Brightening brain science: What genetically engineered sensors tell us about the mind

Date: Jun 17, 2024
Time: 01:00 PM - 02:00 PM (Local Time Germany)
Speaker: Lin Tian
Max Planck Florida Institute for Neuroscience
Location: MPI BI Martinsried
Room: MPI BI, T-Building, Main lecture hall
Host: Manfred Gahr

To study the neural circuitry, the action of one cells under the context of others, one would precisely measure and perturb specific neuronal populations and molecules in behaving animals who are specifically engaged in performing the computation or function of interest. The dataset of millions of neurons firing together underlying a behavior are required to develop and refine theories (hypotheses) explaining animal behavior in terms of brain physiology. The focus of lab is to develop novel genetically encoded indicators based on fluorescence proteins and chemical dyes, especially focusing on direct and specific measurement of myriad input signals with needed spatial and temporal resolutions. In this talk, I will discuss our recent progress into develop genetically encoded indicators for neuromodulators using machine-leanring based single-cell screening. I will discuss the design, characterization and applications of these genetically encoded indicators, especially serotonin probes, for both in vivo imaging and drug discovery. In combination with calcium imaging and optogenetics, these sensors are well poised to permit direct functional analysis of how the spatiotemporal coding of neural input signaling mediates the plasticity and function of target circuits.

How does the brain represent dynamic sensory information in the natural environment? How are sensory signals and motor commands coordinated to direct actions in 3D space? The echolocating bat presents a powerful animal model to address these questions, as it produces the very acoustic signals that guide its behaviors. Importantly, the echolocating bat adapts the timing, duration, bandwidth, and directional aim of its echolocation calls in response to changes in environmental stimuli and task demands, providing an experimental window to quantify on a rapid time scale the sensory information an animal has processed and the information it is seeking. In this talk, I will present data from a series of experiments that illustrate the tight coupling between vocal-motor behavior and sound processing in bats as they execute natural tasks, such as sonar target tracking and obstacle avoidance. Quantitative analyses of adaptive echolocation behaviors lay the foundation for our neurophysiological experiments, and I will report the effects of echolocation call adjustments on the neural coding of 3D sonar object location in flying bats. These findings highlight the dynamics of neural systems in freely behaving animals.