Neuronal mechanism of hydrostatic pressure sensation in zooplankton
2nd NIBB-COS Heidelberg Joint Workshop
Oct 8-10, 2024
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 😎
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
Whole-body volume EM of an entire three-day-old larva
Volume EM with Array Tomograpy
Array tomography workflow
Array tomography workflow
Array tomography workflow
Array tomography workflow
Synaptic connectome
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
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