Henrik Boije – Zebrafish neuronal networks

One of the great unanswered questions of our time is how 100 billion nerve 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

A recently identified population of interneurons has been shown to play a critical role in coordinating locomotion in both horses and mice. Our research aims to deepen the understanding of how these cells influence an animal’s movement patterns.

One hypothesis is that these interneurons function like a gearbox, enabling the animal to switch between different speeds or gaits by modulating and stabilizing the firing frequency of motor neurons. To test this hypothesis, we need to understand how this cell population is generated, how the cells are integrated into the neural network, how they signal during movement, and what effects their activity has on motor output.

Zebrafish as model organism

The zebrafish is an ideal model organism for answering these questions. Its transparent larvae, combined with powerful genetic tools, enable us to image and manipulate nerve cells in intact, living animals. Using time-lapse imaging of fluorescent reporter lines, we can track how specific cells are generated and integrated into the locomotor circuitry. Genetically encoded calcium indicators provide a direct link between neural activity at the cellular level and functional output in the form of swimming behaviour.

By combining cellular-level investigations with behavioural studies, we gain unique insights into how the nervous system operates. We hope that our findings will enhance the understanding of how neural networks are formed – a crucial step toward understanding how their disruption contributes to neurological injuries and diseases.

Watch a film from Swedish Foundation for Strategic Research about Henrik Boije's research: "Zebrafish help scientists understand the nervous system".

Microscope image of a green, genetically engineered spinal cord

A genetically engineered spinal cord (photo: Silvia Vicenzi)

Last modified:

FOLLOW UPPSALA UNIVERSITY ON

Uppsala University on Facebook
Uppsala University on Instagram
Uppsala University on Youtube
Uppsala University on Linkedin