Neurobiology of marine zooplankton
Shimoda Marine Station
Oct 15, 2024
Ciliated zooplankton larvae
Volume EM with Array Tomograpy
Array tomography workflow
Array tomography workflow
Array tomography workflow
Array tomography workflow
Coral larvae
In collaboration with Kirsty Wan (LSI Exeter) and Jamie Craggs (Horniman Museum)
Coral larvae
Emelie Brodrick
Hannah Laeverenz
Rebecca Poon & Kirsty Wan
Light-off induces contraction and ciliary arrest
A coral larval nerve net - simplest nervous system?
Hydrozoan larval phototaxis
Jeff Goddard, iNaturalist
GJ & Jürgen Berger
Clava multicornis
Field trips to explore marine plankton
Ischia, Sorgeto, 2024
Field trips lead to unexpected discoveries
with Alexandra Kerbl, Ischia May 31, 2024
What is this??
with Alexandra Kerbl, Ischia May 31, 2024
Egg plates and Müller’s larvae of polyclad flatworms
-> brought them back to Heidelberg
Planocera ceratommata
Emerging marine model organisms
Image: Patrick Steinmetz
Nematostella vectensis
Platynereis dumerilii
Trichoplax adhaerens
Platynereis dumerilii
- breeding culture, full life-cycle
- embryos daily, year round
- genome sequence
- microinjection, transgenesis
- neuron-specific promoters and antibodies
- knock-out lines
- neuronal connectome
- whole-body neuronal activity imaging
- whole-animal pharmacology by bath application 😎
Whole-body volume EM of an entire three-day-old larva
Synaptic connectome
Neural circuit of the visual eyes
Pressure response in Platynereis larvae
Precise control of pressure in the pressure chamber
Pressure response is graded
Swimming speed increases, trajectories straighten
ctr
pressure
Ciliary beating increases under pressure
Which cells respond to pressure?
Microscopy pressure chamber 
Calcium imaging 
Pressure is sensed by photoreceptors with ramified cilia
Photoreceptor responses to pressure are graded
Defects of pressure response in c-opsin1 mutants
Reduced ciliary compartment in c-opsin1 mutants
Defects of ciliary ultrastructure in c-opsin1 mutants
Circuit of ciliary photoreceptors
Circuit of ciliary photoreceptors
Pressure increases ciliary beating through serotonergic cells
Mechanism of barotaxis
UV response in Platynereis larvae
UV avoidance is dependent on c-opsin1
How can cPRCs mediate two responses with opposing sign?
c-opsin1-dependent UV response
Strong cPRC activation after UV exposure
Nitric-oxide synthase in postsynaptic interneurons
HCR
Transgenic labelling
NO is produced in the neuropil after UV stimulation
Kei Jokura (now @NIBB)
NOS mutants have altered cPRC response
NOS mutants show defective UV avoidance
An unusual guanylyl cyclase in the cPRCs
NIT-GC1 RNA
NIT-GC1 protein
An unusual guanylyl cyclase in the cPRCs
NIT-GC1 mediates NO-feedback
Mixed synaptic and volume signalling
Rhabdomeric and ciliary photoreceptors
Platynereis
Müller’s larva
Acknowledgements
- Sanja Jasek
- Alexandra Kerbl
- Emily Savage
- Simone Wolters
- Lara Keweloh
- Kevin Urbansky
- Karel Mocaer
- David Hug
- Benedikt Dürr
- Ira Maegele
- Emelie Brodrick (Exeter)
Former lab members
- Kei Jokura, Luis A. Bezares-Calderón, Luis A. Yanez-Guerra, Victoria Moris, Daniel Thiel, Albina Asadulina, Cameron Hird, Adam Johnstone, Markus Conzelmann, Nadine Randel, Philipp Bauknecht, Martin Gühmann, Cristina Pineiro-Lopez, Nobuo Ueda, Aurora Panzera, Csaba Verasztó, Elizabeth Williams