Tatsuya Ogura

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Controlling stimulus access to sensory organs allows animals to optimize sensory reception and prevent damage. The vomeronasal organ (VNO) detects pheromones and other semiochemicals to regulate innate social and sexual behaviors. This semiochemical detection generally requires the VNO to draw in chemical fluids, such as bodily secretions, which are complex(More)
Inhaled airborne irritants elicit sensory responses in trigeminal nerves innervating the nasal epithelium, leading to protective reflexes. The sensory mechanisms involved in the detection of odorous irritants are poorly understood. We identified a large population of solitary chemosensory cells expressing the transient receptor potential channel M5 (TRPM5)(More)
Sour taste is mediated by acids with the degree of sourness a function of proton concentration. Recently, several members of the acid-sensing ion channel subfamily (ASICs) were cloned from taste cells and proposed to mediate sour taste. However, it is not known whether sour responses in taste cells resemble the responses mediated by ASICs. Using the whole(More)
Previous studies in rat and mouse have shown that brief exposure to the bitter stimulus denatonium induces an increase in [Ca2+]i due to Ca2+ release from intracellular Ca2+ stores, rather than Ca2+ influx. We report here that prolonged exposure to denatonium induces sustained increases in [Ca2+]i that are dependent on Ca2+ influx. Similar results were(More)
Bitter substances are a structurally diverse group of compounds that appear to act via several transduction mechanisms. The bitter-tasting denatonium ion has been proposed to act via two different G-protein-regulated pathways, one involving inositol 1,4, 5-trisphosphate and raised intracellular calcium levels, the other involving phosphodiesterase and(More)
Ogura, Tatsuya. Acetylcholine increases intracellular Ca in taste cells via activation of muscarinic receptors. J Neurophysiol 87: 2643–2649, 2002; 10.1152/jn.00610.2001. Previous studies suggest that acetylcholine (ACh) is a transmitter released from taste cells as well as a transmitter in cholinergic efferent neurons innervating taste buds. However, the(More)
Extracellular nucleotides such as ATP are the signaling molecules which bind to membrane receptors (P2X ligand-gated ion channels and G-protein-coupled P2Y families). In the gustatory system, it is known that P2X receptors are expressed exclusively in nerve fibers innervating the taste buds. Also, P2Y receptors are suggested to play some important roles in(More)
The sense of taste plays a critical role in the life and nutritional status of organisms. During the last decade, several molecules involved in taste detection and transduction have been identified, providing a better understanding of the molecular physiology of taste receptor cells. However, a comprehensive catalogue of the taste receptor cell signaling(More)
The mammalian olfactory epithelium is made up of ciliated olfactory sensory neurons (OSNs), supporting cells, basal cells, and microvillous cells. Previously, we reported that a population of nonneuronal microvillous cells expresses transient receptor potential channel M5 (TRPM5). Using transgenic mice and immunocytochemical labeling, we identify that these(More)
A variety of substances with different chemical structures elicits a bitter taste. Several different transduction mechanisms underlie detection of bitter tastants; however, these have been described in detail for only a few compounds. In addition, most studies have focused on mammalian taste cells, of which only a small subset is responsive to any(More)