Early development of the peripheral nervous system
Our main focus is the development of the peripheral nervous system (PNS), in particular, the signaling molecules and their mechanisms of action involved in early specification and patterning of the olfactory epithelium and the lens. Our research also aims to understand how progenitor cells converts to differentiated neurons within the olfactory epithelium, and how an EMT-like process allow specific neurons to leave the olfactory epithelium. We are exploring these processes using explant and whole embryo assays in early chick embryos.
The PNS is built up by the cranial placodes and the neural crest cells, which are formed at the border region of the neural plate and the future epidermis. Cranial placodes are transient, discrete regions of thickened epithelium that originate from characteristic positions in the head of vertebrate embryos. The olfactory, lens and otic placodes, associated with olfaction, vision and hearing/balance, respectively will give rise to the nasal epithelium, the lens and the ear.
At present my research group is interested in four major projects;
1) Early development of sensory placodes: Placodes are embryonic structures that give rise to different parts of the peripheral nervous system. The lens, olfactory and otic placodes go through complex morphological changes, to form parts of the different mature sensory organs. We are examining how these complex morphological movements are regulated by sequential molecular signals.
2) Neurogenesis: In the adult mammalian brain there are three regions where neurogenesis normally occurs; in which the olfactory epithelium (giving rise to olfactory receptor neurons) is one of the regions. Currently there is a lack of knowledge of the combination and sequence of molecular signals necessary to induce endogenous precursors to efficiently and precisely proliferate and differentiate into appropriate types of neurons within these regions. Using both gain and loss of function approaches in the olfactory epithelium, we aim to unravel the molecular mechanisms regulating the progression from progenitor cells to differentiated neurons.
3) Early development of the eye: The lens and the retina are two important structures within the eye. One interesting aspect of the lens is that stem cells in the lens epithelium proliferate throughout life and give rise to new mature lens fibre cells. The light- and color- sensory cells are found in the retina. We are identifying the molecular actions of different signaling molecules regulating the early induction of lens fiber cells and retina cells, and how these two structures affect the development of each other.
4) EMT: is a normal cellular process, in which adherent epithelial cells are converted into individual migratory mesenchymal cells by activation of EMT-transcription factors, loss of cell-cell junctions, loss of apico-basal polarity, induction of migratory and invasive properties. EMT is crucial for embryonic development, to allow cells to migrate to their final destinations. EMT can abnormally be re-activated in cancer cells thereby promoting spreading and metastatic properties. A key question in developmental biology and cancer research is to understand how different molecular signals interact to regulate EMT.
If you are interested to work with us as a graduate student (exam-work), Ph.D-student Post-Doc or as a Research Engineer please contact me, Lena Gunhaga.