Markus Meister - Biology and Biological Engineering

Dipl., Technische Universitat Munchen, 1980; Ph.D., Caltech, 1987. Moore Distinguished Scholar, Caltech, 2004; Professor, 2012-13; Hanson Professor, 2013-15; Biaggini Professor, 2015-; Executive Officer, 2017-20.

Email: [email protected]

Phone: 626-395-1782

Office: 301G Beckman Behavioral Biology (76)

Mail Code: MC 216-76

Research Areas

Biological Engineering; Evolutionary and Organismal Biology; Neuroscience;

Research Summary

My goal is to understand how large circuits of neurons work. By "circuit" I mean a brain structure with many neurons that has some anatomical and functional identity, and exchanges signals with other brain circuits. "Understanding" such a neural circuit will require answers to the following: What does the circuit do? Find the function that relates the inputs to the outputs of this part of the brain. How does it do that thing? Spell out the mechanism behind this computation in terms of signals flowing through neurons and synapses. Why does the circuit do that? Explain how the functions of this circuit fit into the larger brain and relate its role to the animal's behavior. For some time the lab's focus was on circuits for visual processing, in particular retina and superior colliculus. We have also worked on circuits for olfaction. I maintain an interest in these sensory areas, but our current research has turned toward problems that are comparatively less well understood: (1) Mechanisms of rapid learning: Animals can learn a complex sequence of actions after just one or a few successful episodes. (2) Task control: Many behaviors require a rapid switching between different tasks. How is that coordinated? In all these pursuits, we try to use the full toolkit of modern neuroscience: electrophysiology, optophysiology, molecular genetics, psychophysics, theory and modeling.

Profile

Lab Website

Function of neuronal circuits

We explore how large circuits of nerve cells work. Ultimately we want to understand large nervous systems in the same way as we understand large electronic circuits. These days we primarily study the visual system, from processing in the retina to the circuits of the superior colliculus to the control of visually guided behaviors and perception. Here are some of the research questions that guide our explorations:

What visual information is encoded by the neurons in the circuit. This involves recording electrical signals from many neurons, while stimulating the retinal input with visual patterns. Interpreting the relationship between sensory input and neural output involves copious mathematical modeling.

How are these computations performed? For this we gain access to the innards of the circuit using fine electrodes or molecular tools. The ultimate goal here is to summarize the system's function with a neural circuit diagram that efficiently simulates its operation.

Why are the circuits built this way? Much of the structure and function of the early visual system is conserved from mouse to man and probably serves a common purpose. Perhaps to pack information efficiently into the optic nerve? Or to rapidly extract some signals that are essential for survival? To test these ideas we modify the neural circuits and monitor the resulting effects on visual behavior.

Markus Meister Publications