Hajime Tei

Hajime Tei (程 肇, テイ ハジメ born March 1959) is a Japanese neuroscientist specializing in the study of chronobiology. He currently serves as a professor at the Kanazawa University Graduate School of Natural Science & Technology. They discovered that hPer (the human homolog of dPer) and mPer (the mouse homolog of dPer) encoded PAS-domain-containing polypeptides that are highly homologous to dPer.

Identification of mammalian Timeless homolog In 1998, Hajime Tei, in collaboration with other researchers, identified a mammalian homolog of the Drosophila timeless gene. During this research project, timeless was analyzed in the adult mouse SCN, but only weak oscillations were observed.

Discovery of circadian clocks in peripheral organs Tei and Shin Yamazaki developed the first rodent model that was used to monitor circadian gene expression rhythms. This was done using a luciferase reporter gene expressed under the Per1. In 2000, using their rodent model, they discovered the existence of circadian clocks in peripheral organs of mammals. He was also part of a team that discovered feeding cycles can entrain liver independently of the suprachiasmatic nucleus (SCN) and the light cycle.

Calcium flux in mammalian pacemaker neurons

In 2005, Tei, G. Lundkvist, Y. Kwak, E. Davis, and G. Block proposed that the molecular clock was linked to neurons' membrane potential via voltage-dependent regulation of Ca2+ influx, as well as secondary action of intracellular Ca2+ on gene transcription. Additionally, the same study found that removal of Ca2+ from the medium, as well as blocking the Ca2+ channels, stopped the SCN's circadian clock, while hyperpolarization of a K+ medium led to altered rhythms in the SCN. Specifically for Bmal1, they found that Bmal1-deficient osteoblasts promote osteoclastogenesis. These findings could lead to future studies of RAR patterns and bone turnover markers.

Collaborators From early in his professional career to his work current projects, Tei has worked with many other chronobiologists. Specifically, he is listed as a recurring co-author with the following scientists: Yoshiyuki Sakaki Shin Yamazaki Gene D. Block Rika Numano Michael Menaker