Dr. Georg Raiser
Main Focus
Using high
resolution multi-photon imaging to study olfactory coding in
insects
Unraveling the mechanisms of brain dynamics is a very exigent task from the technological perspective, since it requires simultaneous high temporal and spatial resolution from as many neurons as possible. Multi-photon imaging provides key advantages compared to other approaches, such as parallel probing of many cells in comparison to electrophysiology, or optical sectioning compared to conventional imaging. However, main caveats such as the low temporal resolution of typically few tens of Hz, or the damage caused by the high laser power needed to achieve deep tissue penetration are hindering its applicability in many experimental situations.
One goal of my work is to develop and test the applicability of alternative light sources. I currently focus on an Erbium:Fiber laser coupled into a highly nonlinear ber, outputting a broad excitation suitable for multiphoton excitation. In combination with a basic microscope stage equipped with a high performance xyz-scanning unit, I am able to limit the scan to arbitrary trajectories in 3 dimensions, thereby minimizing scanner dead time and maximizing the sampling rate.
The biological goal of my work is to shed some light on how the olfactory system of insects deals with the processing of quickly changing olfactory stimuli. In contrast to the common belief that olfaction is a rather slow sense, recent work indicates that olfactory systems make use of short timescale changes and fluctuations in the odor stimulus for improved segregation of dierent odor identities. While the representations of odors in higher brain centers of insects are known for static stimuli, it is completely unknown for such more naturalistic time varying ones.
My work aims to close this gap and by this further elucidate the mechanisms of higher order olfactory processing principles.
Unraveling the mechanisms of brain dynamics is a very exigent task from the technological perspective, since it requires simultaneous high temporal and spatial resolution from as many neurons as possible. Multi-photon imaging provides key advantages compared to other approaches, such as parallel probing of many cells in comparison to electrophysiology, or optical sectioning compared to conventional imaging. However, main caveats such as the low temporal resolution of typically few tens of Hz, or the damage caused by the high laser power needed to achieve deep tissue penetration are hindering its applicability in many experimental situations.
One goal of my work is to develop and test the applicability of alternative light sources. I currently focus on an Erbium:Fiber laser coupled into a highly nonlinear ber, outputting a broad excitation suitable for multiphoton excitation. In combination with a basic microscope stage equipped with a high performance xyz-scanning unit, I am able to limit the scan to arbitrary trajectories in 3 dimensions, thereby minimizing scanner dead time and maximizing the sampling rate.
The biological goal of my work is to shed some light on how the olfactory system of insects deals with the processing of quickly changing olfactory stimuli. In contrast to the common belief that olfaction is a rather slow sense, recent work indicates that olfactory systems make use of short timescale changes and fluctuations in the odor stimulus for improved segregation of dierent odor identities. While the representations of odors in higher brain centers of insects are known for static stimuli, it is completely unknown for such more naturalistic time varying ones.
My work aims to close this gap and by this further elucidate the mechanisms of higher order olfactory processing principles.
Curriculum Vitae
Feb 2018 PhD in Biology, University of Konstanz, Germany
Feb 2011 Diplom in Biology, Georg-August University of Göttingen, Germany