George Boyan

Professor Boyan has retired and cannot offer any positions any more but is still available for consultations and advice should that be desired.

We are interested in the way the brain becomes wired up during development. Of the many model systems available, we have chosen to concentrate on insects, particularly the grasshopper and Drosophila.

The former offers excellent access to developing brain structures at the level of single cells (neurons and glia); the latter, access to the molecular mechanisms regulating the wiring process. These mechanisms have been shown to be universal during early development. Our investigations focus firstly on the origins and fates of the neurons that build the so-called central complex. This midbrain structure is present in all Arthropods and organizes motor behaviours such as walking. In our study we identify and map the stem cells (neuroblasts) of the early embryonic brain, we then reconstruct their lineages of neurons and glia, and look at the structural and biochemical (transmitter, peptide) characteristics of these progeny. We are particularly interested in cells that pioneer neuronal pathways: (a) within the midbrain, such as those that establish the very first connections between the brain hemispheres; (b) within the developing antenna and so allow sensory axons to reach their targets in the brain. Our methods involve confocal, fluorescence and electron microscopy, mass spectrometry, laser ablation, intracellular dye injection, immunocytochemistry (and antibody blocking), advanced imaging, brain slices and cell culture.

Figure legend

A. Confocal image showing stem cells in the embryonic grasshopper brain identified via intracellular dye injection. B. Stem cell lineage reconstructed from a confocal optical stack following immunolabeling with the neuron-specific marker HRP (green). C. Stem cell lineage reconstructed from a confocal optical stack following immunolabeling with the glia-specific marker Repo (magenta). D. Confocal image of an antenna from the embryonic grasshopper showing pioneer neurons in the tip region immunolabeled with the neuron-specific marker HRP (green).

Current research projects in the AG Boyan

• Prof. George Boyan: Comparative studies on central complex development in Drosophila and grasshopper involving identified neural stem cells and their lineages, self-renewing intermediate progenitor cells and their progeny.
• Dr. J.L.D. Williams: Topological properties of identified lineages contributing to the central complex in the developing brain of the grasshopper.
• Dr. Yu Liu (Assistant Prof.): Lineage analysis as a tool to elucidate the contributions of glia and neurons to the development of the central complex.
• Erica Ehrhardt (MSc.): Embyronic development of the sensory system of the antenna of the grasshopper Schistocerca gregaria.
• Michael Loser (Dipl. Biol.): Contribution of glia to the development of the central complex in the midbrain of Schistocerca gregaria.
• Michaela Güntner (Dipl. Biol.): Building the central complex: stem cell maps, commissural formation and characterisation of transmitter and peptide expression in the midbrain of the grasshopper Schistocerca gregaria.