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Functional properties of terminal sprouts elicited by an in vivo injection of Clostridium botulinum type A toxin were studied in endplates of the Levator auris longus muscle of the mouse poisoned from a few days to 28 days beforehand. For this purpose, morphological observations of the extent of terminal sprouts and localization of acetylcholine receptors(More)
1. The effects of botulinum toxin (BoTx) types A and D on spontaneous and evoked phasic transmitter release were studied in the isolated extensor digitorum longus muscle of the rat or the levator auris longus muscle of mice. 2. The toxins were injected subcutaneously into the hindleg of adult rats or the dorsal aspect of the neck of mice. At various times(More)
1. In the present paper we review some presynaptic aspects of the mode of action of botulinal toxins (BoTxs) at vertebrate neuromuscular junctions with emphasis on studies carried out in our laboratories using electrophysiological and morphological techniques. 2. Spontaneous quantal transmitter release recorded as miniature end-plate potentials is(More)
1. Electrophysiological detection of acetylcholine (ACh) release by synaptosomes from the electric organ of Torpedo was searched for by laying the isolated nerve terminals on a culture of Xenopus embryonic muscle cells (myocytes), and by recording the ACh-induced inward currents in the myocytes. 2. Whole-cell recording in one of the myocytes revealed rapid(More)
A study of the K conductance of the presynaptic membrane has been performed in thetriangularis sterni muscle of the mouse. External currents generated in the presynaptic terminals upon invasion by action potentials have been recorded using microelectrodes inserted into the perineurium of preterminal nerve bundles. The voltage-dependent K current could be(More)
We construct an infinite E 9 multiplet of BPS states for 11D supergravity. For each positive real root of E 9 we obtain a BPS solution of 11D supergravity, or of its exotic counterparts , depending on two non-compact transverse space variables. All these solutions are related by U-dualities realised via E 9 Weyl transformations in the regular embedding E 9(More)
1. To study the nature and origin of slow-rising, Ca2+-insensitive miniature end-plate potentials (m.e.p.p.s) in mammalian muscle we used intracellular recording techniques and drugs which block acetylcholine (ACh) synthesis or the uptake of ACh into synaptic vesicles. Slow m.e.p.p.s were induced in vivo by paralysing the extensor digitorum longus muscle of(More)
During synaptogenesis, spontaneous acetylcholine release is rapidly induced by the contact of the growing neurite with the myocyte. Using Xenopus nerve-muscle co-cultures, we investigated the role of Ca2+ in the presynaptic mechanisms mediating this induction process. We found that Ca2+ influx is not necessary to induce spontaneous release and that an(More)
The G ++-content of the formulation of gravity and M-theories as very-extended Kac-Moody invariant theories is further analysed. The different exotic phases of all the G ++ B-theories, which admit exact solutions describing intersecting branes smeared in all directions but one, are derived. This is achieved by analysing for all G ++ the signatures which are(More)