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Kenkel W. Automated behavioral scoring: Do we even need humans? Ann N Y Acad Sci 2023; 1527:25-29. [PMID: 37497814 DOI: 10.1111/nyas.15041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
The development of automated behavior scoring technology has been a tremendous boon to the study of social behavior. However, completely outsourcing behavioral analysis to a computer runs the risk of overlooking important nuances, and researchers risk distancing themselves from their very object of study. Here, I make the case that while automating analysis has been valuable, and overautomating analysis is risky, more effort should be spent automating the collection of behavioral data. Continuous automated behavioral observations conducted in situ have the promise to reduce confounding elements of social behavior research, such as handling stress, novel environments, one-time "snapshot" measures, and experimenter presence. Now that we have the capability to automatically process behavioral observations thanks to machine vision and machine learning, we would do well to leverage the same open-source ethos to increase the throughput of behavioral observation and collection. Fortunately, several such platforms have recently been developed. Repeated testing in the home environment will produce higher qualities and quantities of data, bringing us closer to realizing the ethological goals of studying animal behavior in a naturalistic context.
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Affiliation(s)
- Will Kenkel
- Department of Psychological & Brain Sciences, University of Delaware, Newark, Delaware, USA
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11
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Swain CC, Wischmeier JN, Neifer AE, Lloyd EAR, Neifer KL, Kile KB, Burkett JP. Hereditary convulsions in an outbred prairie vole line. Epilepsy Res 2023; 195:107202. [PMID: 37540927 PMCID: PMC10529651 DOI: 10.1016/j.eplepsyres.2023.107202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/09/2023] [Accepted: 07/31/2023] [Indexed: 08/06/2023]
Abstract
Patients with epilepsy are significantly burdened by the disease due to long-term health risks, the severe side effect profiles of anti-epileptic drugs, and the strong possibility of pharmacoresistant refractory seizures. New animal models of epilepsy with unique characteristics promise to further research to address these ongoing problems. Here, we characterize a newly developed line of prairie voles (Microtus ochrogaster, UTol:HIC or "Toledo" line) that presents with a hereditary, adult-onset, handling-induced convulsion phenotype. Toledo voles were bred for four generations and tested to determine whether the observed phenotype was consistent with epileptic seizures. Toledo voles maintained a stable 22 % incidence of convulsions across generations, with an average age of onset of 12-16 weeks. Convulsions in Toledo voles were reliably evoked by rodent seizure screens and were phenotypically consistent with murine seizures. At the colony level, Toledo voles had a 7-fold increase in risk for sudden unexpected death from unknown causes, which parallels sudden unexpected death in epilepsy (SUDEP) in human patients. Finally, convulsions in Toledo voles were reduced or prevented by treatment with the anti-epileptic drug levetiracetam. Taken in combination, these results suggest that convulsions in Toledo voles may be epileptic seizures. The Toledo prairie vole strain may serve as a new rodent model of epilepsy in an undomesticated, outbred species.
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Affiliation(s)
- Caroline C Swain
- University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - James N Wischmeier
- University of Toledo College of Natural Sciences and Mathematics, Toledo, OH 43606, USA
| | - Asha E Neifer
- University of Toledo College of Natural Sciences and Mathematics, Toledo, OH 43606, USA
| | | | - Kari L Neifer
- Department of Neurosciences, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Kara B Kile
- Department of Physics, University of Toledo College of Natural Sciences and Mathematics, Toledo, OH 43606, USA
| | - James P Burkett
- Department of Neurosciences, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA.
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12
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Hiura LC, Donaldson ZR. Prairie vole pair bonding and plasticity of the social brain. Trends Neurosci 2023; 46:260-262. [PMID: 36369029 PMCID: PMC10389078 DOI: 10.1016/j.tins.2022.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 10/18/2022] [Indexed: 11/10/2022]
Abstract
In monogamous species, pair bonding leads to striking changes in social behavior and neural circuitry. We outline the cognitive building blocks of monogamous pair bonding in prairie voles (Microtus ochrogaster), as well as opportunities afforded by the species to investigate diverse mechanisms underlying social experience-dependent plasticity and gain insights into the neurobiology of complex social behavior more generally.
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Affiliation(s)
- Lisa C Hiura
- Department of Molecular, Cellular, and Developmental Biology, Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA.
| | - Zoe R Donaldson
- Department of Molecular, Cellular, and Developmental Biology, Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA.
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13
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Fricker BA, Roshko VC, Jiang J, Kelly AM. Partner separation rescues pair bond-induced decreases in hypothalamic oxytocin neural densities. Sci Rep 2023; 13:4835. [PMID: 36964221 PMCID: PMC10037388 DOI: 10.1038/s41598-023-32076-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 03/22/2023] [Indexed: 03/26/2023] Open
Abstract
Studies in prairie voles (Microtus ochrogaster) have shown that although formation of the pair bond is accompanied by a suite of behavioral changes, a bond between two voles can dissolve and individuals can form new pair bonds with other conspecifics. However, the neural mechanisms underlying this behavioral flexibility have not been well-studied. Here we examine plasticity of nonapeptide, vasopressin (VP) and oxytocin (OT), neuronal populations in relation to bonding and the dissolution of bonds. Using adult male and female prairie voles, animals were either pair bonded, co-housed with a same-sex sibling, separated from their pair bond partner, or separated from their sibling. We examined neural densities of VP and OT cell groups and observed plasticity in the nonapeptide populations of the paraventricular nucleus of the hypothalamus (PVN). Voles that were pair bonded had fewer PVN OT neurons, suggesting that PVN OT neural densities decrease with pair bonding, but increase and return to a pre-pair bonded baseline after the dissolution of a pair bond. Our findings suggest that the PVN nonapeptide cell groups are particularly plastic in adulthood, providing a mechanism by which voles can exhibit context-appropriate behavior related to bond status.
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Affiliation(s)
- Brandon A Fricker
- Department of Psychology, Emory University, 36 Eagle Row, Atlanta, GA, 30322, USA
| | - Venezia C Roshko
- Department of Psychology, Emory University, 36 Eagle Row, Atlanta, GA, 30322, USA
| | - Jinrun Jiang
- Department of Psychology, Emory University, 36 Eagle Row, Atlanta, GA, 30322, USA
| | - Aubrey M Kelly
- Department of Psychology, Emory University, 36 Eagle Row, Atlanta, GA, 30322, USA.
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Ng H, Ohmura N, Miyazawa E, Yoshihara C, Okuma L, Kuroda KO. Effects of oxytocin ablation on pup rescue, nursing behaviors and response to pup separation in early-to-mid postpartum mice. J Neuroendocrinol 2023:e13247. [PMID: 36973234 DOI: 10.1111/jne.13247] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 02/15/2023] [Accepted: 02/18/2023] [Indexed: 03/06/2023]
Abstract
Oxytocin, a neuropeptide hormone, is indispensable for milk ejection during nursing and is important for uterine contractions during parturition. The exact functions of oxytocin in postpartum maternal behaviors and motivations require further investigation. To this end, we characterized the role of oxytocin in components of maternal motivations during the mid-postpartum period, which has not been previously studied. To maintain suckling stimuli, postpartum oxytocin knockout (Oxt-/- ) and heterozygous (Oxt+/- ) littermates were co-housed with a wild-type lactating mother and its litter, and were examined for their ability to retrieve pups under standard or high-risk conditions, nursing behavior, maternal aggression towards an unfamiliar intruder, and motivation to regain contact with separated pups. One-third of Oxt-/- mothers exhibited prolonged parturition but were otherwise grossly healthy. Despite their inability to eject milk, Oxt-/- mothers displayed nursing behaviors for similar durations to Oxt+/- mothers during the second postpartum week. In addition, Oxt-/- mothers were essentially intact for pup retrieval under standard conditions and were motivated to stay close to pups, although they showed a mild decrease in maternal care under high-risk conditions and increased anxiety-like behaviors in pup-related contexts. The present findings indicate that oxytocin is dispensable for nursing behavior and maternal motivations, yet suggest that oxytocin may be relevant for stress resilience in the postpartum period.
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Affiliation(s)
- Hannah Ng
- Laboratory for Affiliative Social Behavior, RIKEN Center for Brain Science, Saitama, Japan
- Real Chemistry, London, UK
| | - Nami Ohmura
- Laboratory for Affiliative Social Behavior, RIKEN Center for Brain Science, Saitama, Japan
| | - Eri Miyazawa
- Laboratory for Affiliative Social Behavior, RIKEN Center for Brain Science, Saitama, Japan
| | - Chihiro Yoshihara
- Laboratory for Affiliative Social Behavior, RIKEN Center for Brain Science, Saitama, Japan
| | - Lana Okuma
- Laboratory for Human Cognition and Learning, RIKEN Center for Brain Science, Saitama, Japan
| | - Kumi O Kuroda
- Laboratory for Affiliative Social Behavior, RIKEN Center for Brain Science, Saitama, Japan
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15
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Nuccio DA, Normann MC, Zhou H, Grippo AJ, Singh P. Microbiome and Metabolome Variation as Indicator of Social Stress in Female Prairie Voles. Int J Mol Sci 2023; 24:1677. [PMID: 36675193 PMCID: PMC9861106 DOI: 10.3390/ijms24021677] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/17/2023] Open
Abstract
Social isolation is detrimental to the health of social mammals inducing neurochemical and hormonal changes related to depression and anxiety, as well as impairments of cardiovascular and immune functioning. Likewise, perceptions of loneliness are increasingly recognized as detrimental to human psychological well-being, cognitive functioning, and physical health. Few studies, however, have examined the impact of social isolation on the intestinal microbiome and metabolome. To better understand the impact of social isolation on these systems, intestinal microbiota, and the systemic impact via the gut-brain axis, we employed prairie voles. Physiological stress on female prairie voles (n = 22) either with a same-sex sibling (n = 11) or in isolation (n = 11) for four weeks demonstrated behavioral indicators of increased anxiety and depression in isolated voles (p ≤ 0.01). Bacterial DNA from fecal and colon samples, collected at five time points (T0-4), were sequenced for all nine hypervariable regions of the 16S rRNA gene. Microbiome analyses revealed several differences in gut communities of paired and isolated voles with greater differences at T4. Notably, several taxa associated with host health including Anaerostipes and Lactobacillaceae were more prevalent in paired voles, whereas several taxa associated with known pathogens (e.g., Staphylococcaceae and Enterococcus) or disease were elevated in isolated animals. Similarly, metabolome analyses suggested isolated voles, when compared to paired animals, exhibited differences in metabolites associated with diabetes and colitis. These findings further contribute to our understanding of the harmful effects of social isolation, which cause perturbations in the gut microbiome and serum metabolites.
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Affiliation(s)
- Daniel A. Nuccio
- Department of Biological Sciences, Northern Illinois University, Dekalb, IL 60115, USA
| | - Marigny C. Normann
- Department of Psychology, Northern Illinois University, Dekalb, IL 60115, USA
| | - Haiming Zhou
- Department of Statistics and Actuarial Sciences, Northern Illinois University, Dekalb, IL 60115, USA
| | - Angela J. Grippo
- Department of Psychology, Northern Illinois University, Dekalb, IL 60115, USA
| | - Pallavi Singh
- Department of Biological Sciences, Northern Illinois University, Dekalb, IL 60115, USA
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16
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Akinbo OI, McNeal N, Hylin M, Hite N, Dagner A, Grippo AJ. The Influence of Environmental Enrichment on Affective and Neural Consequences of Social Isolation Across Development. AFFECTIVE SCIENCE 2022; 3:713-733. [PMID: 36519141 PMCID: PMC9743881 DOI: 10.1007/s42761-022-00131-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 06/10/2022] [Indexed: 05/15/2023]
Abstract
Social stress is associated with depression and anxiety, physiological disruptions, and altered brain morphology in central stress circuitry across development. Environmental enrichment strategies may improve responses to social stress. Socially monogamous prairie voles exhibit analogous social and emotion-related behaviors to humans, with potential translational insight into interactions of social stress, age, and environmental enrichment. This study explored the effects of social isolation and environmental enrichment on behaviors related to depression and anxiety, physiological indicators of stress, and dendritic structural changes in amygdala and hippocampal subregions in young adult and aging prairie voles. Forty-nine male prairie voles were assigned to one of six groups divided by age (young adult vs. aging), social structure (paired vs. isolated), and housing environment (enriched vs. non-enriched). Following 4 weeks of these conditions, behaviors related to depression and anxiety were investigated in the forced swim test and elevated plus maze, body and adrenal weights were evaluated, and dendritic morphology analyses were conducted in hippocampus and amygdala subregions. Environmental enrichment decreased immobility duration in the forced swim test, increased open arm exploration in the elevated plus maze, and reduced adrenal/body weight ratio in aging and young adult prairie voles. Age and social isolation influenced dendritic morphology in the basolateral amygdala. Age, but not social isolation, influenced dendritic morphology in the hippocampal dentate gyrus. Environmental enrichment did not influence dendritic morphology in either brain region. These data may inform interventions to reduce the effects of social stressors and age-related central changes associated with affective behavioral consequences in humans.
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Affiliation(s)
- Oreoluwa I. Akinbo
- Department of Psychology, Northern Illinois University, DeKalb, IL 60115 USA
| | - Neal McNeal
- Department of Psychology, Northern Illinois University, DeKalb, IL 60115 USA
| | - Michael Hylin
- Department of Psychology, Southern Illinois University, Carbondale, IL 62901 USA
| | - Natalee Hite
- Department of Physiology, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Ashley Dagner
- Department of Psychology, Northern Illinois University, DeKalb, IL 60115 USA
| | - Angela J. Grippo
- Department of Psychology, Northern Illinois University, DeKalb, IL 60115 USA
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17
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Megagiannis P, Suresh R, Rouleau GA, Zhou Y. Reversibility and therapeutic development for neurodevelopmental disorders, insights from genetic animal models. Adv Drug Deliv Rev 2022; 191:114562. [PMID: 36183904 DOI: 10.1016/j.addr.2022.114562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/30/2022] [Accepted: 09/24/2022] [Indexed: 01/24/2023]
Abstract
Neurodevelopmental Disorders (NDDs) encompass a broad spectrum of conditions resulting from atypical brain development. Over the past decades, we have had the fortune to witness enormous progress in diagnosis, etiology discovery, modeling, and mechanistic understanding of NDDs from both fundamental and clinical research. Here, we review recent neurobiological advances from experimental models of NDDs. We introduce several examples and highlight breakthroughs in reversal studies of phenotypes using genetically engineered models of NDDs. The in-depth understanding of brain pathophysiology underlying NDDs and evaluations of reversibility in animal models paves the foundation for discovering novel treatment options. We discuss how the expanding property of cutting-edge technologies, such as gene editing and AAV-mediated gene delivery, are leveraged in animal models for the therapeutic development of NDDs. We envision opportunities and challenges toward faithful modeling and fruitful clinical translation.
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Affiliation(s)
- Platon Megagiannis
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Rahul Suresh
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Guy A Rouleau
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Yang Zhou
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada.
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18
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Powell JM, Garvin MM, Lee NS, Kelly AM. Behavioral trajectories of aging prairie voles (Microtus ochrogaster): Adapting behavior to social context wanes with advanced age. PLoS One 2022; 17:e0276897. [PMCID: PMC9665403 DOI: 10.1371/journal.pone.0276897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/14/2022] [Indexed: 11/16/2022] Open
Abstract
Several studies using mice have examined the effects of aging on cognitive tasks, as well as sensory and motor functions. However, few studies have examined the influence of aging on social behavior. Prairie voles (Microtus ochrogaster) are a socially monogamous and biparental rodent that live in small family groups and are now among the most popular rodent models for studies examining social behavior. Although the social behavioral trajectories of early-life development in prairie voles have been well-studied, how social behavior may change throughout adulthood remains unknown. Here we examined behavior in virgin male and female prairie voles in four different age groups: postnatal day (PND) 60–80, 140–160, 220–240, and 300–320. All animals underwent testing in a novel object task, a dominance test, a resident-intruder test, and several iterations of social approach and social interaction tests with varying types of social stimuli (i.e., novel same-sex conspecific, novel opposite-sex conspecific, familiar same-sex sibling/cagemate, small group of novel same-sex conspecifics). We found that age influenced neophobia and dominance, but not social approach behavior. Further, we found that young adult, but not older adult, prairie voles adapt prosocial and aggressive behavior relative to social context, and that selective aggression occurs in relation to age even in the absence of a pair bond. Our results suggest that prairie voles calibrate social phenotype in a context-dependent manner in young adulthood and stop adjusting behavior to social context in advanced age, demonstrating that social behavior is plastic not only throughout early development, but also well into adulthood. Together, this study provides insight into age-related changes in social behavior in prairie voles and shows that prairie voles may be a viable model for studying the cognitive and physiological benefits of social relationships and social engagement in advanced age.
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Affiliation(s)
- Jeanne M. Powell
- Department of Psychology, Emory University, Atlanta, Georgia, United States of America
| | - Madison M. Garvin
- Department of Psychology, Emory University, Atlanta, Georgia, United States of America
| | - Nicholas S. Lee
- Department of Psychology, Emory University, Atlanta, Georgia, United States of America
| | - Aubrey M. Kelly
- Department of Psychology, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
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19
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Lee NS, Beery AK. Selectivity and Sociality: Aggression and Affiliation Shape Vole Social Relationships. Front Behav Neurosci 2022; 16:826831. [PMID: 35330842 PMCID: PMC8940285 DOI: 10.3389/fnbeh.2022.826831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/14/2022] [Indexed: 11/22/2022] Open
Abstract
The formation of selective social relationships is not a requirement of group living; sociality can be supported by motivation for social interaction in the absence of preferences for specific individuals, and by tolerance in place of social motivation. For species that form selective social relationships, these can be maintained by preference for familiar partners, as well as by avoidance of or aggression toward individuals outside of the social bond. In this review, we explore the roles that aggression, motivation, and tolerance play in the maintenance of selective affiliation. We focus on prairie voles (Microtus ochrogaster) and meadow voles (Microtus pennsylvanicus) as rodent species that both exhibit the unusual tendency to form selective social relationships, but differ with regard to mating system. These species provide an opportunity to investigate the mechanisms that underlie social relationships, and to compare mechanisms supporting pair bonds with mates and same-sex peer relationships. We then relate this to the role of aggression in group composition in a comparative context.
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Affiliation(s)
- Nicole S. Lee
- Department of Psychological and Brain Sciences, Colgate University, Hamilton, NY, United States
| | - Annaliese K. Beery
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, United States
- *Correspondence: Annaliese K. Beery,
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20
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Gustison ML, Phelps SM. Individual differences in social attachment: A multi-disciplinary perspective. GENES, BRAIN, AND BEHAVIOR 2022; 21:e12792. [PMID: 35170839 PMCID: PMC8916993 DOI: 10.1111/gbb.12792] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 11/20/2021] [Accepted: 12/12/2021] [Indexed: 01/23/2023]
Abstract
Social behavior varies across both individuals and species. Research to explain this variation falls under the purview of multiple disciplines, each with its own theoretical and empirical traditions. Integration of these disciplinary traditions is key to developing a holistic perspective. Here, we review research on the biology of social attachment, a phenomena in which individuals develop strong affective connections to one another. We provide a historical overview of research on social attachment from psychological, ethological and neurobiological perspectives. As a case study, we describe work on pair-bonding in prairie voles, a socially monogamous rodent. This specific topic takes advantage of many biological perspectives and techniques to explain social bonds. Lastly, we conclude with an overview of multi-dimensional conceptual frameworks that can be used to explain social phenomena, and we propose a new framework for research on individual variation in attachment behavior. These conceptual frameworks originate from philosophy, physics, ethology, cognitive science and neuroscience. The application and synthesis of such frameworks offers a rich opportunity to advance understanding of social behavior and its mechanisms.
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Affiliation(s)
- Morgan L. Gustison
- Department of Integrative BiologyThe University of Texas at AustinAustinTexasUSA
| | - Steven M. Phelps
- Department of Integrative BiologyThe University of Texas at AustinAustinTexasUSA
- Institute for NeuroscienceThe University of Texas at AustinAustinTexasUSA
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21
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Abstract
In contrast to traditional laboratory animals, prairie voles form socially monogamous partnerships in the wild and exhibit lasting social preferences for familiar individuals-both mates and same-sex peers-in the laboratory. Decades of research into the mechanisms supporting pair bonding behavior have made prairie voles an important model organism for the study of social relationships. The partner preference test is a laboratory test of familiarity preference that takes place over an extended interval (typically 3 hr), during which test subjects can directly interact with conspecifics and often engage in resting side-by-side contact (i.e., huddling). The use of this test has enabled study of the neural pathways and mechanisms involved in promoting or impairing relationship formation. The tendency to form partner preferences is also used as a behavioral indicator of the effects of early life experiences and environmental exposures. While this test was developed to assess the extent of social preference for mates in prairie voles, it has been adapted for use in other social contexts and in multiple other species. This article provides instructions for conducting the classic partner preference test, as well as variations including same-sex "peer" partner preference tests. The effects of several protocol variations are examined, including duration of cohousing, separation interval, use of tethers versus barriers, linear versus branched apparatus configuration, and duration of the test. The roles of social variables including sex of the focal individual, sex of conspecifics, reproductive state, and use of the test in other species are then considered. Finally, sample data are provided along with discussion of scoring and statistical analysis of partner preference tests. © 2021 Wiley Periodicals LLC. Basic Protocol: Partner preference test Support Protocol: Behavioral scoring.
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