The plasma membrane separates the inside from the outside of the cell.  These two environments have a different composition of ions. The activity of membrane proteins enables the passage of ions from the inside to the outside of the cell or vice versa, which creates an electrochemical potential in the membrane. “When it is composed of five alpha 2 sub-units, the glycine receptor forms a transmembrane channel which enables chloride ions to pass through it”, indicates Laurent Nguyen. “In migrating interneurons, the glycine activates these receptors which leads to a modification in the membrane potential which itself promotes the activation of other channels”.  In this case, the channels are known as “voltage-gated calcium channels” which open up to allow calcium to enter the cell. “Calcium is an important messenger for the control of a whole series of intracellular signalling pathways. We think that it is by means of this mechanism that glycine controls the migration of interneurons”, says Laurent Nguyen.

The migration of interneurons is reduced and slowed down

In order to know whether glycine receptors play a role in the migration of interneurons and, where applicable, to determine to what extent they act, there is only one solution: to block the receptors and observe the effects that this causes. “We have used pharmacological agents that bind to these receptors in place of glycine and we have noticed a decrease in the migration of interneurons. This is translated by a problem of mobility in the cells”, explains Laurent Nguyen.

The migration of interneurons is particular (Read The migration of cortical interneurons). This involves a movement of the nucleus, called nuclear translocation and it is the latter that is affected when the glycine receptors are blocked. This has the effect of slowing down and reducing migration. “We think that glycine, by means of the activation of its receptor, controls the movement of the nucleus during the migration of these neurons”, continues the researcher. This work, carried out within the framework of Ariel Avila’s thesis, co-supervised by Laurent Nguyen and Professor Jean-Michel Rigo of the University of Hasselt, have been published in the new Cell Press journal: Cell Reports (1).

(1) Ariel Avila, Pía M. Vidal, T. Neil Dear, Robert J. Harvey, Jean-Michel Rigo and Laurent Nguyen. Glycine Receptor α2 Subunit Activation Promotes Cortical Interneuron Migration. Cell Reports, 15 August 2013. http://dx.doi.org/10.1016/j.celrep.2013.07.016