TY - JOUR
T1 - Additive effects on the energy barrier for synaptic vesicle fusion cause supralinear effects on the vesicle fusion rate
AU - Schotten, Sebastiaan
AU - Meijer, Marieke
AU - Walter, Alexander Matthias
AU - Huson, Vincent
AU - Mamer, Lauren
AU - Kalogreades, Lawrence
AU - Ter Veer, Mirelle
AU - Ruiter, Marvin
AU - Brose, Nils
AU - Rosenmund, Christian
AU - Sørensen, Jakob Balslev
AU - Verhage, Matthijs
AU - Cornelisse, Lennart Niels
PY - 2015/4/14
Y1 - 2015/4/14
N2 - The energy required to fuse synaptic vesicles with the plasma membrane ('activation energy') is considered a major determinant in synaptic efficacy. From reaction rate theory we predict that a class of modulations exists, which utilize linear modulation of the energy barrier for fusion to achieve supralinear effects on the fusion rate. To test this prediction experimentally, we developed a method to assess the number of releasable vesicles, rate constants for vesicle priming, unpriming, and fusion, and the activation energy for fusion by fitting a vesicle state model to synaptic responses induced by hypertonic solutions. We show that Complexinl/II deficiency or phorbol ester stimulation indeed affects responses to hypertonic solution in a supralinear manner. An additive versus multiplicative relationship between activation energy and fusion rate provides a novel explanation for previously observed non-linear effects of genetic/pharmacological perturbations on synaptic transmission and a novel interpretation of the cooperative nature of Ca2+-dependent release.
AB - The energy required to fuse synaptic vesicles with the plasma membrane ('activation energy') is considered a major determinant in synaptic efficacy. From reaction rate theory we predict that a class of modulations exists, which utilize linear modulation of the energy barrier for fusion to achieve supralinear effects on the fusion rate. To test this prediction experimentally, we developed a method to assess the number of releasable vesicles, rate constants for vesicle priming, unpriming, and fusion, and the activation energy for fusion by fitting a vesicle state model to synaptic responses induced by hypertonic solutions. We show that Complexinl/II deficiency or phorbol ester stimulation indeed affects responses to hypertonic solution in a supralinear manner. An additive versus multiplicative relationship between activation energy and fusion rate provides a novel explanation for previously observed non-linear effects of genetic/pharmacological perturbations on synaptic transmission and a novel interpretation of the cooperative nature of Ca2+-dependent release.
U2 - 10.7554/eLife.05531
DO - 10.7554/eLife.05531
M3 - Journal article
C2 - 25871846
SN - 2050-084X
VL - 4
SP - 1
EP - 25
JO - eLife
JF - eLife
M1 - e05531
ER -