Young Lab ~ Autonomic Development
Principal investigator: A/Prof Heather Young
We are interested in:
- The factors that influence the migration of neural crest cells into and along the developing gastrointestinal tract.
- The factors that cause neural crest cells to cease migration at various regions of the gastrointestinal tract.
- The factors that influence neural crest cells to differentiate into neurons and glial cells.
top of pageDevelopment of the enteric nervous system
The enteric nervous system is a large network of neurons and glial cells within the wall of the gastrointestinal tract. It has been estimated that there are more neurons within the gastrointestinal tract than there are in the spinal cord. The enteric nervous system controls many intestinal functions including peristalsis and secretion, and it is therefore essential for all stages of post-natal life.
Mice lacking enteric neurons from the entire gastrointestinal tract, or even from particular regions of the gastrointestinal tract, die within 24 hours of birth. Moreover, most babies suffering from a disease called Hirschsprung's disease, in which enteric neurons are absent from the distal regions of the large intestine, die unless treated by surgery. Understanding the processes controlling the development of the enteric nervous system is therefore of critical importance.
The neurons and glial cells of the enteric nervous system are almost all derived from neural crest cells that migrate from a small region of the hindbrain, termed the vagal region, during early embryonic development. These vagal neural crest cells migrate ventrally and enter the foregut; they then proceed to migrate caudally through the foregut, midgut and hindgut to colonize the entire gastrointestinal tract.
The timetable by which neural crest-derived cells colonise the gastrointestinal tract has now been established in a number of species. It takes 4-5 days for the neural crest-derived cells to colonise completely the gastrointestinal tract in embryonic mice (nearly 25% of the gestation period for mice) and 5-6 weeks in humans. However, the mechanisms controlling the migration and even dispersal of neural crest cells throughout the gastrointestinal tract have yet to be elucidated. After colonising the gut, neural crest-derived cells differentiate into glial cells and a variety of different functional types of enteric neurons.
Ashley Stewart - Mouse embryo stained |
Dr Jaime Foong – Neuron in the intestine of a post-natal mouse. |