Recurrent connections between higher olfactory brain areas and their role in mating state-dependent behaviour in Drosophila

内部状态强烈影响感官知觉，从而影响动物对周围世界的理解。在项目TP 3中，我们关注内部状态的一个非常重要的变化，母性，以及它如何改变雌性嗅觉感知和行为的循环回路机制。雌性黑腹果蝇在交配后很快就改变了行为，优先寻找富含营养的产卵地点。为了找到这些地方，雌性依靠嗅觉来检测关键的气味，包括多胺的腐烂气味。重要的是，她对多胺的偏好是通过交配来调节的，使得交配后的雌性在交配后约2周内更喜欢高浓度的气味。我们以前已经表明，交配引起的变化在几个层次的嗅觉处理。首先，交配诱导的肽能信号调节嗅觉感觉神经元中的多胺感知。第二，交配也通过调节特定的蘑菇体（MB）支配多巴胺能神经元（DAN）来改变高级处理。最近，我们发现，在交配诱导的多胺知觉的持久变化需要MB不仅为表达的偏好改变，但令人惊讶的是，也为它的交配相关的诱导。我们的最新数据表明，本地和远程之间的经常性连接MB输出神经元（MBON）和DAN，和MBON和神经元的侧角（LH）是至关重要的诱导或表达更高的多胺偏好或两者兼而有之。在这里，我们将结合联合收割机的行为分析，遗传操作，和国家的最先进的体内功能成像与最近的连接组学数据映射和功能特性，这些经常性的电路图案在雌性动物的生殖状态依赖的气味感知。

Internal states strongly influence sensory perception and thereby an animal’s interpretation of the world around it. In project TP3, we focus on a highly important change in internal state, motherhood, and the recurrent circuit mechanisms of how it changes female olfactory perception and behaviour. Female Drosophila melanogaster drastically change behaviour shortly after mating and prioritize finding appropriate egglaying sites rich in nutrients. For finding such sites, females rely on the sense of smell to detect key odorants including the putrid odour of polyamines. Importantly, her preference for polyamines is modulated by mating such that a mated female will prefer higher concentrations of the odour for ~2 weeks after mating. We have previously shown that mating induces changes at several levels in olfactory processing. First, a mating-induced peptidergic signalling modulates polyamine sensing in olfactory sensory neurons. Second, mating also changes higher processing through modulation of specific mushroom body (MB)-innervating dopaminergic neurons (DANs). Most recently, we found that the long-lasting change in mating-induced polyamine perception requires the MB not only for the expression of a changed preference but, surprisingly, also for its mating-related induction. Our latest data suggest that local and long-range recurrent connections between MB output neurons (MBON) and DANs, and MBONs and neurons of the lateral horn (LH) are critical for either induction or expression of higher polyamine preference or both. Here, we will combine behavioural analysis, genetic manipulation, and state-of-the-art in vivo functional imaging with recent connectomics data to map and functionally characterize these recurrent circuit motifs in reproductive state-dependent odour perception in female animals.