Search results for "Cholinergic Fibers"

Non-neuronal acetylcholine involved in reproduction in mammals and honeybees.

2017

Bacteria and archaea synthesize acetylcholine (ACh). Thus, it can be postulated that ACh was created by nature roughly three billion years ago. Therefore, the wide expression of ACh in nature (i.e., in bacteria, archaea, unicellular organisms, plants, fungi, non-vertebrates and vertebrates and in the abundance of non-neuronal cells of mammals) is not surprising. The term non-neuronal ACh and non-neuronal cholinergic system have been introduced to describe the auto- and paracrine, that is, local regulatory actions of ACh in cells not innervated by neuronal cholinergic fibers and to communicate among themselves. In this way non-neuronal ACh binds to the nicotinic or muscarinic receptors expre…

Modulation of Hippocampal Circuits by Muscarinic and Nicotinic Receptors

2017

This article provides a review of the effects of activation of muscarinic and nicotinic receptors on the physiological properties of circuits in the hippocampal formation. Previous articles have described detailed computational hypotheses about the role of cholinergic neuromodulation in enhancing the dynamics for encoding in cortical structures and the role of reduced cholinergic modulation in allowing consolidation of previously encoded information. This article will focus on addressing the broad scope of different modulatory effects observed within hippocampal circuits, highlighting the heterogeneity of cholinergic modulation in terms of the physiological effects of activation of muscarin…

The cholinergic system in Down's syndrome

2006

The cholinergic system is one of the most important modulatory neurotransmitter systems in the brain. Alterations of the transmission communicators are accompanied by reduction of the cortical activity, which is associated with a learning and memory deficit. Down's syndrome is a pathological condition characterized by a high number of abnormalities that involve the brain.The cholinergic system is involved in alterations of the neurological system such as severe learning difficulties.To explain these alterations, important results are obtained from studies about murine trisomy 16 (animal model of Down's syndrome).The results obtained provide useful elements in the improvement of knowledge ab…

Characterization of sensory neurotransmission and its inhibition via alpha 2B-adrenoceptors and via non-alpha 2-receptors in rabbit iris.

1993

To find out whether, and which type of, adrenoceptors mediate prejunctional inhibition of sensory neurotransmitter release from trigeminal fibres, the modulation of twitch response to electrical field stimulation on rabbit isolated iris was investigated. Evoked iris sphincter contractions consisted of a minor fast cholinergic and a large slow component. The latter was unaffected by atropine and guanethidine, hence nonadrenergic noncholinergic in nature (NANC), but nearly completely abolished by capsaicin pretreatment and by the neurokinin receptor antagonist spantide. The response was probably not mediated by NK2 receptors as SR 48,968, an NK2 selective nonpeptide antagonist, failed to redu…

Editorial on “Beta-3 adrenergic receptor is expressed in acetylcholine-containing nerve fibers of the human urinary bladder: An immunohistochemical s…

2017

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 …

Involvement of CB1 and CB2 receptors in the modulation of cholinergic neurotransmission in mouse gastric preparations.

2007

Abstract While most of the studies concerning the role of cannabinoids on gastric motility have focused the attention on the gastric emptying in in vivo animal models, there is little information about the cannabinoid peripheral influence in the stomach. In addition, the functional features of CB2 receptors in the gastrointestinal tract have been poorly characterized. The purpose of the present study was to investigate the effects of cannabinoid drugs on the excitatory cholinergic and inhibitory non-adrenergic non-cholinergic (NANC) neurotransmission in mouse isolated gastric preparations. Intraluminal pressure from isolated whole stomach was recorded and mechanical responses induced by ele…

Cholinergic Control of Synchronized Seminal Emissions in Drosophila

2004

0960-9822 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; In many animal species, copulation involves the coordinated release of both sperm and seminal fluid, including substances that change female fertility and postmating behavior. In Drosophila melanogaster, these substances increase female fertility and prevent mating with a second male. By using a PGal4 strain, we targeted together with other cells a dozen cholinergic neurons found only in the male abdominal ganglion (Abg-MAch). Genetic feminization apparently deleted these neurons in males and significantly increased their copulation duration, blocked their fertility in 60% of cases, and only weakly repress…

Vesamicol blocks the recovery, by recycling cholinergic electromotor synaptic vesicles, of the biophysical characteristics of the reserve population.

1993

The effect of vesamicol on the ability of recycling cholinergic synaptic vesicles to recover, during a period of post-stimulation rest, the biophysical properties of the reserve pool was studied in prestimulated perfused blocks of the electric organ of the electric ray, Torpedo marmorata, a tissue rich in cholinergic synapses. The effect of the drug was analysed by high-resolution centrifugal density-gradient fractionation in a zonal rotor of the extracted vesicles. The two vesicle fractions were identified by their ATP and acetylcholine content and the recycled vesicles by their acquisition of [3H]acetylcholine derived from [3H]acetate in the perfusate. Vesamicol (10 microM) blocked the up…

Serotonergic modulation of hippocampal acetylcholine release after long-term neuronal grafting

2000

Adult female rats sustained aspirative fimbria-fornix lesions and, 2 weeks later, received intrahippocampal grafts of fetal septal or mixed septal-raphe cell suspensions. Twenty-four months later, the extracellular concentration of hippocampal acetylcholine (ACh) was determined by microdialysis. Basal ACh levels (5-65 fmol/5 microl sham-operated rats) were strongly reduced after lesioning (3-7 fmol/5 microl). In septally transplanted and septal-raphe co-transplanted rats, hippocampal ACh concentrations were restored to near-normal levels (15-25 fmol/5 microl), indicating long-term functional survival of hippocampal transplants. After administration of citalopram (100 microM by infusion) and…