Properties of Hippocampal Mossy Fibre Synapses in VAMP7 KO Mice

VAMP7 is a vesicular SNARE of the longin family that localizes to axons and dendrites during development, where it is important in neurite growth. In the adult brain, VAMP7 is enriched in a subset of nerve terminals, particularly in hippocampal mossy fibres (Mfs) originating from the dentate gyrus. We analysed the VAMP7 function in neurotransmitter release by detailed functional characterization of Mf synapses onto CA3 pyramidal cells in knockout mutant mice for VAMP7. We have evaluated the role of VAMP7 in different forms of short-term synaptic plasticity and the potential contribution of the co-release of glutamate and zinc. This analysis has not revealed any significant impact of the loss of VAMP7 for basal properties of synaptic transmission, for short-term plasticity, for asynchronous release and for the ability of Mf vesicles to release ionic zinc. Based on these findings, the potential role of VAMP7 in the regulation of presynaptic mechanisms is discussed.