Henrik Boije – Zebrafish neuronal networks
One of the great unanswered questions of our time is how 100 billion cells can create the network that is the foundation for our conscience. An increased knowledge about how the nervous system is formed and functions will also increase our understanding of how diseases and trauma affect cognition, locomotion and memory. Because of the complexity of the brain, a successful approach has been to study small, well-defined, neural circuits which can provide insights into how the nervous system functions as a whole.
The spinal locomotor network operates as an autonomous metronome that creates a rhythmic output via motor neurons to the muscles. The metronome itself consists of populations of interneurons, i.e. nerve cells that communication with other nerve cells.
Nerve cells that affect animal locomotion
Recently, a population of interneurons that are essential for coordinating locomotion in the horse and mouse has been identified. Our research focuses on increasing the understanding of how these cells affect an animal’s motion pattern. One hypothesis is that interneurons function as a gear box that allows the animal to switch between different speeds or gaits by adjusting and stabilizing the frequency of the motor neurons. To find out if this is correct, knowledge is needed about how this cell population is formed, how the cells are integrated in the network, and how they signal during locomotion and what effect this has.
Zebrafish as model organism
Zebrafish is an ideal model organism for finding the answers to these questions. The use of powerful genetic tools, in combination with that the fish have transparent fry, allows us to image and manipulate nerve cells in intact animals. We use time-lapse imaging of fluorescent reporter lines to reveal how cells are generated and integrated within the locomotor circuitry. Genetically encoded calcium-indicators provide a direct link between signalling at a cellular level and functional output in the form of swimming behaviour.
By combining investigations at the cellular level with behaviour studies we collect unique knowledge about how the nervous system functions. We hope that our results will increase the understanding of how the nervous system is formed, which is required to better understand how breakdown of networks relate to neural injuries and diseases.
See a film from Swedish Foundation for Strategic Research about Henrik Boije's research: "Zebrafish help scientists understand the nervous system".