Coffee and tea contain the stimulants caffeine and theophylline. These compounds act as antagonists of adenosine receptors. Adenosine promotes sleep and its extracellular concentration rises in association with prolonged wakefulness, particularly in the basal forebrain (BF) region involved in activating the cerebral cortex. However, the effect of adenosine on identified BF neurons, especially n...

Prepulse inhibition (PPI) of the acoustic startle reflex is a sensorimotor gating process known to be deficient in a number of neurologic and psychiatric conditions, including schizophrenia. Multiple lines of evidence have indicated that the dopaminergic and muscarinic cholinergic systems play an important role in modulating PPI. Moreover, interactions between the dopaminergic and muscarinic ch...

Evidence indicates that blockade of cannabinoid receptors increases acetylcholine (ACh) release in brain cortical regions. Although it is assumed that this type of effect is mediated through CB1 receptor (CB1R) antagonism, several in vitro functional studies recently have suggested non-CB1R involvement. In addition, neither the precise neuroanatomical site nor the exact mechanisms underlying th...

Studies were performed in the rabbit aortic rings, precontracted with norepinephrine, to determine the subtype(s) of muscarinic receptors involved in endothelium-dependent relaxation and contraction in the absence of endothelium elicited by cholinergic stimuli. Acetylcholine (ACh) and arecaidine propargyl ester (APE), a M2 and M3 agonist, produced a dose-dependent relaxation and contraction in ...

Activation of protein kinase C (PKC) stimulates nicotine-induced catecholamine secretion. PKC down-regulation by prolonged pretreatment with phorbol 12-myristate 13-acetate diminished nicotine-induced catecholamine secretion only slightly (approximately 16%), suggesting substantial PKC independence of nicotinic receptor activation. However, we found that bisindolylmaleimide compounds (which are...

Objectives: This study determined the chemical composition of essential oil obtained from fresh leaf Plectranthus aegyptiacus, and evaluated it for novelty-induced behavioural (NIB) determine its mechanism(s) action in mice. Methods: The was hydro-distillated, analyzed using gas chromatography-mass spectrometry. effects (50, 100 150 mg/kg; i.p., n=6) on assessed open field test head dipping hol...

Metoclopramide was described in 1964 as an anti-emetic drug and stimulant of gastrointestinal motility. Dopamine D2 receptor antagonism explained the anti-emetic activity and was suggested to stimulate gastrointestinal motility. An important use of metoclopramide and other D2 receptor antagonists is to inhibit emesis caused by anticancer chemo radiotherapy. However, the use of new platinum-base...

The kinetics of cholinergic ligand binding to membrane-bound acetylcholine receptor from Torpedo californica have been followed in a stopped-flow photometer, by using the fluorescent probe ethidium. The overall reaction amplitude, as a function of ligand concentration, can be fit to the law of mass action for both agonist and antagonists. All agonists show at least biphasic kinetics, and the co...

Camgaroos are yellow fluorescent protein derivatives that hold promise as transgenically encoded calcium sensors in behaving animals. We expressed two versions of camgaroo in Drosophila mushroom bodies using the galactosidase-4 (GAL4) system. Potassium depolarization of brains expressing the reporters produces a robust increase in fluorescence that is blocked by removing extracellular calcium o...

Neuron-glia interactions play a critical role in the maturation of neural circuits; however, little is known about the pathways that mediate their communication in the developing CNS. We investigated neuron-glia signaling in the developing retina, where we demonstrate that retinal waves reliably induce calcium transients in Müller glial cells (MCs). During cholinergic waves, MC calcium transien...