A new type of cell sub-division that is essential to the growth of the nervous system has been recognized by scientists at the University of Dundee.
Neurons are important to the growth of the nervous system and in some areas of our brains they are constantly produced throughout our lives. They are `born’ in a specific place in the early nervous system and then have to move to the appropriate place to make functional neural structures.
A group guided by Professor Kate Storey and Dr Raman Das in the College of Life Sciences at Dundee have now determined a new procedure, apical abscission, which mediates the detachment of new-born neurons from the neural tube ventricle – releasing these cells to migrate.
“Neuron production is an essential process within our bodies. As an example, our memory center, the hippocampus, continues to generate neurons during our lives,” stated Professor Storey.
“What we have recognized are the molecular activities, the `letting-go’ process, which enable newborn neurons to move to their appropriate place in the nervous system.
“This is a new type of cell sub-division so it is of important interest as it informs us about mechanisms that management how we build that we didn’t know before. We were very shocked when we initial saw cells shedding their tip-ends as they started to separate into neurons, it is not what we had anticipated at all.
“Our finding comes with the progression of novel live-tissue imaging techniques in my lab, which enables us to observe cell behaviour over long periods. We have also been to make use of state of the art super-resolution microscopy in the Light Microscopy Facility dependent here within the College of Life Sciences.”
The study has been financed by the Wellcome Trust and the outcomes are published this week in the journal Science.
The work recognizes molecular activities that manage the shedding of the cell’s tip. It takes place as cells lose a key adhesion molecule and includes enhanced action of a cell constriction mechanism.
Amazingly, this event, also involves dismantling of an essential structure in the cell, the major cilium, identified to convey signals that enhance cell proliferation. Das and Storey recommend that Apical Abscission mediates a essential cell state transition in the neuronal differentiation process, quickly changing the polarity and signalling exercise of the new-born neuron.
The scientists preparing to expand the work to identify if this new mechanism also operates in other contexts such as different regions of the brain, but will also deal with if this takes place in some cancers, where cells are recognized to lose polarity, shed primary cilia and detach from their neighbours as a prelude to tissue invasion.
“We require to look more extensively now to identify whether this controlled mechanism allows other cells to make fast cell state transitions and to move in other tissues of the body,” stated Professor Storey.