Heterogeneity of the Suprachiasmatic Nucleus: Quantification, Simulation, and Functional Analysis

• Applicant: Dr. Grigory Bordyugov
• Subject Area: Cognitive, Systems and Behavioural Neurobiology
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 235843329

The outstanding challenge of circadian biology has been and remains the understanding of the mechanisms of behavioural and psychological adaptation to changes in the light-dark cycles. Such changes can be either rather abrupt, as in the case of jet lag phase shift; or they can be seasonal which sometimes causes mood disorders as seasonal affected disorder (SAD). In mammals, including humans, the circadian rhythm of the whole body is modulated by a small hypothalamic region called suprachiasmatic nucleus (SCN). Recently, we have found that the SCN features a rich heterogeneity not only in variations in neuropeptide contents but also in distribution of intrinsic circadian periods which are surprisingly well-structured and labile to external input of light duration (Myung et al , 2012). Yet, the strength of coupling among SCN neurons can determine the fate of their overall rhythmicity in response to external driving (Abraham et al , 2010). Both results provide new clues to unravel the mechanism of how light information is coded in the SCN through controlled management of its heterogeneity. However, the sheer number of neurons available for simultaneous recording and the size of parameter set as a result make it impossible to tackle this challenge without computational methods and advanced non-linear mathematical techniques such as bifurcation analysis. We aim to supplement each other with respective specialities in computational and theoretical biology (Germany) and molecular and systems biology (Japan).

• DFG Programme: Research Grants
• International Connection: Japan
• Participating Persons: Professor Dr. Hanspeter Herzel; Professor Dr. Achim Kramer; Professor Dr. Henning Sprekeler; Professor Dr. Toru Takumi