Recent advances in studies of nicotinic agents in humans have begun to more carefully define cognitive operations that can be influenced by nicotinic stimulation and/or blockade. Careful separation of the cognitive domains affected by nicotinic stimulation has identified attentional performance as the most likely candidate to be positively influenced by nicotinic receptor activation. Studies of...

Nicotinic acetylcholine receptors are pentameric ligand-gated ion channels, which are involved in a wide range of neuronal functions. During the past decade, a large number of nicotinic acetylcholine receptor subunits have been cloned and showed a discreet yet overlapping distribution pattern. Recently, several groups have produced mutant mice lacking specific nicotinic acetylcholine receptor s...

1. Acetylcholine (ACh) elicited depolarization and an increase in input conductance of the somatic muscle cells of the parasitic nematode Ascaris suum. 2. The relative potency of nicotinic and muscarinic agents was studied in this preparation. The order of potency of these compounds was metahydroxy-phenylpropyltrimethylammonium (HPPT) greater than 1.1 dimethyl-4-phenylpiperazinium (DMPP) greate...

The goal of the present study was to assess the catecholamine secretory capabilities of rainbow trout Oncorhynchus mykiss chromaffin cells experiencing desensitization of the nicotinic receptor. It was hypothesized that the potential to secrete catecholamines could be maintained under conditions of nicotinic receptor desensitization owing to activation of non-cholinergic release pathways. An in...

Altered function of neuronal nicotinic acetylcholine receptors in the brain has recently been associated with an idiopathic form of partial epilepsy, suggesting that functional alterations of these receptors can be involved in the processes leading to epileptic seizures. Thus, nicotinic acetylcholine receptors may form a novel target for antiepileptic drug development. In the present study, var...

The purpose of this study was to evaluate the expression patterns of nicotinic and muscarinic ACh receptors (nAChRs and mAChRs, respectively) in relation to one another and to understand their effects on rabbit retinal ganglion cell response properties. Double-label immunohistochemistry revealed labeled inner-retinal cell bodies and complex patterns of nAChR and mAChR expression in the inner pl...

We investigated the effects of neomycin on nicotinic acetylcholine receptor-induced responses in bovine adrenal chromaffin cells. Neomycin inhibited the nicotinic agonist dimethylphenylpiperazinium iodide (DMPP)-induced norepinephrine secretion in a concentration-dependent manner. Neomycin had also an inhibitory effect on the DMPP-induced increase in cytosolic Ca++ concentration ([Ca++]i). This...

Nicotinic acid has been used for decades to treat dyslipidaemic states. In particular its ability to raise the plasma HDL cholesterol concentration has led to an increased interest in its pharmacological potential. The clinical use of nicotinic acid is somewhat limited due to several harmless but unpleasant side effects, most notably a cutaneous flushing phenomenon. With the recent discovery of...

BACKGROUND Ketamine inhibits the activation of both heteromeric and homomeric nicotinic acetylcholine receptors. The site of molecular interaction is unknown. METHODS The inhibition of alpha7 nicotinic acetylcholine receptors by ketamine was compared to that of 5-hydroxytryptamine-3A (5HT3A) receptors that are resistant to ketamine inhibition in Xenopus laevis oocytes. To determine whether th...