Photoreceptor ribbon synapses are continuously active synapses with large active zones that contain synaptic ribbons. Synaptic ribbons are anchored to the active zones and are associated with large numbers of synaptic vesicles. The base of the ribbon that is located close to L-type voltage-gated Ca(2+) channels is a hotspot of exocytosis. The continuous exocytosis at the ribbon synapse needs to...

In nerve terminals, synaptic vesicles form large clusters anchored to the presynaptic plasmalemma. Recently, FM1-43 photobleaching experiments carried out a frog motor end-plates demonstrated lack of lateral intermixing of synaptic vesicles within clusters, even during sustained nerve terminal stimulation (Henkel and Betz, 1995; Henkel et al., 1996b). We now have investigated the mobility of sy...

BCL-2 family proteins are known to regulate cell death during development by influencing the permeability of mitochondrial membranes. The anti-apoptotic BCL-2 family protein BCL-xL is highly expressed in the adult brain and localizes to mitochondria in the presynaptic terminal of the adult squid stellate ganglion. Application of recombinant BCL-xL through a patch pipette to mitochondria inside ...

Application of black widow spider venom to the neuromuscular junction of the frog causes an increase in the frequency of miniature end-plate potentials (min.e.p.p.) and a reduction in the number of synaptic vesicles in the nerve terminal. Shortly after the increase in min.e.p.p. frequency, the presynaptic membrane of the nerve terminal has either infolded or "lifted." Examination of these infol...

In Drosophila, we have found that some of the motor terminals in wandering third-instar larvae are sexually differentiated. In three out of the four body-wall muscle fibers that we examined, we found female terminals that produced a larger synaptic response than their male counterparts. The single motor terminal that innervates muscle fiber 5 produces an EPSP that is 69% larger in females than ...

The mobility of transposable elements via a cut-and-paste mechanism depends on the elaboration of a nucleoprotein complex known as the synaptic complex. We show here that the Mos1 synaptic complex consists of the two inverted terminal repeats of the element brought together by a transposase tetramer and is designated paired-end complex 2 (PEC2). The assembly of PEC2 requires the formation of a ...

Synapsin I is a synaptic vesicle-associated protein which inhibits neurotransmitter release, an effect which is abolished upon its phosphorylation by Ca2÷/calmodulin-dependent protein kinase II (CaM kinase ]I). Based on indirect evidence, it was suggested that this effect on neurotransmitter release may be achieved by the reversible anchoring of synaptic vesicles to the actin cytoskeleton of th...

Action potentials invading the presynaptic terminal trigger discharge of docked synaptic vesicles (SVs) by opening voltage-dependent calcium channels (CaVs) and admitting calcium ions (Ca(2+)), which diffuse to, and activate, SV sensors. At most synapses, SV sensors and CaVs are sufficiently close that release is gated by individual CaV Ca(2+) nanodomains centered on the channel mouth. Other sy...

In a forward genetic screen for mutations that destabilize the neuromuscular junction, we identified a novel long isoform of Drosophila ankyrin2 (ank2-L). We demonstrate that loss of presynaptic Ank2-L not only causes synapse disassembly and retraction but also disrupts neuronal excitability and NMJ morphology. We provide genetic evidence that ank2-L is necessary to generate the membrane constr...

Glial cell processes are part of the synaptic structure and sense spillover of transmitter, while some glial cells can even receive direct synaptic input. Here, we report that a defined type of glial cell in the medial nucleus of the trapezoid body (MNTB) receives excitatory glutamatergic synaptic input from the calyx of Held (CoH). This giant glutamatergic terminal forms an axosomatic synapse ...