The effect of various non-depolarizing neuromuscular blocking agents (gallamine, pancuronium, vecuronium, d-tubocurarine, metocurine, atracurium and pipecuronium) on [3H]acetylcholine release in the response to field electrical stimulation was investigated in vitro in preparations of the guinea pig right atrium. In this preparation, atropine enhanced and oxotremorine, a muscarinic agonist, redu...

Acetylcholine is a neurotransmitter synthesized from choline and acetyl coenzyme A. It is localized in large reticular formation neurons, and is the chemical mediator in the synapse of a motor endplate. The electrical signal of the motor nerve terminal causes release of many packets of acetylcholine. The packets are released into the synaptic cleft, where receptors in the postjunctional membran...

We previously reported the occurrence and function of plasma membrane estrogen receptors in cultured bovine adrenal medullary cells. Here we report the effects of raloxifene and tamoxifen, selective estrogen receptor modulators, on plasma membrane estrogen receptors and catecholamine synthesis and secretion in these cells. Raloxifene caused dual effects on the specific binding of [(3)H]17β-estr...

Here we report the discovery, by high-throughput screening, of three novel (2-amino-5-keto)thiazole compounds that act as selective potentiators of nicotinic acetylcholine receptors. Compound selectivity was assessed at seven human nicotinic acetylcholine receptors (alpha1beta1gammadelta, alpha2beta4, alpha3beta2, alpha3beta4, alpha4beta2, alpha4beta4, and alpha7) expressed in mammalian cells o...

1. The release of acetylcholine by parasympathetic ganglion stimulants from the nerve terminals of the guinea-pig longitudinal muscle strip was studied. The acetylcholine released was collected in the presence of physostigmine sulphate.2. Nicotine and 1,1-dimethyl-4'-phenylpiperazinium iodide (DMPP) released acetylcholine. Tetrodotoxin (50 ng/ml) and hexamethonium completely prevented their act...

The mammalian mesopontine tegmentum (MPT) contains two cholinergic nuclei, the pedunculopontine tegmental nucleus (PPTg) and the laterodorsal tegmental nucleus (LDTg). These provide the cholinergic innervation of, among other brain areas, the dopaminergic A9 and A10 cell groups. Their axons are thus the source of endogenous acetylcholine (ACh) acting on somato-dendritic acetylcholine receptors ...

Neuroactive substances play important roles as transmitters and neuromodulators. Although many of these substances and/or their receptors are known to be present in taste receptor cells and nerve fibers innervating taste buds, physiological functions of these substances are not well understood (Nagai et al., 1996). Using Ca2+ imaging and immunocytochemical techniques, we have examined the physi...

ELIC, the pentameric ligand-gated ion channel from Erwinia chrysanthemi, is a prototype for Cys-loop receptors. Here we show that acetylcholine is a competitive antagonist for ELIC. We determine the acetylcholine-ELIC cocrystal structure to a 2.9-Å resolution and find that acetylcholine binding to an aromatic cage at the subunit interface induces a significant contraction of loop C and other st...

Despite extensive studies on nicotinic acetylcholine receptors (nAChRs) and homologues, details of acetylcholine binding are not completely resolved. Here, we report the crystal structure of acetylcholine bound to the receptor homologue acetylcholine binding protein from Lymnaea stagnalis. This is the first structure of acetylcholine in a binding pocket containing all five aromatic residues con...

Nicotinic acetylcholine receptors are synthesized in chick embryo retina before synapses appear. Most of the receptors are found associated with neurites in the inner synaptic layer of the retina; later in development the receptors appear in the outer synaptic layer. Cells dissociated from retina and cultured in vitro form aggregates and also sort out into regions comprised either of neurites o...