Search results for "Cholinergic"

Role of non-neuronal and neuronal acetylcholine in the airways

2001

It is well known that acetylcholine represents a dominant neurotransmitter within mammalian airways and that airway functions, like smooth muscle activity and secretion, are under a continuous cholinergic tone. However, the teleology of this basal cholinergic tone, assumed to originate from neuronal activity, appears difficult to understand, whereas neuronal cholinergic reflex activity can be regarded as a rational regulatory pathway to protect the airways from injury [1-3]. Based on recent experimental observations, both phenomena may reflect two different biological roles of acetylcholine, acting first as a universal cytomolecule (non-neuronal) and second as a classical neurotransmitter (…

Persistent activity in layer 5 pyramidal neurons following cholinergic activation of mouse primary cortices

2011

Persistent spiking activity is thought to be a cellular process involved in working memory. We have been interested in whether persistent activity also exists in cortical areas which are not involved in this memory process. To study the possible presence and the mechanisms of persistent activity in layer 5 pyramidal cells of the mouse primary somatosensory, visual and motor cortices, we used patch-clamp and calcium imaging techniques. A combination of cholinergic receptor activation and suprathreshold depolarization or sufficient extracellular stimulation leads to either a subthreshold afterdepolarization or suprathreshold persistent activity in these cortices. There is a continuum of respo…

Carbachol-induced network oscillations in the intact cerebral cortex of the newborn rat.

2003

In mature cortex, activation of the cholinergic system induces oscillatory network activity and facilitates synaptic plasticity. We used an in vitro preparation of the intact cerebral cortex and cortical slices of the neonatal rat to study carbachol (CCh, >or=30 micro M)-induced network oscillations during the early postnatal period. Multi-site extracellular recordings revealed CCh-induced transient beta oscillations with an average duration of 4.6 +/- 0.2 s, amplitude of 123 +/- 7.4 microV and frequency of 17.7 +/- 0.5 Hz. These oscillations propagated uniformly at 0.5-1.5 mm/s over the cortex and were reversibly blocked by tetrodotoxin (TTX) and atropine, indicating that they depended on …

Spatio-temporal dynamics of oscillatory network activity in the neonatal mouse cerebral cortex

2007

We used a 60-channel microelectrode array to study in thick (600-1000 microm) somatosensory cortical slices from postnatal day (P)0-P3 mice the spatio-temporal properties of early network oscillations. We recorded local non-propagating as well as large-scale propagating spontaneous oscillatory activity. Both types of activity patterns could never be observed in neocortical slices of conventional thickness (400 microm). Local non-propagating spontaneous oscillations with an average peak frequency of 15.6 Hz, duration of 1.7 s and maximal amplitude of 66.8 microV were highly synchronized in a network of approximately 200 microm in diameter. Spontaneous oscillations of lower frequency (10.4 Hz…

The extracorporeal perfusion of the female pig detrusor as an experimental model for the study of bladder contractility.

2007

Aims The objective of the study was to establish an experimental model for the extracorporeal perfusion of the pig detrusor. In order to validate this model we examined some biochemical parameters and determined the effect of carbachol on the contractility of perfused female pig bladders. Methods Twenty-six pig bladders were perfused with Krebs–Ringer bicarbonate-glucose buffer for a period up to 5 hr with the aim to preserve a viable organ, which would be responsive to contraction-inducing agents. The intravesical pressure of the bladder as well as the intraarterial pressure of the vesical arteries were recorded before and after administration of carbachol. Results The perfusate pH, lactat…

A novel cholinergic-specific antigen (Chol-2) in mammalian brain.

1993

Three new antisera have been raised in sheep against cholinergic electromotor presynaptic plasma membranes prepared from the electric organs of the electric ray, Torpedo marmorata. They all recognized one or more cholinergic-specific antigens in the mammalian nervous system by the following criteria: they sensitized the cholinergic subpopulation of rat-brain synaptosomes--and only this subpopulation--to lysis by the complement system and, in an immunocytochemical study, selectively stained choline acetyltransferase-positive cholinergic neurons in the rat spinal cord. However, two of the three antisera failed to recognize Chol-1 alpha and -beta, two closely related minor gangliosides already…

Chapter 27: Peptidergic and cholinergic receptors on cultured astrocytes of different regions of the rat CNS

1992

Publisher Summary This chapter discusses whether astrocytes possess peptidergic and cholinergic receptors. There is strong evidence that in addition to neurons, astrocytes also express receptors for neurotransmitters and neuromodulators. The investigations were carried out in explant cultures of the spinal cord, brain-stem, cerebellum, and neocortex of fetal and newborn rats. By the means of autoradiography, it was demonstrated that astrocytes possess binding sites for the vasoactive peptides 3 H-Ang II, 125 I- VIP, 125 I-ET-l, ET-3, and 125 I-AVP. These findings are consistent with electrophysiological studies demonstrating that Ang II, ET, and AVP cause a depolarization of the glial membr…

Cholinergic-Adrenergic Interactions at the Presynaptic Level as Studied in the Heart

1982

Brain choline has a typical precursor profile.

1998

Choline is product and precursor to both acetylcholine and membrane phospholipids, and, in the brain, is ultimately provided by the circulation. The brain is protected from excess choline and choline deprivation by a refined system of homeostatic mechanisms that maintain a level of extracellular choline that, for its role as precursor, meets saturation criteria under normal conditions. The kinetic and activity profiles of choline are typical for a biosynthetic precursor.

Synthesis and in vitro evaluation of galanthamine derivatives for examination of nicotinic acetylcholine receptor system

2001

ISunmrary: The syntheses and radioactive labeling of several galanthamine derivatives, 6-O-demethyl-6-O-fluoroethylgalanthamine, 10-N-demethyl-lO-Nfluoroethylgalanthamine and N-methylgalanthaminium are reported. First ill vitro evaluations were carried out to determine their properties as allosterically potentiating ligands of nicotinic receptors. N-methylgalanthaminium was found to be a promising candidate for further investigations. The most commonly applied therapeutic approach to balance nicotinic cholinergic deficits in Alzheimer’s disease (AD) patients is the administration of acetylcholinesterase inhibitors (AChE-I) although they have been proven to be of limited therapeutic value [ …