Cortical processing is strongly influenced by the actions of neuromodulators such as acetylcholine (ACh). Early studies in anaesthetized cats argued that acetylcholine can cause a sharpening of orientation tuning functions and an improvement of the signal-to-noise ratio (SNR) of neuronal responses in primary visual cortex (V1). Recent in vitro studies have ...

... Title : Meproadifen Enhances Activitation and Desensitization of the Acetylcholine Receptor-Ionic Channel Complex (AChR): Single Channel ...

There is increasing evidence that the cholinergic habenulo-interpeduncular pathway and the dopaminergic mesolimbic pathway may jointly mediate the reinforcing properties of addictive drugs. However, the effects of addictive drug on the functioning of the habenulo-interpeduncular pathway have not been well-characterized. Thus, several drugs of abuse (i.e., nicotine, cocaine, amphetamine) have been ...

It was demonstrated in our previous studies of the frog retinotectal transmission that retinotectal synaptic potentials are enhanced by a factor of 1.5 due to the tonic presynaptic nicotinic potentiation, caused by the ambient level of the acetylcholine in the frog tectum. Furthermore, the results of those studies have indicated that ...

... mRNA LeveLs at Early and Late Time Points. ... T (1987) Acetylcholine receptors and sodium channels in ... in skeletal muscle by blockers of protein ...

1 Diazepam administered intraperitoneally (0.25 mg/kg) enhanced the rate of efflux of [3H]-adenosine and its metabolites from rat cerebral cortex. At a lower dose (0.05 mg/kg), this effect could be detected in only one of four rats. 2 Diazepam (0.05 and 0.25 mg/kg i.p.) depressed acetylcholine release from the rat cerebral cortex. Its effect was reversed ...

The preventive effect of schisandrin B (Sch B), an antioxidant ingredient of Schisandra chinensis, was studied on scopolamine-induced dementia in mouse. Scopolamine developed oxidative stress in the brain with the decreased levels of antioxidant enzymes and increased nitrite level. At the same time, a significant impairment of learning and memory occurred ...

1. Left atrial preparations isolated from rabbits were stimulated electrically at frequencies between 6 and 240/min. Tension-frequency curves were obtained from control preparations and preparations treated with ouabain and acetylcholine. Transmembrane potentials were recorded from single cells of the left atrium stimulated at different frequencies. 2. The tension-frequency ...

Coronary heart disease (CHD) that is due to atherosclerosis is associated with low-grade systemic inflammation. Congestive cardiac failure and arrhythmias that are responsible for mortality in CHD can be suppressed by appropriate vagal stimulation that is anti-inflammatory in nature. Acetylcholine, the principal vagal neurotransmitter, is a potent anti-inflammatory molecule. ...

We have reported previously that amiodarone interacts with muscarinic receptors via a novel allosteric site. This study presents mechanistic details on the nature of that interaction. Amiodarone enhanced the maximal level of agonist-stimulated release of arachidonic acid (AA) from Chinese hamster ovary cells that expressed M(3) muscarinic receptors; this ...

Nicotinic acetylcholine receptors mediate fast synaptic transmission by fluxing ions across the membrane in response to neurotransmitter binding. We show here that during affinity purification of the nicotinic acetylcholine receptor from Torpedo, phosphatidic acid, but not other anionic or zwitterionic phospholipids, is hydrolyzed to diacylglycerol. The ...

Nicotinic acetylcholine receptors mediate fast synaptic transmission by fluxing ions across the membrane in response to neurotransmitter binding. We show here that during affinity purification of the nicotinic acetylcholine receptor from Torpedo, phosphatidic acid, but not other anionic or zwitterionic phospholipids, is hydrolyzed to diacylglycerol. The ...

The tonic flexor muscles of the crayfish abdomen respond with a large depolarizing potential to acetylcholine iontophoresed onto a neuromuscular junction, but not to glutamate. Excitatory junctional potentials are abolished by d-tubocurarine and enhanced by a cholinesterase inhibitor. The membrane is depolarized and the junctional potentials are ...

The effects of intraventricular injection of acetylcholine at doses of 50 mug were studied in male rats. Under ether anesthesia, acetylcholine did not modify plasma prolactin and LH levels. Contrarily, in rats anesthetized with pentobarbital, acetylcholine at the same doses induced significant decreases of ...

1. Pretreatment of rats for 5 days with phenobarbitone (80 mg kg-1 day-1) enhanced the potency enhanced the potency of acetylcholine in opposing noradrenaline-induced vasoconstriction in the isolated perfused superior mesenteric arterial bed; in 10 saline-pretreated control animals the ED50 was 14.0 +/- 3.9 ng whereas it was 3.23 +/- ...

Acetylcholine receptor phosphorylation has been compared in sealed and lysed right-side-out membrane vesicles prepared from Torpedo californica electric organ. Phosphorylation was increased 5- to 12-fold in hypotonically lysed vesicles as compared with untreated vesicles. Control experiments confirm that this enhancement is a result of increased ...

Mammalian motor nerve terminals contain hundreds of thousands of synaptic vesicles, but only a fraction of these vesicles is immediately available for release, the remainder forming a reserve pool. The supply of vesicles is replenished through endocytosis, and newly formed vesicles are refilled with acetylcholine through a process that depends on the vesicular ...

Sprouting of motor nerve terminals was evoked by functional denervation of skeletal muscles brought about by presynaptic blockade or disuse. The amount of sprouting, determined by morphometric measurement, was correlated with the level of extrajunctional acetylcholine receptors. Sprouting was inhibited by blockade of acetylcholine ...

Immune-active substance of Staphylococcus aureus, cell-bound protein A (CBPA), enhances the acetylcholine- or hyperpotassium (K+) Krebs solution-evoked excitation in Taenia coli smooth muscles. CBPA increases caffeine- and carbachole-evoked Ca2+ signals in smooth muscle cells suspension, loaded with indo-1, and also caffeine- and ...

Olfactory perceptual learning is a relatively long-term, learned increase in perceptual acuity, and has been described in both humans and animals. Data from recent electrophysiological studies have indicated that olfactory perceptual learning may be correlated with changes in odorant receptive fields of neurons in the olfactory bulb and piriform cortex. These changes include ...

Airway hyperresponsiveness, manifested by increased flow resistance and resulting drop in oxygen partial pressure when conducting provocation tests, is considered an early sign of a developing obstructive airway disease, an example of which is a professionally conditioned asthma. We conducted a detailed study exploring the interrelation between the respiratory mechanical parameters and the partial ...

The resting levels of blood and the effects of adrenaline, acetylcholine and their agonists and antagonists on blood flow and oxygen uptake was determined. ...

For a combined study of levels of adrenaline, related transmitter ... 3) Record the effects of temperature, acetylcholine and adrenaline on cardiac rate in ...

Metabolism of acetylcholine in the small intestine and liver during an exposure to 300 r of Co/sup 60/ gamma radiation at 450 to 460 r/min was studied. Before exposure the arterioperipheral blood and blood from the liver and intestine showed only traces of acetylcholine; 2 hours after exposure acetylcholine appeared in blood ...

Synaptosomes are an excellent model system for examining metabolic processes that occur in nerve endings. In this study they were used to examine the effects of halothane, an inhalational anesthetic, on metabolic processes associated with the synthesis of the neurotransmitter, acetylcholine. They were also used to study possible mechanisms involved with supplying the cytosol ...

Several lines of evidence suggest that acetylcholinesterase inhibitors (AChE) inhibitors have their cognitive enhancing effects by stimulating cholinergic receptors within the medial septum. However, intraseptal administration of cholinergic enhancing drugs produce mixed results that appear to depend on both the integrity of the medial septum as well as ...

The level of binding of a labeled acetylcholine muscarinic antagonist (quinuclidinyl benzilate) to different cerebral membranes has been measured. Of the regions examined, circadian rhythmicity of binding could only be detected significantly in the hippocampus and the hypothalamus and not in the cerebral cortex, striatum, or cerebellum.

Previous studies suggest that m2 muscarinic receptors serve as presynaptic autoreceptors. Blocking these receptors by selective antagonist may, therefore, lead to increased acetylcholine (ACh) release. This study assessed changes in extracellular ACh leve...

Flp-In^TM T-REx^TM 293 cells expressing a wild type human M₃ muscarinic acetylcholine receptor construct constitutively and able to express a receptor activated solely by synthetic ligand (RASSL) form of this receptor on demand maintained response to the muscarinic agonist carbachol but developed response to ...

Flp-In(TM) T-REx(TM) 293 cells expressing a wild type human M(3) muscarinic acetylcholine receptor construct constitutively and able to express a receptor activated solely by synthetic ligand (RASSL) form of this receptor on demand maintained response to the muscarinic agonist carbachol but developed response to clozapine N-oxide only upon induction of the RASSL. The two ...

Whole-body X irradiation (0.155 and 0.310 C/kg) was shown to modify the biphase effect of acetylcholine and GABA on antigradient K+ uptake by rat brain sections. Radiation made the effects of neuromediators on active K+ transport be differently directed: acetylcholine enhanced the inhibitory effect of radiation and GABA restored the ...

1. The interaction between the cholinergic and nitrergic innervation was investigated in circular muscle strips of the pig gastric fundus. 2. In physiological salt solution containing 4 x 10(-6) M guanethidine, electrical field stimulation (EFS; 40 V, 0.5 ms, 0.5-32 Hz, 10 s at 4 min intervals) induced small transient relaxations at 0.5-4 Hz, and large frequency-dependent contractions, sometimes ...

... ACh levels were measured in six areas of brains of male Sprague-Dawley rats after a single dose of ethanol or after the induction of ethanol ...

We investigated the effect of peripherally administered caffeine (50 mg/kg), choline (30, 60, or 120

Chemical neurotransmission has been the subject of intensive investigations in recent years. Acetylcholine is an essential neurotransmitter in the central nervous system as it has an effect on alertness, memory and learning. Enzymatic hydrolysis of acetylcholine in the synaptic cleft is fast and quickly metabolizes to choline and acetate by ...

A specific sensitisation of blood T lymphocytes against the nicotinic acetylcholine receptor has been demonstrated in myasthenic patients. After thymectomy the T lymphocytes response was quickly decreased and in most patients it reached normal values. The T response remained at low or normal levels for at least two years. In patients who had undergone ...

The nicotine receptor for the neurotransmitter acetylcholine is an allosteric protein composed of four different subunits assembled in a transmembrane pentamer ? 2? ? ? . The protein carries two acetylcholine sites at the level of the ? subunits and contains the ion channel. The complete sequence of the four subunits is known. The ...

In the isolated rabbit sinus node, adrenaline induced a pacemaker shift toward the inferior part of the node (distance, 2.5 mm). Acetylcholine gave a pacemaker shift either toward the inferior part of the node (distance, 1.2 mm) or, at higher acetylcholine concentrations, toward cells near the upper part of the crista terminalis. After severing the ...

DYT1 dystonia is a severe form of inherited dystonia, characterized by involuntary twisting movements and abnormal postures. It is linked to a deletion in the dyt1 gene, resulting in a mutated form of the protein torsinA. The penetrance for dystonia is incomplete, but both clinically affected and non-manifesting carriers of the DYT1 mutation exhibit impaired motor learning and evidence of altered ...

A new model of an autoimmune disease of the neuromuscular junction was obtained by injection of acetylcholine receptor purified from rat denervated muscles into Balb/c mice. Anti-rat, then anti-mouse acetylcholine receptor antibodies, appear in mouse serum during the immunization procedure. Electrophysiological investigations performed on immunized mice ...

The injection of acetylcholine (15 to 150 micrograms/100 g) to rats or preincubation in the hepatic homogenate with acetylcholine (10(-6) to 10(-3) M) induces a decrease in the catalase activity, mainly in its bound form. Acetylcholine effect does not manifest in the presence of actinomycine D and puromycine. Noradrenaline injection to ...

PC12 cells habituate during repetitive stimulation with acetylcholine, bradykinin, or high potassium. Interspersing these stimulants did not affect the rate of habituation of the others, but it could modulate the amplitude of the norepinephrine secretion each could achieve. Stimulation with acetylcholine inhibited norepinephrine secretion caused by high ...

PC12 cells habituate during repetitive stimulation with acetylcholine, bradykinin, or high potassium. Interspersing these stimulants did not affect the rate of habituation of the others, but it could modulate the amplitude of the norepinephrine secretion each could achieve. Stimulation with acetylcholine inhibited norepinephrine secretion caused by high ...

Human keratinocytes synthesize and secrete non-neuronal acetylcholine, which acts as a local cell signaling molecule, regulating functions like proliferation, cell adhesion, motility, desmosomal cell contact, and glandular activity. The keratinocyte acetylcholine axis is composed of the enzymes mediating acetylcholine synthesis ...

Although cholinergic drugs are known to modulate nociception, the role of endogenous acetylcholine in nociceptive processing remains unclear. In the current study, we evaluated the role of cholinergic transmission through spinal ?(2)-subunit-containing nicotinic acetylcholine receptors in the control of nociceptive thresholds. We show that mechanical and ...

Dihydroisohistrionicotoxin inhibits acetylcholine receptor-dependent 22Na+ uptake of cultured chick muscle cells with a KI of 0.2 micrometer. The inhibition is noncompetitive with respect to agonists. The toxin enhances desensitization of the receptor by agonists which is accompanied by a 10-fold increase in receptor affinity for agonists. ...

We investigated the interaction between ambient histamine and acetylcholine by studying ? oscillations in rat hippocampus, induced by bath application of acetylcholine (10 �M combined with 2 �M physostigmine). The power of ? was significantly increased by the H1 antagonist, fexofenadine, and H2 receptor agonist, dimaprit, and reduced by the H2 receptor ...

Gradients of acetylcholine can stimulate growth cone turning when applied to neurons grown in culture and it has been suggested that acetylcholine could act as a guidance cue. However, the role acetylcholine plays in directing axon migrations in vivo is not clear. Here, we show that acetylcholine positively ...

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. ...

Stimulation-induced increases in the efflux of radioactivity (S-I efflux) were measured in the bathing medium following labelling of the noradrenergic transmitter pools of rat atria and rabbit artery preparations with [3H]-noradrenaline. In atria stimulated with trains of 16 or 60 pulses at 2 Hz, phentolamine enhanced, whereas acetylcholine inhibited S-I ...

Neuronal membrane gangliosides, forming a large family of sialylated glycosphingolipids, have been hypothesized to play important roles in synaptic transmission. We studied the ex vivo electrophysiological function of neuromuscular junctions of GM2/GD2-synthase*GD3-synthase compound null-mutant mice after acute removal of GM3, the only remaining ganglioside in this mouse, by in vitro treatment ...

More than one-third of all people are estimated to experience mild to severe cognitive impairment as they age. Acetylcholine (ACh) levels in the brain diminish with aging, and nicotinic ACh receptor (nAChR) stimulation is known to enhance cognitive performance. The prefrontal cortex (PFC) is involved in a range of cognitive functions ...

Worldwide, 100 million people are expected to die this century from the consequences of nicotine addiction, but nicotine is also known to enhance cognitive performance. Identifying the molecular mechanisms involved in nicotine reinforcement and cognition is a priority and requires the development of new in vivo experimental paradigms. The ventral tegmental area (VTA) of the ...

Carbamazepine (CBZ), phenytoin (PHT), and gabapentine (GBP) are classical antiepileptic drugs (AEDs) that act through a variety of mechanisms. We have tested the in vitro effects of CBZ, PHT, and GBP at different concentrations on ectonucleotidase and acetylcholinesterase activities in zebrafish brain. CBZ inhibited ATP hydrolysis at 1000 microM (32%) whereas acetylcholine ...

Acetylcholine receptors (AChRs) and other postsynaptic molecules cluster spontaneously on cultured C2 myotubes. The frequency of clustering is enhanced by neural agrin, neuraminidase, or calcium through a signaling pathway which includes tyrosine phosphorylation of a muscle-specific kinase (MuSK) and the AChR beta-subunit. Vicia villosa agglutinin (VVA) ...

may affect the nervous system by inhibiting the activity of an enzyme called cholinesterase. At normal levels, cholinesterase breaks down a chemical called acetylcholine,...

Authentic foods affect brain serotonin synthesis by modifying brain tryptophan levels, carbohydrates

Learning through experience underlies the ability to adapt to novel tasks and unfamiliar environments. However, learning must be regulated so that relevant aspects of the environment are selectively encoded. Acetylcholine (ACh) has been suggested to regulate learning by enhancing the responses of sensory cortical neurons to behaviorally relevant stimuli. ...

A study of brain acetylcholine (ACh) levels was undertaken in an attempt to reconcile discrepancies reported on the effects of ethanol treatment on the cholinergic system. ACh levels were measured in six areas of brains of male Sprague-Dawley rats after a...

The effect of selective histamine H3-receptor agonists and antagonists on the acetylcholine release from peripheral nerves was evaluated in the guinea pig longitudinal muscle-myenteric plexus preparations, preloaded with ({sup 3}H)choline. In the presence of H1 and H2 blockade, histamine and (R)-{alpha}-methylhistamine inhibited the electrically-evoked ...

Experiments carried out on 13 male dogs, 2 to 5 years old and weighing 10 to 20 kg, showed that in the initial stages of chroric radiation sickness the blood content of acetylcholine increased and the cholinesterase decreased. Moreove r, the increase in the acetylcholine level during the first 3 to 4 hrs proceeded at a greater ...

The interaction between the cholinergic and nitrergic innervation was investigated in circular muscle strips of the pig gastric fundus.In physiological salt solution containing 4�10^?6?M guanethidine, electrical field stimulation (EFS; 40?V, 0.5?ms, 0.5�32?Hz, 10?s at 4?min intervals) induced small transient relaxations at 0.5�4?Hz, and large frequency-dependent ...

Pyrithiamine-induced thiamine deficiency (PTD) was used to produce a rodent model of Wernicke-Korsakoff syndrome that results in acute neurological disturbances, thalamic lesions, and learning and memory impairments. There is also cholinergic septo-hippocampal dysfunction in the PTD model. Systemic (Experiment 1) and intrahippocampal (Experiment 2) injections of the acetylcholinesterase inhibitor ...

Excess dietary salt intake differentially modulates the activity of cytochrome (CYP) P450 enzymes in kidney cortex. Exactly how increased angiotensin (Ang) II levels and hypertension change the regulatory effect of high salt on CYP450 enzymes remains unclear. The present study investigated the effects of combined administration of Ang II and a high-salt diet on P450 ...

The time-course changes of spinal cord cholinesterase (ChE) and acetylcholine (ACh) levels in six discrete regions of the rat brain were studied and compared. Rats were injected subcutaneously with a 0.9 LD50 dose of GA, GE, GD, GF or VX. They were observ...

The hippocampal slice preparation was used to study the role of acetylcholine as a synaptic transmitter. Bath-applied acetylcholine had three actions on pyramidal cells: (i) depolarization associated with increased input resistance, (ii) blockade of calcium-activated potassium responses, and (iii) blockade of accommodation of cell discharge. All these ...

The obese spontaneously hypertensive rat (SHROB) is a model of metabolic syndrome in which, to our knowledge, vascular function has never been studied. The actions of the insulin sensitizers, glitazones, on vascular function have not been analyzed either. Our purpose is to characterize micro- and macrovascular responses of SHROB and to study the effects of glitazones on these responses. Reactivity ...

. In particular, we describe separate lines with human a7 and human a4b2 nicotinic acetylcholine receptors, mouse Introduction Nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels (LGICAChR is targeted for schizophrenia [2], Alzheimer's disease [3], and cognition enhancement [4], and the a4b2-n