Trial Lecture – time and place
See Trial Lecture.
Adjudication committee
- First opponent: Professor Gay R. Holstein, Icahn School of Medicine at Mount Sinai
- Second opponent: Professor Robert Brownstone, University College London
- Third member and chair of the evaluation committee: Professor Koen Gerard Alois Vervaeke, University of Oslo
Chair of the Defence
Associate Professor Greg Jablonski, University of Oslo
Principal Supervisor
Professor Joel Glover, University of Oslo
Summary
The brainstem contains many neuronal circuits involved in movement control. A group of brainstem neurons called vestibulospinal (VS) neurons evolved early in vertebrates. They receive balance information from the inner ear and respond by activating spinal cord neurons to stabilize animal posture in a reflexive manner.
There are different functional groups of VS neurons, which is reflected in their axon paths down the spinal cord. During embryonic development, the different groups extend their axons 1) down the entire spinal cord, 2) to the upper part only, or 3) across the midline and to the upper part.
In his dissertation entitled "Transcription factor expression patterns in developing vestibulospinal neurons" Lunde has hypothesized that the different VS groups are related to differences in gene expression.
Gene expression in the two largest VS groups in mouse and chicken embryos was quantified by collecting RNA from purified neurons and performing high throughput RNA sequencing. Immunofluorescence was used to detail patterns of transcription factor (TF) expression in the groups, since TFs are important for cell development.
This revealed TFs that are expressed in most VS neurons, and others that are specific to either group. For each group, sets of 4 TFs were uniquely expressed in the group neurons and some vicinal neurons. No other CNS neurons had the same expression signatures, making them useful markers for the VS groups.
To facilitate the extensive analysis, a software toolbox for high-throughput immunofluorescence image analysis was created as an ImageJ plugin, with a Matlab tool for 3D visualization of neuron and TF distribution.
This thesis work shows that the major VS groups differ on a genetic level, in an evolutionary conserved manner. By uncovering TFs related to functional divisions of VS neurons, this work opens for possibilities to perform targeted genetic experiments on VS cells, to learn more about how these neurons contribute to balance.
Additional information
Contact the research support staff.