Skip to main content
. Author manuscript; available in PMC: 2011 Sep 1.
Published in final edited form as: Int J Biochem Cell Biol. 2010 Apr 22;42(9):1430–1445. doi: 10.1016/j.biocel.2010.04.006

Figure 4. A model for an Ion exchange–dependent secretory response mediated via TRPM7.

Figure 4

A scheme of synaptic vesicle is presented

Left panel: The fixed negative charges of an ion exchange matrix (heavily tinted circles marked by “−“) are compensated by an equal number of cationic secretory products of the neurotransmitter acetylcholine. Release by ion exchange consists on replacing an existing cation (acetylcholine, medium tinted circles) by a new cation (slightly tinted circles). The movement of all ions through the matrix is determined by its ion exchange properties.

Right panel: The opening of a fusion pore triggers ion exchange

The flow of counter-ions through the TRPM7 channel, located on the vesicle membrane, and through the fusion pore, replaces the positive charged acetylcholine that can exit from the vesicle.

The figure was modified from (Rahamimoff & Fernandez, 1997)