{"doi":"10.1101/2023.12.01.569590","title":"Desynchronized Somas and Terminals in a Morning Clock Neuron: Presynaptic Ca <sup>2+</sup> Spiking and Native Neuropeptide Release Peak As Somatic Ca <sup>2+</sup> Declines","abstract":"Summary Drosophila sLNv clock neurons release the co-packaged neuropeptides PDF and sNPF to regulate circadian behaviors (e.g., morning anticipation) and nighttime sleep 1-3 . Previous studies of membrane potential and cytoplasmic Ca 2+ at the soma suggested that sLNv neuron activity peaks at night 4,5 , but exocytosis of neuropeptide-containing dense-core vesicles (DCVs) at their terminals peaks hours later at midmorning 6 . To resolve the basis of the timing mismatch between somatic physiology and terminal exocytosis, recently developed probes were used to measure daily rhythms in sLNv neuron synaptic Ca 2+ and sNPF release. Remarkably, at midmorning after soma Ca 2+ has dropped, both Ca 2+ spiking and clock-dependent native neuropeptide release peak in the distal terminals of the protocerebrum. Furthermore, Ca 2+ in the soma and terminals differ in dependence on Ca 2+ influx. Finally, synaptic DCV exocytosis requires Ca 2+ spike activity at terminals that is not evident at the soma. These results lead to two striking conclusions. First, soma Ca 2+ recording, which is the focus of many circuit studies, is not indicative of presynaptic Ca 2+ and neuropeptide release in distal sLNv terminals. Second, daily clock- and activity-dependent sLNv terminal neuropeptide release occurs ∼9-18 hours in advance of known sLNv neuropeptide effects on nighttime sleep and morning behavior.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2023,"id":395438,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":3,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9542,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1171060,"name":"Junghun Kim","orcid":"0000-0002-0982-6373","position":1,"is_corresponding":false},{"id":1171061,"name":"Sydney N. Gregg","orcid":null,"position":2,"is_corresponding":false},{"id":562246,"name":"Brigitte F. Schmidt","orcid":"0000-0002-2892-493X","position":3,"is_corresponding":false},{"id":1024104,"name":"Xiju Xia","orcid":"0000-0001-7179-1100","position":4,"is_corresponding":false},{"id":151125,"name":"Yulong Li","orcid":"0000-0002-9166-9919","position":5,"is_corresponding":false},{"id":660224,"name":"Edwin S. Levitan","orcid":"0000-0003-3319-1344","position":6,"is_corresponding":false},{"id":801006,"name":"Markus K. Klose","orcid":"0000-0001-5861-2366","position":0,"is_corresponding":true}],"reference_count":34,"raw_metadata":null,"created_at":"2026-07-19T01:19:22.857556Z","pmid":"38106047","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}