Neuroplasticity in songbirds: how changing behaviour and experience affect learning and the brain

鸣禽的神经可塑性：行为和经验的变化如何影响学习和大脑

• 批准号: RGPIN-2018-04060
• 负责人: Phillmore, Leslie
• 金额: $ 4.23万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=764312
• 关键词: Neuroplasticity; songbirds; how; changing; behaviour

Over the course of a year, animals must change their behaviour in response to their changing environment. For example, birds use changes in day length or availability of resources as a cue to tell them when to breed or when not to breed. Animals must also adapt their behaviour to different situations on a daily basis: females may hear and evaluate a potential mate and learn to respond to that male's vocalizations. In order to change behaviour, the brain must have the potential and capacity to change as well. It is therefore important to measure how environmental change affects the brain. My research program aims to understand the neuroplasticity that occurs in response to the environment resulting in appropriate behavioural response. To do this, I study how both breeding condition (the physiological state of animal as ready to breed or not) and learning affect the brain of two species of songbirds: black-capped chickadees and zebra finches. Black-capped chickadees are seasonal breeders they respond to changes in day length, and in turn their behaviour and brains change with the season. In spring when in breeding condition, they sing more songs and regions in their brain important for song are larger than when they are in non-breeding condition. In winter, when in non-breeding condition, they spend a lot of time hiding and retrieving seeds (a task requiring spatial learning memory for “where”) and the hippocampus, a brain region critical for spatial memory, has more new neurons (neurogenesis) than at other times of year. One study I will perform will be to determine whether performing a task appropriate to the season (discriminating among songs when in breeding condition, remembering where seeds are hidden when in non-breeding condition) helps more new neurons live longer than when performing a task not appropriate to the season. This will tell us whether breeding condition, learning, or both affect neuroplasticity.Zebra finches are opportunistic breeders they respond to changes in resource availability, however much less is known about how their brains change depending on breeding condition. I will study how neural activity and neurogenesis (cell birth and survival) are affected by breeding condition in zebra finches by exposing some birds to resources such as a mate and nesting materials and comparing their brains to those without resources. I will also study whether exposure to a difficult learning task promotes neurogenesis compared to birds that do not perform a cognitively enriching task, to determine whether active learning helps more new neurons live longer.I will integrate the results of my experiments to achieve my long-term goal of determining how behavioural change in response to internal (breeding condition) and external factors (experience) affect neuroplasticity. My results have the potential to impact understanding of behavioural and neuroplasticity in songbirds and other organisms.

在一年的时间里，动物必须改变自己的行为以应对不断变化的环境。例如，鸟类利用白天长度或资源可用性的变化作为提示，告诉它们何时繁殖或何时不繁殖。动物还必须每天根据不同的情况调整自己的行为：雌性可能会听到并评估潜在的配偶，并学会对雄性的发声做出反应。为了改变行为，大脑也必须具有改变的潜力和能力。因此，测量环境变化如何影响大脑非常重要。我的研究项目旨在了解对环境做出反应而产生的神经可塑性，从而产生适当的行为反应。为此，我研究了繁殖条件（动物准备繁殖与否的生理状态）和学习如何影响两种鸣禽的大脑：黑冠山雀和斑胸草雀。黑顶山雀是季节性繁殖者，它们对白天长度的变化做出反应，反过来，它们的行为和大脑也会随着季节而变化。在春季，当处于繁殖状态时，它们会唱更多的歌曲，并且大脑中对歌曲重要的区域比非繁殖状态时更大。在冬季，当处于非繁殖状态时，它们会花费大量时间隐藏和检索种子（这项任务需要空间学习记忆“在哪里”），而海马体（对空间记忆至关重要的大脑区域）比一年中的其他时间有更多的新神经元（神经发生）。 我将进行的一项研究是确定执行适合季节的任务（在繁殖条件下区分歌曲，在非繁殖条件下记住种子隐藏的位置）是否可以帮助更多的新神经元比执行不适合季节的任务更长的寿命。这将告诉我们繁殖条件、学习或两者是否会影响神经可塑性。斑胸草雀是机会主义繁殖者，它们会对资源可用性的变化做出反应，但人们对它们的大脑如何根据繁殖条件而变化知之甚少。我将通过将一些鸟类暴露于配偶和筑巢材料等资源中，并将它们的大脑与没有资源的鸟类进行比较，研究斑胸草雀的神经活动和神经发生（细胞诞生和存活）如何受到繁殖条件的影响。我还将研究与不执行认知丰富任务的鸟类相比，接触困难的学习任务是否会促进神经发生，以确定主动学习是否有助于更多新神经元活得更长。我将整合我的实验结果，以实现我的长期目标，即确定响应内部（繁殖条件）和外部因素（经验）的行为变化如何影响神经可塑性。我的研究结果有可能影响对鸣禽和其他生物体的行为和神经可塑性的理解。