Gaspar Jekely @jekely@qoto.org
- Platynereis connectome
- https://catmaid.jekelylab.ex.ac.uk
Professor at Centre for Organismal Studies (COS), University of Heidelberg, Germany
and
Living Systems Institute (LSI), University of Exeter, UK.
#neuroscience of marine larvae, #connectomics, #cilia, ciliary swimming, cell and nervous system #evolution, #GPCR, #neuropeptides, #Platynereis, #Trichoplax, #Nematostella, #Schistosoma, #coral #neuroscience #rstat #evolution
Joined Nov 2022
In collaboration with Alison Cole and Ulrich Technau we also mapped the peptidergic #connectome of #Nematostella, by linking peptide-expressing to receptor-expressing cells.
In #Cnidaria, tissues are extensively connected via #neuropeptide signalling.
#neuroscience
By phylogenetic reconstruction, Daniel Thiel and Luis Yanez could show that #cnidarian #neuropeptide receptors diversified independent from #GPCRs in bilateria. This parallel #evolution and expansion confirms that cnidarians do not represent the ancestral state in neuronal signalling (as implied by terms like 'pre-bilaterian') any more than bilaterians.
#receptor #evolution #neuroscience #phylogeny
To get a comprehensive list of #neuropeptides, we combined #bioinformatic screening and mass spectrometry in collaboration with Amanda Kieswetter and Liesbet Temmerman at KU Leuven. We found 15 new proneuropeptides and confirmed the endogenous processing (cleavage, amidation etc) of many of them. #Nematostella has at least 33 neuropeptide precursors.
#cnidaria #neuroscience
Consider organising a Royal Society scientific meeting (fully funded) and guest-edit a RS journal #royalsociety #conference
https://royalsociety.org/blog/2022/07/organise-a-scientific-meeting-and-guest-edit-a-theme-issue/
For #neuropeptide afficionados:
Interesting new paper from James Checco's lab on two #Aplysia #allatotropin / #orexin receptors, one activated by a D-peptide the other one by an L-peptide.
Conversion of an L-stereoisomer to a D-stereoisomer is a big mystery in peptide biology - but it matters for rec specificity and lifetime.
https://www.pnas.org/doi/10.1073/pnas.2217604120
Currently we are trying to understand what underlies the extreme sensitivity of the ciliary photoreceptors to pressure Stay tuned.
9/9
We propose a model for a pressure gauge in zooplankton, including ciliary photoreceptos as sensors and a circuit linking these to the ciliary band cells, leading to increased beating through the action of serotonin, driving faster upward swimming.
8/9
By #connectome analysis, we previously showed that the ciliary photoreceptors synaptically connect through interneurons to the head serotonergic ciliomotor neurons (Ser-h1). Serotonin increases ciliary beating and genetic inhibition of these cells blocked the effect of pressure on cilia, confirming that the pressure signal reaches the ciliated cells via the mapped circuit.
#connectomics
7/9
To identify the #neuronal mechanisms, Luis carried out #calcium #imaging experiments and found that the brain ciliary #photoreceptor cells showed graded activation by pressure stimuli.
4/9
Luis Bezares, the first author of the study, built custom pressure chambers where he could precisely control pressure levels while imaging the swimming activity of the #larvae.
Larvae showed graded and adaptable responses to relative changes in pressure. Increased pressure led to faster beating of locomotor cilia.
The larvae were extremely sensitive to pressure changes, reacting already to 10-20 mbar increase in pressure, corresponding to 10-20 cm water depth.
3/9
Hydrostatic pressure is a dominant cue in the sea and many aquatic organisms are known to respond to changes in pressure, however the neuronal mechanisms have remained unclear.
We studied the larvae of the marine #annelid #Platynereis and found that they respond to increases in pressure by increased upward swimming.
#neuroscience
2/9
We published a new preprint on the mechanism of hydrostatic pressure sensation in marine #zooplankton.
https://www.biorxiv.org/content/10.1101/2023.02.28.530398v1?ct=ct
Click on the toot to see a thread about our findings. 1/9
The full version of our desmosomal #connectome paper is now out, with all videos, supplements, source data nicely integrated
https://elifesciences.org/articles/71231#content
#neuroscience #annelid #microscopy
Alternatively, if you have experience in electron microscopy or image analysis and are interested in volume EM, you can join our #volumeEM projects either to do EM or work on the data analysis side of volume EM and connectomics projects
5/5
There will be new #postdoc and #PhD openings, if you are interested to work with us, please get in touch. Possible topics include #Platynereis neurobiology, eye #evolution, #connectomics, the behaviour of ciliated #larvae etc. You can work on a growing selection of organisms kept in the lab, including Platynereis (still our no. 1), #Trichoplax, #Nematostella or join more exotic projects investigating hard-to-culture marine animals including polyclads, hemichordates or amphioxus.
4/5
We am very excited to move to COS and join its vibrant community. We have a shared interest in the study of organismal biology across the boundaries of biological levels of organization.
3/5
We will build up a new department on Evolutionary Neurobiology with a focus on marine larval behaviour, comparative #connectomics, molecular organismal biology, #neuromodulation and related topics.
#neuroscience #evolution
2/5
- Platynereis connectome
- https://catmaid.jekelylab.ex.ac.uk
Professor at Centre for Organismal Studies (COS), University of Heidelberg, Germany
and
Living Systems Institute (LSI), University of Exeter, UK.
#neuroscience of marine larvae, #connectomics, #cilia, ciliary swimming, cell and nervous system #evolution, #GPCR, #neuropeptides, #Platynereis, #Trichoplax, #Nematostella, #Schistosoma, #coral #neuroscience #rstat #evolution
Joined Nov 2022
