Search results for "choline"
showing 10 items of 1138 documents
High pancuronium sensitivity of axonal nicotinic-acetylcholine receptors in humans during organophosphate intoxication.
1991
The effect of low-dose pancuronium on neuromuscular transmission was studied in 2 patients during the early and late stages of severe organophosphate intoxication. Single evoked compound muscle action potentials (CMAP) were followed by repetitive discharges and a decrement-increment (D-I) phenomenon with 10-, 20-, and 50-Hz supramaximal nerve stimulation. Intravenous pancuronium, 1 mg, abolished the D-I phenomenon, while the repetitive discharges of the CMAP were only partially reduced. It is postulated, that the disappearance of the D-I phenomenon with persistence of the CMAP repetitive discharges results from blockade of nicotinic-acetylcholine receptors located on the terminal axon respo…
Distribution of the vesicular acetylcholine transporter (VAChT) in the central and peripheral nervous systems of the rat.
1994
Expression of the acetylcholine biosynthetic enzyme choline acetyltransferase (ChAT), the vesicular acetylcholine transporter (VAChT), and the high-affinity plasma membrane choline transporter uniquely defines the cholinergic phenotype in the mammalian central (CNS) and peripheral (PNS) nervous systems. The distribution of cells expressing the messenger RNA encoding the recently cloned VAChT in the rat CNS and PNS is described here. The pattern of expression of VAChT mRNA is consistent with anatomical, pharmacological, and histochemical information on the distribution of functional cholinergic neurons in the brain and peripheral tissues of the rat. VAChT mRNA-containing cells are present in…
Corrigendum to “Hsp60 and AChR cross-reactivity in myasthenia gravis: An update.” [J. Neurol. Sci. 292 (2010) 117–118]
2012
Corrigendum to “Hsp60 and AChR cross-reactivity in myasthenia gravis: An update.” [J. Neurol. Sci. 292 (2010) 117–118] Francesco Cappello ⁎, Antonella Marino Gammazza, Leila Zummo, Everly Conway de Macario, Alberto J.L. Macario a Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Via del Vespro 129, 90127, Palermo, Italy b University of Maryland, IMET, 701 East Pratt Street, 21202, Baltimore, MD, USA
Differences in the temperature dependencies of uptake of botulinum and tetanus toxins in Aplysia neurons
1992
The respective neuroselective actions of botulinum type A (BoNT) and tetanus (TeTx) neurotoxins on cholinergic and non-cholinergic synapses of Aplysia are mainly due to differences in their extracellular neuronal targetting. Further information was gained on this neuroselectivity by examining the temperature dependencies of binding, internalization and intracellular action of both toxins. After reduction of temperature from 22 degrees C to 10 degrees C, the binding of neither BoNT nor TeTx was significantly altered whereas the neuronal uptake of BoNT, but not of TeTx, was prevented. Although TeTx internalization could be detected at the low temperature, its intracellular activity was greatl…
Functional nicotinic acetylcholine receptors on subplate neurons in neonatal rat somatosensory cortex.
2004
The establishment of cortical synaptic circuits during early development requires the presence of subplate neurons (SPn's), a heterogeneous population of neurons capable to integrate and process synaptic information from the thalamus, cortical plate, and neighboring SPn's. An accumulation of cholinergic afferents and nicotinic acetylcholine receptors (nAChRs) has been documentated in the subplate around birth. To assess the developmental role of the cholinergic innervation onto SPn's, we used whole cell patch-clamp recordings of visually identified and biocytin-labeled SPn's in neonatal rat somatosensory cortex. Functional nAChRs were present in 92% of the investigated SPn's. Activation of…
Allosterically potentiating ligands of nicotinic receptors as a treatment strategy for Alzheimer's disease.
2000
Abstract One of the most prominent cholinergic deficit in Alzheimer’s disease (AD) is the reduced number of nicotinic acetylcholine receptors (nAChR) in the hippocampus and cortex of AD patients, as compared to age-matched controls. This deficit results in reduced nicotinic cholinergic excitation which may not only impair postsynaptic depolarization but also presynaptic neurotransmitter release and Ca 2+ -dependent intracellular signaling, including transcriptional activity. Presently, the most common approach to correct the nicotinic cholinergic deficit in AD is the application of cholinesterase inhibitors. Due to the resulting increase in synaptic acetylcholine levels, both in concentrati…
Differentiation of Y79 cells induced by prolonged exposure to insulin
1997
Y79 human retinoblastoma cells are known to contain receptors for both insulin and insulin-like growth factors (IGFs), to produce these cytokines and release them in the culture medium. Previously we have demonstrated that IGFs and insulin stimulate Y79 cell proliferation through the involvement of type I IGF receptor and Insulin Receptor Substrate 1 (IRS-1). This paper studies the effect of prolonged exposure to insulin on Y79 cells. Cells grown for 10 days in the presence of insulin were reseeded and incubated once more with insulin. In the reseeded cells proliferation lowered and morphological changes appeared. After 10 days of reseeding, cells stopped proliferating and showed long ramif…
Synaptic connectivity of the cholinergic axons in the olfactory bulb of the cynomolgus monkey.
2015
The olfactory bulb (OB) of mammals receives cholinergic afferents from the horizontal limb of the diagonal band of Broca (HDB). At present, the synaptic connectivity of the cholinergic axons on the circuits of the OB has only been investigated in the rat. In this report, we analyze the synaptic connectivity of the cholinergic axons in the OB of the cynomolgus monkey (Macaca fascicularis). Our aim is to investigate whether the cholinergic innervation of the bulbar circuits is phylogenetically conserved between macrosmatic and microsmatic mammals. Our results demonstrate that the cholinergic axons form synaptic contacts on interneurons. In the glomerular layer, their main targets are the peri…
Effects of Neuromuscular Blocking Agents on Neuronal Nicotine Receptors of Motor Nerves: Blockade of Nicotinic Autofacilitation and Backfiring
1991
ABSTRACT Tubocurarine reduced (60%) [3H]acetylcholine release from the isolated rat phrenic nerve at concentrations of 1 or 10 μM, but blocked backfiring of the phrenic nerve occuring after partial blockade of cholinesterase already at a concentration of 100 nM. The distinct potency of tubocurarine suggests differences between the presynaptic nicotine receptors mediating autofacilitation of release and preterminal nicotine receptors mediating backfiring of the motor nerve or a low agonist concentration at the latter receptors. The new neuromuscular blocking agents atracurium, pancuronium and vecuronium less effectively reduced [3H]acetylcholine release than tubocurarine indicating a lower a…
Sensitivity of neuronal nicotinic acetylcholine receptors to the opiate antagonists naltrexone and naloxone: receptor blockade and up-regulation
2003
In HEK293 cells stably expressing alpha4beta2 nAChRs, naltrexone, but not naloxone, blocked alpha4beta2 nAChRs via an open-channel blocking mechanism. In primary hippocampal cultures, naltrexone inhibited alpha7 nAChRs up-regulated by nicotine, and in organotypic hippocampal cultures naltrexone caused a time-dependent up-regulation of functional alpha7 nAChRs that was detected after removal of the drug. These results indicate that naltrexone could be used as a smoking cessation aid.