BACKGROUND The differentiation of floor plate cells and motor neurons in the vertebrate neural tube appears to be induced by signals from the notochord. The secreted protein encoded by the Sonic hedgehog (Shh) gene is expressed by axial midline cells and can induce floor plate cells in vivo and in vitro. Motor neurons can also be induced in vitro by cells that synthesize Sonic hedgehog protein ...

To determine the effects of nerve explants on the integrity of motor end plates in vitro, cholinesterase activity and structure of end plates were compared in newt muscle denervated in vivo, cultured in the absence of nerve explants, and cultured in the presence of sensory ganglia . In neuromuscular junctions denervated in vivo or in vitro, the synaptic vesicles become clumped and fragmented . ...

abstract   background : although, different studies on end-to-side nerve repair, results are controversial. the importance of this method in case is unavailability of proximal nerve. in this method, donor nerves also remain intact and without injury. in compare to other classic procedures, end-to-side repair is not much time consuming and needs less dissection. overall, the previous studies in ...

In the present investigation the sole plate area of motor end plates of the frog is ultrastructurally examined with different postfixation methods. We concentrated in this case on the proof of the smooth and rough sarcoplasmic reticulum of the sole plate. The relations of the smooth and rough sarcoplasmic reticulum to subsynaptic folds and the local T-system and its connections to diads and tri...

BACKGROUND AND OBJECTIVES Low level laser therapy (LLLT) in specific wavelengths and fluence maintains the electrophysiological activity of injured peripheral nerve in rats, preventing scar formation (at injury site) as well as degenerative changes in the corresponding motor neurons of the spinal cord, thus accelerating regeneration of the injured nerve. We studied the effect of LLLT on the neu...

It has long been known that the neuromuscular junction is very sensitive to carbon dioxide and the transmission across this junction is easily blocked under the effect of this gas. The aim of the present experiment is to clarify the underlying mechanism of this blockage by analysing the effects of carbon dioxide on the preand postsynaptic elements. According to the chemical transmission hypothe...

Abnormal humoral responses toward motor end plate constituents in muscle induce myasthenia gravis (MG). To study the etiology of this disease, and whether it could be induced by host defense molecules, we examined the consequences of interferon (IFN) gamma production within the neuromuscular junction of transgenic mice. The transgenic mice exhibited gradually increasing muscular weakness, flacc...

In the developing nervous system, motor axons grow away from the ventral midline floor plate, suggesting that the latter might be a source of repulsive axonal guidance cues. In donor to host transplantation experiments, ectopic pieces of floor plate were positioned between chick hindbrain motor neurons and their exit points. Immunohistochemistry and retrograde axonal labeling techniques demonst...