iTHEMS Biology Seminar

Timetable
15:00-16:00 Hiroyuki Kubota (Kyushu Univ.)
16:00-16:20 Break
16:20-17:20 Yasufumi Uezu (NTT)

Time: 15:00-16:00
Speaker: Hiroyuki Kubota (Kyushu Univ.)
Title: Regulation of insulin action by temporal patterns of insulin

Abstract: Cells respond to various extracellular stimuli through a limited number of signaling pathways. One strategy to process such stimuli is to code the information into the temporal patterns of molecules. Almost all hormones exhibit distinct temporal patterns and the importance of their patterns has been reported. However, the mechanisms of how hormones regulate downstream molecules depending on their temporal patterns remain unknown. We focused on insulin which plays crucial roles on glucose homeostasis and shows several temporal patterns in vivo. In this study, we show how the Insulin signaling pathway processes the information encoded into the temporal patterns of blood insulin using a cultured cell line and mice. We found that insulin patterns selectively regulate the insulin-AKT pathway, metabolites, and mRNAs. Mathematical modeling revealed the mechanisms via differences in network structures and from sensitivity and time constants. Given that almost all hormones exhibit distinct temporal patterns, temporal coding may be a general principle of system homeostasis by hormones.

Time: 16:20-17:20
Speaker: Yasufumi Uezu (NTT)
Title: Source-filter interaction brings various representation in speech and singing voice

Abstract: Speech plays a very important role in human communication. The source-filter interaction, a model that takes into account the actual speech production process, assumes that the sound source generation mechanism and the vocal-tract filter are not independent, but affect each other physiologically and acoustically. It is known that the source-filter interaction brings about non-linearity of speech and singing, such as singing voice with a loud volume and wide pitch range like an opera singer, or voice register transition where the vocal suppression and/or the voice pitch jump occurs. I would like to introduce my researches targeting non-linear vocalization phenomena due to the source-filter interaction and results of measuring and analyzing the time waveform of speech sound and vocal-fold vibrations through measurement experiments.