Universiteit Leiden

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LCN2 Seminar: Dynamical networks of the biological clock

  • Jos Rohling
Date
27 January 2017
Time
Address
Gorlaeus Laboratories
Einsteinweg 55
2333 CC Leiden
Room
Science club

Speaker: Jos Rohling
Title: Dynamical networks of the biological clock
Understanding how neurons and brain regions communicate, coordinate, synchronize, and collectively respond to signals and perturbations is one of the most intriguing, yet unsolved problems in neuroscience. We investigate one brain area that is involved in time regulation of the body. This circadian clock, which is located in the suprachiasmatic nuclei (SCN) and drives the daily 24-hour rhythms in our body, is functionally dependent on emergent network properties. While the ability of individual SCN neurons to produce 24-hour rhythms is a cell-autonomous property, the ability of the SCN to respond to light, to adjust to the seasons and to synchronize after a jet-lag is critically dependent upon the state of the neuronal network. The synchronized network output regulates all daily rhythms in our body and is heavily dependent on the interactions between the neurons and the network topology of the clock. We investigated methods to assess network properties on our data, such as small-worldness and scale-freeness for this cellular network.
We have observed that temporal behavioral patterns and the central clock show scale invariant behavior. With disease and aging, scale invariance is lost, and also in a brain slice preparation when the clock is not communicating with other brain areas, scale invariance is absent.
Currently we investigate how we can use our data to extract the network topology for the SCN. A complicating factor is that this functional network is not static during its oscillation cycle: for example, the network appears to be different between day and night time. This dynamical nature of the network is normally not taken into account in network studies. I will discuss our latest results, highlighting the advances that were made in recent years, but also discussing the challenges we still face in this field.

 

About the LCN2 seminar: This talk is part of a series of seminars organized within an ongoing scientific initiative called "Leiden Complex Networks Network (LCN2), which aims at bringing together scientists with a common interest in both theoretical models and empirical analyses of complex networks and random graphs. The LCN2 community that is being established shares the approach of using networks for describing real-world complex systems and aims at developing related analytical and numerical methods, while also being open to other research approaches for studying complex systems. The talks are designed for a broad audience, allowing for constructive exchanges of ideas between scientists from different disciplines. After the talk, some drinks and simple snacks are provided.