198 Oral - Techniques and Technology Session
Saturday April 09, 5:30 PM - 5:45 PM

Spying on the dynamics of neuropeptides by the GRAB sensors in Drosophila


Authors:
xiju xia 1,2,3; Yulong Li 1,2,3,4

Affiliations:
1) State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China; 2) PKU-IDG/McGovern Institute for Brain Research, Beijing, China; 3) Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; 4) Chinese Institute for Brain Research, Beijing, China

Keywords:
b. live imaging; s. other (neuropeptide release)

Neuropeptides are essential signaling molecules transported and secreted by large dense-core vesicles (DCVs). Neuropeptides play a critical role in many physiological processes, including brain development, sleep, circadian rhythm, and feeding behaviors, alterations in neuropeptide levels have been associated to many pathological states, such as anxiety, stress and addition related disorders. For a precise understanding of neuropeptides’ functions, it is important to probe when, where and how they are released in brain. Here, we developed a series of genetically-encoded green GRAB (GPCR activation based) sensors for detecting neuropeptides in living flies, including sNPF, CCha1, DH31 and FMRFa. These peptide sensors exhibited nanomolar to micromolar EC50 affinity and exquisite selectivity for cognate peptide ligands. Preliminary results suggested that transgenic expressing sNPF sensors are capable of detecting in vivo peptide release events triggered by high K+ and optogenetic stimulation. Furthermore, calyx and horizontal lobe of mushroom body neurons (Kenyon cells) shows distinct release probabilities. Thus, these GRAB sensors provide sensitive and specific molecular probes to unravel the in vivo dynamics and molecular mechanisms of neuropeptide release in Drosophila.

Key words: neuropeptides, GRAB sensors, sNPF