Acetylcholine (ACh) is known to modulate neuronal activity in the rodent primary visual cortex (V1). Although cholinergic modulation has been extensively examined in vitro, far less is understood regarding how ACh modulates visual information processing in vivo. We therefore extracellularly recorded visual responses to drifting sinusoidal grating stimuli from V1 of anesthetized rats and tested ...

Attempts to mimic synaptic delivery of acetylcholine (ACh) with brief, repetitive pulses of high concentration ACh at synapses of medial habenula (MHN) and interpeduncular nucleus (IPN) neurons in vitro elicited temporally distinct facilitation and inhibition of glutamate secretion via nicotinic and muscarinic ACh receptor-mediated pathways, respectively. ACh-induced nicotinic facilitation was ...

In GH3 pituitary cell homogenates, acetylcholine (ACh) (IC50 200 nM) inhibits adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] activity in a concentration- and GTP-dependent manner. Maximal inhibition was obtained with 10 microM ACh and corresponded to approximately a 50% decrease in basal enzyme activity. ACh inhibition is antagonized by atropine and is mimicked by muscarini...

To evaluate the acute effect of lovastatin on diabetic endothelial dysfunction, we examined this effect on the aortic rings of streptozotocin-diabetic rats. The endothelial function was assessed in aortic rings isolated from diabetic rats, 12 weeks after treatment with streptozotocin (45 mg/kg, i.p.). The concentration-response curve to acetylcholine (Ach) in the aortic rings precontracted with...

To evaluate the acute effect of lovastatin on diabetic endothelial dysfunction, we examined this effect on the aortic rings of streptozotocin-diabetic rats. The endothelial function was assessed in aortic rings isolated from diabetic rats, 12 weeks after treatment with streptozotocin (45 mg/kg, i.p.). The concentration-response curve to acetylcholine (Ach) in the aortic rings precontracted with...

To establish the relationship between cholinergic ligand occupancy and channel open states, we recorded single-channel currents activated by different acetylcholine (ACh) concentrations from Torpedo californica ACh receptors reconstituted in lipid bilayers. Inspection of single-channel records shows that the frequency of occurrence of long openings increases with ACh concentration. Analysis of ...

The cornea has one of the highest acetylcholine (ACh) concentrations of any tissue but the function of the ACh has remained enigmatic. During studies on corneal arachidonic acid metabolism, we observed that ACh stimulates formation of labeled phosphatidic acid in rat corneas whose phospholipids were prelabeled with [14C]arachidonate. ACh did not affect the metabolism of free [14C]arachidonate. ...

Previous studies performed in marine fish (I. conceptionis and G. laevifrons) showed that indomethacin blocked arterial contraction mediated by acetylcholine (ACh). The objective of this study was to determine if contraction induced by acetylcholine is mediated by the cyclooxygenase pathway in several arterial vessels in the Chilean frog Calyptocephalella gayi. Arteries from the pulmonary (PA),...

Taste bud cells (TBCs) express various neurotransmitter receptors assumed to facilitate or modify taste information processing within taste buds. We investigated the functional expression of muscarinic acetylcholine receptor (mAChR) subtypes, M1-M5, in mouse fungiform TBCs. ACh applied to the basolateral membrane of TBCs elevates the intracellular Ca(2+) level in a concentration-dependent manne...

Alterations in expression patterns of a4b2 nicotinic acetylcholine receptors have been demonstrated to alter cholinergic neurotransmission and are implicated in neurologic disorders, including autism, nicotine addiction, Alzheimer’s disease, and Parkinson’s disease. Positive allosteric modulators (PAMs) represent promising new leads in the development of therapeutic agents for the treatment of ...