The mutation in the alpha(1A) subunit gene of the P/Q-type (Ca(v)2.1) Ca(2+) channel present in tottering (tg) mice causes ataxia and motor seizures that resemble absence epilepsy in humans. P/Q-type Ca(2+)channels are primarily involved in acetylcholine (ACh) release at mammalian neuromuscular junctions. Unmasking of L-type (Ca(v)1.1-1.2) Ca(2+) channels occurs in cerebellar Purkinje cells of ...

The floor plate of the vertebrate nervous system has been implicated in the guidance of commissural axons at the ventral midline. Experiments in chick have also suggested that at earlier stages of development the floor plate induces the differentiation of motor neurons and other neurons of the ventral spinal cord. Here we have examined the development of the spinal cord in a mouse mutant, Danfo...

The clinical pharmacology of neuromuscular blocking agents is described. During neuromuscular blockade, succinylcholine attaches to receptors in the motor end plate and depolarizes the neuromuscular junction, making the end plate refractory to acetylcholine. The nondepolarizing relaxants have a structure similar to that of succinylcholine and bind to the same receptors. Instead of depolarizing ...

Members of the Slit family are large extracellular glycoproteins that may function as chemorepellents in axon guidance and neuronal cell migration. Their actions are mediated through members of the Robo family that act as their receptors. In vertebrates, Slit causes chemorepulsion of embryonic olfactory tract, spinal motor, hippocampal and retinal ganglion cell axons. Since Slits are expressed ...

Conventional electrophysiological techniques were used to study the effects of Ba on the release of acetylcholine (ACh) from frog motor nerve terminals. Equimolar substitution of Ba for Ca eliminated end-plate potentials (e.p.ps) without a corresponding decline in the amplitude of the nerve terminal action potential. Miniature end-plate potentials (m.e.p.ps) were readily detectable in Ba soluti...

The electroplates of the electric organ of Torpedo are embryonically derived from striated muscle fibres which lose their ability to contract and develop greatly expanded end-plate surfaces (cf. Rosenberg, 1928). From consideration of the thermodynamics of the Torpedo organ discharge, Bernstein (1912) concluded that the electric energy of the discharge was derived from a difference between the ...

BACKGROUND AND OBJECTIVE Treating patients with a Gallium-Aluminum-Arsenide (GaAlAs) infrared (IR) diode laser reduces muscle spasm and increases mobility in the muscles. The effect of low intensity laser irradiation on nerve function, growth, and repair mechanisms is a contentious area of research. We have addressed one aspect of this controversy by systematically examining the influence of 83...

Interaction between different choline derivatives has been studied by applying them simul­ taneously to a motor end-plate and recording the resulting changes in the membrane potential of the muscle fibre. Choline potentiates the depolarizing effect of acetylcholine (Ach) when applied in normal Ringer. Decamethonium has a ‘diphasic’ action, initial depression of the Ach effect being followed by ...

End anchors have been shown to significantly reduce premature plate end debonding failure of plate bonded strengthened reinforced concrete (r. c.) beams. One of the main interest in designing end anchors is to determine the minimum or optimal length of end anchors for a given thickness and height of the end anchor. This paper presents experimental and numerical studies in determining those opti...