Yang-Keun Oh

Sleep, a reversible quiescent state found in both invertebrate and vertebrate animals, disconnects animals from their environment and is highly regulated for coordination with wakeful activities, such as reproduction. The fruit fly, Drosophila melanogaster, has proven to be a valuable model for studying the regulation of sleep by circadian clock and homeostatic mechanisms. Here, we demonstrate that the sex peptide receptor (SPR) of Drosophila, known for its role in female reproduction, is also i

Across animal species, meals are terminated after ingestion of large food volumes, yet underlying mechanosensory receptors have so far remained elusive. Here, we identify an essential role for Drosophila Piezo in volume-based control of meal size. We discover a rare population of fly neurons that express Piezo, innervate the anterior gut and crop (a food reservoir organ), and respond to tissue distension in a Piezo-dependent manner. Activating Piezo neurons decreases appetite, while Piezo knocko

SIFamide receptor (SIFR) is a Drosophila G protein-coupled receptor for the neuropeptide SIFamide (SIFa). Although the sequence and spatial expression of SIFa are evolutionarily conserved among insect species, the physiological function of SIFa/SIFR signaling remains elusive. Here, we provide genetic evidence that SIFa and SIFR promote sleep in Drosophila. Either genetic ablation of SIFa-expressing neurons in the pars intercerebralis (PI) or pan-neuronal depletion of SIFa expression shortened ba

Histamine and its two receptors, histamine-gated chloride channel subunit 1 (HisCl1) and ora transientless (Ort), are known to control photoreception and temperature sensing in Drosophila. However, histamine signaling in the context of neural circuitry for sleep-wake behaviors has not yet been examined in detail. Here, we obtained mutant flies with compromised or enhanced histamine signaling and tested their baseline sleep. Hypomorphic mutations in histidine decarboxylase (HDC), an enzyme cataly

-dependent response. This review discusses the physiological and behavioral roles of DH44 and DH31 signaling pathways, consisting of neuroendocrine cells that secrete DH44 or DH31 peptides and their receptor-expressing organs. Further research is needed to understand the regulatory mechanisms of the behavioral processes mediated by these neuroendocrine systems. [BMB Reports 2023; 56(4): 209-215].

Mammalian T-type Ca(2+) channels are encoded by three separate genes (Cav3.1, 3.2, 3.3). These channels are reported to be sleep stabilizers important in the generation of the delta rhythms of deep sleep, but controversy remains. The identification of precise physiological functions for the T-type channels has been hindered, at least in part, by the potential for compensation between the products of these three genes and a lack of specific pharmacological inhibitors. Invertebrates have only one

brain, including diuretic hormone 44 (DH44)-, CN-, and cupcake-expressing neurons, detect circulating glucose levels in the internal milieu, regulate the insulin and glucagon secretion and promote food consumption. Food deprivation is known to reduce sleep duration, but a potential role mediated by the nutrient and hunger sensors in regulating sleep and locomotion activity remains unclear. Here, we show that DH44 neurons are involved in regulating starvation-induced sleep suppression, but CN neu

Kohlschutter-Tönz syndrome (KTS) is a rare genetic disorder with neurological dysfunctions including seizure and intellectual impairment. Mutations at the Rogdi locus have been linked to development of KTS, yet the underlying mechanisms remain elusive. Here we demonstrate that a Drosophila homolog of Rogdi acts as a novel sleep-promoting factor by supporting a specific subset of gamma-aminobutyric acid (GABA) transmission. Rogdi mutant flies displayed insomnia-like behaviors accompanied by sleep

Significance Fruit flies release a previously unreported signal when they consume nutritive food. This signal communicates the presence of nutritive food to other flies and guides them to aggregate around the nutritive food. The nutritional value of food, rather than its taste, is critical for the release of calorie-induced secreted factor (CIF) from the gut end. This signal is not detected by the olfactory system and is not limited to one species in Drosophila . We propose that CIF acts as an e

SUMMARY Across animal species, meals are terminated after ingestion of large food volumes, yet underlying mechanosensory receptors have so far remained elusive. Here, we identify an essential role for Drosophila Piezo in volume-based control of meal size. We discover a rare population of fly neurons that express Piezo, innervate the anterior gut and crop (a food reservoir organ), and respond to tissue distension in a Piezo-dependent manner. Activating Piezo neurons decreases appetite, while Piez

Systemic nutrient sensing is a fundamental process that aligns nutrient availability with an organism's metabolic demands. This mini-review explores nutrient sensors in the intestine, pancreas, portal vein, and the brain-organs that detect and convey nutrient status to other tissues via neuronal and hormonal signaling. Unlike oral taste receptors that sense external nutrient inputs, these nutrient sensors monitor post ingestive levels of macronutrients (carbohydrates, proteins, and lipids) and m