Friday, January 10 at 12:00pm to 1:00am
Irani Hall (RRI), 101
1050 Childs Way, Los Angeles, CA 90089
Title: Untangling the web of behaviors used to produce spider orb webs.
Abstract: Many innate behaviors are the result of multiple sensorimotor programs that are dynamically coordinated to produce higher-order behaviors such as courtship and architecture. Extendend phenotypes such as architecture are particularly useful for ethological study because the structure itself is a physical record of behavioral intent. A particularly elegant and easily quantifiable structure is the spider orb-web. The geometric complexity and stereotypy of these webs have long generated interest in their algorithmic origin. Yet despite the inherently analytical nature of web-making, quantitative analyses of this behavior have been sparse due to the difficulty of recording web-making in real-time. To address this, we have developed a novel assay enabling real-time, high-resolution tracking of limb movements and web structure produced by the hackled orb-weaver Uloborus diversus. With its small brain size of approximately 100,000 neurons, the spider U. diversus offers a tractable model organism for the study of complex and likely cognitive behaviors. Using deep learning frameworks for limb tracking, and unsupervised behavioral clustering methods, we have developed an atlas of stereotyped movement motifs and are investigating the behavioral state transitions of which the geometry of the web is an emergent property. In addition to tracking limb movements, we have developed algorithms to track the web’s dynamic graph structure. We aim to model the relationship between the spider’s sensory experience on the web and its motor decisions, thereby identifying the sensory and internal states contributing to this sensorimotor transformation. Parallel efforts in our group are establishing 2-photon in vivo calcium imaging protocols in this spider, eventually facilitating a search for neural correlates underlying the internal and sensory state variables identified by our behavioral models. In addition, we have assembled a genome, and are developing genetic perturbation methods to investigate the genetic underpinnings of orb-weaving behavior. Together, we aim to understand how complex innate behaviors are coordinated by underlying neuronal and genetic mechanisms.