Professor of Biological Sciences
PhD, 1997 University of Notre Dame
Mechanisms of learning and memory in fruit fly
Research descriptionWe study the molecular / cellular, systems, and behavioral control of learning using Drosophila. These learning mechanisms are examined in three interdependent approaches. We identify new gene function in neural systems to support learning in behavioral paradigms that we define.
Molecular / cellular mechanisms of learning. Because of the commonality of some gene function in resistance to ethanol effects on behavior and learning, we characterized the memory phenotypes of several novel ethanol sensitive mutants. We found three new genes that have learning functions in operant place learning and classical olfactory conditioning. These genes implicate novel and different processes in memory formation. We continue to characterize these mutant flies.
Neural system mechanisms of learning. Using genetic and pharmacological approaches, we found that the serotonergic system is necessary for memory formation. Indeed, we find that altering excitability of these neurons leads to memory performance levels of different strengths. Furthermore, we discovered that the serotonergic system is critical for a process that enhances memory performance after experience with unpredicted experience with negative reinforcement. We are determining the role of the serotonergic system in olfactory memory and developing tools for manipulating subsets of the serotonergic nervous system.
Behavioral analysis. We examined the role of reinforcement pre-exposure on subsequent memory acquisition. This manipulation leads to either enhancement or decrement in later memory formation in many animal models. It was an open question how reinforcement pre-exposure would alter learning in Drosophila. We found that reinforcement pre-exposure increases associative memory performance, the first example of this sort in an invertebrate animal. Furthermore, yoking experiments show that it is the lack of an accurate predictor that is important for acquisition of this effect.
Mishra, A*, A. Salari*, B.R. Berigan*, K.C. Miguel, M. Amirsheneva, A. Robinson, B.C. Zars, J.L. Lin, L.S. Milescu#, M. Milescu#, and T. Zars# The Drosophila Gr28bD product is a non-specific cation channel that can be used as a novel thermogenetic tool. Scientific Reports. in press.
Baggett, V., A. Mishra, A.L. Kehrer, A.O. Robinson, P. Shaw, and T. Zars. Place learning overrides innate behaviors in Drosophila. Learning and Memory. in press.
LaFerriere, H, and T. Zars. (2017) The Drosophila melanogaster tribbles pseudokinase is necessary for proper memory formation. Neurobiology of Learning and Memory. 144, 68-76.
Zars, T. Working Memory: It's a Gas, Gas, Gas (2017) Current Biology, 27 (5), R179-R181.
Sitaraman, D., E.F. Kramer, L. Kahsai, D. Ostrowski, and T. Zars. (2017) Discrete serotonin systems mediate memory enhancement and escape latencies after unpredicted aversive experience in Drosophila place memory. Front. Syst. Neurosci. | doi: 10.3389/fnsys.2017.00092
Ostrowski, D., L. Kahsai, E.F. Kramer, P. Knutson, and T. Zars (2015) Place memory retention in Drosophila. Neurobiology of Learning and Memory. 123, 217-224.
Mendoza E, J. Colomb, J. Rybak J, H.-J. Pflüger, T. Zars, C. Scharff, and B. Brembs. (2014) Drosophila FoxP mutants are deficient in operant self-learning. PLoS ONE, 9(6): e100648.
Ostrowski, D., and T. Zars. (2014) Place memory. in Handbook of Behavior Genetics of Drosophila melanogaster: Behavioral Phenotypes and Models of Neurobehavioral Disorders. J. Dubnau, ed. Cambridge, UK. Cambridge University Press. ISBN: 9781139950084
Honors & Awards
Selected honors and awards
Zars, T. (2017) Visual working memory: It’s a gas, gas, gas. Current Biology. 27, R179-181. 2017
Richard Wallace Alumni Research Award 2012
March 20, 2018
MU scientists expand toolbox to study the brain
June 5, 2017
Zars, King receive grant to uncover the genetic basis of learning and memory in flies
May 30, 2017
Two biology students selected as Cherng Summer Scholars
Aug. 12, 2015
Zars, Milescu labs awarded NSF ‘Early Concept’ grant to build new protein switches for neurons
June 26, 2014
Origin of language found in fruit fly gene
March 19, 2012
Zars' Perspective Article in Science Receives National Attention
March 25, 2008
Fly's tiny brain may hold huge human benefits
March 29, 2005
Neurobiologist Works to Localize Memory