261 research outputs found
Loss of AP-3 function affects spontaneous and evoked release at hippocampal mossy fiber synapses
Synaptic vesicle (SV) exocytosis mediating neurotransmitter release occurs
spontaneously at low intraterminal calcium concentrations and is stimulated by
a rise in intracellular calcium. Exocytosis is compensated for by the
reformation of vesicles at plasma membrane and endosomes. Although the adaptor
complex AP-3 was proposed to be involved in the formation of SVs from
endosomes, whether its function has an indirect effect on exocytosis remains
unknown. Using mocha mice, which are deficient in functional AP-3, we identify
an AP-3-dependent tetanus neurotoxin-resistant asynchronous release that can be
evoked at hippocampal mossy fiber (MF) synapses. Presynaptic targeting of the
tetanus neurotoxin-resistant vesicle soluble N-ethylmaleimide-sensitive factor
attachment protein receptor (SNARE) tetanus neurotoxin-insensitive
vesicle-associated membrane protein (TI-VAMP) is lost in mocha hippocampal MF
terminals, whereas the localization of synaptobrevin 2 is unaffected. In
addition, quantal release in mocha cultures is more frequent and more sensitive
to sucrose. We conclude that lack of AP-3 results in more constitutive
secretion and loss of an asynchronous evoked release component, suggesting an
important function of AP-3 in regulating SV exocytosis at MF terminals
Differences in the macrozoobenthic fauna colonising empty bivalve shells before and after invasion by Corbicula fluminea
Bivalve shells can potentially alter the structure of aquatic benthic communities. However, little is known
about the effect that different shell morphologies have on their associated fauna. This study aimed to understand how empty shells, from four different freshwater bivalve species, affect macrozoobenthic communities, using the River Minho (Iberian Peninsula) as a study area. Three native (Anodonta anatina, Potomida littoralis, Unio delphinus) and one non-indigenous (Corbicula fluminea) species were used for this research. Comparisons among species and between scenarios (i.e. before and after invasion by C. fluminea) were performed. Our results suggest that macrozoobenthic community structure did not vary among treatments, with the exception of species richness, which was higher on shells of native species. Furthermore, little difference was detected when comparing scenarios with and without C. fluminea shells, despite dissimilarities in size and morphology between species. The empty shells of C. fluminea partially (in terms of density and biomass, but not in species richness) replaced the role of empty shells of native species as a physical substratum for the associated macrozoobenthic community.Martina Ilarri is supported by a Post-doc grant (SFRH/BPD/90088/2012)
from the Portuguese Foundation for Science and Technology – FCT through
POPH/FSE funds. This study was conducted within the scope of the project
ECO-IAS: Ecosystem-level impacts of an invasive alien species, supported
by FCT and COMPETE funds (contract: PTDC/AAC-AMB/116685/2010)
and was also partially supported by the European Regional Development
Fund (ERDF) through COMPETE funds (PEst-C/MAR/LA0015/2011) and
by FCT/MEC through Portuguese funds (PIDDAC – PEst-OE/BIA/UI4050/2014).info:eu-repo/semantics/publishedVersio
On the Estimation Stability of Efficiency and Economies of Scale in Microfinance Institutions
On the Existence and Uniqueness of Equilibrium in the Bottleneck Model with Atomic Users
A Multivariate Approach for Identification of Optimal Locations with in Ethiopia's Wheat Market to Tackle Soaring Inflation on Food Price (Extended Version)
Spatial Commuting Patterns of German Regional Labour Markets: A Sustainability Perspective
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