My lab studies mechanisms of synaptic transmission. We use the neuromuscular junction (NMJ) of the nematode C. elegans, as it is accessible for genetic, behavioral, optical, electrophysiological and electron microscopy approaches. In particular, we study how the excitation – inhibition balance at the NMJ is maintained, thus ensuring proper locomotion of the animal, and allowing to adapt to different situations.
I will discuss how, in addition to the excitatory and inhibitory neurotransmitters Acetylcholine and GABA, also neuropeptides play a vital role in shaping activity at the NMJ. These neuropeptides regulate the extent of synaptic transmission by setting the filling state of synaptic vesicles in an acute manner. In particular, I will show how the NMJ adapts to the loss of these neuropeptides by homeostatically upregulating postsynaptic excitability through L-type voltage gated Ca2+ channels in muscles.
In the second part of the talk, I will discuss our findings on the elusive ‘Flower’ protein, that has been implicated in synaptic Ca2+ signaling and recycling of synaptic vesicles (SVs) in Drosophila. Our findings challenge the idea that Flower could form Ca2+ channels after being delivered to the plasma membrane upon fusion of SVs. Instead, we suggest that C. elegans FLWR-1 is a regulatory subunit of the plasma membrane Ca2+ ATPase (PMCA), and stimulates Ca2+ removal upon SV fusion. In addition, it appears to regulate synaptic plasma membrane levels of phosphatidyl-inosiotol-4,5-bisphosphate (PIP2), thus affecting SV recycling.
Loss of neuropeptidergic regulation of cholinergic transmission induces homeostatic compensation in muscle cells to preserve synaptic strength. Shao J, Liewald J, Steuer Costa W, Ruse C, Gruber J, Djamshedzad MS, Gebhardt W, Gottschalk A. (2025) PLoS Biology, https://doi.org/10.1371/journal.pbio.3003171
Loss of Flower/FLWR-1 regulates neuronal activity via the plasma membrane Ca2+ ATPase to promote recycling of synaptic vesicles. Seidenthal M, Redzovic J, Liewald J, Rentsch D, Shapiguzov S, Schuh N, Eimer S, Gottschalk A. (2025) eLife 13:RP103870 DOI: https://elifesciences.org/articles/103870
More information:
| Talk: | Neuropeptides and the protein Flower affect synaptic transmission and synaptic vesicle recycling in Caenorhabditis elegans | |
| Speaker: | Alexander Gottschalk Goethe University, Frankfurt am Main | |
| Date: | Tuesday, June 3, 2025 at 4 pm | |
| Location: | Seminar room „Nucleus“, FLI 1, Beutenbergstraße 11, Jena | |
| Host: | Janine Kirstein & FOR Syntophagy |
The seminar will take place as a hybrid event.
