Dr Vincenzo Marra
Department of Neuroscience
University of Leicester
Neuroscience, Psychology and Behaviour
Neuron-Neuron communication relies largely on action potential-triggered release of synaptic vesicles. For several years action potentials have been described as an all-or-none phenomenon. However, evidence Vincenzo Marra Research page Image 1obtained using modern electrophysiological and imaging techniques have shown that action potentials’ size and shape in the axon can be influenced by the membrane potential at the soma. I am interested in how subtle changes in action potentials affect neurotransmitter release and, as a consequence, communication between neurons. In the central nervous system, the number of vesicles contained in each pre-synaptic terminal can vary from few tens to several hundreds and within the same terminal the probability of each vesicle to be released is not homogeneous. This high degree of variability is a substrate for both homeostatic and activity-dependent plasticity at individual synapses. Using a combination of fluorescence and electron microscopy, it is possible to identify synaptic vesicles which have recently undergone a release cycle. This ultrastructural readout of physiological activity opens up new opportunities to explore the link between morphology and function at the level of a single synaptic terminal in native tissue.
Rama S., Zbili M., Bialowas A., Fronzaroli-Molinieres L., Ankri N., Carlier E., Marra V., Debanne D. Presynaptic hyperpolatization induces a fast analogue modulation of spike-evoked transmission mediated by axonal sodium channels Nat Commun 2015 Dec 10; 6:10163