Seminars
Abstract: Learned associations between stimuli in different sensory modalities can shape the way we perceive these stimuli (Mcgurk and Macdonald, 1976). During audio-visual associative learning, auditory cortex has been shown to underlie multi-modal plasticity in visual cortex (McIntosh et al., 1998; Zangenehpour and Zatorre, 2010). However, how processing in visual cortex is altered when an auditory stimulus signals a visual event and what the neural mechanisms are that mediate such experience-dependent audio-visual associations is not well understood. Here we describe a neural mechanism that contributes to shaping visual representations of behaviorally relevant stimuli through direct interactions between auditory and visual cortices. We show that auditory association with a visual stimulus leads to an experience-dependent suppression of visual responses in visual cortex. This suppression of the predictable visual stimulus response is driven in part by input from auditory cortex. By recording from auditory cortex axons in visual cortex, we find that these axons carry a mixture of auditory and retinotopically matched visual input. Moreover, optogenetic stimulation of auditory cortex axons in visual cortex selectively suppresses the neurons responsive to the associated visual stimulus after, but not before, learning. Our results are consistent with the interpretation that cross-modal associations can be stored in long-range cortical connections and that with learning these cross-modal connections function to suppress the responses to predictable input.
This seminar was rescheduled to the NCS timeslot at 4pm in LISB 217. Please join us!
Animal behavior contains rich structure across many timescales, but there is a dearth of methods for the identification of relevant long run behavioral components. Inspired by the goals and techniques of genome-wide association studies, I will present our development of a data-driven method—the choice-wide behavioral association study: CBAS—that systematically identifies such behavioral features. CBAS breaks down the actions of subjects into all sequences of choices during behavior, then uses powerful, resampling-based, multiple comparisons methods to identify the sequences that either differ significantly between groups or significantly correlate with a covariate of interest. I will show that CBAS works across different tasks and species (flies, rats, and humans). I will then focus on our application of CBAS to compare WT rats to those haploinsufficient for a high-confidence, large effect, autism spectrum disorder risk gene (Scn2a+/-). CBAS identifies specific and consistent ways that Scn2a haploinsufficient rats differ throughout all phases of learning a spatial alternation task, and CBAS shows that Scn2a+/- rats differentially rely on their hippocampus for behavior. Through identifying relevant choices during behavior, CBAS provides a uniquely informative framework to interpret neural function and its changes in the context of disease processes.
Abstract: From object detection to successful prey capture, insect aerial predators gather appropriate cues, make fast decisions and translate them into precise motor commands. To compensate for biological delays and noisy data, some dragonflies and robber fly species employ predictive strategies, in addition to visual feedback. Aerial predation therefore presents as an ideal substrate to investigate how animals with very limited resources deal with uncertainty in decision-making. In this talk, I will focus on the strategies that predatory aerial insects use when deciding whether to attack an object. In particular, we will compare the temporal and depth cues used by robber flies and damselflies. I will link the behavior to the neural and morphological adaptations, and discuss how they match particular ecological niches and evolutionary paths.
Bio: Paloma grew up in Malaga, a coastal city in southern Spain. She obtained her undergraduate degree from the University of Queensland (Australia; 2000- 2002) majoring in Zoology and Marine Biology. While at UQ, Paloma was an undergraduate in the Justin Marshall laboratory, part of what was the Vision, Touch and Hearing Research Centre (VTHRC), directed by Jack Pettigrew. During her PhD (U. of Sheffield, UK. 2006-2009) she studied the neural basis of visually guided predation in killer flies. For her work on the adaptations that can make a miniature fly deadly she received the Capranica Prize from the Society for Neuroethology. During a short postdoc at Janelia HHMI Campus (2010-2011), she studied the neural basis of predation on dragonflies, and was awarded the PNAS Cozzarelli prize for this work. A dream opportunity arose: to study the neural basis of camouflage on cephalopods at the Marine Biological Laboratory (MBL, MA). During her time at the MBL (2011-2013), in the Roger Hanlon Laboratory, she discovered a nerve that controls the tunable skin iridescence present in squid skin, and demonstrated that cuttlefish achieve texture in their skin with combinations of ‘catch-like’ muscles. In 2013 she started her own laboratory, the Fly Systems Lab, at the University of Cambridge (UK), which she moved to U. Minnesota in 2018. Her laboratory continues the focus on high quality, integrative and comparative work on predatory aerial insects, and was recently awarded the outstanding paper prize for Fabian et al. 2022, a study of interception through obstacles. In addition to her flight work, Paloma continues to work on cephalopods via collaborative efforts with the Wardill laboratory.
This seminar remains unscheduled for participation in the Undergraduate Research Symposium, held annually in May. For more information please visit the symposium website.
Abstract:
House mice (Mus musculus) are omnivores and have an innate predatory instinct for small invertebrates like crickets. Our lab is interested in the evolutionary, behavioral, and neural mechanisms underlying hunting behaviors. In this talk, I will discuss the lab's neuroethological approaches to studying hunting at multiple levels: in feral mice on Skokholm island, free-living “re-wilded” lab mice in large outdoor enclosures, and in the lab. I will spend the majority of the time talking about our lab work, where we have created a large arena where we hide crickets and let our mice find them using auditory cues (chirps), focusing on what we have learned from our first cohorts of animals, and where we’re headed next
www.janelia.org/lab/dennis-lab
The Reinagel Lab at UCSD