Hiroaki Norimoto
Professor, Graduate School of Science, Nagoya University
Lecture Title
Sleep and hibernation in lizards
Abstract
Brumation, also known as hibernation in reptiles and amphibians, is a form of hibernation in which body temperature, heart rate, and blood flow are reduced in dependence on external temperature. Since little is known about the physiological aspects of brumation so far, the main questions remain unanswered: What changes in neuronal signal processing occur when brain temperature drops to values near or below the freezing point? Is it a kind of sleep, or can it be clearly separated from sleep in terms of neuronal activity? Does the forebrain have a system for storing memories at low temperatures? To answer these questions, we have recorded local field potentials from brumating Australian dragons (Pogona vitticeps). Unexpectedly, unlike during sleep, the CLA is completely silenced, and another forebrain area started to be active during brumation. In this talk, I will first introduce the reasons for using lizards in neuroscience research. After that, I will discuss in detail the behavior and neural activity of lizards during brumation.
Reference
- Mark Shein-Idelson, Janie M Ondracek, Hua-Peng Liaw, Sam Reiter, and Gilles Laurent. Slow waves, sharp waves, ripples, and REM in sleeping dragons. Science. 352(6285):590-595, 2016. DOI: 10.1126/science.aaf3621.
- Hiroaki Norimoto, Lorenz A Fenk, Hsing-Hsi Li, Maria Antonietta Tosches, Tatiana Gallego-Flores, David Hain, Sam Reiter, Riho Kobayashi, Angeles Macias, Anja Arends, Michaela Klinkmann, and Gilles Laurent. A claustrum in reptiles and its role in slow-wave sleep. Nature. 578(7795):413-418, 2020. DOI: 10.1038/s41586-020-1993-6.
- Sena Hatori, Sho T. Yamaguchi, Riho Kobayashi, Futaba Matsui, Zhiwen Zhou, and Hiroaki Norimoto. Sleep homeostasis in lizards and the role of cortex. bioRxiv. 2024. DOI: 10.1101/2024.07.31.605950.