BRC-BIO: Neuroendocrinology of flying squirrel social behavior

南方鼯鼠是美国东半部常见的本地物种。这些松鼠全年都有选择性地与不相关的个体筑巢。人们一直认为，这些松鼠聚在一起筑巢是因为当它们挤在一起时，它们可以保暖并节省能量。然而，研究表明，这些松鼠继续在温暖的纬度和夏季聚集在一起。相反，这些松鼠似乎会形成选择性的“友谊”，并选择特定的松鼠在一年中挤在一起。这个项目将研究激素和大脑如何影响这种筑巢行为，以鼯鼠作为非亲属友谊的模型。这项研究的目的是量化大脑中特定激素（催产素和抗利尿激素）对这种行为的影响，并描述大脑中对这些激素的敏感性如何变化，包括季节性变化，以促进鼯鼠的共同筑巢。这些数据将有助于确定大脑如何支持非家庭关系（即“友谊般的”）和社会行为。该项目通过付费研究机会和顶点项目支持本科生参与动手神经科学研究。最后，虽然飞鼠在当地很丰富，但大多数马里兰人从未见过飞鼠，也不知道飞鼠生活在当地的森林里。通过在当地动物园的宣传，研究小组将与公众分享鼯鼠的奇迹。尽管人们对识别、记忆和家庭关系的机制进行了大量研究，但我们对选择性、附属关系中的神经过程缺乏了解。因此，本工作将通过研究非肽、催产素和加压素在以鼯鼠为模型的非家族选择性隶属关系调节中的作用来弥补这一空白。本项目采用三种策略：首先，将检查鼻内催产素或拮抗剂对群落筑巢行为的影响。其次，非肽表达神经元的荧光共标记和即时早期基因表达将用于识别在共筑巢过程中释放非肽的大脑区域。最后，季节（即光周期）对非肽受体的存在和密度的影响将被确定，并检查与跨季节共巢行为的关系。为了理解社会性进化的统一原则，需要从行为范围从非社会性到群居性的物种中获得可靠的实验数据。本研究将填补这一领域的重要空白，通过长期的从属关系来研究社会性的神经机制。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The southern flying squirrel is a common native species in the eastern half of the United States. These squirrels selectively nest with un-related individuals throughout the year. It has been assumed that these squirrels co-nest because when they huddle together, they can keep warm and save energy. However, research has shown that these squirrels continue to group in warm latitudes and during summer months. Instead, it appears that these squirrels form selective ‘friendships’ and choose specific squirrels to huddle in the nest with throughout the year. This project will examine how hormones and the brain affect this nesting behavior, using the flying squirrel as a model of friendship in non-kin. The aims of this research are to quantify the effects of specific hormones in the brain (oxytocin and vasopressin) on this behavior and to characterize how sensitivity to these hormones in the brain changes, including seasonaly, to facilitate co-nesting in flying squirrels. These data will help determine how the brain functions to support non-familial (i.e., ‘friendship-like’) relationships and social behaviors. This project supports engaging undergraduates in hands-on neuroscience research through paid research opportunities and a capstone project. Finally, though the flying squirrel is locally abundant, most Marylanders have never seen a flying squirrel nor are they aware that flying squirrels are living in the local forests. Through outreach at the local zoo, the research team will share the wonders of the flying squirrel with the public.Despite the body of work on the mechanisms of recognition, memory, and familial bonding, we lack understanding of the neural processes in selective, affiliative relationships. Therefore, this work will bridge this gap by studying the role of the nonapeptides, oxytocin and vasopressin, in the regulation of non-familial selective affiliation using the flying squirrel as a model. This project employs three strategies: First, the impacts of intranasal oxytocin or antagonist on communal nesting behavior will be examined. Second, fluorescent co-labeling of nonapeptide-expressing neurons and immediate early gene expression will be used to identify brain regions where the nonapeptides are released during co-nesting. Finally, the impact of season (i.e., photoperiod) on the presence and density of nonapeptide receptors will be determined, and examined in relation to co-nesting behaviors across the seasons. To understand the unifying principles of the evolution of sociality, robust, experimental data are needed from species with behaviors that range from asocial to gregarious. This work will fill a critical gap in this field by studying the neural mechanisms of sociality via long-term affiliative relationships.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.