Univ.-Prof. Dr. Thomas Hummel
Research of the Hummel lab is aiming at a better understanding of neural circuit dynamics at various levels, from molecular and developmental programs to behavioral and evolutionary plasticity. Using a broad spectrum of experimental approaches and resources available in Drosophila including a complete description of the central brain connectome and transgenic tools for cell-type specific manipulation, we could identify conserved gene functions and signaling pathways in the regulation of synaptic recognition and plasticity. With the focus on different sensory systems (olfactory and visual maps) as well the interhemispheric communication and brain lateralization, we are fascinated by the interplay between genetic programs and environmental factors in shaping the functional integration of distinct neuron types into complex brain circuits. In collaboration with Prof. Sucic and Dr. Kasture from the Medical University of Vienna, we utilize Drosophila to investigate how disease-associated mutations in human neurotransmitter transporters, essential for synaptic homeostasis, disrupt circuit function, leading to neurological disorders.
Focal points of interest
In the context of the CoE research initiative we will analyze 3 aspects of GABAergic modulation for circuit function and animal behavior:
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Valence coding and multimodal integration: For understanding context-dependent plasticity of innate behavioral responses we are using the synaptic organization of olfactory relay circuits in which we compare the activity of glomerular GABA-mediated modulation with a novel class of extraglomerular local interneurons for multi-modal sensory integration.
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Lateralization in interhemispheric communication: The role of GABAergic interneurons in regulating cellular and circuit asymmetry will be addressed using bilateral olfactory neurons as well as central brain neurons for sensory-motor transition with differences in synaptic release sites between the ipsi- and contralateral hemisphere.
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Human GAT mutations associated with epilepsy: To gain insights into the modified E/I balance of epileptic seizures induced by mutant GABA transporter GAT1 we recapitulate the behavioral phenotypes in mutant-specific transgenic Drosophila lines and determine the underlying changes in circuit architecture before and after drug treatment.
Technical proficiency and instrumentation
In the context of the CoE research initiative we will analyze 3 aspects of GABAergic modulation for circuit function and animal behavior:
-
Valence coding and multimodal integration: For understanding context-dependent plasticity of innate behavioral responses we are using the synaptic organization of olfactory relay circuits in which we compare the activity of glomerular GABA-mediated modulation with a novel class of extraglomerular local interneurons for multi-modal sensory integration.
-
Lateralization in interhemispheric communication: The role of GABAergic interneurons in regulating cellular and circuit asymmetry will be addressed using bilateral olfactory neurons as well as central brain neurons for sensory-motor transition with differences in synaptic release sites between the ipsi- and contralateral hemisphere.
-
Human GAT mutations associated with epilepsy: To gain insights into the modified E/I balance of epileptic seizures induced by mutant GABA transporter GAT1 we recapitulate the behavioral phenotypes in mutant-specific transgenic Drosophila lines and determine the underlying changes in circuit architecture before and after drug treatment.
Aspirations for the next 5 years
Aiming to understand the logic of neural circuit design and plasticity in animal behavior, our CoE research program addressing 3 aspects of GABAergic modulation will include a critical player important at multiple levels of information processing. Through scientific interactions and exchange of novel technologies and ideas with experts from various disciplines I expect the CoE platform to be very beneficial and inspiring in elucidating common principles in nervous system organization.
References
- Kaur R, Surala M, Hoger S, Groessmann N Grimm A, Timaeus L, Kallina W, Hummel T (2019). Pioneer interneurons instruct bilaterality in the Drosophila olfactory sensory map. Science Advances, DOI 10.1126/sciadv.aaw5537.
- Goyal G, Zheng J, Adam E, Steffes G, Jain M, Klavins K, Hummel T (2019). Sphingolipid-dependent Dscam sorting regulates axon segregation. Nat Commun.10(1):813.
- Kasture AS, Fischer FP, Kunert L, Burger ML, Burgstaller AC, El-Kasaby A, Hummel T, Sucic S (2023). Drosophila melanogaster as a model for unraveling unique molecular features of epilepsy elicited by human GABA transporter 1 variants. Front Neurosci. 2023 Jan 19;16:1074427.
