During mammalian development, neuromuscular junctions and some other postsynaptic cells transition from multiple- to single-innervation as synaptic sites are exchanged between different axons. It is unclear whether one axon invades synaptic sites to drive off other inputs or alternatively axons expand their territory in response to sites vacated by other axons. Here we show that soon-to-be-elim...

ALBERTO L . POLITOFF, STEVEN ROSE, and GEORGE D . PAPPAS . From the Department of Anatomy and the Rose F . Kennedy Center for Mental Retardation and Human Development, Albert Einstein College of Medicine, Bronx, New York 10461 and the Marine Biological Laboratory, Woods Hole, Massachusetts 02543 . Dr . Politoffs present address is the Department of Physiology, Boston University School of Medici...

If such a nerve fiberwere to be directly joined to amuscle fiber of, say, 50μmin diameter, then as the propagating action potential reached the nerve–muscle junction, the local circuit current density set up in the muscle would be considerably reduced from that in the nerve. This reduction would occur because the nerve and muscle must have the same total current, a consequence of current conser...

Short-term synaptic facilitation occurs during high-frequency stimulation, is known to be dependent on presynaptic calcium ions, and persists for tens of milliseconds after a presynaptic action potential. We have used the frog neuromuscular junction as a model synapse for both experimental and computer simulation studies aimed at testing various mechanistic hypotheses proposed to underlie short...

25 26 Short-term synaptic facilitation occurs during high frequency stimulation, is known to be dependent on 27 presynaptic calcium ions, and persists for tens of milliseconds after a presynaptic action potential. We 28 have used the frog neuromuscular junction as a model synapse for both experimental and computer 29 simulation studies aimed at testing various mechanistic hypotheses proposed to...

We used an antibody prepared against Aplysia (mollusc) body-wall actin that specifically reacts with certain forms of cytoplasmic actin in mammalian cells to probe for the presence of actin at the neuromuscular junction. Immunocytochemical studies showed that actin or an actinlike molecule is concentrated at neuromuscular junctions of normal and denervated adult rat muscle fibers. Actin is pres...

Age-dependent declines in muscle function are observed across species. The loss of mobility resulting from the decline in muscle function represents an important health issue and a key determinant of quality of life for the elderly. It is believed that changes in the structure and function of the neuromuscular junction are important contributors to the observed declines in motor function with i...

Neuromuscular transmission in invertebrates has been studied extensively (see Bullock & Horridge, 1965). However, the neuromuscular junctions in the earthworm have only been studied by Horridge & Robertes (i960). The present experiments were carried out to investigate the transmission in the neuromuscular junctions which could be recorded from the postsynaptic membranes of the longitudinal musc...

A formalism is introduced to represent the connective organization of an evolving neuronal network and the effects of environment on this organization by stabilization or degeneration of labile synapses associated with functioning. Learning, or the acquisition of an associative property, is related to a characteristic variability of the connective organization: the interaction of the environmen...