PDF(Pubmed)
Abstract：
BACKGROUND: Social behaviour plays a key role in mental health and wellbeing, and developing greater understanding of mechanisms underlying social interaction-particularly social motivation-holds substantial transdiagnostic impact. Common rodent behavioural assays used to assess social behaviour are limited in their assessment of social motivation, whereas the social operant conditioning model can provide unique and valuable insights into social motivation. Further characterisation of common experimental parameters that may influence social motivation within the social operant model, as well as complementary methodological and analytical approaches, are warranted.
METHODS: This study investigated the effects of biological sex, housing condition, and time-of-day, on social motivation using the social operant model. This involved training rats to lever press (FR1) for 60-s access to a social reward (same-sex conspecific stimulus). Subjects were male and female Wistar rats, housed under individual or paired conditions, and sessions were conducted either in the mid-late light phase (ZT6-10) or early-mid dark phase (ZT13-17). A behavioural economics approach was implemented to measure social demand and the influence of stimulus partner sex (same- vs. opposite-sex stimulus) on social operant responding. Additionally, video tracking analyses were conducted to assess the degree of convergence between social appetitive and consummatory behaviours.
RESULTS: Biological sex, housing conditions, the interaction between sex and housing, and stimulus partner sex potently influenced social motivation, whereas time-of-day did not. Behavioural economics demonstrated that sex, housing, and their interaction influence both the hedonic set-point and elasticity of social demand. Video analysis of social interaction during social operant sessions revealed that social appetitive and consummatory behaviours are not necessarily convergent, and indicate potential social satiety. Lastly, oestrus phase of female experimental and stimulus rats did not impact social motivation within the model.
CONCLUSIONS: Social isolation-dependent sex differences exist in social motivation for rats, as assessed by social operant conditioning. The social operant model represents an optimal preclinical assay that comprehensively evaluates social motivation and offers a platform for future investigations of neurobiological mechanisms underlying sex differences in social motivation. These findings highlight the importance of continued consideration and inclusion of sex as a biological variable in future social operant conditioning studies. Humans are social creatures-our everyday interactions with others and the support this provides play a key role in our wellbeing. For those experiencing mental health conditions, people\'s motivation to engage with others can wane, which can lead them to withdraw from those who support them. Therefore, to develop better treatment strategies for these conditions, we need to gain a deeper understanding of social motivation. Studying social behaviour in animals can facilitate this investigation of social motivation as it allows for a causal understanding of underlying neurobiology that is not possible in human experiments. An optimal way to study social motivation in animals is using the social operant conditioning model, where rats learn to press a lever that opens a door and allows them to interact with another rat for a short time. This study characterised the social operant model by testing whether sex, housing conditions, time-of-day, and the sex of the stimulus partner influence rats\' motivation to seek interaction with another rat. We found that female rats were more socially motivated than males, and that rats living alone were more motivated than those living with another rat; interestingly, this effect of housing affected females more than males. Regardless of sex, rats were more motivated to interact with a rat of the opposite sex. These findings provide insights into sex differences in social motivation in rats and new insights into the social operant model which will help guide future research into social motivation and other mental health conditions.
METHODS: This study investigated the effects of biological sex, housing condition, and time-of-day, on social motivation using the social operant model. This involved training rats to lever press (FR1) for 60-s access to a social reward (same-sex conspecific stimulus). Subjects were male and female Wistar rats, housed under individual or paired conditions, and sessions were conducted either in the mid-late light phase (ZT6-10) or early-mid dark phase (ZT13-17). A behavioural economics approach was implemented to measure social demand and the influence of stimulus partner sex (same- vs. opposite-sex stimulus) on social operant responding. Additionally, video tracking analyses were conducted to assess the degree of convergence between social appetitive and consummatory behaviours.
RESULTS: Biological sex, housing conditions, the interaction between sex and housing, and stimulus partner sex potently influenced social motivation, whereas time-of-day did not. Behavioural economics demonstrated that sex, housing, and their interaction influence both the hedonic set-point and elasticity of social demand. Video analysis of social interaction during social operant sessions revealed that social appetitive and consummatory behaviours are not necessarily convergent, and indicate potential social satiety. Lastly, oestrus phase of female experimental and stimulus rats did not impact social motivation within the model.
CONCLUSIONS: Social isolation-dependent sex differences exist in social motivation for rats, as assessed by social operant conditioning. The social operant model represents an optimal preclinical assay that comprehensively evaluates social motivation and offers a platform for future investigations of neurobiological mechanisms underlying sex differences in social motivation. These findings highlight the importance of continued consideration and inclusion of sex as a biological variable in future social operant conditioning studies. Humans are social creatures-our everyday interactions with others and the support this provides play a key role in our wellbeing. For those experiencing mental health conditions, people\'s motivation to engage with others can wane, which can lead them to withdraw from those who support them. Therefore, to develop better treatment strategies for these conditions, we need to gain a deeper understanding of social motivation. Studying social behaviour in animals can facilitate this investigation of social motivation as it allows for a causal understanding of underlying neurobiology that is not possible in human experiments. An optimal way to study social motivation in animals is using the social operant conditioning model, where rats learn to press a lever that opens a door and allows them to interact with another rat for a short time. This study characterised the social operant model by testing whether sex, housing conditions, time-of-day, and the sex of the stimulus partner influence rats\' motivation to seek interaction with another rat. We found that female rats were more socially motivated than males, and that rats living alone were more motivated than those living with another rat; interestingly, this effect of housing affected females more than males. Regardless of sex, rats were more motivated to interact with a rat of the opposite sex. These findings provide insights into sex differences in social motivation in rats and new insights into the social operant model which will help guide future research into social motivation and other mental health conditions.
摘要：
背景：社会行为在心理健康和幸福中起着关键作用，并加深对社会互动机制的理解，特别是社会动机，具有重大的诊断影响。用于评估社会行为的常见啮齿动物行为测定法在评估社会动机方面受到限制。而社会运行条件模型可以为社会动机提供独特而有价值的见解。进一步表征可能影响社会操作模型中的社会动机的常见实验参数，以及互补的方法论和分析方法，是有保证的。
方法：本研究调查了生物性别的影响，住房条件,和一天的时间，关于使用社会操作模型的社会动机。这涉及训练大鼠以杠杆按压（FR1）60秒获得社会奖励（同性特异性刺激）。受试者是雄性和雌性Wistar大鼠，在个人或配对条件下居住，并且在中后期光照阶段（ZT6-10）或早中期黑暗阶段（ZT13-17）进行会议。实施了一种行为经济学方法来衡量社会需求和刺激性伴侣性行为的影响(相同与异性刺激)对社会操作反应的影响。此外,进行了视频跟踪分析，以评估社会食欲行为和完善行为之间的融合程度。
结果：生物性别，住房条件,性与住房之间的相互作用，刺激性伴侣的性行为有力地影响了社会动机，而一天的时间却没有。行为经济学证明了性别，住房,它们之间的相互作用同时影响着社会需求的享乐设定点和弹性。在社会运营会议期间对社交互动进行的视频分析显示，社会食欲和消费行为不一定是趋同的，并表明潜在的社会饱腹感。最后,雌性实验和刺激大鼠的发情期没有影响模型中的社会动机。
结论：大鼠的社会动机存在社会隔离依赖性性别差异，通过社会运行条件评估。社会操作模型代表了一种最佳的临床前测定，可全面评估社会动机，并为未来研究社会动机中性别差异的神经生物学机制提供了平台。这些发现强调了在未来的社会操作条件研究中继续考虑和纳入性别作为生物学变量的重要性。人类是社会生物-我们与他人的日常互动，这提供的支持在我们的福祉中起着关键作用。对于那些经历心理健康状况的人来说，人们与他人交往的动机可能会减弱，这可能会导致他们退出支持他们的人。因此,为了制定更好的治疗策略，我们需要对社会动机有更深入的了解。研究动物的社会行为可以促进对社会动机的这种调查，因为它可以对人体实验中不可能的潜在神经生物学进行因果理解。研究动物社会动机的最佳方法是使用社会操作条件模型，老鼠学会按下打开门的杠杆，并允许它们与另一只老鼠短时间互动。这项研究通过测试性别是否，住房条件,时间,刺激伴侣的性别会影响大鼠寻求与另一只大鼠互动的动机。我们发现雌性老鼠比雄性老鼠更有社交动机，独自生活的老鼠比与另一只老鼠一起生活的老鼠更有动力；有趣的是，住房的这种影响对女性的影响大于对男性的影响。不管性别,大鼠更有动力与异性大鼠互动。这些发现提供了对大鼠社会动机性别差异的见解，以及对社会操作模型的新见解，这将有助于指导未来对社会动机和其他心理健康状况的研究。
方法：本研究调查了生物性别的影响，住房条件,和一天的时间，关于使用社会操作模型的社会动机。这涉及训练大鼠以杠杆按压（FR1）60秒获得社会奖励（同性特异性刺激）。受试者是雄性和雌性Wistar大鼠，在个人或配对条件下居住，并且在中后期光照阶段（ZT6-10）或早中期黑暗阶段（ZT13-17）进行会议。实施了一种行为经济学方法来衡量社会需求和刺激性伴侣性行为的影响(相同与异性刺激)对社会操作反应的影响。此外,进行了视频跟踪分析，以评估社会食欲行为和完善行为之间的融合程度。
结果：生物性别，住房条件,性与住房之间的相互作用，刺激性伴侣的性行为有力地影响了社会动机，而一天的时间却没有。行为经济学证明了性别，住房,它们之间的相互作用同时影响着社会需求的享乐设定点和弹性。在社会运营会议期间对社交互动进行的视频分析显示，社会食欲和消费行为不一定是趋同的，并表明潜在的社会饱腹感。最后,雌性实验和刺激大鼠的发情期没有影响模型中的社会动机。
结论：大鼠的社会动机存在社会隔离依赖性性别差异，通过社会运行条件评估。社会操作模型代表了一种最佳的临床前测定，可全面评估社会动机，并为未来研究社会动机中性别差异的神经生物学机制提供了平台。这些发现强调了在未来的社会操作条件研究中继续考虑和纳入性别作为生物学变量的重要性。人类是社会生物-我们与他人的日常互动，这提供的支持在我们的福祉中起着关键作用。对于那些经历心理健康状况的人来说，人们与他人交往的动机可能会减弱，这可能会导致他们退出支持他们的人。因此,为了制定更好的治疗策略，我们需要对社会动机有更深入的了解。研究动物的社会行为可以促进对社会动机的这种调查，因为它可以对人体实验中不可能的潜在神经生物学进行因果理解。研究动物社会动机的最佳方法是使用社会操作条件模型，老鼠学会按下打开门的杠杆，并允许它们与另一只老鼠短时间互动。这项研究通过测试性别是否，住房条件,时间,刺激伴侣的性别会影响大鼠寻求与另一只大鼠互动的动机。我们发现雌性老鼠比雄性老鼠更有社交动机，独自生活的老鼠比与另一只老鼠一起生活的老鼠更有动力；有趣的是，住房的这种影响对女性的影响大于对男性的影响。不管性别,大鼠更有动力与异性大鼠互动。这些发现提供了对大鼠社会动机性别差异的见解，以及对社会操作模型的新见解，这将有助于指导未来对社会动机和其他心理健康状况的研究。
