Science.gov

Sample records for cell nicotinic cholinergic

  1. Mixed nicotinic and muscarinic features of cholinergic receptor coupled to secretion in bovine chromaffin cells.

    PubMed Central

    Shirvan, M H; Pollard, H B; Heldman, E

    1991-01-01

    Acetylcholine evokes release from cultured bovine chromaffin cells by a mechanism that is believed to be classically nicotinic. However, we found that the full muscarinic agonist oxotremorine-M (Oxo-M) induced a robust catecholamine (CA) secretion. By contrast, muscarine, pilocarpine, bethanechol, and McN-A-343 did not elicit any secretory response. Desensitization of the response to nicotine by Oxo-M and desensitization of the response to Oxo-M by nicotine suggest that both nicotine and Oxo-M were acting at the same receptor. Additional experiments supporting this conclusion show that nicotine-induced secretion and Oxo-M-induced secretion were similarly blocked by various muscarinic and nicotinic antagonists. Moreover, secretion induced by nicotine and Oxo-M were Ca2+ dependent, and both agonists induced 45Ca2+ uptake. Equilibrium binding studies showed that [3H]Oxo-M bound to chromaffin cell membranes with a Kd value of 3.08 x 10(-8) M and a Hill coefficient of 1.00, suggesting one binding site for this ligand. Nicotine inhibited Oxo-M binding in a noncompetitive manner, suggesting that both ligands bind at two different sites on the same receptor. We propose that the receptor on bovine chromaffin cells that is coupled to secretion represents an unusual cholinergic receptor that has both nicotinic and muscarinic features. Images PMID:2052567

  2. Mixed nicotinic and muscarinic features of cholinergic receptor coupled to secretion in bovine chromaffin cells

    SciTech Connect

    Shirvan, M.H.; Pollard, H.B.; Heldman, E. )

    1991-06-01

    Acetylcholine evokes release from cultured bovine chromaffin cells by a mechanism that is believed to be classically nicotinic. However, the authors found that the full muscarinic agonist oxotremorine-M (Oxo-M) induced a robust catecholamine (CA) secretion. By contrast, muscarine, pilocarpine, bethanechol, and McN-A-343 did not elicit any secretory response. Desensitization of the response to nicotine by Oxo-M and desensitization of the response to Oxo-M by nicotine suggest that both nicotine and Oxo-M were acting at the same receptor. Additional experiments supporting this conclusion show that nicotine-induced secretion and Oxo-M-induced secretion were similarly blocked by various muscarinic and nicotinic antagonists. Moreover, secretion induced by nicotine and Oxo-M were Ca{sup 2+} dependent, and both agonists induced {sup 45}Ca{sup 2+} uptake. Equilibrium binding studies showed that ({sup 3}H)Oxo-M bound to chromaffin cell membranes with a K{sub d} value of 3.08 {times} 10{sup {minus}8}M and a Hill coefficient of 1.00, suggesting one binding site for this ligand. Nicotine inhibited Oxo-M binding in a noncompetitive manner, suggesting that both ligands bind at two different sites on the same receptor. They propose that the receptor on bovine chromaffin cells that is coupled to secretion represents an unusual cholinergic receptor that has both nicotinic and muscarinic features.

  3. Cholinergic modulation of dopamine pathways through nicotinic acetylcholine receptors.

    PubMed

    de Kloet, Sybren F; Mansvelder, Huibert D; De Vries, Taco J

    2015-10-15

    Nicotine addiction is highly prevalent in current society and is often comorbid with other diseases. In the central nervous system, nicotine acts as an agonist for nicotinic acetylcholine receptors (nAChRs) and its effects depend on location and receptor composition. Although nicotinic receptors are found in most brain regions, many studies on addiction have focused on the mesolimbic system and its reported behavioral correlates such as reward processing and reinforcement learning. Profound modulatory cholinergic input from the pedunculopontine and laterodorsal tegmentum to dopaminergic midbrain nuclei as well as local cholinergic interneuron projections to dopamine neuron axons in the striatum may play a major role in the effects of nicotine. Moreover, an indirect mesocorticolimbic feedback loop involving the medial prefrontal cortex may be involved in behavioral characteristics of nicotine addiction. Therefore, this review will highlight current understanding of the effects of nicotine on the function of mesolimbic and mesocortical dopamine projections in the mesocorticolimbic circuit. PMID:26208783

  4. Dopaminergic and cholinergic learning mechanisms in nicotine addiction.

    PubMed

    Subramaniyan, Manivannan; Dani, John A

    2015-09-01

    Nicotine addiction drives tobacco use by one billion people worldwide, causing nearly six million deaths a year. Nicotine binds to nicotinic acetylcholine receptors that are normally activated by the endogenous neurotransmitter acetylcholine. The widespread expression of nicotinic receptors throughout the nervous system accounts for the diverse physiological effects triggered by nicotine. A crucial influence of nicotine is on the synaptic mechanisms underlying learning that contribute to the addiction process. Here, we focus on the acquisition phase of smoking addiction and review animal model studies on how nicotine modifies dopaminergic and cholinergic signaling in key nodes of the reinforcement circuitry: ventral tegmental area, nucleus accumbens (NAc), amygdala, and hippocampus. Capitalizing on mechanisms that subserve natural rewards, nicotine activates midbrain dopamine neurons directly and indirectly, and nicotine causes dopamine release in very broad target areas throughout the brain, including the NAc, amygdala, and hippocampus. In addition, nicotine orchestrates local changes within those target structures, alters the release of virtually all major neurotransmitters, and primes the nervous system to the influence of other addictive drugs. Hence, understanding how nicotine affects the circuitry for synaptic plasticity and learning may aid in developing reasoned therapies to treat nicotine addiction. PMID:26301866

  5. Habenula cholinergic neurons regulate anxiety during nicotine withdrawal via nicotinic acetylcholine receptors.

    PubMed

    Pang, Xueyan; Liu, Liwang; Ngolab, Jennifer; Zhao-Shea, Rubing; McIntosh, J Michael; Gardner, Paul D; Tapper, Andrew R

    2016-08-01

    Cholinergic neurons in the medial habenula (MHb) modulate anxiety during nicotine withdrawal although the molecular neuroadaptation(s) within the MHb that induce affective behaviors during nicotine cessation is largely unknown. MHb cholinergic neurons are unique in that they robustly express neuronal nicotinic acetylcholine receptors (nAChRs), although their behavioral role as autoreceptors in these neurons has not been described. To test the hypothesis that nAChR signaling in MHb cholinergic neurons could modulate anxiety, we expressed novel "gain of function" nAChR subunits selectively in MHb cholinergic neurons of adult mice. Mice expressing these mutant nAChRs exhibited increased anxiety-like behavior that was alleviated by blockade with a nAChR antagonist. To test the hypothesis that anxiety induced by nicotine withdrawal may be mediated by increased MHb nicotinic receptor signaling, we infused nAChR subtype selective antagonists into the MHb of nicotine naïve and withdrawn mice. While antagonists had little effect on nicotine naïve mice, blocking α4β2 or α6β2, but not α3β4 nAChRs in the MHb alleviated anxiety in mice undergoing nicotine withdrawal. Consistent with behavioral results, there was increased functional expression of nAChRs containing the α6 subunit in MHb neurons that also expressed the α4 subunit. Together, these data indicate that MHb cholinergic neurons regulate nicotine withdrawal-induced anxiety via increased signaling through nicotinic receptors containing the α6 subunit and point toward nAChRs in MHb cholinergic neurons as molecular targets for smoking cessation therapeutics. PMID:27020042

  6. Neurocircuitry of the nicotinic cholinergic system

    PubMed Central

    Bertrand, Daniel

    2010-01-01

    Continuing to discover how the brain works is one of the great challenges ahead of us. Although understanding the brain anatomy and its functional organization provided a first and indispensable foundation, it became clear that a static view was insufficient. To understand the complexity of neuronal communication, it is necessary to examine the chemical nature of the neurotransmission and, using the example of the acetylcholine receptors, follow the different layers of networks that can be distinguished. The natural alkaloid nicotine contained in tobacco leaves acts as an agonist with a subclass of acetylcholine receptors, and provides an interesting tool to approach brain functions. Analysis of the nicotinic acetylcholine receptors, which are ligand gated channels, revealed that these receptors are expressed at different critical locations on the neurons including the synaptic boutons, neurites, cell bodies, and even on the axons. These receptors can modulate the activity at the microcircuit synaptic level, in the cell processing of information, and, by acting on the velocity of action potential, the synchrony of communication between brain areas. These actions at multiple levels of brain organization provide an example of the complexity of brain neurocircuitry and an illustration of the relevance of this knowledge for psychiatry. PMID:21319492

  7. Physical Chemistry to the Rescue: Differentiating Nicotinic and Cholinergic Agonists

    ERIC Educational Resources Information Center

    King, Angela G.

    2005-01-01

    Researches suggest that two agonists can bind to the same binding site of an important transmembrane protein and elicit a biological response through strikingly different binding interactions. Evidence is provided which suggests two possible types of nicotinic acetylcholine receptor agonist binding like acetlycholine (cholinergic) or like nicotine…

  8. The α7-nicotinic receptor is upregulated in immune cells from HIV-seropositive women: consequences to the cholinergic anti-inflammatory response

    PubMed Central

    Delgado-Vélez, Manuel; Báez-Pagán, Carlos A; Gerena, Yamil; Quesada, Orestes; Santiago-Pérez, Laura I; Capó-Vélez, Coral M; Wojna, Valerie; Meléndez, Loyda; León-Rivera, Rosiris; Silva, Walter; Lasalde-Dominicci, José A

    2015-01-01

    Antiretroviral therapy partially restores the immune system and markedly increases life expectancy of HIV-infected patients. However, antiretroviral therapy does not restore full health. These patients suffer from poorly understood chronic inflammation that causes a number of AIDS and non-AIDS complications. Here we show that chronic inflammation in HIV+ patients may be due to the disruption of the cholinergic anti-inflammatory pathway by HIV envelope protein gp120IIIB. Our results demonstrate that HIV gp120IIIB induces α7 nicotinic acetylcholine receptor (α7) upregulation and a paradoxical proinflammatory phenotype in macrophages, as activation of the upregulated α7 is no longer capable of inhibiting the release of proinflammatory cytokines. Our results demonstrate that disruption of the cholinergic-mediated anti-inflammatory response can result from an HIV protein. Collectively, these findings suggest that HIV tampering with a natural strategy to control inflammation could contribute to a crucial, unresolved problem of HIV infection: chronic inflammation. PMID:26719799

  9. The α7-nicotinic receptor is upregulated in immune cells from HIV-seropositive women: consequences to the cholinergic anti-inflammatory response.

    PubMed

    Delgado-Vélez, Manuel; Báez-Pagán, Carlos A; Gerena, Yamil; Quesada, Orestes; Santiago-Pérez, Laura I; Capó-Vélez, Coral M; Wojna, Valerie; Meléndez, Loyda; León-Rivera, Rosiris; Silva, Walter; Lasalde-Dominicci, José A

    2015-12-01

    Antiretroviral therapy partially restores the immune system and markedly increases life expectancy of HIV-infected patients. However, antiretroviral therapy does not restore full health. These patients suffer from poorly understood chronic inflammation that causes a number of AIDS and non-AIDS complications. Here we show that chronic inflammation in HIV+ patients may be due to the disruption of the cholinergic anti-inflammatory pathway by HIV envelope protein gp120IIIB. Our results demonstrate that HIV gp120IIIB induces α7 nicotinic acetylcholine receptor (α7) upregulation and a paradoxical proinflammatory phenotype in macrophages, as activation of the upregulated α7 is no longer capable of inhibiting the release of proinflammatory cytokines. Our results demonstrate that disruption of the cholinergic-mediated anti-inflammatory response can result from an HIV protein. Collectively, these findings suggest that HIV tampering with a natural strategy to control inflammation could contribute to a crucial, unresolved problem of HIV infection: chronic inflammation. PMID:26719799

  10. An autoradiographic analysis of cholinergic receptors in mouse brain after chronic nicotine treatment

    SciTech Connect

    Pauly, J.R.; Marks, M.J.; Gross, S.D.; Collins, A.C. )

    1991-09-01

    Quantitative autoradiographic procedures were used to examine the effects of chronic nicotine infusion on the number of central nervous system nicotinic cholinergic receptors. Female DBA mice were implanted with jugular cannulas and infused with saline or various doses of nicotine (0.25, 0.5, 1.0 or 2.0 mg/kg/hr) for 10 days. The animals were then sacrificed and the brains were removed and frozen in isopentane. Cryostat sections were collected and prepared for autoradiographic procedures as previously described. Nicotinic cholinergic receptors were labeled with L-(3H)nicotine or alpha-(125I)bungarotoxin; (3H)quinuclidinyl benzilate was used to measure muscarinic cholinergic receptor binding. Chronic nicotine infusion increased the number of sites labeled by (3H)nicotine in most brain areas. However, the extent of the increase in binding as well as the dose-response curves for the increase were widely different among brain regions. After the highest treatment dose, binding was increased in 67 of 86 regions measured. Septal and thalamic regions were most resistant to change. Nicotinic binding measured by alpha-(125I)bungarotoxin also increased after chronic treatment, but in a less robust fashion. At the highest treatment dose, only 26 of 80 regions were significantly changes. Muscarinic binding was not altered after chronic nicotine treatment. These data suggest that brain regions are not equivalent in the mechanisms that regulate alterations in nicotinic cholinergic receptor binding after chronic nicotine treatment.

  11. Developmental Neurotoxicity of Tobacco Smoke Directed Toward Cholinergic and Serotonergic Systems: More Than Just Nicotine.

    PubMed

    Slotkin, Theodore A; Skavicus, Samantha; Card, Jennifer; Stadler, Ashley; Levin, Edward D; Seidler, Frederic J

    2015-09-01

    Tobacco smoke contains thousands of compounds in addition to nicotine, a known neuroteratogen. We evaluated the developmental neurotoxicity of tobacco smoke extract (TSE) administered to pregnant rats starting preconception and continued through the second postnatal week. We simulated nicotine concentrations encountered with second-hand smoke, an order of magnitude below those seen in active smokers, and compared TSE with an equivalent dose of nicotine alone, and to a 10-fold higher nicotine dose. We conducted longitudinal evaluations in multiple brain regions, starting in adolescence (postnatal day 30) and continued to full adulthood (day 150). TSE exposure impaired presynaptic cholinergic activity, exacerbated by a decrement in nicotinic cholinergic receptor concentrations. Although both nicotine doses produced presynaptic cholinergic deficits, these were partially compensated by hyperinnervation and receptor upregulation, effects that were absent with TSE. TSE also produced deficits in serotonin receptors in females that were not seen with nicotine. Regression analysis showed a profound sex difference in the degree to which nicotine could account for overall TSE effects: whereas the 2 nicotine doses accounted for 36%-46% of TSE effects in males, it accounted for only 7%-13% in females. Our results show that the adverse effects of TSE on neurodevelopment exceed those that can be attributed to just the nicotine present in the mixture, and further, that the sensitivity extends down to levels commensurate with second-hand smoke exposure. Because nicotine itself evoked deficits at low exposures, "harm reduction" nicotine products do not eliminate the potential for neurodevelopmental damage. PMID:26085346

  12. Multiple cholinergic nicotinic receptor genes affect nicotine dependence risk in African and European Americans

    PubMed Central

    Saccone, Nancy L.; Schwantes-An, Tae-Hwi; Wang, Jen C.; Grucza, Richard A.; Breslau, Naomi; Hatsukami, Dorothy; Johnson, Eric O.; Rice, John P.; Goate, Alison M.; Bierut, Laura J.

    2010-01-01

    Several independent studies show that the chromosome 15q25.1 region, which contains the CHRNA5-CHRNA3-CHRNB4 gene cluster, harbors variants strongly associated with nicotine dependence, other smoking behaviors, lung cancer, and chronic obstructive pulmonary disease. We investigated whether variants in other cholinergic nicotinic receptor subunit (CHRN) genes affect risk for nicotine dependence in a new sample of African-Americans (N = 710). We also analyzed this African-American sample together with a European-American sample (N=2062, 1608 of which have been previously studied), allowing for differing effects in the two populations. Cases are current nicotine-dependent smokers and controls are non-dependent smokers. Variants in or near CHRND-CHRNG, CHRNA7, and CHRNA10 show modest association with nicotine dependence risk in the African-American sample. In addition, CHRNA4, CHRNB3-CHRNA6, and CHRNB1 show association in at least one population. CHRNG and CHRNA4 harbor SNPs that have opposite directions of effect in the two populations. In each of the population samples, these loci substantially increase the trait variation explained, although no loci meet Bonferroni-corrected significance in the African-American sample alone. The trait variation explained by three key associated SNPs in CHRNA5-CHRNA3-CHRNB4 is 1.9% in European-Americans and also 1.9% in African-Americans; this increases to 4.5% in EAs and 7.3% in AAs when we add six variants representing associations at other CHRN genes. Multiple nicotinic receptor subunit genes outside of chromosome 15q25 are likely to be important in the biological processes and development of nicotine dependence, and some of these risks may be shared across diverse populations. PMID:20584212

  13. The α2-subunit of the nicotinic cholinergic receptor is specifically expressed in medial subpallium-derived cells of mammalian amygdala.

    PubMed

    Pombero, Ana; Martinez, Salvador

    2015-08-01

    Nicotinic acetylcholine receptor (nAChR) subtypes are expressed in specific neuronal populations, which are involved in numerous neural functions such as sleep, fatigue, anxiety, and cognition, as well as the central processing of pain and food intake. Moreover, mutations in nAChRs subunits have been related to frontal lobe epilepsy, neurodegenerative diseases, and other neurological disorders, including schizophrenia and attention deficit and hyperactivity disorder (ADHD). Previous studies have shown that the α2-subunit of the AChR (Chrna2) is expressed in the basal forebrain, in the septum, and in some amygdalar nuclei in the adult rodent brain. However, although the importance of this amygdalar expression in emotion-related behavior and the physiopathology of neuropsychiatric disorders has been accepted, a detailed study of the Chrna2 expression pattern during development has been lacking. In this study we found that Chrna2 is specifically expressed in medial subpallium-derived amygdalar nuclei from early developmental stages to adult. This finding could help us to better understand the role of Chrna2 in the differentiation and functional maturation of amygdalar neurons involved in cholinergic-regulated emotional behavior. PMID:25641263

  14. Nicotine-Induced Modulation of the Cholinergic Twitch Response in the Ileum of Guinea Pig.

    PubMed

    Donnerer, Josef; Liebmann, Ingrid

    2015-01-01

    In the present study, the direct drug effects of nicotine and its effects on the cholinergic twitch responses of the electrically stimulated longitudinal muscle-myenteric plexus strip from the ileum of guinea pig were investigated. Nicotine dose-dependently (0.3-10 µmol/l) evoked the well-known contractile responses on its own. Whereas the interposed twitch responses remained present without a change in height at 1 µmol/l nicotine, a nicotine concentration of 3 µmol/l slightly and a concentration of 10 µmol/l markedly diminished the twitch during their presence. After the washout of 1-10 µmol/l nicotine, the height of the twitch response was also temporarily and significantly reduced by 30-77%. The P2X purinoceptor agonist αβ-methylene ATP (1-10 µmol/l) dose-dependently induced contractions on its own and reduced the twitch response during its presence in the organ bath; however, it did not diminish the twitch responses after washout of the drug as nicotine did. The P2X antagonist pyridoxalphosphate-6-azophenyl-2'-4'-disulphonic acid, the NMDA channel blocker MK-801 and the inhibitor of small conductance Ca(2+)-activated K(+) (SK) channels apamin reduced the contractile effect of 1 µmol/l nicotine. Apamin also significantly prevented the 'post-nicotine inhibition of the twitch' following the washout of 1-3 µmol/l nicotine. As a conclusion, we provide evidence for a functional interaction between nicotinic receptors and the P2X receptors in the ileum of the guinea pig. The 'post-nicotine inhibition of the twitch' is not due to nicotinic acetylcholine receptor desensitization or transmitter depletion, but most probably the secondary effects of nicotine on SK channels determine the reduced cholinergic motor neuron excitability. PMID:26088942

  15. In vivo labeling of nicotinic cholinergic receptors in brain with [3H]cytisine.

    PubMed

    Flesher, J E; Scheffel, U; London, E D; Frost, J J

    1994-01-01

    [3H]Cytisine was evaluated as an in vivo ligand for the nicotinic cholinergic receptor (nAchR) in mouse brain. The tracer was injected intravenously, and radioactivity in brain regions was analyzed. Radioactivity peaked in the brain at 30 minutes. It was highest in the thalamus, intermediate in the superior colliculi, prefrontal cortex and hippocampus, and low in the cerebellum. Pretreatment with unlabeled cytisine inhibited binding in the thalamus, but not in the cerebellum. Binding was displaced by l-nicotine, but not by d-nicotine or dexetimide. The results suggest that cytisine, appropriately labeled with a positron emitting radionuclide, may be useful for study of nicotinic cholinergic receptors in humans by emission computed tomography. PMID:8196506

  16. ( sup 3 H)cytisine binding to nicotinic cholinergic receptors in brain

    SciTech Connect

    Pabreza, L.A.; Dhawan, S.; Kellar, K.J. )

    1991-01-01

    Cytisine, a ganglionic agonist, competes with high affinity for brain nicotinic cholinergic receptors labeled by any of several nicotinic {sup 3}H-agonist ligands. Here we have examined the binding of ({sup 3}H)cytisine in rat brain homogenates. ({sup 3}H)Cytisine binds with high affinity (Kd less than 1 nM), and specific binding represented 60-90% of total binding at all concentrations examined up to 15 nM. The nicotinic cholinergic agonists nicotine, acetylcholine, and carbachol compete with high affinity for ({sup 3}H)cytisine binding sites, whereas among nicotinic receptor antagonists only dihydro-beta-erythroidine competes with high affinity (in the nanomolar range). Comparison of binding in several brain regions showed that ({sup 3}H)cytisine binding is higher in the thalamus, striatum, and cortex than in the hippocampus, cerebellum, or hypothalamus. The pharmacology and brain regional distribution of ({sup 3}H)cytisine binding sites are those predicted for neuronal nicotinic receptor agonist recognition sites. The high affinity and low nonspecific binding of ({sup 3}H)cytisine should make it a very useful ligand for studying neuronal nicotinic receptors.

  17. Optogenetic studies of nicotinic contributions to cholinergic signaling in the central nervous system

    PubMed Central

    Jiang, Li; López-Hernández, Gretchen Y.; Lederman, James; Talmage, David A.; Role, Lorna W.

    2015-01-01

    Molecular manipulations and targeted pharmacological studies provide a compelling picture of which nicotinic receptor subtypes are where in the central nervous system (CNS) and what happens if one activates or deletes them. However, understanding the physiological contribution of nicotinic receptors to endogenous acetylcholine (ACh) signaling in the CNS has proven a more difficult problem to solve. In this review, we provide a synopsis of the literature on the use of optogenetic approaches to control the excitability of cholinergic neurons and to examine the role of CNS nicotinic ACh receptors (nAChRs). As is often the case, this relatively new technology has answered some questions and raised others. Overall, we believe that optogenetic manipulation of cholinergic excitability in combination with some rigorous pharmacology will ultimately advance our understanding of the many functions of nAChRs in the brain. PMID:25051276

  18. Nicotinic cholinergic receptors in rat brain. Annual report No. 2

    SciTech Connect

    Kellar, K.J.

    1985-05-13

    We have conducted experiments to determine if 3H acetylcholine (3Hach) nicotinic recognition sites are located presynaptically on catecholamine and/or serotonin axons. Lesions of these axons by intraventricular injections of neurotoxins resulted in marked decreases in 3Hach binding sites in the striatum and hypothalamus, but not in the cortex or thalamus. These results indicate that 3Hach nicotinic binding sites are located on catecholamine and serotonin axons in specific areas of the brain. In other experiments, we determined that repeated administration of nicotine results in enhanced behavioral responses to a subsequent injection of nicotine, and that there appears to be a correlation between the enhanced response to nicotine and increased 3Hach binding sites in cerebral cortex.

  19. Preclinical Evidence for a Role of the Nicotinic Cholinergic System in Parkinson's Disease.

    PubMed

    Perez, Xiomara A

    2015-12-01

    One of the primary deficits in Parkinson's disease (PD) is the loss of dopaminergic neurons in the substantia nigra pars compacta which leads to striatal dopaminergic deficits that underlie the motor symptoms associated with the disease. A plethora of animal models have been developed over the years to uncover the molecular alterations that lead to PD development. These models have provided valuable information on neurotransmitter pathways and mechanisms involved. One such a system is the nicotinic cholinergic system. Numerous studies show that nigrostriatal damage affects nicotinic receptor-mediated dopaminergic signaling; therefore therapeutic modulation of the nicotinic cholinergic system may offer a novel approach to manage PD. In fact, there is evidence showing that nicotinic receptor drugs may be useful as neuroprotective agents to prevent Parkinson's disease progression. Additional preclinical studies also show that nicotinic receptor drugs may be beneficial for the treatment of L-dopa induced dyskinesias. Here, we review preclinical findings supporting the idea that nicotinic receptors are valuable therapeutic targets for PD. PMID:26553323

  20. The effect of the augmentation of cholinergic neurotransmission by nicotine on EEG indices of visuospatial attention.

    PubMed

    Logemann, H N A; Böcker, K B E; Deschamps, P K H; Kemner, C; Kenemans, J L

    2014-03-01

    The cholinergic system has been implicated in visuospatial attention but the exact role remains unclear. In visuospatial attention, bias refers to neuronal signals that modulate the sensitivity of sensory cortex, while disengagement refers to the decoupling of attention making reorienting possible. In the current study we investigated the effect of facilitating cholinergic neurotransmission by nicotine (Nicorette Freshmint 2mg, polacrilex chewing gum) on behavioral and electrophysiological indices of bias and disengagement. Sixteen non-smoking participants performed in a Visual Spatial Cueing (VSC) task while EEG was recorded. A randomized, single-blind, crossover design was implemented. Based on the scarce literature, it was expected that nicotine would specifically augment disengagement related processing, especially manifest as an increase of the modulation of the Late Positive Deflection (LPD) by validity of cueing. No effect was expected on bias related components (cue-locked: EDAN, LDAP; target-locked: P1 and N1 modulations). Results show weak indications for a reduction of the reaction time validity effect by nicotine, but only for half of the sample in which the validity effect on the pretest was largest. Nicotine reduced the result of bias as indexed by a reduced P1 modulation by validity, especially in subjects with strong peripheral responses to nicotine. Nicotine did not affect ERP manifestations of the directing of bias (EDAN, LDAP) or disengagement (LPD). PMID:24316088

  1. Activated cholinergic signaling provides a target in squamous cell lung carcinoma.

    PubMed

    Song, Pingfang; Sekhon, Harmanjatinder S; Fu, Xiao Wen; Maier, Michelle; Jia, Yibing; Duan, Jie; Proskosil, Becky J; Gravett, Courtney; Lindstrom, Jon; Mark, Gregory P; Saha, Saurabh; Spindel, Eliot R

    2008-06-15

    The binding of exogenous nicotine to nicotinic acetylcholine (ACh) receptors (nAChR) and the binding of endogenous ACh to both nAChR and muscarinic ACh receptors (mAChR) stimulate growth of both small cell and non-small cell lung carcinomas. Understanding how cholinergic signaling is up-regulated in lung cancer may suggest new therapeutic approaches. Analysis of 28 squamous cell lung carcinomas (SCC) showed increased levels of alpha5 and beta3 nAChR mRNA and increased levels of ACh associated with increased levels of choline acetyltransferase mRNA and decreased cholinesterase mRNAs. Lynx1, an allosteric inhibitor of nAChR activity, was also decreased in SCC. Thus, cholinergic signaling is broadly increased in SCC caused by increased levels of receptors, increased levels of ligands, and decreased levels of receptor inhibitors. Partially explaining the cholinergic up-regulation seen in SCC, incubation of the H520 SCC cell line with nicotine increased levels of ACh secretion, increased expression of nAChR, and, as measured by electrophysiologic recording, increased activity of the expressed nAChR. Consistent with these effects, nicotine stimulated proliferation of H520 cells. One approach to blocking proliferative effects of nicotine and ACh on growth of lung cancers may be through M3 mAChR antagonists, which can limit the activation of mitogen-activated protein kinase that is caused by both nicotinic and muscarinic signaling. This was tested with the M3-selective muscarinic antagonist darifenacin. Darifenacin blocked nicotine-stimulated H520 growth in vitro and also blocked H520 growth in nude mice in vivo. Thus, cholinergic signaling is broadly up-regulated in SCC and blocking cholinergic signaling can limit basal and nicotine-stimulated growth of SCC. PMID:18559515

  2. Nicotinic Cholinergic Synaptic Mechanisms in the Ventral Tegmental Area Contribute to Nicotine Addiction

    ERIC Educational Resources Information Center

    Pidoplichko, Volodymyr I.; Noguchi, Jun; Areola, Oluwasanmi O.; Liang, Yong; Peterson, Jayms; Zhang, Tianxiang; Dani, John A.

    2004-01-01

    Tobacco use is a major health problem that is estimated to cause 4 million deaths a year worldwide. Nicotine is the main addictive component of tobacco. It acts as an agonist to activate and desensitize nicotinic acetylcholine receptors (nAChRs). A component of nicotine's addictive power is attributable to actions on the mesolimbic dopaminergic…

  3. Selective lesions of the cholinergic neurons within the posterior pedunculopontine do not alter operant learning or nicotine sensitization.

    PubMed

    MacLaren, Duncan A A; Wilson, David I G; Winn, Philip

    2016-04-01

    Cholinergic neurons within the pedunculopontine tegmental nucleus have been implicated in a range of functions, including behavioral state control, attention, and modulation of midbrain and basal ganglia systems. Previous experiments with excitotoxic lesions have found persistent learning impairment and altered response to nicotine following lesion of the posterior component of the PPTg (pPPTg). These effects have been attributed to disrupted input to midbrain dopamine systems, particularly the ventral tegmental area. The pPPTg contains a dense collection of cholinergic neurons and also large numbers of glutamatergic and GABAergic neurons. Because these interdigitated populations of neurons are all susceptible to excitotoxins, the effects of such lesions cannot be attributed to one neuronal population. We wished to assess whether the learning impairments and altered responses to nicotine in excitotoxic PPTg-lesioned rats were due to loss of cholinergic neurons within the pPPTg. Selective depletion of cholinergic pPPTg neurons is achievable with the fusion toxin Dtx-UII, which targets UII receptors expressed only by cholinergic neurons in this region. Rats bearing bilateral lesions of cholinergic pPPTg neurons (>90 % ChAT+ neuronal loss) displayed no deficits in the learning or performance of fixed and variable ratio schedules of reinforcement for pellet reward. Separate rats with the same lesions had a normal locomotor response to nicotine and furthermore sensitized to repeated administration of nicotine at the same rate as sham controls. Previously seen changes in these behaviors following excitotoxic pPPTg lesions cannot be attributed solely to loss of cholinergic neurons. These findings indicate that non-cholinergic neurons within the pPPTg are responsible for the learning deficits and altered responses to nicotine seen after excitotoxic lesions. The functions of cholinergic neurons may be related to behavioral state control and attention rather than learning

  4. Early postnatal nicotine exposure causes hippocampus-dependent memory impairments in adolescent mice: association with altered nicotinic cholinergic modulation of LTP, but not impaired LTP

    PubMed Central

    Nakauchi, Sakura; Malvaez, Melissa; Su, Hailing; Kleeman, Elise; Dang, Richard; Wood, Marcelo A.; Sumikawa, Katumi

    2014-01-01

    Fetal nicotine exposure from smoking during pregnancy causes long-lasting cognitive impairments in offspring, yet little is known about the mechanisms that underlie this effect. Here we demonstrate that early postnatal exposure of mouse pups to nicotine via maternal milk impairs long-term, but not short-term, hippocampus-dependent memory during adolescence. At the Schaffer collateral (SC) pathway, the most widely studied synapses for a cellular correlate of hippocampus-dependent memory, the induction of N-methyl-d-aspartate receptor-dependent transient long-term potentiation (LTP) and protein synthesis-dependent long-lasting LTP are not diminished by nicotine exposure, but rather unexpectedly the threshold for LTP induction becomes lower after nicotine treatment. Using voltage sensitive dye to visualize hippocampal activity, we found that early postnatal nicotine exposure also results in enhanced CA1 depolarization and hyperpolarization after SC stimulation. Furthermore, we show that postnatal nicotine exposure induces pervasive changes to the nicotinic modulation of CA1 activity: activation of nicotinic receptors no longer increases CA1 network depolarization, acute nicotine inhibits rather than facilitates the induction of LTP at the SC pathway by recruiting an additional nicotinic receptor subtype, and acute nicotine no longer blocks LTP induction at the temporoammonic pathway. These findings reflect the pervasive impact of nicotine exposure during hippocampal development, and demonstrate an association of hippocampal memory impairments with altered nicotinic cholinergic modulation of LTP, but not impaired LTP. The implication of our results is that nicotinic cholinergic-dependent plasticity is required for long-term memory formation and that postnatal nicotine exposure disrupts this form of plasticity. PMID:25545599

  5. Electrophysiological and pharmacological evaluation of the nicotinic cholinergic system in chagasic rats

    PubMed Central

    2013-01-01

    Background Two theories attempt to explain the changes observed in the nicotinic acetylcholine receptors (nAChRs) in chagasic cardiomyopathy. The neurogenic theory proposes that receptor changes are due to loss of intracardiac ganglia parasympathetic neurons. The immunogenic theory proposes that the nAChRs changes are the result of autoantibodies against these receptors. Both theories agreed that nAChRs functional expression could be impaired in Chagas disease. Methods We evaluated nAChRs functional integrity in 54 Sprague Dawley rats, divided in two groups: healthy and chronic chagasic rats. Rats were subjected to electrocardiographic studies in the whole animal under pentobarbital anesthesia, by isolation and stimulation of vagus nerves and in isolated beating hearts (Langendorff’s preparation). Results Nicotine, 10 μM, induced a significant bradycardia in both groups. However, rats that had previously received reserpine did not respond to nicotine stimulation. β-adrenergic stimulation, followed by nicotine treatment, induced tachycardia in chagasic rats; while inducing bradycardia in healthy rats. Bilateral vagus nerve stimulation induced a significantly higher level of bradycardia in healthy rats, compared to chagasic rats; physostigmine potentiated the bradycardic response to vagal stimulation in both experimental groups. Electric stimulation (e.g., ≥ 2 Hz), in the presence of physostigmine, produced a comparable vagal response in both groups. In isolated beating-heart preparations 1 μM nicotine induced sustained bradycardia in healthy hearts while inducing tachycardia in chagasic hearts. Higher nicotine doses (e.g.,10 – 100 uM) promoted the characteristic biphasic response (i.e., bradycardia followed by tachycardia) in both groups. 10 nM DHβE antagonized the effect of 10 μM nicotine, unmasking the cholinergic bradycardic effect in healthy rats only. 1 nM α-BGT alone induced bradycardia in healthy hearts but antagonized the 10 μM nicotine

  6. A ten fold reduction of nicotine yield in tobacco smoke does not spare the central cholinergic system in adolescent mice.

    PubMed

    Abreu-Villaça, Yael; Correa-Santos, Monique; Dutra-Tavares, Ana C; Paes-Branco, Danielle; Nunes-Freitas, Andre; Manhães, Alex C; Filgueiras, Cláudio C; Ribeiro-Carvalho, Anderson

    2016-08-01

    The tobacco industry has gradually decreased nicotine content in cigarette smoke but the impact of this reduction on health is still controversial. Since the central cholinergic system is the primary site of action of nicotine, here, we investigated the effects of exposure of adolescent mice to tobacco smoke containing either high or low levels of nicotine on the central cholinergic system and the effects associated with cessation of exposure. From postnatal day (PN) 30 to 45, male and female Swiss mice were exposed to tobacco smoke (whole body exposure, 8h/day, 7 days/week) generated from 2R1F (HighNic group: 1.74mg nicotine/cigarette) or 4A1 (LowNic group: 0.14mg nicotine/cigarette) research cigarettes, whereas control mice were exposed to ambient air. Cholinergic biomarkers were assessed in the cerebral cortex and midbrain by the end of exposure (PN45), at short- (PN50) and long-term (PN75) deprivation. In the cortex, nicotinic cholinergic receptor upregulation was observed with either type of cigarette. In the midbrain, upregulation was detected only in HighNic mice and remained significant in females at short-term deprivation. The high-affinity choline transporter was reduced in the cortex: of HighNic mice by the end of exposure; of both HighNic and LowNic females at short-term deprivation; of LowNic mice at long-term deprivation. These decrements were separable from effects on choline acetyltransferase and acetylcholinesterase activities, suggesting cholinergic synaptic impairment. Here, we demonstrated central cholinergic alterations in an animal model of tobacco smoke exposure during adolescence. This system was sensitive even to tobacco smoke with very low nicotine content. PMID:27287270

  7. Nicotine inhibits potassium currents in Aplysia bag cell neurons.

    PubMed

    White, Sean H; Sturgeon, Raymond M; Magoski, Neil S

    2016-06-01

    Acetylcholine and the archetypal cholinergic agonist, nicotine, are typically associated with the opening of ionotropic receptors. In the bag cell neurons, which govern the reproductive behavior of the marine snail, Aplysia californica, there are two cholinergic responses: a relatively large acetylcholine-induced current and a relatively small nicotine-induced current. Both currents are readily apparent at resting membrane potential and result from the opening of distinct ionotropic receptors. We now report a separate current response elicited by applying nicotine to cultured bag cell neurons under whole cell voltage-clamp. This current was ostensibly inward, best resolved at depolarized voltages, presented a noncooperative dose-response with a half-maximal concentration near 1.5 mM, and associated with a decrease in membrane conductance. The unique nicotine-evoked response was not altered by intracellular perfusion with the G protein blocker GDPβS or exposure to classical nicotinic antagonists but was occluded by replacing intracellular K(+) with Cs(+) Consistent with an underlying mechanism of direct inhibition of one or more K(+) channels, nicotine was found to rapidly reduce the fast-inactivating A-type K(+) current as well as both components of the delayed-rectifier K(+) current. Finally, nicotine increased bag cell neuron excitability, which manifested as reduction in spike threshold, greater action potential height and width, and markedly more spiking to continuous depolarizing current injection. In contrast to conventional transient activation of nicotinic ionotropic receptors, block of K(+) channels could represent a nonstandard means for nicotine to profoundly alter the electrical properties of neurons over prolonged periods of time. PMID:26864763

  8. Nicotinic Antagonists Enhance Process Outgrowth by Rat Retinal Ganglion Cells in Culture

    NASA Astrophysics Data System (ADS)

    Lipton, Stuart A.; Frosch, Matthew P.; Phillips, Micheal D.; Tauck, David L.; Aizenman, Elias

    1988-03-01

    Functional nicotinic cholinergic receptors are found on mammalian retinal ganglion cell neurons in culture. The neurotransmitter acetylcholine (ACh) can be detected in the medium of many of these retinal cultures, after release presumably from the choline acetyltransferase-positive amacrine cells. The postsynaptic effect of endogenous or applied ACh on the ganglion cells can be blocked with specific nicotinic antagonists. Here it is shown that within 24 hours of producing such a pharmacologic blockade, the retinal ganglion cells begin to sprout or regenerate neuronal processes. Thus, the growth-enhancing effect of nicotinic antagonists may be due to the removal of inhibition to growth by tonic levels of ACh present in the culture medium. Since there is a spontaneous leak of ACh in the intact retina, the effects of nicotinic cholinergic drugs on process outgrowth in culture may reflect a normal control mechanism for growth or regeneration of retinal ganglion cell processes that is exerted by ACh in vivo.

  9. A novel cholinergic receptor mediates inhibition of chick cochlear hair cells.

    PubMed

    Fuchs, P A; Murrow, B W

    1992-04-22

    The central nervous system provides feedback regulation at several points within the peripheral auditory apparatus. One component of that feedback is inhibition of cochlear hair cells by release of acetylcholine (ACh) from efferent brainstem neurons. The mechanism of hair cell inhibition, and the character of the presumed cholinergic receptor, however, have eluded understanding. Both nicotinic and muscarinic, as well as some non-cholinergic ligands can affect the efferent action. We have made whole-cell, tight-seal recordings from short (outer) hair cells isolated from the chick's cochlea. These are the principal targets of cochlear efferents in birds. ACh hyperpolarizes short hair cells by opening a cation channel through which Ca2+ enters the cell and subsequently activates Ca(2+)-dependent K+ current (Fuchs & Murrow 1991, 1992). Both curare and atropine are effective-antagonists of cholinergic inhibition at 3 microM, whereas trimethaphan camsylate and strychnine block at 1 microM. The normally irreversible nicotinic antagonist, alpha-bungarotoxin, reversibly blocked the hair cell response, as did kappa-bungarotoxin. The half-blocking concentration for alpha-bungarotoxin was 26 nM. It is proposed that the hair cell AChR is a ligand-gated cation channel related to the nicotinic receptor of nerve and muscle. PMID:1355909

  10. Nicotinic acetylcholine receptor-mediated GABAergic inputs to cholinergic interneurons in the striosomes and the matrix compartments of the mouse striatum.

    PubMed

    Inoue, Ritsuko; Suzuki, Takeo; Nishimura, Kinya; Miura, Masami

    2016-06-01

    The striatum consists of two neurochemically distinct compartments: the striosomes (or patches) and the extrastriosomal matrix. Although striatal neurons are strongly innervated by intrinsic cholinergic interneurons, acetylcholinesterase is expressed more abundantly in the matrix than in the striosomes. At present, little is known about the different cholinergic functions of the striatal compartments. In this study, we examined gamma-aminobutyric acidergic (GABAergic) inputs to cholinergic interneurons in both compartments. We found that nicotinic receptor-mediated GABAergic responses were evoked more frequently in the matrix than in the striosomes. Furthermore, a single action potential of cholinergic neurons induced nicotinic receptor-mediated GABAergic inputs to the cholinergic neurons themselves, suggesting mutual connections that shape the temporal firing pattern of cholinergic neurons. The nicotinic receptor-mediated GABAergic responses were attenuated by continuous application of acetylcholine or the acetylcholinesterase inhibitor eserine and were enhanced by desformylflustrabromine, a positive allosteric modulator of the α4β2 subunit containing a nicotinic receptor. These results suggest that the nicotinic impact on the GABAergic responses are not uniform despite the massive and continuous cholinergic innervation. It has been reported that differential activation of neurons in the striosomes and the matrix produce a repetitive behavior called stereotypy. Drugs acting on α4β2 nicotinic receptors might provide potential tools for moderating the imbalanced activities between the compartments. PMID:26808315

  11. Nicotinic cholinergic receptors in esophagus: Early alteration during carcinogenesis and prognostic value

    PubMed Central

    Chianello Nicolau, Marina; Pinto, Luis Felipe Ribeiro; Nicolau-Neto, Pedro; de Pinho, Paulo Roberto Alves; Rossini, Ana; de Almeida Simão, Tatiana; Soares Lima, Sheila Coelho

    2016-01-01

    AIM To compare expression of nicotinic cholinergic receptors (CHRNs) in healthy and squamous cell carcinoma-affected esophagus and determine the prognostic value. METHODS We performed RT-qPCR to measure the expression of CHRNs in 44 esophageal samples from healthy individuals and in matched normal surrounding mucosa, and in tumors from 28 patients diagnosed with esophageal squamous cell carcinoma (ESCC). Next, we performed correlation analysis for the detected expression of these receptors with the habits and clinico-pathological characteristics of all study participants. In order to investigate the possible correlations between the expression of the different CHRN subunits in both healthy esophagus and tissues from ESCC patients, correlation matrices were generated. Subsequently, we evaluated whether the detected alterations in expression of the various CHRNs could precede histopathological modifications during the esophageal carcinogenic processes by using receiver operating characteristic curve analysis. Finally, we evaluated the impact of CHRNA5 and CHRNA7 expression on overall survival by using multivariate analysis. RESULTS CHRNA3, CHRNA5, CHRNA7 and CHRNB4, but not CHRNA1, CHRNA4, CHRNA9 or CHRNA10, were found to be expressed in normal (healthy) esophageal mucosa. In ESCC, CHRNA5 and CHRNA7 were overexpressed as compared with patient-matched surrounding non-tumor mucosa (ESCC-adjacent mucosa; P < 0.0001 and P = 0.0091, respectively). Positive correlations were observed between CHRNA3 and CHRNB4 expression in all samples analyzed. Additionally, CHRNB4 was found to be differentially expressed in the healthy esophagus and the normal-appearing ESCC-adjacent mucosa, allowing for distinguishment between these tissues with a sensitivity of 75.86% and a specificity of 78.95% (P = 0.0002). Finally, CHRNA5 expression was identified as an independent prognostic factor in ESCC; patients with high CHRNA5 expression showed an increased overall survival, in comparison with

  12. Impairment of reward-related learning by cholinergic cell ablation in the striatum.

    PubMed

    Kitabatake, Yasuji; Hikida, Takatoshi; Watanabe, Dai; Pastan, Ira; Nakanishi, Shigetada

    2003-06-24

    The striatum in the basal ganglia-thalamocortical circuitry is a key neural substrate that is implicated in motor balance and procedural learning. The projection neurons in the striatum are dynamically modulated by nigrostriatal dopaminergic input and intrastriatal cholinergic input. The role of intrastriatal acetylcholine (ACh) in learning behaviors, however, remains to be fully clarified. In this investigation, we examine the involvement of intrastriatal ACh in different categories of learning by selectively ablating the striatal cholinergic neurons with use of immunotoxin-mediated cell targeting. We show that selective ablation of cholinergic neurons in the striatum impairs procedural learning in the tone-cued T-maze memory task. Spatial delayed alternation in the T-maze learning test is also impaired by cholinergic cell elimination. In contrast, the deficit in striatal ACh transmission has no effect on motor learning in the rota-rod test or spatial learning in the Morris water-maze test or on contextual- and tone-cued conditioning fear responses. We also report that cholinergic cell elimination adaptively up-regulates nicotinic ACh receptors not only within the striatum but also in the cerebral cortex and substantia nigra. The present investigation indicates that cholinergic modulation in the local striatal circuit plays a pivotal role in regulation of neural circuitry involving reward-related procedural learning and working memory. PMID:12802017

  13. Nicotinic cholinergic receptors in rat brain. Annual report No. 3, 1 May 85-30 Apr 86

    SciTech Connect

    Kellar, K.J.

    1986-05-01

    We have compared the characteristics of the recognition sites for 3(H)acetylcholine and 3H(-)nicotine in rat brain and found that the pharmacology, distribution, disulfide bond requirement, and regulation by chronic administration of nicotine and soman are identical. From these studies we conclude that 3Hacetylcholine and 3H(-)nicotine recognize the same recognition site which has the characteristics expected of a nicotinic cholinergic receptor. We have also determined that 3Hacetylcholine of high specific radioactivity (80 Ci/mmol) is an excellent ligand with which to study muscarinic receptors that have high affinity for agonists. These receptors may represent a subtype of muscarinic receptors found in brain, heart, glands, an some smooth muscle. (JS)

  14. The effect of enhancing cholinergic neurotransmission by nicotine on EEG indices of inhibition in the human brain.

    PubMed

    Logemann, H N A; Böcker, K B E; Deschamps, P K H; Kemner, C; Kenemans, J L

    2014-07-01

    The role of the cholinergic system in inhibition remains to be elucidated. Nicotine is a potent tool to augment this system, but most studies investigated its effects solely on behavior. Reference to brain activity is important to specifically identify inhibition-related mechanisms. In the current study the objective was to elucidate the role of the cholinergic system in inhibition. 16 healthy non-smokers performed in a stop task while EEG was recorded. A pre- versus post-treatment, within subjects, placebo controlled, single-blind design was used. It was hypothesized that nicotine would decrease stop-signal reaction time (SSRT) and increase the amplitude of inhibition-related event related potentials, the stop N2 and stop P3. Behavioral measures show nicotine shortened SSRT, but only when pretreatment values were not taken into account. On EEG measures, an enhanced stop P3 under nicotine was found, but only in a subsample sensitive to nicotine based on diastolic blood pressure. The results are indicative of enhanced inhibitory activity possibly reflecting enhanced activation in the superior frontal gyrus. PMID:24690513

  15. Structural characteristics of the recognition site for cholinergic ligands in the nicotinic acetylcholine receptor from squid optical ganglia

    SciTech Connect

    Plyashkevich, Yu.G.; Demushkin, V.P.

    1986-01-20

    The influence of chemical modification on the parameters of the binding of cholinergic ligands by the nicotinic acetylcholine receptor of squid optical ganglia was investigated. The presence of two subpopulations of recognition sites, differing in the composition of the groups contained in them, was detected. It was established with high probability that subpopulation I contains arginine and tyrosine residues and a carboxyl group while subpopulation II contains an amino group, a thyrosine residue, and a carboxyl group. Moreover, in both subpopulations there is an amino group important only for the binding of tubocurarin. On the basis of the results obtained, a model of the recognition sites for cholinergic ligands of the nicotinic acetylcholine receptor of squid optical ganglia is proposed.

  16. Dorsal raphe nucleus acetylcholine-mediated neurotransmission modulates post-ictal antinociception: The role of muscarinic and nicotinic cholinergic receptors.

    PubMed

    de Oliveira, Rithiele Cristina; de Oliveira, Ricardo; Biagioni, Audrey Francisco; Falconi-Sobrinho, Luiz Luciano; Coimbra, Norberto Cysne

    2016-01-15

    The dorsal raphe nucleus (DRN) is a key structure of the endogenous pain inhibitory system. Although the DRN is rich in serotoninergic neurons, cholinergic neurons are also found in that nucleus. Both ictal and inter-ictal states are followed by post-ictal analgesia. The present study investigated the role of cholinergic mechanisms in postictal antinociceptive processes using microinjections of atropine and mecamylamine, muscarinic and nicotinic cholinergic receptor antagonists, respectively, in the DRN of rats. Intraperitoneal injection of pentylenetetrazole (PTZ) (at 64mg/kg) caused tonic and tonic-clonic seizures. The convulsive motor reactions were followed by an increase in pain thresholds, a phenomenon known as post-ictal analgesia. Pre-treatment of the DRN with atropine or mecamylamine at 1µg, 3µg and 5µg/0.2µL decreased the post-ictal antinociceptive phenomenon. The present results showed that the post-ictal analgesia was mediated by muscarinic and nicotinic cholinergic receptors in the DRN, a structure crucially involved in the neural network that organises post-ictal hypoalgesia. PMID:26620541

  17. Involvement of nicotinic and muscarinic receptors in the endogenous cholinergic modulation of the balance between excitation and inhibition in the young rat visual cortex.

    PubMed

    Lucas-Meunier, Estelle; Monier, Cyril; Amar, Muriel; Baux, Gérard; Frégnac, Yves; Fossier, Philippe

    2009-10-01

    This study aims to clarify how endogenous release of cortical acetylcholine (ACh) modulates the balance between excitation and inhibition evoked in visual cortex. We show that electrical stimulation in layer 1 produced a significant release of ACh measured intracortically by chemoluminescence and evoked a composite synaptic response recorded intracellularly in layer 5 pyramidal neurons of rat visual cortex. The pharmacological specificity of the ACh neuromodulation was determined from the continuous whole-cell voltage clamp measurement of stimulation-locked changes of the input conductance during the application of cholinergic agonists and antagonists. Blockade of glutamatergic and gamma-aminobutyric acid (GABAergic) receptors suppressed the evoked response, indicating that stimulation-induced release of ACh does not directly activate a cholinergic synaptic conductance in recorded neurons. Comparison of cytisine and mecamylamine effects on nicotinic receptors showed that excitation is enhanced by endogenous evoked release of ACh through the presynaptic activation of alpha(*)beta4 receptors located on glutamatergic fibers. DHbetaE, the selective alpha4beta2 nicotinic receptor antagonist, induced a depression of inhibition. Endogenous ACh could also enhance inhibition by acting directly on GABAergic interneurons, presynaptic to the recorded cell. We conclude that endogenous-released ACh amplifies the dominance of the inhibitory drive and thus decreases the excitability and sensory responsiveness of layer 5 pyramidal neurons. PMID:19176636

  18. Activation of Alpha 7 Cholinergic Nicotinic Receptors Reduce Blood–Brain Barrier Permeability following Experimental Traumatic Brain Injury

    PubMed Central

    Zhao, Jing; Kobori, Nobuhide; Redell, John B.; Hylin, Michael J.; Hood, Kimberly N.; Moore, Anthony N.

    2016-01-01

    Traumatic brain injury (TBI) is a major human health concern that has the greatest impact on young men and women. The breakdown of the blood–brain barrier (BBB) is an important pathological consequence of TBI that initiates secondary processes, including infiltration of inflammatory cells, which can exacerbate brain inflammation and contribute to poor outcome. While the role of inflammation within the injured brain has been examined in some detail, the contribution of peripheral/systemic inflammation to TBI pathophysiology is largely unknown. Recent studies have implicated vagus nerve regulation of splenic cholinergic nicotinic acetylcholine receptor α7 (nAChRa7) signaling in the regulation of systemic inflammation. However, it is not known whether this mechanism plays a role in TBI-triggered inflammation and BBB breakdown. Following TBI, we observed that plasma TNF-α and IL-1β levels, as well as BBB permeability, were significantly increased in nAChRa7 null mice (Chrna7−/−) relative to wild-type mice. The administration of exogenous IL-1β and TNF-α to brain-injured animals worsened Evans Blue dye extravasation, suggesting that systemic inflammation contributes to TBI-triggered BBB permeability. Systemic administration of the nAChRa7 agonist PNU-282987 or the positive allosteric modulator PNU-120596 significantly attenuated TBI-triggered BBB compromise. Supporting a role for splenic nAChRa7 receptors, we demonstrate that splenic injection of the nicotinic receptor blocker α-bungarotoxin increased BBB permeability in brain-injured rats, while PNU-282987 injection decreased such permeability. These effects were not seen when α-bungarotoxin or PNU-282987 were administered to splenectomized, brain-injured rats. Together, these findings support the short-term use of nAChRa7-activating agents as a strategy to reduce TBI-triggered BBB permeability. SIGNIFICANCE STATEMENT Breakdown of the blood–brain barrier (BBB) in response to traumatic brain injury (TBI

  19. Cholinergic neurotransmission links solitary chemosensory cells to nasal inflammation

    PubMed Central

    Saunders, Cecil J.; Christensen, Michael; Finger, Thomas E.; Tizzano, Marco

    2014-01-01

    Solitary chemosensory cells (SCCs) of the nasal cavity are specialized epithelial chemosensors that respond to irritants through the canonical taste transduction cascade involving Gα-gustducin and transient receptor potential melastatin 5. When stimulated, SCCs trigger peptidergic nociceptive (or pain) nerve fibers, causing an alteration of the respiratory rate indicative of trigeminal activation. Direct chemical excitation of trigeminal pain fibers by capsaicin evokes neurogenic inflammation in the surrounding epithelium. In the current study, we test whether activation of nasal SCCs can trigger similar local inflammatory responses, specifically mast cell degranulation and plasma leakage. The prototypical bitter compound, denatonium, a well-established activator of SCCs, caused significant inflammatory responses in WT mice but not mice with a genetic deletion of elements of the canonical taste transduction cascade, showing that activation of taste signaling components is sufficient to trigger local inflammation. Chemical ablation of peptidergic trigeminal fibers prevented the SCC-induced nasal inflammation, indicating that SCCs evoke inflammation only by neural activity and not by release of local inflammatory mediators. Additionally, blocking nicotinic, but not muscarinic, acetylcholine receptors prevents SCC-mediated neurogenic inflammation for both denatonium and the bacterial signaling molecule 3-oxo-C12-homoserine lactone, showing the necessity for cholinergic transmission. Finally, we show that the neurokinin 1 receptor for substance P is required for SCC-mediated inflammation, suggesting that release of substance P from nerve fibers triggers the inflammatory events. Taken together, these results show that SCCs use cholinergic neurotransmission to trigger peptidergic trigeminal nociceptors, which link SCCs to the neurogenic inflammatory pathway. PMID:24711432

  20. Targeting the Nicotinic Cholinergic System to Treat Attention-Deficit/Hyperactivity Disorder: Rationale and Progress to Date

    PubMed Central

    Potter, Alexandra S.; Schaubhut, Geoffrey; Shipman, Megan

    2014-01-01

    Attention-Deficit/Hyperactivity Disorder (ADHD) is a common, chronic neurobehavioral disorder related to clinically significant levels of inattention, hyperactivity and/or impulsivity. ADHD begins in childhood and symptoms persist into adulthood for the majority of those with the disorder. Associated features of ADHD include emotion dysregulation and cognitive impairments which contribute to the considerable functional impairments in this disorder. Current approved treatments are reasonably effective however a significant need remains for new pharmacotherapies, both for individuals who do not achieve a full therapeutic response and for symptoms that are under-treated including cognition and emotion regulation. The striking relationship between ADHD and cigarette smoking and the known effects of nicotine on cognition has spurred research into the therapeutic potential of nicotinic agents for ADHD. Although there are no approved medications for ADHD that target nicotinic acetylcholine receptor (nAChR) function, results from many trials of nicotinic drugs are available and reviewed in this article. ADHD symptoms were reduced in the majority of published studies of nicotine and novel α4β2 nicotinic agonists in adult ADHD. The drugs were generally well tolerated, with mild to moderate side effects reported, which were largely consistent with cholinergic stimulation and included nausea, dizziness, and gastrointestinal distress. Within-subject crossover study designs were used in the majority of positive studies. This design may be particularly useful in ADHD trials because it minimizes variability in this notoriously heterogeneous diagnostic group. In addition, many studies found evidence for a beneficial effect of nicotinic stimulation on cognitive and emotional domains. Thus, targeting nAChRs in ADHD appears to have modest clinical benefit in adult ADHD. Continued refinement of nAChR agonists with greater specificity and fewer side effects may lead to even more

  1. Neural Stem Cell Transplant-Induced Effect on Neurogenesis and Cognition in Alzheimer Tg2576 Mice Is Inhibited by Concomitant Treatment with Amyloid-Lowering or Cholinergic α7 Nicotinic Receptor Drugs

    PubMed Central

    Lilja, Anna M.; Malmsten, Linn; Röjdner, Jennie; Voytenko, Larysa; Verkhratsky, Alexei; Ögren, Sven Ove; Nordberg, Agneta; Marutle, Amelia

    2015-01-01

    Stimulating regeneration in the brain has the potential to rescue neuronal networks and counteract progressive pathological changes in Alzheimer's disease (AD). This study investigated whether drugs with different mechanisms of action could enhance neurogenesis and improve cognition in mice receiving human neural stem cell (hNSC) transplants. Six- to nine-month-old AD Tg2576 mice were treated for five weeks with the amyloid-modulatory and neurotrophic drug (+)-phenserine or with the partial α7 nicotinic receptor (nAChR) agonist JN403, combined with bilateral intrahippocampal hNSC transplantation. We observed improved spatial memory in hNSC-transplanted non-drug-treated Tg2576 mice but not in those receiving drugs, and this was accompanied by an increased number of Doublecortin- (DCX-) positive cells in the dentate gyrus, a surrogate marker for newly generated neurons. Treatment with (+)-phenserine did however improve graft survival in the hippocampus. An accumulation of α7 nAChR-expressing astrocytes was observed around the injection site, suggesting their involvement in repair and scarring processes. Interestingly, JN403 treatment decreased the number of α7 nAChR-expressing astrocytes, correlating with a reduction in the number of DCX-positive cells in the dentate gyrus. We conclude that transplanting hNSCs enhances endogenous neurogenesis and prevents further cognitive deterioration in Tg2576 mice, while simultaneous treatments with (+)-phenserine or JN403 result in countertherapeutic effects. PMID:26257960

  2. Analysis of cyclic and acyclic nicotinic cholinergic agonists using radioligand binding, single channel recording, and nuclear magnetic resonance spectroscopy.

    PubMed Central

    McGroddy, K A; Carter, A A; Tubbert, M M; Oswald, R E

    1993-01-01

    The relationship between the structure and function of a series of nicotinic cholinergic agonists has been studied using radioligand binding, single channel recording, and nuclear magnetic resonance spectroscopy. The cyclic compound 1,1-dimethyl-4-acetylpiperazinium iodide and its trifluoromethyl analogue (F3-PIP) interact with nicotinic acetylcholine receptors (nAChRs) from both Torpedo electroplaque and BC3H-1 cells at lower concentrations than the acyclic derivatives, N,N,N,N'-tetramethyl-N'-acetylethylenediamine iodide and its fluorinated analogue (F3-TED). The magnitude of the difference in potencies depends on the type of measurement. In binding experiments, the differences between the two classes of compounds depends mainly on the conditions of the experiment. In measurements of the initial interaction with the nAChR, the PIP compounds have an affinity approximately one order of magnitude higher than that of the TED compounds. Longer incubations indicated that the PIP compounds were able to induce a time-dependent shift in receptor affinity consistent with desensitization, whereas the TED compounds were unable to induce such a shift. The activation of single channel currents by the cyclic compounds occurs at concentrations approximately two orders of magnitude lower than for the acyclic compounds, but the TED compounds exhibit a larger degree of channel blockade than the PIP compounds. Previous work (McGroddy, K.A., and R.E. Oswald. 1992. Biophys. J. 64:314-324) has shown that the TED compounds can exist in two energetically distinct conformational states related by an isomerization of the amide bond. 19F nuclear magnetic resonance experiments suggest that the higher energy population of the TED compounds may interact preferentially with the ACh binding sites on the nAChRs and that a significant fraction of the difference between the initial affinity of the PIP and TED compounds may be accounted for by the predominance in solution of a conformational state

  3. Blockade of cholinergic transmission elicits somatic signs in nicotine-naïve adolescent rats

    PubMed Central

    Schmidt, Clare E.; Manbeck, Katherine E.; Shelley, David; Harris, Andrew C.

    2015-01-01

    High doses of the nicotinic acetylcholine receptor (nAChR) antagonist mecamylamine can elicit somatic signs resembling those associated with nicotine withdrawal in nicotine-naïve adult rats. Understanding this phenomenon, and its possible modulation by acute nicotine and age, could inform the use of mecamylamine as both an experimental tool and potential pharmacotherapy for tobacco dependence and other disorders. This study evaluated the ability of high-dose mecamylamine to elicit somatic signs in adolescent rats, and the potential for acute nicotine pretreatment to potentiate this effect as previously reported in adults. Single or repeated injections of mecamylamine (1.5 or 3.0 mg/kg, s.c.) elicited somatic signs in nicotine-naïve adolescents, but this effect was not influenced by 2 h pretreatment with acute nicotine (0.5 mg/kg, s.c.). In an initial evaluation of the effects of age in this model, mecamylamine (2.25 mg/kg, s.c.) elicited somatic signs in nicotine-naïve adolescents and adults. This effect was modestly enhanced following acute nicotine injections in adults but not in adolescents, even when a higher nicotine dose (1.0 rather than 0.5 mg/kg, s.c.) was used in adolescents to account for age differences in nicotine pharmacokinetics. These studies are the first to show that mecamylamine elicits somatic signs in nicotine-naïve adolescent rats, an effect that should be considered when designing and interpreting studies examining effects of high doses of mecamylamine in adolescents. Our findings also provide preliminary evidence that these signs may be differentially modulated by acute nicotine pretreatment in adolescents versus adults. PMID:26539119

  4. Cholinergic activation enhances retinoic acid-induced differentiation in the human NB-4 acute promyelocytic leukemia cell line.

    PubMed

    Chotirat, Sadudee; Suriyo, Tawit; Hokland, Marianne; Hokland, Peter; Satayavivad, Jutamaad; Auewarakul, Chirayu U

    2016-07-01

    The non-neuronal cholinergic system (NNCS) has been shown to play a role in regulating hematopoietic differentiation. We determined the expression of cholinergic components in leukemic cell lines by Western blotting and in normal leukocyte subsets by flow cytometry and found a heterogeneous expression of choline acetyltransferase (ChAT), acetylcholinesterase (AChE), choline transporter (CHT), M3 muscarinic acetylcholine receptor (M3-mAChR) and α7 nicotinic acetylcholine receptor (α7-nAChR). We then evaluated NNCS role in differentiation of human NB-4 acute promyelocytic leukemia cell line and discovered a dramatic induction of M3-mAChR after all-trans retinoic acid (ATRA) treatment (p<0.0001). Adding carbachol which is a cholinergic agonist to the ATRA treatment resulted in an increase of a granulocytic differentiation marker (CD11b) as compared with ATRA treatment alone (p<0.05), indicating that cholinergic activation enhanced ATRA in inducing NB-4 maturation. The combination of carbachol and ATRA treatment for 72h also resulted in decreased viability and increased cleaved caspase-3 expression when compared with ATRA treatment alone (p<0.05). However, this combination did not cause poly (ADP-ribose) polymerase (PARP) cleavage. Overall, we have shown that NB-4 cells expressed M3-mAChR in a differentiation-dependent manner and cholinergic stimulation induced maturation and death of ATRA-induced differentiated NB-4 cells. PMID:27282572

  5. Cholinergic modulation of the medial prefrontal cortex: the role of nicotinic receptors in attention and regulation of neuronal activity

    PubMed Central

    Bloem, Bernard; Poorthuis, Rogier B.; Mansvelder, Huibert D.

    2014-01-01

    Acetylcholine (ACh) release in the medial prefrontal cortex (mPFC) is crucial for normal cognitive performance. Despite the fact that many have studied how ACh affects neuronal processing in the mPFC and thereby influences attention behavior, there is still a lot unknown about how this occurs. Here we will review the evidence that cholinergic modulation of the mPFC plays a role in attention and we will summarize the current knowledge about the role between ACh receptors (AChRs) and behavior and how ACh receptor activation changes processing in the cortical microcircuitry. Recent evidence implicates fast phasic release of ACh in cue detection and attention. This review will focus mainly on the fast ionotropic nicotinic receptors and less on the metabotropic muscarinic receptors. Finally, we will review limitations of the existing studies and address how innovative technologies might push the field forward in order to gain understanding into the relation between ACh, neuronal activity and behavior. PMID:24653678

  6. Neuroanatomical and neuropharmacological approaches to postictal antinociception-related prosencephalic neurons: the role of muscarinic and nicotinic cholinergic receptors.

    PubMed

    de Freitas, Renato Leonardo; Bolognesi, Luana Iacovelo; Twardowschy, André; Corrêa, Fernando Morgan Aguiar; Sibson, Nicola R; Coimbra, Norberto Cysne

    2013-05-01

    Several studies have suggested the involvement of the hippocampus in the elaboration of epilepsy. There is evidence that suggests the hippocampus plays an important role in the affective and motivational components of nociceptive perception. However, the exact nature of this involvement remains unclear. Therefore, the aim of this study was to determine the role of muscarinic and nicotinic cholinergic receptors in the dorsal hippocampus (dH) in the organization of postictal analgesia. In a neuroanatomical study, afferent connections were found from the somatosensory cortex, the medial septal area, the lateral septal area, the diagonal band of Broca, and the dentate gyrus to the dH; all these areas have been suggested to modulate convulsive activity. Outputs to the dH were also identified from the linear raphe nucleus, the median raphe nucleus (MdRN), the dorsal raphe nucleus, and the locus coeruleus. All these structures comprise the endogenous pain modulatory system and may be involved either in postictal pronociception or antinociception that is commonly reported by epileptic patients. dH-pretreatment with cobalt chloride (1.0 mmol/L CoCl2/0.2 μL) to transiently inhibit local synapses decreased postictal analgesia 10 min after the end of seizures. Pretreatment of the dH with either atropine or mecamylamine (1.0 μg/0.2 μL) attenuated the postictal antinociception 30 min after seizures, while the higher dose (5.0 μg/0.2 μL) decreased postictal analgesia immediately after the end of seizures. These findings suggest that the dH exerts a critical role in the organization of postictal analgesia and that muscarinic and nicotinic cholinergic receptor-mediated mechanisms in the dH are involved in the elaboration of antinociceptive processes induced by generalized tonic-clonic seizures. PMID:23785660

  7. Neuroanatomical and neuropharmacological approaches to postictal antinociception-related prosencephalic neurons: the role of muscarinic and nicotinic cholinergic receptors

    PubMed Central

    de Freitas, Renato Leonardo; Bolognesi, Luana Iacovelo; Twardowschy, André; Corrêa, Fernando Morgan Aguiar; Sibson, Nicola R; Coimbra, Norberto Cysne

    2013-01-01

    Several studies have suggested the involvement of the hippocampus in the elaboration of epilepsy. There is evidence that suggests the hippocampus plays an important role in the affective and motivational components of nociceptive perception. However, the exact nature of this involvement remains unclear. Therefore, the aim of this study was to determine the role of muscarinic and nicotinic cholinergic receptors in the dorsal hippocampus (dH) in the organization of postictal analgesia. In a neuroanatomical study, afferent connections were found from the somatosensory cortex, the medial septal area, the lateral septal area, the diagonal band of Broca, and the dentate gyrus to the dH; all these areas have been suggested to modulate convulsive activity. Outputs to the dH were also identified from the linear raphe nucleus, the median raphe nucleus (MdRN), the dorsal raphe nucleus, and the locus coeruleus. All these structures comprise the endogenous pain modulatory system and may be involved either in postictal pronociception or antinociception that is commonly reported by epileptic patients. dH-pretreatment with cobalt chloride (1.0 mmol/L CoCl2/0.2 μL) to transiently inhibit local synapses decreased postictal analgesia 10 min after the end of seizures. Pretreatment of the dH with either atropine or mecamylamine (1.0 μg/0.2 μL) attenuated the postictal antinociception 30 min after seizures, while the higher dose (5.0 μg/0.2 μL) decreased postictal analgesia immediately after the end of seizures. These findings suggest that the dH exerts a critical role in the organization of postictal analgesia and that muscarinic and nicotinic cholinergic receptor-mediated mechanisms in the dH are involved in the elaboration of antinociceptive processes induced by generalized tonic-clonic seizures. PMID:23785660

  8. Nicotine increases impulsivity and decreases willingness to exert cognitive effort despite improving attention in "slacker" rats: insights into cholinergic regulation of cost/benefit decision making.

    PubMed

    Hosking, Jay G; Lam, Fred C W; Winstanley, Catharine A

    2014-01-01

    Successful decision making in our daily lives requires weighing an option's costs against its associated benefits. The neuromodulator acetylcholine underlies both the etiology and treatment of a number of illnesses in which decision making is perturbed, including Alzheimer's disease, attention-deficit/hyperactivity disorder, and schizophrenia. Nicotine acts on the cholinergic system and has been touted as a cognitive enhancer by both smokers and some researchers for its attention-boosting effects; however, it is unclear whether treatments that have a beneficial effect on attention would also have a beneficial effect on decision making. Here we utilize the rodent Cognitive Effort Task (rCET), wherein animals can choose to allocate greater visuospatial attention for a greater reward, to examine cholinergic contributions to both attentional performance and choice based on attentional demand. Following the establishment of baseline behavior, four drug challenges were administered: nicotine, mecamylamine, scopolamine, and oxotremorine (saline plus three doses for each). As per previous rCET studies, animals were divided by their baseline preferences, with "worker" rats choosing high-effort/high-reward options more than their "slacker" counterparts. Nicotine caused slackers to choose even fewer high-effort trials than at baseline, but had no effect on workers' choice. Despite slackers' decreased willingness to expend effort, nicotine improved their attentional performance on the task. Nicotine also increased measures of motor impulsivity in all animals. In contrast, scopolamine decreased animals' choice of high-effort trials, especially for workers, while oxotremorine decreased motor impulsivity for all animals. In sum, the cholinergic system appears to contribute to decision making, and in part these contributions can be understood as a function of individual differences. While nicotine has been considered as a cognitive enhancer, these data suggest that its modest

  9. IL-4 Induces Cholinergic Differentiation of Retinal Cells In Vitro.

    PubMed

    Granja, Marcelo Gomes; Braga, Luis Eduardo Gomes; Carpi-Santos, Raul; de Araujo-Martins, Leandro; Nunes-Tavares, Nilson; Calaza, Karin C; Dos Santos, Aline Araujo; Giestal-de-Araujo, Elizabeth

    2015-07-01

    Interleukin-4 (IL-4) is a pleiotropic cytokine that regulates several phenomena, among them survival and differentiation of neuronal and glial cells. The aim of this work was to investigate the effect of IL-4 on the cholinergic differentiation of neonatal rat retinal cells in vitro, evaluating its effect on the levels of cholinergic markers (CHT1-high-affinity choline transporter; VAChT-vesicular acetylcholine transporter, ChAT-choline acetyltransferase, AChE-acetylcholinesterase), muscarinic receptors, and on the signaling pathways involved. Lister Hooded rat pups were used in postnatal days 0-2 (P0-P2). Our results show that IL-4 treatment (50 U/mL) for 48 h increases the levels of the cholinergic transporters VAChT and CHT1, the acetylcholinesterase activity, and the number of ChAT-positive cells. It also induces changes in muscarinic receptor levels, leading to a small decrease in M1 levels and a significant increase in M3 and M5 levels after 48 h of treatment. We also showed that IL-4 effect on M3 receptors is dependent on type I IL-4 receptor and on an increase in NFκB phosphorylation. These results indicate that IL-4 stimulates cholinergic differentiation of retinal cells. PMID:25682112

  10. Genetic Risk For Nicotine Dependence in the Cholinergic System and Activation of the Brain Reward System in Healthy Adolescents

    PubMed Central

    Nees, F; Witt, S H; Lourdusamy, A; Vollstädt-Klein, S; Steiner, S; Poustka, L; Banaschewski, T; Barker, G J; Büchel, C; Conrod, P J; Frank, J; Gallinat, J; Garavan, H; Heinz, A; Ittermann, B; Loth, E; Mann, K; Artiges, E; Paus, T; Pausova, Z; Smolka, M N; Struve, M; Schumann, G; Rietschel, M; Flor, H

    2013-01-01

    Genetic variation in a genomic region on chromosome 15q25.1, which encodes the alpha5, alpha3, and beta4 subunits of the cholinergic nicotinic receptor genes, confers risk to smoking and nicotine dependence (ND). Neural reward-related responses have previously been identified as important factors in the development of drug dependence involving ND. Applying an imaging genetics approach in two cohorts (N=487; N=478) of healthy non-smoking adolescents, we aimed to elucidate the impact of genome-wide significant smoking-associated variants in the CHRNA5–CHRNA3–CHRNB4 gene cluster on reward-related neural responses in central regions such as the striatum, orbitofrontal and anterior cingulate cortex (ACC), and personality traits related to addiction. In both samples, carriers of the rs578776 GG compared with AG/AA genotype showed a significantly lower neural response to reward outcomes in the right ventral and dorsal ACC but not the striatum or the orbitofrontal cortex. Rs578776 was unrelated to neural reward anticipation or reward magnitude. Significantly higher scores of anxiety sensitivity in GG compared with AG/AA carriers were found only in sample 1. Associations with other personality traits were not observed. Our findings suggest that the rs578776 risk variant influences susceptibility to ND by dampening the response of the ACC to reward feedback, without recruiting the striatum or orbitofrontal cortex during feedback or anticipation. Thus, it seems to have a major role in the processing of and behavioral adaptation to changing reward outcomes. PMID:23689675

  11. Genetic risk for nicotine dependence in the cholinergic system and activation of the brain reward system in healthy adolescents.

    PubMed

    Nees, F; Witt, S H; Lourdusamy, A; Vollstädt-Klein, S; Steiner, S; Poustka, L; Banaschewski, T; Barker, G J; Büchel, C; Conrod, P J; Frank, J; Gallinat, J; Garavan, H; Heinz, A; Ittermann, B; Loth, E; Mann, K; Artiges, E; Paus, T; Pausova, Z; Smolka, M N; Struve, M; Schumann, G; Rietschel, M; Flor, H

    2013-10-01

    Genetic variation in a genomic region on chromosome 15q25.1, which encodes the alpha5, alpha3, and beta4 subunits of the cholinergic nicotinic receptor genes, confers risk to smoking and nicotine dependence (ND). Neural reward-related responses have previously been identified as important factors in the development of drug dependence involving ND. Applying an imaging genetics approach in two cohorts (N=487; N=478) of healthy non-smoking adolescents, we aimed to elucidate the impact of genome-wide significant smoking-associated variants in the CHRNA5-CHRNA3-CHRNB4 gene cluster on reward-related neural responses in central regions such as the striatum, orbitofrontal and anterior cingulate cortex (ACC), and personality traits related to addiction. In both samples, carriers of the rs578776 GG compared with AG/AA genotype showed a significantly lower neural response to reward outcomes in the right ventral and dorsal ACC but not the striatum or the orbitofrontal cortex. Rs578776 was unrelated to neural reward anticipation or reward magnitude. Significantly higher scores of anxiety sensitivity in GG compared with AG/AA carriers were found only in sample 1. Associations with other personality traits were not observed. Our findings suggest that the rs578776 risk variant influences susceptibility to ND by dampening the response of the ACC to reward feedback, without recruiting the striatum or orbitofrontal cortex during feedback or anticipation. Thus, it seems to have a major role in the processing of and behavioral adaptation to changing reward outcomes. PMID:23689675

  12. Distribution of cholinergic cells in guinea pig brainstem

    PubMed Central

    Motts, S.D.; Slusarczyk, A.S.; Sowick, C.S.; Schofield, B.R.

    2008-01-01

    We used an antibody to choline acetyltransferase (ChAT) to label cholinergic cells in guinea pig brainstem. ChAT-immunoreactive (ChAT-IR) cells comprise several prominent groups, including the pedunculopontine tegmental nucleus, laterodorsal tegmental nucleus, and parabigeminal nucleus, as well as the cranial nerve somatic motor and parasympathetic nuclei. Additional concentrations are present in the parabrachial nuclei and superior colliculus. Among auditory nuclei, the majority of ChAT-IR cells are in the superior olive, particularly in and around the lateral superior olive, the ventral nucleus of the trapezoid body and the superior paraolivary nucleus. A discrete group of ChAT-IR cells is located in the sagulum, and additional cells are scattered in the nucleus of the brachium of the inferior colliculus. A group of ChAT-IR cells lies dorsal to the dorsal nucleus of the lateral lemniscus. A few ChAT-IR cells are found in the cochlear nucleus and the ventral nucleus of the lateral lemniscus. The distribution of cholinergic cells in guinea pigs is largely similar to that of other species; differences occur mainly in cell groups that have few ChAT-IR cells. The results provide a basis for further studies to characterize the connections of these cholinergic groups. PMID:18222049

  13. Onset of cholinergic efferent synaptic function in sensory hair cells of the rat cochlea.

    PubMed

    Roux, Isabelle; Wersinger, Eric; McIntosh, J Michael; Fuchs, Paul A; Glowatzki, Elisabeth

    2011-10-19

    In the developing mammalian cochlea, the sensory hair cells receive efferent innervation originating in the superior olivary complex. This input is mediated by α9/α10 nicotinic acetylcholine receptors (nAChRs) and is inhibitory due to the subsequent activation of calcium-dependent SK2 potassium channels. We examined the acquisition of this cholinergic efferent input using whole-cell voltage-clamp recordings from inner hair cells (IHCs) in acutely excised apical turns of the rat cochlea from embryonic day 21 to postnatal day 8 (P8). Responses to 1 mm acetylcholine (ACh) were detected from P0 on in almost every IHC. The ACh-activated current amplitude increased with age and demonstrated the same pharmacology as α9-containing nAChRs. Interestingly, at P0, the ACh response was not coupled to SK2 channels, so that the initial cholinergic response was excitatory and could trigger action potentials in IHCs. Coupling to SK current was detected earliest at P1 in a subset of IHCs and by P3 in every IHC studied. Clustered nAChRs and SK2 channels were found on IHCs from P1 on using Alexa Fluor 488 conjugated α-bungarotoxin and SK2 immunohistochemistry. The number of nAChRs clusters increased with age to 16 per IHC at P8. Cholinergic efferent synaptic currents first appeared in a subset of IHCs at P1 and by P3 in every IHC studied, contemporaneously with ACh-evoked SK currents, suggesting that SK2 channels may be necessary at onset of synaptic function. An analogous pattern of development was observed for the efferent synapses that form later (P6-P8) on outer hair cells in the basal cochlea. PMID:22016543

  14. Requisite Role of the Cholinergic α7 Nicotinic Acetylcholine Receptor Pathway in Suppressing Gram-Negative Sepsis-Induced Acute Lung Inflammatory Injury

    PubMed Central

    Su, Xiao; Matthay, Michael A.; Malik, Asrar B.

    2010-01-01

    Although activation of the α7 nicotinic acetylcholine receptor (α7 nAChR) modulates the response to sepsis, the role of this pathway in the development of sepsis-induced acute lung injury (ALI) is not known. In this study, we addressed the contribution of α7 nAChR in mediating endotoxin- and live Escherichia coli–induced ALI in mice. Because we found that α7 nAChR+ alveolar macrophages and neutrophils were present in bronchoalveolar lavage and injured lungs of mice, we tested whether acetylcholine released by lung vagal innervation stimulated these effector cells and thereby down-regulated proinflammatory chemokine/cytokine generation. Administration of α7 nAChR agonists reduced bronchoalveolar lavage MIP-2 production and transalveolar neutrophil migration and reduced mortality in E. coli pneumonia mice, whereas vagal denervation increased MIP-2 production and airway neutrophil accumulation and increased mortality. In addition, α7 nAChR−/− mice developed severe lung injury and had higher mortality compared with α7 nAChR+/+ mice. The immunomodulatory cholinergic α7 nAChR pathway of alveolar macrophages and neutrophils blocked LPS- and E. coli–induced ALI by reducing chemokine production and transalveolar neutrophil migration, suggesting that activation of α7 nAChR may be a promising strategy for treatment of sepsis-induced ALI. PMID:19949071

  15. Central Muscarinic Cholinergic Activation Alters Interaction between Splenic Dendritic Cell and CD4+CD25- T Cells in Experimental Colitis

    PubMed Central

    Pavlov, Valentin A.; Tracey, Kevin J.; Khafipour, Ehsan; Ghia, Jean-Eric

    2014-01-01

    Background The cholinergic anti-inflammatory pathway (CAP) is based on vagus nerve (VN) activity that regulates macrophage and dendritic cell responses in the spleen through alpha-7 nicotinic acetylcholine receptor (a7nAChR) signaling. Inflammatory bowel disease (IBD) patients present dysautonomia with decreased vagus nerve activity, dendritic cell and T cell over-activation. The aim of this study was to investigate whether central activation of the CAP alters the function of dendritic cells (DCs) and sequential CD4+/CD25−T cell activation in the context of experimental colitis. Methods The dinitrobenzene sulfonic acid model of experimental colitis in C57BL/6 mice was used. Central, intracerebroventricular infusion of the M1 muscarinic acetylcholine receptor agonist McN-A-343 was used to activate CAP and vagus nerve and/or splenic nerve transection were performed. In addition, the role of α7nAChR signaling and the NF-kB pathway was studied. Serum amyloid protein (SAP)-A, colonic tissue cytokines, IL-12p70 and IL-23 in isolated splenic DCs, and cytokines levels in DC-CD4+CD25−T cell co-culture were determined. Results McN-A-343 treatment reduced colonic inflammation associated with decreased pro-inflammatory Th1/Th17 colonic and splenic cytokine secretion. Splenic DCs cytokine release was modulated through α7nAChR and the NF-kB signaling pathways. Cholinergic activation resulted in decreased CD4+CD25−T cell priming. The anti-inflammatory efficacy of central cholinergic activation was abolished in mice with vagotomy or splenic neurectomy. Conclusions Suppression of splenic immune cell activation and altered interaction between DCs and T cells are important aspects of the beneficial effect of brain activation of the CAP in experimental colitis. These findings may lead to improved therapeutic strategies in the treatment of IBD. PMID:25295619

  16. Nicotinic α4 Receptor-Mediated Cholinergic Influences on Food Intake and Activity Patterns in Hypothalamic Circuits

    PubMed Central

    Schaaf, Laura; Heeley, Nicholas; Heuschmid, Lena; Bai, Yunjing; Barrantes, Francisco J.; Apergis-Schoute, John

    2015-01-01

    Nicotinic acetylcholine receptors (nAChRs) play an important role in regulating appetite and have been shown to do so by influencing neural activity in the hypothalamus. To shed light on the hypothalamic circuits governing acetylcholine’s (ACh) regulation of appetite this study investigated the influence of hypothalamic nAChRs expressing the α4 subunit. We found that antagonizing the α4β2 nAChR locally in the lateral hypothalamus with di-hydro-ß-erythroidine (DHβE), an α4 nAChR antagonist with moderate affinity, caused an increase in food intake following free access to food after a 12 hour fast, compared to saline-infused animals. Immunocytochemical analysis revealed that orexin/hypocretin (HO), oxytocin, and tyrosine hydroxylase (TH)-containing neurons in the A13 and A12 of the hypothalamus expressed the nAChR α4 subunit in varying amounts (34%, 42%, 50%, and 51%, respectively) whereas melanin concentrating hormone (MCH) neurons did not, suggesting that DHβE-mediated increases in food intake may be due to a direct activation of specific hypothalamic circuits. Systemic DHβE (2 mg/kg) administration similarly increased food intake following a 12 hour fast. In these animals a subpopulation of orexin/hypocretin neurons showed elevated activity compared to control animals and MCH neuronal activity was overall lower as measured by expression of the immediate early gene marker for neuronal activity cFos. However, oxytocin neurons in the paraventricular hypothalamus and TH-containing neurons in the A13 and A12 did not show differential activity patterns. These results indicate that various neurochemically distinct hypothalamic populations are under the influence of α4β2 nAChRs and that cholinergic inputs to the lateral hypothalamus can affect satiety signals through activation of local α4β2 nAChR-mediated transmission. PMID:26247203

  17. Nicotine induces fibrogenic changes in human liver via nicotinic acetylcholine receptors expressed on hepatic stellate cells

    SciTech Connect

    Soeda, Junpei; Morgan, Maelle; McKee, Chad; Mouralidarane, Angelina; Lin, ChingI; Roskams, Tania; Oben, Jude A.

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Cigarette smoke may induce liver fibrosis via nicotine receptors. Black-Right-Pointing-Pointer Nicotine induces proliferation of hepatic stellate cells (HSCs). Black-Right-Pointing-Pointer Nicotine activates hepatic fibrogenic pathways. Black-Right-Pointing-Pointer Nicotine receptor antagonists attenuate HSC proliferation. Black-Right-Pointing-Pointer Nicotinic receptor antagonists may have utility as novel anti-fibrotic agents. -- Abstract: Background and aims: Cigarette smoke (CS) may cause liver fibrosis but possible involved mechanisms are unclear. Among the many chemicals in CS is nicotine - which affects cells through nicotinic acetylcholine receptors (nAChR). We studied the effects of nicotine, and involved pathways, on human primary hepatic stellate cells (hHSCs), the principal fibrogenic cells in the liver. We then determined possible disease relevance by assaying nAChR in liver samples from human non-alcoholic steatohepatitis (NASH). Methods: hHSC were isolated from healthy human livers and nAChR expression analyzed - RT-PCR and Western blotting. Nicotine induction of hHSC proliferation, upregulation of collagen1-{alpha}2 and the pro-fibrogenic cytokine transforming growth factor beta 1 (TGF-{beta}1) was determined along with involved intracellular signaling pathways. nAChR mRNA expression was finally analyzed in whole liver biopsies obtained from patients diagnosed with non-alcoholic steatohepatitis (NASH). Results: hHSCs express muscle type ({alpha}1, {beta}1, delta and epsilon) and neuronal type ({alpha}3, {alpha}6, {alpha}7, {beta}2 and {beta}4) nAChR subunits at the mRNA level. Among these subunits, {alpha}3, {alpha}7, {beta}1 and {epsilon} were predominantly expressed as confirmed by Western blotting. Nicotine induced hHSC proliferation was attenuated by mecamylamine (p < 0.05). Additionally, collagen1-{alpha}2 and TGF-{beta}1 mRNA expression were significantly upregulated by nicotine and inhibited by

  18. Identification, characterization, and regulation of a nicotinic acetylcholine receptor on bovine adrenal chromaffin cells in culture

    SciTech Connect

    Higgins, L.S.

    1988-01-01

    Synaptic input to bovine adrenal chromaffin cells is mediated by nicotinic acetylcholine receptors (AChRs) and results in secretion of catecholamines. Three probes previously shown to recognize AChRs on neurons were used to identify the AChR on bovine adrenal chromaffin cells in culture: monoclonal antibody mAb 35, a toxin that blocks receptor function, and the agonist nicotine. Competition for {sup 3}H-nicotine binding was used to measure the affinity of cholinergic ligands, and revealed the pharmacological profile expected for a neuronal-type AChR. At steady state the rate both of receptor insertion into and loss from the plasma membrane is about 3%/hour, resulting in a half-life in the surface of about 24 hours. Exposure to the anti-AChR antibody results in a loss of AChRs from the surface of the cells through a process that has the characteristics of antigenic modulation. The number of AChRs on the surface of the chromaffin cells can also be modulated by agonists and hormones, including glucocotricoids. Catecholamines, three peptides that may be secreted by chromaffin cells, and K{sup +}-induced secretion reduce agonist-induced catecholamine release by decreasing the number of AChRs, providing a mechanism for autoregulation.

  19. Modulation of muscarinic and micotinic cholinergic receptor mediated catecholamine secretion in guinea pig chromaffin cells by phorbol esters

    SciTech Connect

    Figueiredo, J.C.; Fisher, S.K.; Horowitz, M.I.

    1986-05-01

    Isolated guinea pig chromaffin cells possess both nicotinic (nAChR) and muscarinic (mAChR) cholinergic receptors that are positively coupled to catecholamine (CA) release. Sixty to 70% of CA release is mediated by nAChRs and 30-40% by mAChRs. In the absence of added calcium, nAChR mediated CA release was reduced by 65% whereas the muscarinic response was unaffected. The addition of 100nM 12-0-tetradecanoylphorbol-13-acetate (TPA), an activator of protein kinase C (PKC), also resulted in an increased CA release. Temporally and quantitatively, this response resembled that of mAChR activation. Addition of optimal concentrations of nicotine (50..mu..M) and TPA (100nM) induced a synergistic increase in CA release. Addition of muscarine (1mM) and TPA resulted in an additive response despite a 40-60% inhibition of mAChR mediated inositol phosphate release by TPA. Thus, in guinea pig chromaffin cells, it appears that PKC activation alone is a sufficient stimulus for CA release and that activation of both nicotinic and muscarinic receptors may further increase this enzyme's activity.

  20. Cholinergic urethral brush cells are widespread throughout placental mammals.

    PubMed

    Deckmann, Klaus; Krasteva-Christ, Gabriela; Rafiq, Amir; Herden, Christine; Wichmann, Judy; Knauf, Sascha; Nassenstein, Christina; Grevelding, Christoph G; Dorresteijn, Adriaan; Chubanov, Vladimir; Gudermann, Thomas; Bschleipfer, Thomas; Kummer, Wolfgang

    2015-11-01

    We previously identified a population of cholinergic epithelial cells in murine, human and rat urethrae that exhibits a structural marker of brush cells (villin) and expresses components of the canonical taste transduction signaling cascade (α-gustducin, phospholipase Cβ2 (PLCβ2), transient receptor potential cation channel melanostatin 5 (TRPM5)). These cells serve as sentinels, monitoring the chemical composition of the luminal content for potentially hazardous compounds such as bacteria, and initiate protective reflexes counteracting further ingression. In order to elucidate cross-species conservation of the urethral chemosensory pathway we investigated the occurrence and molecular make-up of urethral brush cells in placental mammals. We screened 11 additional species, at least one in each of the five mammalian taxonomic units primates, carnivora, perissodactyla, artiodactyla and rodentia, for immunohistochemical labeling of the acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT), villin, and taste cascade components (α-gustducin, PLCβ2, TRPM5). Corresponding to findings in previously investigated species, urethral epithelial cells with brush cell shape were immunolabeled in all 11 mammals. In 8 species, immunoreactivities against all marker proteins and ChAT were observed, and double-labeling immunofluorescence confirmed the cholinergic nature of villin-positive and chemosensory (TRPM5-positive) cells. In cat and horse, these cells were not labeled by the ChAT antiserum used in this study, and unspecific reactions of the secondary antiserum precluded conclusions about ChAT-expression in the bovine epithelium. These data indicate that urethral brush cells are widespread throughout the mammalian kingdom and evolved not later than about 64.5millionyears ago. PMID:26044348

  1. Cholinergic Enhancement of Cell Proliferation in the Postnatal Neurogenic Niche of the Mammalian Spinal Cord

    PubMed Central

    Corns, Laura F.; Atkinson, Lucy; Daniel, Jill; Edwards, Ian J.; New, Lauryn

    2015-01-01

    Abstract The region surrounding the central canal (CC) of the spinal cord is a highly plastic area, defined as a postnatal neurogenic niche. Within this region are ependymal cells that can proliferate and differentiate to form new astrocytes and oligodendrocytes following injury and cerebrospinal fluid contacting cells (CSFcCs). The specific environmental conditions, including the modulation by neurotransmitters that influence these cells and their ability to proliferate, are unknown. Here, we show that acetylcholine promotes the proliferation of ependymal cells in mice under both in vitro and in vivo conditions. Using whole cell patch clamp in acute spinal cord slices, acetylcholine directly depolarized ependymal cells and CSFcCs. Antagonism by specific nicotinic acetylcholine receptor (nAChR) antagonists or potentiation by the α7 containing nAChR (α7*nAChR) modulator PNU 120596 revealed that both α7*nAChRs and non‐α7*nAChRs mediated the cholinergic responses. Using the nucleoside analogue EdU (5‐ethynyl‐2'‐deoxyuridine) as a marker of cell proliferation, application of α7*nAChR modulators in spinal cord cultures or in vivo induced proliferation in the CC region, producing Sox‐2 expressing ependymal cells. Proliferation also increased in the white and grey matter. PNU 120596 administration also increased the proportion of cells coexpressing oligodendrocyte markers. Thus, variation in the availability of acetylcholine can modulate the rate of proliferation of cells in the ependymal cell layer and white and grey matter through α7*nAChRs. This study highlights the need for further investigation into how neurotransmitters regulate the response of the spinal cord to injury or during aging. Stem Cells 2015;33:2864–2876 PMID:26038197

  2. Effect of Oxidative Phytochemicals on Nicotine-stressed UMNSAH/DF-1 Cell Line.

    PubMed

    Chakraborty, Amlan; Gupta, Apoorv; Singh, Abhinay Kr; Patni, Pranav

    2014-04-01

    Nicotine is a parasympathomimetic alkaloid found in the nightshade family of plants (Solanaceae) and is a cholinergic drug. It acts directly by stimulating the nicotinic or muscarinic receptors or indirectly by inhibiting cholinesterase, promoting acetylcholine release, or by other mechanisms. 3% of tobacco or one cigarette yields 1 mg of nicotine. As nicotine enters the body, it disturbs the healthy functioning of the body. In this study, we isolated UMNSAH/DF-1 cell line from Gallus gallus. For this, 9 ± 2 day old chicken embryo was taken. This was followed by the extraction of nicotine (1 mg/ml) from cigarette. The cells were then given nicotine stress and were observed for blackening after 24 h of incubation under 40× resolution of microscope. It was found that this blackening of the cells was permanent even after a wash with 1× phosphate-buffered saline (PBS) followed by replenishing the medium. The phytochemicals extracted were from the dried powder, which included Curcuma longa ( Jiāng Huáng; Turmeric) 40 mg/ml, Azadirachta indica (neem) 50 mg/ml, Cinnamomum tamala (bay leaf) 30 mg/ml, Camellia sinensis ( Lǜ Chá; Green Tea) 100 mg/ml, and Ocimum sanctum (tulsi) 30 mg/ml. When applied to nicotine-stressed cells, it was observed that ursolic acid in neem recovered 70%, followed by 65% recovery by tulsi (having triterpenoid), 50% recovery by the catechins in Ca. sinensis, and very little recovery shown by Ci. tamala. Due to the yellow coloration of the cells by Cu. longa, much could not be inferred, although it was inferable that it had resulted in little effects. Mixtures of these phytochemicals were used, and it was found that neem: tulsi diluted in 3:1 ratio was highly effective and cell recovery was almost 80%. 68% was recovered by tulsi: green tea in a ratio 1:3 and 42% by turmeric:green tea in a ratio of 1:5. PMID:24860736

  3. Effect of Oxidative Phytochemicals on Nicotine-stressed UMNSAH/DF-1 Cell Line

    PubMed Central

    Chakraborty, Amlan; Gupta, Apoorv; Singh, Abhinay Kr.; Patni, Pranav

    2014-01-01

    Nicotine is a parasympathomimetic alkaloid found in the nightshade family of plants (Solanaceae) and is a cholinergic drug. It acts directly by stimulating the nicotinic or muscarinic receptors or indirectly by inhibiting cholinesterase, promoting acetylcholine release, or by other mechanisms. 3% of tobacco or one cigarette yields 1 mg of nicotine. As nicotine enters the body, it disturbs the healthy functioning of the body. In this study, we isolated UMNSAH/DF-1 cell line from Gallus gallus. For this, 9 ± 2 day old chicken embryo was taken. This was followed by the extraction of nicotine (1 mg/ml) from cigarette. The cells were then given nicotine stress and were observed for blackening after 24 h of incubation under 40× resolution of microscope. It was found that this blackening of the cells was permanent even after a wash with 1× phosphate-buffered saline (PBS) followed by replenishing the medium. The phytochemicals extracted were from the dried powder, which included Curcuma longa (薑黃 Jiāng Huáng; Turmeric) 40 mg/ml, Azadirachta indica (neem) 50 mg/ml, Cinnamomum tamala (bay leaf) 30 mg/ml, Camellia sinensis (綠茶 Lǜ Chá; Green Tea) 100 mg/ml, and Ocimum sanctum (tulsi) 30 mg/ml. When applied to nicotine-stressed cells, it was observed that ursolic acid in neem recovered 70%, followed by 65% recovery by tulsi (having triterpenoid), 50% recovery by the catechins in Ca. sinensis, and very little recovery shown by Ci. tamala. Due to the yellow coloration of the cells by Cu. longa, much could not be inferred, although it was inferable that it had resulted in little effects. Mixtures of these phytochemicals were used, and it was found that neem: tulsi diluted in 3:1 ratio was highly effective and cell recovery was almost 80%. 68% was recovered by tulsi: green tea in a ratio 1:3 and 42% by turmeric:green tea in a ratio of 1:5. PMID:24860736

  4. Single-Cell Gene Expression Analysis of Cholinergic Neurons in the Arcuate Nucleus of the Hypothalamus.

    PubMed

    Jeong, Jae Hoon; Woo, Young Jae; Chua, Streamson; Jo, Young-Hwan

    2016-01-01

    The cholinoceptive system in the hypothalamus, in particular in the arcuate nucleus (ARC), plays a role in regulating food intake. Neurons in the ARC contain multiple neuropeptides, amines, and neurotransmitters. To study molecular and neurochemical heterogeneity of ARC neurons, we combine single-cell qRT-PCR and single-cell whole transcriptome amplification methods to analyze expression patterns of our hand-picked 60 genes in individual neurons in the ARC. Immunohistochemical and single-cell qRT-PCR analyses show choline acetyltransferase (ChAT)-expressing neurons in the ARC. Gene expression patterns are remarkably distinct in each individual cholinergic neuron. Two-thirds of cholinergic neurons express tyrosine hydroxylase (Th) mRNA. A large subset of these Th-positive cholinergic neurons is GABAergic as they express the GABA synthesizing enzyme glutamate decarboxylase and vesicular GABA transporter transcripts. Some cholinergic neurons also express the vesicular glutamate transporter transcript gene. POMC and POMC-processing enzyme transcripts are found in a subpopulation of cholinergic neurons. Despite this heterogeneity, gene expression patterns in individual cholinergic cells appear to be highly regulated in a cell-specific manner. In fact, membrane receptor transcripts are clustered with their respective intracellular signaling and downstream targets. This novel population of cholinergic neurons may be part of the neural circuitries that detect homeostatic need for food and control the drive to eat. PMID:27611685

  5. Nicotine and angiogenesis: a new paradigm for tobacco-related diseases.

    PubMed

    Cooke, John P; Bitterman, Haim

    2004-01-01

    The pathophysiology of tobacco-related diseases is complex and multifactorial. Among the approximately 4,000 compounds in tobacco smoke are carcinogens such as nitrosamines, irritants such as a variety of phenolic compounds, volatiles such as carbon monoxide, and of course nicotine. Nicotine itself has quite complex actions, mediated in part by nicotinic cholinergic receptors that may have extraneuronal, as well as neuronal distribution. This review discusses the mechanisms by which nicotine contributes to tobacco-related disease, with a focus on the surprising new finding that nicotine is a potent angiogenic agent. Nicotine hijacks an endogenous nicotinic cholinergic pathway present in endothelial cells that is involved in physiological, as well as pathological angiogenesis. PMID:15000345

  6. Nicotine improves the functional activity of late endothelial progenitor cells via nicotinic acetylcholine receptors.

    PubMed

    Yu, Min; Liu, Qian; Sun, Jing; Yi, Kaihong; Wu, Libiao; Tan, Xuerui

    2011-08-01

    The aim of this study is to investigate whether nicotinic acetylcholine receptors (nAChRs) are involved in the modulation of functional activity of late endothelial progenitor cells (EPCs) induced by nicotine. Total mononuclear cells (MNCs) were isolated from human umbilical cord blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture plates. Late EPCs were positive for 1,1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine-labeled acetylated low-density lipoprotein (DiI-acLDL) uptake and fluorescein-isothiocyanate-conjugated Ulex europaeus agglutinin lectin (UEA-1) binding. Expression of von Willbrand factor (vWF), kinase insert domain receptor (KDR), and α7 nAChR was detected by indirect immunofluorescence staining. Late EPCs of 3-5 passages were treated for 32 h with either vehicle or nicotine with or without pre-incubation of nAChR antagonism, mecamylamine, or α-bungarotoxin. The viability, migration, and in vitro vasculogenesis activity of late EPCs were assayed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, modified Boyden chamber assay, and in vitro angiogenesis assay, respectively. Late EPCs adhesion assay was performed by replating cells on fibronectin-coated plates, and then adherent cells were counted. Incubation with 10 nmol/L nicotine enhanced viable, migratory, adhesive, and in vitro vasculogenesis capacity of late EPCs. The effect of nicotine on late EPCs can be attenuated by mecamylamine or α-bungarotoxin. In conclusion, nicotine improves the functional activity of late EPCs via nAChRs. PMID:21774635

  7. Mast cell-cholinergic nerve interaction in mouse airways.

    PubMed

    Weigand, Letitia A; Myers, Allen C; Meeker, Sonya; Undem, Bradley J

    2009-07-01

    We addressed the mechanism by which antigen contracts trachea isolated from actively sensitized mice. Trachea were isolated from mice (C57BL/6J) that had been actively sensitized to ovalbumin (OVA). OVA (10 microg ml(-1)) caused histamine release (approximately total tissue content), and smooth muscle contraction that was rapid in onset and short-lived (t(1/2) < 1 min), reaching approximately 25% of the maximum tissue response. OVA contraction was mimicked by 5-HT, and responses to both OVA and 5-HT were sensitive to 10 microm-ketanserin (5-HT(2) receptor antagonist) and strongly inhibited by atropine (1microm). Epithelial denudation had no effect on the OVA-induced contraction. Histological assessment revealed about five mast cells/tracheal section the vast majority of which contained 5-HT. There were virtually no mast cells in the mast cell-deficient (sash -/-) mouse trachea. OVA failed to elicit histamine release or contractile responses in trachea isolated from sensitized mast cell-deficient (sash -/-) mice. Intracellular recordings of the membrane potential of parasympathetic neurons in mouse tracheal ganglia revealed a ketanserin-sensitive 5-HT-induced depolarization and similar depolarization in response to OVA challenge. These data support the hypothesis that antigen-induced contraction of mouse trachea is epithelium-independent, and requires mast cell-derived 5-HT to activate 5-HT(2) receptors on parasympathetic cholinergic neurons. This leads to acetylcholine release from nerve terminals, and airway smooth muscle contraction. PMID:19403609

  8. The Role of Muscarinic and Nicotinic Cholinergic Neurotransmission in Aversive Conditioning: Comparing Pavlovian Fear Conditioning and Inhibitory Avoidance

    ERIC Educational Resources Information Center

    Tinsley, Matthew R.; Quinn, Jennifer J.; Fanselow, Michael S.

    2004-01-01

    Aversive conditioning is an ideal model for studying cholinergic effects on the processes of learning and memory for several reasons. First, deficits produced by selective lesions of the anatomical structures shown to be critical for Pavlovian fear conditioning and inhibitory avoidance (such as the amygdala and hippocampus) resemble those deficits…

  9. Muscarinic and nicotinic cholinergic receptor antagonists differentially mediate acquisition of fructose-conditioned flavor preference and quinine-conditioned flavor avoidance in rats.

    PubMed

    Rotella, Francis M; Olsson, Kerstin; Vig, Vishal; Yenko, Ira; Pagirsky, Jeremy; Kohen, Ilanna; Aminov, Alon; Dindyal, Trisha; Bodnar, Richard J

    2015-09-01

    Rats display both conditioned flavor preference (CFP) for fructose, and conditioned flavor avoidance (CFA) following sweet adulteration with quinine. Previous pharmacological analyses revealed that fructose-CFP expression was significantly reduced by dopamine (DA) D1 or D2 antagonists, but not NMDA or opioid antagonists. Fructose-CFP acquisition was significantly reduced by DA D1, DA D2 or NMDA antagonists, but not opioid antagonists. Quinine-CFA acquisition was significantly enhanced and prolonged by DA D1, NMDA or opioid, but not DA D2 antagonists. Cholinergic interneurons and projections interact with DA systems in the nucleus accumbens and ventral tegmental area. Further, both muscarinic and nicotinic cholinergic receptor signaling have been implicated in sweet intake and development of food-related preferences. Therefore, the present study examined whether systemic administration of muscarinic (scopolamine: SCOP) or nicotinic (mecamylamine: MEC) cholinergic receptor antagonists mediated fructose-CFP expression, fructose-CFP acquisition and quinine-CFA acquisition. For fructose-CFP expression, rats were trained over 10 sessions with a CS+ flavor in 8% fructose and 0.2% saccharin and a CS- flavor in 0.2% saccharin. Two-bottle choice tests with CS+ and CS- flavors mixed in 0.2% saccharin occurred following vehicle, SCOP (0.1-10mg/kg) and MEC (1-8mg/kg). For fructose-CFP acquisition, six groups of rats received vehicle, SCOP (1 or 2.5mg/kg), MEC (4 or 6mg/kg) or a limited intake vehicle control 0.5h prior to 10 CS+ and CS- training sessions followed by six 2-bottle CS+ and CS- choice tests in 0.2% saccharin. For quinine-CFA acquisition, five groups of rats received vehicle, SCOP (1 or 2.5mg/kg) or MEC (4 or 6mg/kg) 0.5h prior to 8 one-bottle CS- (8% fructose+0.2% saccharin: FS) and CS+ (fructose+saccharin+quinine (0.030%: FSQ) training sessions followed by six 2-bottle CS- and CS+ choice tests in fructose-saccharin solutions. Fructose-CFP expression was

  10. Cholinergic regulation of protein phosphorylation in bovine adrenal chromaffin cells

    SciTech Connect

    Haycock, J.W.; Browning, M.D.; Greengard, P.

    1988-03-01

    Chromaffin cells were isolated from bovine adrenal medullae and maintained in primary culture. After prelabeling with /sup 32/PO/sub 4/, exposure of the chromaffin cells to acetylcholine increased the phosphorylation of a M/sub r/ approx. = 100,000 protein and a M/sub r/ approx. = 60,000 protein (tyrosine hydroxylase), visualized after separation of total cellular proteins in NaDodSO/sub 4//polyacrylamide gels. Immunoprecipitation with antibodies to three known phosphoproteins (100-kDa, 87-kDa, and protein III) revealed an acetylcholine-dependent phosphorylation of these proteins. These three proteins were also shown to be present in bovine adrenal chromaffin cells by immunolabeling techniques. 100-kDa is a M/sub r/ approx. = 100,000 protein selectively phosphorylated by calcium/calmodulin-dependent protein kinase III, 87-kDa is a M/sub r/ approx. = 87,000 protein selectively phosphorylated by protein kinase C, and protein III is a phosphoprotein doublet of M/sub r/ approx. = 74,000 (IIIa) and M/sub r/ approx. = 55,000 (IIIb) phosphorylated by cAMP-dependent protein kinase and calcium/calmodulin-dependent protein kinase I. The data demonstrate that cholinergic activation of chromaffin cells increases the phosphorylation of several proteins and that several protein kinase systems may be involved in these effects.

  11. The Nicotinic Receptor of Cochlear Hair Cells: A Possible Pharmacotherapeutic Target?

    PubMed Central

    Elgoyhen, Ana Belén; Katz, Eleonora; Fuchs, Paul A.

    2009-01-01

    Mechanosensory hair cells of the organ of Corti transmit information regarding sound to the central nervous system by way of peripheral afferent neurons. In return, the central nervous system provides feedback and modulates the afferent stream of information through efferent neurons. The medial olivocochlear efferent system makes direct synaptic contacts with outer hair cells and inhibits amplification brought about by the active mechanical process inherent to these cells. This feedback system offers the potential to improve the detection of signals in background noise, to selectively attend to particular signals, and to protect the periphery from damage caused by overly loud sounds. Acetylcholine released at the synapse between efferent terminals and outer hair cells activates a peculiar nicotinic cholinergic receptor subtype, the α9α10 receptor. At present no pharmacotherapeutic approaches have been designed that target this cholinergic receptor to treat pathologies of the auditory system. The potential use of α9α10 selective drugs in conditions such as noise-induced hearing loss, tinnitus and auditory processing disorders is discussed. PMID:19481062

  12. Cholinergic regulation of the vasopressin neuroendocrine system

    SciTech Connect

    Michels, K.M.

    1987-01-01

    To clarify the physical and functional relationship between the cholinergic system, and the neurodocrine cells of the supraoptic nucleus, a combination of experiments on receptor binding, localization and function were carried out. The putative nicotinic receptor probe (/sup 125/I)alpha bungarotoxin ((/sup 125/I)alpha BTX) bound with high affinity and specificity to the vasopressin and oxytocin magnocellular neurons of the supraoptic nucleus, nucleus circularis, and paraventricular nucleus. Binding of (/sup 125/I)alpha BTX within the neural lobe was very low. In contrast, the muscarinic cholinergic receptor probe (/sup 3/H)quinuclidinylbenzilate ((/sup 3/H)QNB) did not bind to magnocellular vasopressin and oxytocin cell groups. The median eminence, which contains the neurosecretory axons, and the neural lobe of the pituitary contain low levels of (/sup 3/H)QNB binding. The physiological significance of these cholinergic receptors in regulation of vasopressin release was tested using an in vitro preparation of the supraoptic - neural lobe system.

  13. Higher sensitivity to cadmium induced cell death of basal forebrain cholinergic neurons: a cholinesterase dependent mechanism.

    PubMed

    Del Pino, Javier; Zeballos, Garbriela; Anadon, María José; Capo, Miguel Andrés; Díaz, María Jesús; García, Jimena; Frejo, María Teresa

    2014-11-01

    Cadmium is an environmental pollutant, which is a cause of concern because it can be greatly concentrated in the organism causing severe damage to a variety of organs including the nervous system which is one of the most affected. Cadmium has been reported to produce learning and memory dysfunctions and Alzheimer like symptoms, though the mechanism is unknown. On the other hand, cholinergic system in central nervous system (CNS) is implicated on learning and memory regulation, and it has been reported that cadmium can affect cholinergic transmission and it can also induce selective toxicity on cholinergic system at peripheral level, producing cholinergic neurons loss, which may explain cadmium effects on learning and memory processes if produced on central level. The present study is aimed at researching the selective neurotoxicity induced by cadmium on cholinergic system in CNS. For this purpose we evaluated, in basal forebrain region, the cadmium toxic effects on neuronal viability and the cholinergic mechanisms related to it on NS56 cholinergic mourine septal cell line. This study proves that cadmium induces a more pronounced, but not selective, cell death on acetylcholinesterase (AChE) on cholinergic neurons. Moreover, MTT and LDH assays showed a dose dependent decrease of cell viability in NS56 cells. The ACh treatment of SN56 cells did not revert cell viability reduction induced by cadmium, but siRNA transfection against AChE partially reduced it. Our present results provide new understanding of the mechanisms contributing to the harmful effects of cadmium on the function and viability of neurons, and the possible relevance of cadmium in the pathogenesis of neurodegenerative diseases. PMID:25201352

  14. A two-layer biophysical model of cholinergic neuromodulation in olfactory bulb

    PubMed Central

    Li, Guoshi; Cleland, Thomas A.

    2013-01-01

    Cholinergic inputs from the basal forebrain regulate multiple olfactory bulb (OB) functions including odor discrimination, perceptual learning, and short term memory. Previous studies have shown that nicotinic cholinergic receptor activation sharpens mitral cell chemoreceptive fields, likely via intraglomerular circuitry. Muscarinic cholinergic activation is less well understood, though muscarinic receptors are implicated in olfactory learning and in the regulation of synchronized oscillatory dynamics in hippocampus and cortex. To understand the mechanisms underlying cholinergic neuromodulation in OB, we developed a biophysical model of the OB neuronal network including both glomerular layer and external plexiform layer (EPL) computations and incorporating both nicotinic and muscarinic neuromodulatory effects. Our simulations show how nicotinic activation within glomerular circuits sharpens mitral cell chemoreceptive fields, even in the absence of EPL circuitry, but does not facilitate intrinsic oscillations or spike synchronization. In contrast, muscarinic receptor activation increases mitral cell spike synchronization and field oscillatory power by potentiating granule cell excitability and lateral inhibitory interactions within the EPL, but has little effect on mitral cell firing rates and hence will not sharpen olfactory representations under a rate metric. These results are consistent with the theory that EPL interactions regulate the timing, rather than the existence, of mitral cell action potentials, and perform their computations with respect to a spike timing-based metric. This general model suggests that the roles of nicotinic and muscarinic receptors in olfactory bulb are both distinct and complementary to one another, together regulating the effects of ascending cholinergic inputs on olfactory bulb transformations. PMID:23407960

  15. Serotonin 5-HT4 receptors and forebrain cholinergic system: receptor expression in identified cell populations.

    PubMed

    Peñas-Cazorla, Raúl; Vilaró, M Teresa

    2015-11-01

    Activation of serotonin 5-HT4 receptors has pro-cognitive effects on memory performance. The proposed underlying neurochemical mechanism is the enhancement of acetylcholine release in frontal cortex and hippocampus elicited by 5-HT4 agonists. Although 5-HT4 receptors are present in brain areas related to cognition, e.g., hippocampus and cortex, the cellular localization of the receptors that might modulate acetylcholine release is unknown at present. We have analyzed, using dual label in situ hybridization, the cellular localization of 5-HT4 receptor mRNA in identified neuronal populations of the rat basal forebrain, which is the source of the cholinergic innervation to cortex and hippocampus. 5-HT4 receptor mRNA was visualized with isotopically labeled oligonucleotide probes, whereas cholinergic, glutamatergic, GABAergic and parvalbumin-synthesizing neurons were identified with digoxigenin-labeled oligonucleotide probes. 5-HT4 receptor mRNA was not detected in the basal forebrain cholinergic cell population. In contrast, basal forebrain GABAergic, parvalbumin synthesizing, and glutamatergic cells contained 5-HT4 receptor mRNA. Hippocampal and cortical glutamatergic neurons also express this receptor. These results indicate that 5-HT4 receptors are not synthesized by cholinergic cells, and thus would be absent from cholinergic terminals. In contrast, several non-cholinergic cell populations within the basal forebrain and its target hippocampal and cortical areas express these receptors and are thus likely to mediate the enhancement of acetylcholine release elicited by 5-HT4 agonists. PMID:25183542

  16. Muscarinic signaling influences the patterning and phenotype of cholinergic amacrine cells in the developing chick retina

    PubMed Central

    Stanke, Jennifer J; Lehman, Bret; Fischer, Andy J

    2008-01-01

    Background Many studies in the vertebrate retina have characterized the differentiation of amacrine cells as a homogenous class of neurons, but little is known about the genes and factors that regulate the development of distinct types of amacrine cells. Accordingly, the purpose of this study was to characterize the development of the cholinergic amacrine cells and identify factors that influence their development. Cholinergic amacrine cells in the embryonic chick retina were identified by using antibodies to choline acetyltransferase (ChAT). Results We found that as ChAT-immunoreactive cells differentiate they expressed the homeodomain transcription factors Pax6 and Islet1, and the cell-cycle inhibitor p27kip1. As differentiation proceeds, type-II cholinergic cells, displaced to the ganglion cell layer, transiently expressed high levels of cellular retinoic acid binding protein (CRABP) and neurofilament, while type-I cells in the inner nuclear layer did not. Although there is a 1:1 ratio of type-I to type-II cells in vivo, in dissociated cell cultures the type-I cells (ChAT-positive and CRABP-negative) out-numbered the type-II cells (ChAT and CRABP-positive cells) by 2:1. The relative abundance of type-I to type-II cells was not influenced by Sonic Hedgehog (Shh), but was affected by compounds that act at muscarinic acetylcholine receptors. In addition, the abundance and mosaic patterning of type-II cholinergic amacrine cells is disrupted by interfering with muscarinic signaling. Conclusion We conclude that: (1) during development type-I and type-II cholinergic amacrine cells are not homotypic, (2) the phenotypic differences between these subtypes of cells is controlled by the local microenvironment, and (3) appropriate levels of muscarinic signaling between the cholinergic amacrine cells are required for proper mosaic patterning. PMID:18254959

  17. Prenatal Ablation of Nicotinic Receptor alpha7 Cell Lineages Produces Lumbosacral Spina Bifida the Severity of Which is Modified by Choline and Nicotine Exposure

    PubMed Central

    Rogers, Scott W; Tvrdik, Petr; Capecchi, Mario R; Gahring, Lorise C

    2012-01-01

    Lumbosacral spina bifida is a common debilitating birth defect whose multiple causes are poorly understood. Here, we provide the first genetic delineation of cholinergic nicotinic receptor alpha7 (Chrna7) expression and link the ablation of the Chrna7 cell lineage to this condition in the mouse. Using homologous recombination, an IRES-Cre bi-cistronic cassette was introduced into the 3′ noncoding region of Chrna7 (Chrna7:Cre) for identifying cell lineages expressing this gene. This lineage first appears at embryonic day E9.0 in rhombomeres 3 and 5 of the neural tube and extends to cell subsets in most tissues by E14.5. Ablation of the Chrna7:Cre cell lineage in embryos from crosses with conditionally expressed attenuated diphtheria toxin results in precise developmental defects including omphalocele (89%) and open spina bifida (SB; 80%). We hypothesized that like humans, this defect would be modified by environmental compounds not only folic acid or choline but also nicotine. Prenatal chronic oral nicotine administration substantially worsened the defect to often include the rostral neural tube. In contrast, supplementation of the maternal diet with 2% choline decreased SB prevalence to 38% and dramatically reduced the defect severity. Folic acid supplementation only trended towards a reduced SB frequency. The omphalocele was unaffected by these interventions. These studies identify the Chrna7 cell lineage as participating in posterior neuropore closure and present a novel model of lower SB that can be substantially modified by the prenatal environment. © 2012 Wiley Periodicals, Inc. PMID:22473653

  18. Cholinergic pesticides cause mushroom body neuronal inactivation in honeybees

    PubMed Central

    Palmer, Mary J.; Moffat, Christopher; Saranzewa, Nastja; Harvey, Jenni; Wright, Geraldine A.; Connolly, Christopher N.

    2013-01-01

    Pesticides that target cholinergic neurotransmission are highly effective, but their use has been implicated in insect pollinator population decline. Honeybees are exposed to two widely used classes of cholinergic pesticide: neonicotinoids (nicotinic receptor agonists) and organophosphate miticides (acetylcholinesterase inhibitors). Although sublethal levels of neonicotinoids are known to disrupt honeybee learning and behaviour, the neurophysiological basis of these effects has not been shown. Here, using recordings from mushroom body Kenyon cells in acutely isolated honeybee brain, we show that the neonicotinoids imidacloprid and clothianidin, and the organophosphate miticide coumaphos oxon, cause a depolarization-block of neuronal firing and inhibit nicotinic responses. These effects are observed at concentrations that are encountered by foraging honeybees and within the hive, and are additive with combined application. Our findings demonstrate a neuronal mechanism that may account for the cognitive impairments caused by neonicotinoids, and predict that exposure to multiple pesticides that target cholinergic signalling will cause enhanced toxicity to pollinators. PMID:23535655

  19. Impact of nicotine on the interplay between human periodontal ligament cells and CD4+ T cells.

    PubMed

    Ge, Xin; Liu, Ying-Feng; Wong, Yong; Wu, Li-Zheng; Tan, Ling; Liu, Fen; Wang, Xiao-Jing

    2016-09-01

    Periodontitis is a common infectious disease associated with destruction of periodontal ligaments and alveolar bones. CD4(+) T cell-mediated immune response is involved in the progression of periodontitis. Tobacco consumption increases the risk of periodontal disease. However, the impact of nicotine on the interaction between human periodontal ligament (PDL) cells and CD4(+) T cells remains unrevealed. Our study aims to investigate the effect of nicotine on PDL cells and the cocultured CD4(+) T cells. The PDL cell cultures were established by explants from healthy individuals, exposed to nicotine or α-bungarotoxin (α-BTX), and incubated solely or in combination with CD4(+) T cells. Afterwards, cell viability, secreted cytokines, and matrix metalloproteinases (MMPs) were evaluated. In monoculture of PDL cells, nicotine dramatically repressed cell viability and increased apoptosis. Meanwhile, α-BTX largely reversed the nicotine-induced apoptosis and increased viability of PDL cells. Compared with the monoculture, MMP-1, MMP-3, interleukin (IL)-1β, IL-6, IL-17, and IL-21 in supernatant of cocultures were markedly elevated after treatment with nicotine. Moreover, α-BTX significantly attenuated nicotine-triggered production of these components either in mono- or co-cultures. In addition, PDL cell-derived CXCL12 following nicotine treatment recruited CD4(+) T cells. Above all, nicotine deteriorated periodontitis partially by promoting PDL cell-CD4(+) T cell-mediated inflammatory response and matrix degradation. PMID:26553320

  20. Sox2 Regulates Cholinergic Amacrine Cell Positioning and Dendritic Stratification in the Retina

    PubMed Central

    Whitney, Irene E.; Keeley, Patrick W.; St. John, Ace J.; Kautzman, Amanda G.; Kay, Jeremy N.

    2014-01-01

    The retina contains two populations of cholinergic amacrine cells, one positioned in the ganglion cell layer (GCL) and the other in the inner nuclear layer (INL), that together comprise ∼1/2 of a percent of all retinal neurons. The present study examined the genetic control of cholinergic amacrine cell number and distribution between these two layers. The total number of cholinergic amacrine cells was quantified in the C57BL/6J and A/J inbred mouse strains, and in 25 recombinant inbred strains derived from them, and variations in their number and ratio (GCL/INL) across these strains were mapped to genomic loci. The total cholinergic amacrine cell number was found to vary across the strains, from 27,000 to 40,000 cells, despite little variation within individual strains. The number of cells was always lower within the GCL relative to the INL, and the sizes of the two populations were strongly correlated, yet there was variation in their ratio between the strains. Approximately 1/3 of that variation in cell ratio was mapped to a locus on chromosome 3, where Sex determining region Y box 2 (Sox2) was identified as a candidate gene due to the presence of a 6-nucleotide insertion in the protein-coding sequence in C57BL/6J and because of robust and selective expression in cholinergic amacrine cells. Conditionally deleting Sox2 from the population of nascent cholinergic amacrine cells perturbed the normal ratio of cells situated in the GCL versus the INL and induced a bistratifying morphology, with dendrites distributed to both ON and OFF strata within the inner plexiform layer. PMID:25057212

  1. Striatal cholinergic interneurons drive GABA release from dopamine terminals

    PubMed Central

    Nelson, Alexandra B.; Hammack, Nora; Yang, Cindy F.; Shah, Nirao M.; Seal, Rebecca P.; Kreitzer, Anatol C.

    2014-01-01

    Summary Striatal cholinergic interneurons are implicated in motor control, associative plasticity, and reward-dependent learning. Synchronous activation of cholinergic interneurons triggers large inhibitory synaptic currents in dorsal striatal projection neurons, providing one potential substrate for control of striatal output, but the mechanism for these GABAergic currents is not fully understood. Using optogenetics and whole-cell recordings in brain slices, we find that a large component of these inhibitory responses derive from action-potential-independent disynaptic neurotransmission mediated by nicotinic receptors. Cholinergically-driven IPSCs were not affected by ablation of striatal fast-spiking interneurons, but were greatly reduced after acute treatment with vesicular monoamine transport inhibitors or selective destruction of dopamine terminals with 6-hydroxydopamine, indicating that GABA release originated from dopamine terminals. These results delineate a mechanism in which striatal cholinergic interneurons can co-opt dopamine terminals to drive GABA release and rapidly inhibit striatal output neurons. PMID:24613418

  2. Acetylcholine induces GABA release onto rod bipolar cells through heteromeric nicotinic receptors expressed in A17 amacrine cells

    PubMed Central

    Elgueta, Claudio; Vielma, Alex H.; Palacios, Adrian G.; Schmachtenberg, Oliver

    2015-01-01

    Acetylcholine (ACh) is a major retinal neurotransmitter that modulates visual processing through a large repertoire of cholinergic receptors expressed on different retinal cell types. ACh is released from starburst amacrine cells (SACs) under scotopic conditions, but its effects on cells of the rod pathway have not been investigated. Using whole-cell patch clamp recordings in slices of rat retina, we found that ACh application triggers GABA release onto rod bipolar (RB) cells. GABA was released from A17 amacrine cells and activated postsynaptic GABAA and GABAC receptors in RB cells. The sensitivity of ACh-induced currents to nicotinic ACh receptor (nAChR) antagonists (TMPH ~ mecamylamine > erysodine > DhβE > MLA) together with the differential potency of specific agonists to mimic ACh responses (cytisine >> RJR2403 ~ choline), suggest that A17 cells express heteromeric nAChRs containing the β4 subunit. Activation of nAChRs induced GABA release after Ca2+ accumulation in A17 cell dendrites and varicosities mediated by L-type voltage-gated calcium channels (VGCCs) and intracellular Ca2+ stores. Inhibition of acetylcholinesterase depolarized A17 cells and increased spontaneous inhibitory postsynaptic currents in RB cells, indicating that endogenous ACh enhances GABAergic inhibition of RB cells. Moreover, injection of neostigmine or cytisine reduced the b-wave of the scotopic flash electroretinogram (ERG), suggesting that cholinergic modulation of GABA release controls RB cell activity in vivo. These results describe a novel regulatory mechanism of RB cell inhibition and complement our understanding of the neuromodulatory control of retinal signal processing. PMID:25709566

  3. A novel cholinergic epithelial cell with chemosensory traits in the murine conjunctiva.

    PubMed

    Wiederhold, Stephanie; Papadakis, Tamara; Chubanov, Vladimir; Gudermann, Thomas; Krasteva-Christ, Gabriela; Kummer, Wolfgang

    2015-11-01

    We recently identified a specialized cholinergic cell type in tracheal and urethral epithelium that utilizes molecules of the canonical taste transduction signaling cascade to sense potentially harmful substances in the luminal content. Upon stimulation, this cell initiates protective reflexes. Assuming a sentinel role of such cells at mucosal surfaces exposed to bacteria, we hypothesized their occurrence also in ocular mucosal surfaces. Utilizing a mouse strain expressing eGFP under the promoter of the acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT-eGFP), we observed a cholinergic cell in the murine conjunctiva. Singular cholinergic cells reaching the epithelial surface with slender processes were detected in fornical, but neither in bulbar nor palpebral epithelia. These cells were found neither in the lacrimal canaliculi, nor in the lacrimal sac and the nasolacrimal duct. Cholinergic conjunctival epithelial cells were immunoreactive for components of the canonical taste transduction signaling cascade, i.e. α-gustducin, phospholipase Cβ2 and the monovalent cation channel TRPM5. Calcitonin gene-related peptide- and substance P-immunoreactive sensory nerve fibers were observed extending into the conjunctival epithelium approaching slender ChAT-eGFP-positive cells. In addition, we noted both ChAT-eGFP expression and α-gustducin-immunoreactivity, albeit in different cell populations, in occasionally occurring lymphoid follicles of the nictitating membrane. The data show a previously unidentified cholinergic cell in murine conjunctiva with chemosensory traits that presumably utilizes acetylcholine for signaling. In analogy to similar cells described in the respiratory and urethral epithelium, it might serve to detect bacterial products and to initiate protective reflexes. PMID:26119492

  4. Nicotine induces mitochondrial fission through mitofusin degradation in human multipotent embryonic carcinoma cells.

    PubMed

    Hirata, Naoya; Yamada, Shigeru; Asanagi, Miki; Sekino, Yuko; Kanda, Yasunari

    2016-02-01

    Nicotine is considered to contribute to the health risks associated with cigarette smoking. Nicotine exerts its cellular functions by acting on nicotinic acetylcholine receptors (nAChRs), and adversely affects normal embryonic development. However, nicotine toxicity has not been elucidated in human embryonic stage. In the present study, we examined the cytotoxic effects of nicotine in human multipotent embryonal carcinoma cell line NT2/D1. We found that exposure to 10 μM nicotine decreased intracellular ATP levels and inhibited proliferation of NT2/D1 cells. Because nicotine suppressed energy production, which is a critical mitochondrial function, we further assessed the effects of nicotine on mitochondrial dynamics. Staining with MitoTracker revealed that 10 μM nicotine induced mitochondrial fragmentation. The levels of the mitochondrial fusion proteins, mitofusins 1 and 2, were also reduced in cells exposed to nicotine. These nicotine effects were blocked by treatment with mecamylamine, a nonselective nAChR antagonist. These data suggest that nicotine degrades mitofusin in NT2/D1 cells and thus induces mitochondrial dysfunction and cell growth inhibition in a nAChR-dependent manner. Thus, mitochondrial function in embryonic cells could be used to assess the developmental toxicity of chemicals. PMID:26774337

  5. Functional chromaffin cell plasticity in response to stress: focus on nicotinic, gap junction, and voltage-gated Ca2+ channels.

    PubMed

    Guérineau, Nathalie C; Desarménien, Michel G; Carabelli, Valentina; Carbone, Emilio

    2012-10-01

    An increase in circulating catecholamines constitutes one of the mechanisms whereby human body responds to stress. In response to chronic stressful situations, the adrenal medullary tissue exhibits crucial morphological and functional changes that are consistent with an improvement of chromaffin cell stimulus-secretion coupling efficiency. Stimulus-secretion coupling encompasses multiple intracellular (chromaffin cell excitability, Ca(2+) signaling, exocytosis, endocytosis) and intercellular pathways (splanchnic nerve-mediated synaptic transmission, paracrine and endocrine communication, gap junctional coupling), each of them being potentially subjected to functional remodeling upon stress. This review focuses on three chromaffin cell incontrovertible actors, the cholinergic nicotinic receptors and the voltage-dependent T-type Ca(2+) channels that are directly involved in Ca(2+)-dependent events controlling catecholamine secretion and electrical activity, and the gap junctional communication involved in the modulation of catecholamine secretion. We show here that these three actors react differently to various stressors, sometimes independently, sometimes in concert or in opposition. PMID:22252244

  6. Functional chromaffin cell plasticity in response to stress: focus on nicotinic, gap junction, and voltage-gated Ca2+ channels

    PubMed Central

    Guérineau, Nathalie C.; Desarménien, Michel G.; Carabelli, Valentina; Carbone, Emilio

    2012-01-01

    An increase in circulating catecholamines constitutes one of the mechanisms whereby human body responds to stress. In response to chronic stressful situations, the adrenal medullary tissue exhibits crucial morphological and functional changes that are consistent with an improvement of chromaffin cell stimulus-secretion coupling efficiency. Stimulus-secretion coupling encompasses multiple intracellular (chromaffin cell excitability, Ca2+ signaling, exocytosis, endocytosis) and intercellular pathways (splanchnic nerve-mediated synaptic transmission, paracrine and endocrine communication, gap junctional coupling), each of them being potentially subjected to functional remodeling upon stress. This review focuses on three chromaffin cell incontrovertible actors, the cholinergic nicotinic receptors and the voltage-dependent T-type Ca2+ channels that are directly involved in Ca2+-dependent events controlling catecholamine secretion and electrical activity, and the gap junctional communication involved in the modulation of catecholamine secretion. We show here that these three actors react differently to various stressors, sometimes independently, sometimes in concert or in opposition. PMID:22252244

  7. Cellular Basis for the Olfactory Response to Nicotine

    PubMed Central

    2010-01-01

    Smokers regulate their smoking behavior on the basis of sensory stimuli independently of the pharmacological effects of nicotine (RoseJ. E., et al. (1993) Pharmacol., Biochem. Behav.1 (3), 891−9008469698). A better understanding of sensory mechanisms underlying smoking behavior may help to develop more effective smoking alternatives. Olfactory stimulation by nicotine makes up a considerable part of the flavor of tobacco smoke, yet our understanding of the cellular mechanisms responsible for olfactory detection of nicotine remains incomplete. We used biophysical methods to characterize the nicotine sensitivity and response mechanisms of neurons from olfactory epithelium. In view of substantial differences in the olfactory receptor repertoire between rodent and human (MombaertsP. (1999) Annu. Rev. Neurosci.1, 487−50910202546), we studied biopsied human olfactory sensory neurons (OSNs), cultured human olfactory cells (GomezG., et al. (2000) J. Neurosci. Res.1 (3), 737−74911104513), and rat olfactory neurons. Rat and human OSNs responded to S(−)-nicotine with a concentration dependent influx of calcium and activation of adenylate cyclase. Some rat OSNs displayed some stereoselectivity, with neurons responding to either enantiomer alone or to both. Freshly biopsied and primary cultured human olfactory neurons were less stereoselective. Nicotinic cholinergic antagonists had no effect on the responses of rat or human OSNs to nicotine. Patch clamp recording of rat OSNs revealed a nicotine-activated, calcium-sensitive nonspecific cation channel. These results indicate that nicotine activates a canonical olfactory receptor pathway rather than nicotinic cholinergic receptors on OSNs. Further, because the nicotine-sensitive mechanisms of rodents appear generally similar to those of humans, this animal model is an appropriate one for studies of nicotine sensation. PMID:22777075

  8. Cellular basis for the olfactory response to nicotine.

    PubMed

    Bryant, Bruce; Xu, Jiang; Audige, Valery; Lischka, Fritz W; Rawson, Nancy E

    2010-03-17

    Smokers regulate their smoking behavior on the basis of sensory stimuli independently of the pharmacological effects of nicotine (Rose J. E., et al. (1993) Pharmacol., Biochem. Behav.44 (4), 891-900). A better understanding of sensory mechanisms underlying smoking behavior may help to develop more effective smoking alternatives. Olfactory stimulation by nicotine makes up a considerable part of the flavor of tobacco smoke, yet our understanding of the cellular mechanisms responsible for olfactory detection of nicotine remains incomplete. We used biophysical methods to characterize the nicotine sensitivity and response mechanisms of neurons from olfactory epithelium. In view of substantial differences in the olfactory receptor repertoire between rodent and human (Mombaerts P. (1999) Annu. Rev. Neurosci.22, 487-509), we studied biopsied human olfactory sensory neurons (OSNs), cultured human olfactory cells (Gomez G., et al. (2000) J. Neurosci. Res.62 (5), 737-749), and rat olfactory neurons. Rat and human OSNs responded to S(-)-nicotine with a concentration dependent influx of calcium and activation of adenylate cyclase. Some rat OSNs displayed some stereoselectivity, with neurons responding to either enantiomer alone or to both. Freshly biopsied and primary cultured human olfactory neurons were less stereoselective. Nicotinic cholinergic antagonists had no effect on the responses of rat or human OSNs to nicotine. Patch clamp recording of rat OSNs revealed a nicotine-activated, calcium-sensitive nonspecific cation channel. These results indicate that nicotine activates a canonical olfactory receptor pathway rather than nicotinic cholinergic receptors on OSNs. Further, because the nicotine-sensitive mechanisms of rodents appear generally similar to those of humans, this animal model is an appropriate one for studies of nicotine sensation. PMID:22777075

  9. Identification of cholinergic chemosensory cells in mouse tracheal and laryngeal glandular ducts.

    PubMed

    Krasteva-Christ, G; Soultanova, A; Schütz, B; Papadakis, T; Weiss, C; Deckmann, K; Chubanov, V; Gudermann, T; Voigt, A; Meyerhof, W; Boehm, U; Weihe, E; Kummer, W

    2015-11-01

    Specialized epithelial cells in the respiratory tract such as solitary chemosensory cells and brush cells sense the luminal content and initiate protective reflexes in response to the detection of potentially harmful substances. The majority of these cells are cholinergic and utilize the canonical taste signal transduction cascade to detect "bitter" substances such as bacterial quorum sensing molecules. Utilizing two different mouse strains reporting expression of choline acetyltransferase (ChAT), the synthesizing enzyme of acetylcholine (ACh), we detected cholinergic cells in the submucosal glands of the murine larynx and trachea. These cells were localized in the ciliated glandular ducts and were neither found in the collecting ducts nor in alveolar or tubular segments of the glands. ChAT expression in tracheal gland ducts was confirmed by in situ hybridization. The cholinergic duct cells expressed the brush cell marker proteins, villin and cytokeratin-18, and were immunoreactive for components of the taste signal transduction cascade (Gα-gustducin, transient receptor potential melastatin-like subtype 5 channel = TRPM5, phospholipase C(β2)), but not for carbonic anhydrase IV. Furthermore, these cells expressed the bitter taste receptor Tas2r131, as demonstrated utilizing an appropriate reporter mouse strain. Our study identified a previously unrecognized presumptive chemosensory cell type in the duct of the airway submucosal glands that likely utilizes ACh for paracrine signaling. We propose that these cells participate in infection-sensing mechanisms and initiate responses assisting bacterial clearance from the lower airways. PMID:26033492

  10. Immunodominant regions for T helper-cell sensitization on the human nicotinic receptor alpha subunit in myasthenia gravis.

    PubMed Central

    Protti, M P; Manfredi, A A; Straub, C; Howard, J F; Conti-Tronconi, B M

    1990-01-01

    In myasthenia gravis an autoimmune response against the nicotinic acetylcholine receptor (AChR) occurs. The alpha subunit of the AChR contains both the epitope(s) that dominates the antibody response (main immunogenic region) and epitopes involved in T helper cell sensitization. In this study, overlapping synthetic peptides corresponding to the complete AChR alpha-subunit sequence were used to propagate polyclonal AChR-specific T helper cell lines from four myasthenic patients of different HLA types. Response of the T helper lines to the individual peptides was studied. Four immunodominant sequence segments were identified--i.e., residues 48-67, 101-120, 304-322, and 419-437. These regions did not include residues known to form the main immunogenic region or the cholinergic binding site, and they frequently contained sequence motifs that have been proposed to be related to T-epitope formation. Images PMID:2145582

  11. Prostate stem cell antigen interacts with nicotinic acetylcholine receptors and is affected in Alzheimer's disease.

    PubMed

    Jensen, Majbrit M; Arvaniti, Maria; Mikkelsen, Jens D; Michalski, Dominik; Pinborg, Lars H; Härtig, Wolfgang; Thomsen, Morten S

    2015-04-01

    Alzheimer's disease (AD) is a neurodegenerative disorder involving impaired cholinergic neurotransmission and dysregulation of nicotinic acetylcholine receptors (nAChRs). Ly-6/neurotoxin (Lynx) proteins have been shown to modulate cognition and neural plasticity by binding to nAChR subtypes and modulating their function. Hence, changes in nAChR regulatory proteins such as Lynx proteins could underlie the dysregulation of nAChRs in AD. Using Western blotting, we detected bands corresponding to the Lynx proteins prostate stem cell antigen (PSCA) and Lypd6 in human cortex indicating that both proteins are present in the human brain. We further showed that PSCA forms stable complexes with the α4 nAChR subunit and decreases nicotine-induced extracellular-signal regulated kinase phosphorylation in PC12 cells. In addition, we analyzed protein levels of PSCA and Lypd6 in postmortem tissue of medial frontal gyrus from AD patients and found significantly increased PSCA levels (approximately 70%). In contrast, no changes in Lypd6 levels were detected. In concordance with our findings in AD patients, PSCA levels were increased in the frontal cortex of triple transgenic mice with an AD-like pathology harboring human transgenes that cause both age-dependent β-amyloidosis and tauopathy, whereas Tg2576 mice, which display β-amyloidosis only, had unchanged PSCA levels compared to wild-type animals. These findings identify PSCA as a nAChR-binding protein in the human brain that is affected in AD, suggesting that PSCA-nAChR interactions may be involved in the cognitive dysfunction observed in AD. PMID:25680266

  12. Nicotine promotes cell proliferation via {alpha}7-nicotinic acetylcholine receptor and catecholamine-synthesizing enzymes-mediated pathway in human colon adenocarcinoma HT-29 cells

    SciTech Connect

    Wong, Helen Pui Shan; Yu Le; Lam, Emily Kai Yee; Tai, Emily Kin Ki; Wu, William Ka Kei; Cho, Chi Hin . E-mail: chcho@cuhk.edu.hk

    2007-06-15

    Cigarette smoking has been implicated in colon cancer. Nicotine is a major alkaloid in cigarette smoke. In the present study, we showed that nicotine stimulated HT-29 cell proliferation and adrenaline production in a dose-dependent manner. The stimulatory action of nicotine was reversed by atenolol and ICI 118,551, a {beta}{sub 1}- and {beta}{sub 2}-selective antagonist, respectively, suggesting the role of {beta}-adrenoceptors in mediating the action. Nicotine also significantly upregulated the expression of the catecholamine-synthesizing enzymes [tyrosine hydroxylase (TH), dopamine-{beta}-hydroxylase (D{beta}H) and phenylethanolamine N-methyltransferase]. Inhibitor of TH, a rate-limiting enzyme in the catecholamine-biosynthesis pathway, reduced the actions of nicotine on cell proliferation and adrenaline production. Expression of {alpha}7-nicotinic acetylcholine receptor ({alpha}7-nAChR) was demonstrated in HT-29 cells. Methyllycaconitine, an {alpha}7-nAChR antagonist, reversed the stimulatory actions of nicotine on cell proliferation, TH and D{beta}H expression as well as adrenaline production. Taken together, through the action on {alpha}7-nAChR nicotine stimulates HT-29 cell proliferation via the upregulation of the catecholamine-synthesis pathway and ultimately adrenaline production and {beta}-adrenergic activation. These data reveal the contributory role {alpha}7-nAChR and {beta}-adrenoceptors in the tumorigenesis of colon cancer cells and partly elucidate the carcinogenic action of cigarette smoke on colon cancer.

  13. Cholinergic chemosensory cells of the thymic medulla express the bitter receptor Tas2r131.

    PubMed

    Soultanova, Aichurek; Voigt, Anja; Chubanov, Vladimir; Gudermann, Thomas; Meyerhof, Wolfgang; Boehm, Ulrich; Kummer, Wolfgang

    2015-11-01

    The thymus is the site of T cell maturation which includes positive selection in the cortex and negative selection in the medulla. Acetylcholine is locally produced in the thymus and cholinergic signaling influences the T cell development. We recently described a distinct subset of medullary epithelial cells in the murine thymus which express the acetylcholine-synthesizing enzyme choline acetyltransferase (ChAT) and components of the canonical taste transduction cascade, i.e. transient receptor potential melastatin-like subtype 5 channel (TRPM5), phospholipase Cβ(2), and Gα-gustducin. Such a chemical phenotype is characteristic for chemosensory cells of mucosal surfaces which utilize bitter receptors for detection of potentially hazardous compounds and cholinergic signaling to initiate avoidance reflexes. We here demonstrate mRNA expression of bitter receptors Tas2r105, Tas2r108, and Tas2r131 in the murine thymus. Using a Tas2r131-tauGFP reporter mouse we localized the expression of this receptor to cholinergic cells expressing the downstream elements of the taste transduction pathway. These cells are distinct from the medullary thymic epithelial cells which promiscuously express tissue-restricted self-antigens during the process of negative selection, since double-labeling immunofluorescence showed no colocalization of autoimmune regulator (AIRE), the key mediator of negative selection, and TRPM5. These data demonstrate the presence of bitter taste-sensing signaling in cholinergic epithelial cells in the thymic medulla and opens a discussion as to what is the physiological role of this pathway. PMID:26102274

  14. Cellular and molecular basis of cholinergic function

    SciTech Connect

    Dowdall, M.J.; Hawthorne, J.N.

    1987-01-01

    This book contains 105 selections. Some of the titles are: Functional correlates of brain nicotine receptors; Muscarinic receptor subclasses; Cholinergic innervation and levels of nerve growth factor and its mRNA in the central nervous system; Developmentally regulated neurontrophic activities of Torpedo electric organ tissue; and Association of a regulatory peptide with cholinergic neurons.

  15. Generation of Human Embryonic Stem Cell Line Expressing zsGreen in Cholinergic Neurons Using CRISPR/Cas9 System.

    PubMed

    Zhou, Jing; Wang, Chencheng; Zhang, Kunshan; Wang, Yingying; Gong, Xi; Wang, Yanlu; Li, Siguang; Luo, Yuping

    2016-08-01

    Lineage specific human embryonic stem cell (hESC) reporter cell line is a versatile tool for biological studies on real time monitoring of differentiation, physiological and biochemical features of special cell types and pathological mechanism of disease. Here we report the generation of ChAT-zsGreen reporter hESC line that express zsGreen under the control of the choline acetyltransferase (ChAT) promoter using CRISPR (Clustered Regularly Interspersed Short Palindromic Repeats)/Cas9 system. We show that the ChAT-zsGreen hESC reporter cell lines retain the features of undifferentiated hESC. After cholinergic neuronal differentiation, cholinergic neurons were clearly labeled with green fluorescence protein (zsGreen). The ChAT-zsGreen reporter hESC lines are invaluable not only for the monitoring cholinergic neuronal differentiation but also for study physiological and biochemical hallmarks of cholinergic neurons. PMID:27113041

  16. Functional expression of human α7 nicotinic acetylcholine receptor in human embryonic kidney 293 cells.

    PubMed

    Gong, Yuan; Jiang, Ji-Hong; Li, Shi-Tong

    2016-09-01

    The functional expression of recombinant α7 nicotinic acetylcholine receptors in human embryonic kidney (HEK) 293 cells has presented a challenge. Resistance to inhibitors of cholinesterase 3 (RIC‑3) has been confirmed to act as a molecular chaperone of nicotinic acetylcholine receptors. The primary objectives of the present study were to investigate whether the co‑expression of human (h)RIC‑3 with human α7 nicotinic acetylcholine receptor in HEK 293 cells facilitates functional expression of the α7 nicotinic acetylcholine receptor. Subsequent to transfection, western blotting and polymerase chain reaction were used to test the expression of α7 nicotinic acetylcholine receptor and RIC-3. The α7 nicotinic acetylcholine receptor was expressed alone or co‑expressed with hRIC‑3 in the HEK 293 cells. Drug‑containing solution was then applied to the cells via a gravity‑driven perfusion system. Calcium influx in the cells was analyzed using calcium imaging. Nicotine did not induce calcium influx in the HEK 293 cells expressing human α7 nicotinic acetylcholine receptor only. However, in the cells co‑expressing human RIC‑3 and α7 nicotinic acetylcholine receptor, nicotine induced calcium influx via the α7 nicotinic acetylcholine receptor in a concentration‑dependent manner (concentration required to elicit 50% of the maximal effect=29.21 µM). Taken together, the results of the present study suggested that the co‑expression of RIC‑3 in HEK 293 cells facilitated the functional expression of the α7 nicotinic acetylcholine receptor. PMID:27430244

  17. Chagas’ disease parasite-derived neurotrophic factor activates cholinergic gene expression in neuronal PC12 cells

    PubMed Central

    Akpan, Nsikan; Caradonna, Kacey; Chuenkova, Marina V.; PereiraPerrin, Mercio

    2008-01-01

    A parasite-derived neurotrophic factor (PDNF) produced by the Chagas’ disease parasite Trypanosoma cruzi binds nerve growth factor (NGF) receptor TrkA, increasing receptor autophosphorylation, activating phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK/Erk) pathways, and transcription factor CREB. The end-result is enhanced survival and neuritogenesis of various types of neurons. PDNF also enhances the expression and activity of tyrosine hydroxylase, a rate limiting enzyme in the synthesis of dopamine and other catecholamine neurotransmitters. It remains unknown, however, if PDNF alters expression and metabolism of acetylcholine (ACh), a neurotransmitter thought to play a role in Chagas’ disease progression. Here we demonstrate that PDNF stimulates mRNA and protein expression of choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT), which are critical for synthesis and storage of ACh. Stimulation requires functional TrkA because it did not occur in cell mutants that lack the receptor and in TrkA-expressing wild-type cells treated with K252a, an inhibitor of TrkA kinase activity. It also requires TrkA-dependent PI3K and MAPK/Erk signaling pathways because PDNF stimulation of cholinergic transcripts is abolished by specific pharmacological inhibitors. Furthermore, the cholinergic actions of PDNF were reproduced by PDNF-expressing extracellular T. cruzi trypomastigotes at the start of host cell invasion. In contrast, host cells bearing intracellular T. cruzi showed decreased, rather than increased, cholinergic gene expression. These results suggest that T. cruzi invasion of the nervous system alters cholinergic gene expression and that could play a role in neuropathology, and/or lack thereof, in Chagas’ disease patients. PMID:18502403

  18. Chagas' disease parasite-derived neurotrophic factor activates cholinergic gene expression in neuronal PC12 cells.

    PubMed

    Akpan, Nsikan; Caradonna, Kacey; Chuenkova, Marina V; PereiraPerrin, Mercio

    2008-06-27

    A parasite-derived neurotrophic factor (PDNF) produced by the Chagas' disease parasite Trypanosoma cruzi binds nerve growth factor (NGF) receptor TrkA, increasing receptor autophosphorylation, and activating phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK/Erk) pathways, and transcription factor CREB. The end-result is enhanced survival and neuritogenesis of various types of neurons. PDNF also enhances the expression and activity of tyrosine hydroxylase, a rate limiting enzyme in the synthesis of dopamine and other catecholamine neurotransmitters. It remains unknown, however, if PDNF alters expression and metabolism of acetylcholine (ACh), a neurotransmitter thought to play a role in Chagas' disease progression. Here we demonstrate that PDNF stimulates mRNA and protein expression of choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT), which are critical for synthesis and storage of ACh. Stimulation requires functional TrkA because it did not occur in cell mutants that lack the receptor and in TrkA-expressing wild-type cells treated with K252a, an inhibitor of TrkA kinase activity. It also requires TrkA-dependent PI3K and MAPK/Erk signaling pathways because PDNF stimulation of cholinergic transcripts is abolished by specific pharmacological inhibitors. Furthermore, the cholinergic actions of PDNF were reproduced by PDNF-expressing extracellular T. cruzi trypomastigotes at the start of host cell invasion. In contrast, host cells bearing intracellular T. cruzi showed decreased, rather than increased, cholinergic gene expression. These results suggest that T. cruzi invasion of the nervous system alters cholinergic gene expression and that could play a role in neuropathology, and/or lack thereof, in Chagas' disease patients. PMID:18502403

  19. Mesopontine organization of cholinergic and catecholaminergic cell groups in the normal and narcoleptic dog.

    PubMed

    Tafti, M; Nishino, S; Liao, W; Dement, W C; Mignot, E

    1997-03-10

    Canine narcolepsy is a unique experimental model of a human sleep disorder characterized by excessive daytime sleepiness and cataplexy. There is a consensus recognition of an imbalance between cholinergic and catecholaminergic systems in narcolepsy although the underlying mechanisms remain poorly understood. Possible substrates could be an abnormal organization, numbers and/or ratio of cholinergic to catecholaminergic cells in the brain of narcoleptic dogs. Therefore, we sought to characterize the corresponding neuronal populations in normal and narcoleptic dogs (Doberman Pinscher) by using choline acetyltransferase (ChAT), nicotinamide adenosine dinucleotide phosphate (NADPH)-diaphorase, tyrosine hydroxylase (TH), and dopamine beta-hydroxylase (DBH). Cholinergic cell groups were found in an area extending from the central to the gigantocellular tegmental field and the periventricular gray corresponding to the pedunculopontine tegmental nucleus (PPT), the laterodorsal tegmental nucleus (LDT), and the parabrachial nucleus. An almost perfect co-localization of ChAT and NADPH-diaphorase was also observed. Catecholaminergic cell groups detected included the ventral tegmental area, the substantia nigra, and the locus coeruleus nucleus (LC). The anatomical distribution of catecholaminergic neurons was unusual in the dog in two important aspects: i) TH- and/or DBH-immunoreactive neurons of the LC were found almost exclusively in the reticular formation and not within the periventricular gray, ii) very few, if any TH-positive neurons were found in the central gray and dorsal raphe. Quantitative analysis did not reveal any significant differences in the organization and the number of cells identified in the LDT, PPT, and LC of normal and narcoleptic dogs. Moreover, the cholinergic to catecholaminergic ratio was found identical in the two groups. In conclusion, the present results do not support the hypothesis that the neurochemical imbalance in narcolepsy could result from

  20. Bromoenol Lactone Attenuates Nicotine-Induced Breast Cancer Cell Proliferation and Migration

    PubMed Central

    Calderon, Lindsay E.; Liu, Shu; Arnold, Nova; Breakall, Bethany; Rollins, Joseph; Ndinguri, Margaret

    2015-01-01

    Objectives Calcium independent group VIA phospholipase A2 (iPLA2β) and Matrix Metalloproteinase-9 (MMP-9) are upregulated in many disease states; their involvement with cancer cell migration has been a recent subject for study. Further, the molecular mechanisms mediating nicotine-induced breast cancer cell progression have not been fully investigated. This study aims to investigate whether iPLA2β mediates nicotine-induced breast cancer cell proliferation and migration through both in-vitro and in-vivo techniques. Subsequently, the ability of Bromoenol Lactone (BEL) to attenuate the severity of nicotine-induced breast cancer was examined. Method and Results We found that BEL significantly attenuated both basal and nicotine-induced 4T1 breast cancer cell proliferation, via an MTT proliferation assay. Breast cancer cell migration was examined by both a scratch and transwell assay, in which, BEL was found to significantly decrease both basal and nicotine-induced migration. Additionally, nicotine-induced MMP-9 expression was found to be mediated in an iPLA2β dependent manner. These results suggest that iPLA2β plays a critical role in mediating both basal and nicotine-induced breast cancer cell proliferation and migration in-vitro. In an in-vivo mouse breast cancer model, BEL treatment was found to significantly reduce both basal (p<0.05) and nicotine-induced tumor growth (p<0.01). Immunohistochemical analysis showed BEL decreased nicotine-induced MMP-9, HIF-1alpha, and CD31 tumor tissue expression. Subsequently, BEL was observed to reduce nicotine-induced lung metastasis. Conclusion The present study indicates that nicotine-induced migration is mediated by MMP-9 production in an iPLA2β dependent manner. Our data suggests that BEL is a possible chemotherapeutic agent as it was found to reduce both nicotine-induced breast cancer tumor growth and lung metastasis. PMID:26588686

  1. Nicotine-Mediated Ca(2+)-Influx Induces IL-8 Secretion in Oral Squamous Cell Carcinoma Cell.

    PubMed

    Tsunoda, Kou; Tsujino, Ichiro; Koshi, Ryosuke; Sugano, Naoyuki; Sato, Shuichi; Asano, Masatake

    2016-04-01

    Cigarette smoking is one of the most important risk factors for the development of various diseases. Nicotine is the most extensively investigated component of cigarette smoke, and a comprehensive analysis of the genes induced by nicotine stimulation revealed that interleukin-8 (IL-8) was induced in oral squamous cell carcinoma cell (OSCC). Based on this background, the signaling mechanisms of nicotine-mediated IL-8 induction in OSCC was investigated. Augmented IL-8 secretion by Ca9-22 cells was blocked by the NF-κB inhibitor L-1-4'-tosylamino-phenylethyl-chloromethyl ketone (TPCK) and the nicotinic acetylcholine receptor (nAChR)-specific inhibitor α-bungarotoxin (αBtx). The downstream signaling pathway was further examined by pre-incubating the cells with inhibitors against mitogen-activated protein kinase (MEK), protein kinase C (PKC), and Ca(2+)/calmodulin-dependent kinase II (CaMK II). Only the CaMK II inhibitor was found to exert an inhibitory effect on nicotine-mediated IL-8 secretion. Pre-treatment of the Ca9-22 cells with the Ca(2+) chelator BAPTA-AM drastically inhibited IL-8 secretion. Although nicotine stimulation induced the phosphorylation of the NF-κB p65 subunit, pre-treatment with BAPTA-AM was found to inhibit this activity significantly. CaMK II-dependent p65 phosphorylation was confirmed by pre-incubation of the cells with CaMK II inhibitor. The results from this study indicate that the binding of nicotine to nAChR induces Ca(2+) influx, which results in the activation and phosphorylation of CaMK II and NF-κB p65, respectively. Nicotine-mediated IL-8 induction should be a trigger for the initiation of various diseases. PMID:26418512

  2. A Cell Line Producing Recombinant Nerve Growth Factor Evokes Growth Responses in Intrinsic and Grafted Central Cholinergic Neurons

    NASA Astrophysics Data System (ADS)

    Ernfors, Patrik; Ebendal, Ted; Olson, Lars; Mouton, Peter; Stromberg, Ingrid; Persson, Hakan

    1989-06-01

    The rat β nerve growth factor (NGF) gene was inserted into a mammalian expression vector and cotransfected with a plasmid conferring resistance to neomycin into mouse 3T3 fibroblasts. From this transfection a stable cell line was selected that contains several hundred copies of the rat NGF gene and produces excess levels of recombinant NGF. Such genetically modified cells were implanted into the rat brain as a probe for in vivo effects of NGF on central nervous system neurons. In a model of the cortical cholinergic deficits in Alzheimer disease, we demonstrate a marked increase in the survival of, and fiber outgrowth from, grafts of fetal basal forebrain cholinergic neurons, as well as stimulation of fiber formation by intact adult intrinsic cholinergic circuits in the cerebral cortex. Adult cholinergic interneurons in intact striatum also sprout vigorously toward implanted fibroblasts. Our results suggest that this model has implications for future treatment of neurodegenerative diseases.

  3. The distribution and morphological characteristics of cholinergic cells in the brain of monotremes as revealed by ChAT immunohistochemistry.

    PubMed

    Manger, P R; Fahringer, H M; Pettigrew, J D; Siegel, J M

    2002-01-01

    The present study employs choline acetyltransferase (ChAT) immunohistochemistry to identify the cholinergic neuronal population in the central nervous system of the monotremes. Two of the three extant species of monotreme were studied: the platypus (Ornithorhynchus anatinus) and the short-beaked echidna (Tachyglossus aculeatus). The distribution of cholinergic cells in the brain of these two species was virtually identical. Distinct groups of cholinergic cells were observed in the striatum, basal forebrain, habenula, pontomesencephalon, cranial nerve motor nuclei, and spinal cord. In contrast to other tetrapods studied with this technique, we failed to find evidence for cholinergic cells in the hypothalamus, the parabigeminal nucleus (or nucleus isthmus), or the cerebral cortex. The lack of hypothalamic cholinergic neurons creates a hiatus in the continuous antero-posterior aggregation of cholinergic neurons seen in other tetrapods. This hiatus might be functionally related to the phenomenology of monotreme sleep and to the ontogeny of sleep in mammals, as juvenile placental mammals exhibit a similar combination of sleep elements to that found in adult monotremes. PMID:12476054

  4. Cholinergic innervation and receptors in the cerebellum.

    PubMed

    Jaarsma, D; Ruigrok, T J; Caffé, R; Cozzari, C; Levey, A I; Mugnaini, E; Voogd, J

    1997-01-01

    We have studied the source and ultrastructural characteristics of ChAT-immunoreactive fibers in the cerebellum of the rat, and the distribution of muscarinic and nicotinic receptors in the cerebellum of the rat, rabbit, cat and monkey, in order to define which of the cerebellar afferents may use ACh as a neurotransmitter, what target structures are they, and which cholinergic receptor mediate the actions of these pathways. Our data confirm and extend previous observations that cholinergic markers occur at relatively low density in the cerebellum and show not only interspecies variability, but also heterogeneity between cerebellar lobules in the same species. As previously demonstrated by Barmack et al. (1992a,b), the predominant fiber system in the cerebellum that might use ACh as a transmitter or a co-transmitter is formed by mossy fibers originating in the vestibular nuclei and innervating the nodulus and ventral uvula. Our results show that these fibers innervate both granule cells and unipolar brush cells, and that the presumed cholinergic action of these fibers most likely is mediated by nicotinic receptors. In addition to cholinergic mossy fibers, the rat cerebellum is innervated by beaded ChAT-immunoreactive fibers. We have demonstrated that these fibers originate in the pedunculopontine tegmental nucleus (PPTg), the lateral paragigantocellular nucleus (LPGi), and to a lesser extent in various raphe nuclei. In both the cerebellar cortex and the cerebellar nuclei these fibers make asymmetric synaptic junctions with small and medium-sized dendritic profiles. Both muscarinic and nicotinic receptor could mediate the action of these diffuse beaded fibers. In the cerebellar nuclei the beaded cholinergic fibers form a moderately dense network, and could in principle have a significant effect on neuronal activity. For instance, the cholinergic fibers arising in the PPTg may modulate the excitability of the cerebellonuclear neurons in relation to sleep and arousal (e

  5. Effects of estrogen on beta-amyloid-induced cholinergic cell death in the nucleus basalis magnocellularis.

    PubMed

    Szego, Eva M; Csorba, Attila; Janáky, Tamás; Kékesi, Katalin A; Abrahám, István M; Mórotz, Gábor M; Penke, Botond; Palkovits, Miklós; Murvai, Unige; Kellermayer, Miklós S Z; Kardos, József; Juhász, Gábor D

    2011-01-01

    Alzheimer disease is characterized by accumulation of β-amyloid (Aβ) and cognitive dysfunctions linked to early loss of cholinergic neurons. As estrogen-based hormone replacement therapy has beneficial effects on cognition of demented patients, and it may prevent memory impairments, we investigated the effect of estrogen-pretreatment on Aβ-induced cholinergic neurodegeneration in the nucleus basalis magnocellularis (NBM). We tested which Aβ species induces the more pronounced cholinotoxic effect in vivo. We injected different Aβ assemblies in the NBM of mice, and measured cholinergic cell and cortical fiber loss. Spherical Aβ oligomers had the most toxic effect. Pretreatment of ovariectomized mice with estrogen before Aβ injection decreased cholinergic neuron loss and partly prevented fiber degeneration. By using proteomics, we searched for proteins involved in estrogen-mediated protection and in Aβ toxicity 24 h following injection. The change in expression of, e.g., DJ-1, NADH ubiquinone oxidoreductase, ATP synthase, phosphatidylethanolamine-binding protein 1, protein phosphatase 2A and dimethylarginine dimethylaminohydrolase 1 support our hypothesis that Aβ induces mitochondrial dysfunction, decreases MAPK signaling, and increases NOS activation in NBM. On the other hand, altered expression of, e.g., MAP kinase kinase 1 and 2, protein phosphatase 1 and 2A by Aβ might increase MAPK suppression and NOS signaling in the cortical target area. Estrogen pretreatment reversed most of the changes in the proteome in both areas. Our experiments suggest that regulation of the MAPK pathway, mitochondrial pH and NO production may all contribute to Aβ toxicity, and their regulation can be prevented partly by estrogen pretreatment. PMID:20938166

  6. Nicotine-Induced Apoptosis in Human Renal Proximal Tubular Epithelial Cells

    PubMed Central

    Joo, Soo Yeon; Bae, Eun Hui; Ma, Seong Kwon; Lee, JongUn; Kim, Soo Wan

    2016-01-01

    Background Nicotine is, to a large extent, responsible for smoking-mediated renal dysfunction. This study investigated nicotine’s effects on renal tubular epithelial cell apoptosis in vitro and it explored the mechanisms underlying its effects. Methods Human proximal tubular epithelial (HK-2) cells were treated with nicotine. Cell viability was examined by using the WST-1 assay. Intracellular levels of reactive oxygen species (ROS) and the expression of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) proteins were determined. The messenger ribonucleic acid and the protein expression associated with the nicotine acetylcholine receptors (nAChRs) in HK-2 cells was examined, and apoptosis was detected using flow cytometry, cell cycle analysis, and immunoblot analysis. Results The HK-2 cells were endowed with nAChRs. Nicotine treatment reduced cell viability dose dependently, increased ROS levels, and increased extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK expression. Nicotine increased NF-κB activation, which was attenuated by N-acetyl-L-cysteine, and ERK and JNK inhibitors, but was not affected by a p38 MAPK inhibitor. Nicotine increased the Bax/Bcl-2 ratio, which was attenuated by N-acetyl-L-cysteine, the NF-κB inhibitor, Bay 11–7082, and hexamethonium, a non-specific nAChR blocker. Flow cytometry revealed nicotine-induced G2/M phase arrest. While nicotine treatment increased the expression of phosphorylated cdc2 and histone H3, a marker of G2/M phase arrest, hexamethonium and Bay 11–7082 pretreatment reduced their expression. Conclusions Nicotine caused apoptosis in HK-2 cells by inducing ROS generation that activated the NF-κB signaling pathway via the MAPK pathway and it arrested the cell cycle at the G2/M phase. Nicotine-induced apoptosis in HK-2 cells involves the nAChRs. PMID:27028622

  7. Recurrent exposure to nicotine differentiates human bronchial epithelial cells via epidermal growth factor receptor activation

    SciTech Connect

    Martinez-Garcia, Eva; Irigoyen, Marta; Anso, Elena; Martinez-Irujo, Juan Jose; Rouzaut, Ana

    2008-05-01

    Cigarette smoking is the major preventable cause of lung cancer in developed countries. Nicotine (3-(1-methyl-2-pyrrolidinyl)-pyridine) is one of the major alkaloids present in tobacco. Besides its addictive properties, its effects have been described in panoply of cell types. In fact, recent studies have shown that nicotine behaves as a tumor promoter in transformed epithelial cells. This research focuses on the effects of acute repetitive nicotine exposure on normal human bronchial epithelial cells (NHBE cells). Here we show that treatment of NHBE cells with recurrent doses of nicotine up to 500 {mu}M triggered cell differentiation towards a neuronal-like phenotype: cells emitted filopodia and expressed neuronal markers such as neuronal cell adhesion molecule, neurofilament-M and the transcription factors neuronal N and Pax-3. We also demonstrate that nicotine treatment induced NF-kB translocation to the nucleus, phosphorylation of the epidermal growth factor receptor (EGFR), and accumulation of heparin binding-EGF in the extracellular medium. Moreover, addition of AG1478, an inhibitor of EGFR tyrosine phosphorylation, or cetuximab, a monoclonal antibody that precludes ligand binding to the same receptor, prevented cell differentiation by nicotine. Lastly, we show that differentiated cells increased their adhesion to the extracellular matrix and their protease activity. Given that several lung pathologies are strongly related to tobacco consumption, these results may help to better understand the damaging consequences of nicotine exposure.

  8. Protein kinase C-α attenuates cholinergically stimulated gastric acid secretion of rabbit parietal cells

    PubMed Central

    Fährmann, Michael; Kaufhold, Marc; Pfeiffer, Andreas F; Seidler, Ursula

    2003-01-01

    The phorbolester 12-O-tetradecanoyl phorbol-13-acetate (TPA), an activator of protein kinase C (PKC), inhibits cholinergic stimulation of gastric acid secretion. We observed that this effect strongly correlated with the inhibition of Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity in rabbit parietal cells. The aim of this study was to specify the function of PKC-α in cholinergically stimulated H+ secretion. PKC-α represents the only calcium-dependent PKC isoenzyme that has been detected in rabbit parietal cells. Gö 6976, an inhibitor of calcium-dependent PKC, concentration-dependently antagonized the inhibitory effect of TPA, and, therefore, revealed the action of PKC-α on carbachol-induced acid secretion in rabbit parietal cells. TPA exerted no additive inhibition of carbachol-stimulated acid secretion if acid secretion was partially inhibited by the potent CaMKII inhibitor 1-[N,O-bis(5-isoquinolinsulfonyl)-N-methyl-L-tyrosyl]-4-phenyl-piperazine (KN-62). Since both kinase modulators, TPA and KN-62, affected no divergent signal transduction pathways in the parietal cell, an in vitro model has been used to study if PKC directly targets CaMKII. CaMKII purified from parietal cell-containing gastric mucosa of pig, was transphosphorylated by purified cPKC containing PKC-α up to 1.8 mol Pi per mol CaMKII in vitro. The autonomy site of CaMKII was not transphosphorylated by PKC. The phosphotransferase activity of the purified CaMKII was in vitro inhibited after transphosphorylation by PKC if calmodulin was absent during transphosphorylation. Attenuation of CaMKII activity by PKC showed strong similarity to the downregulation of CaMKII by basal autophosphorylation. Our results suggest that PKC-α and CaMKII are closely functionally linked in a cholinergically induced signalling pathway in rabbit parietal cells. We assume that in cholinergically stimulated parietal cells PKC-α transinhibits CaMKII activity, resulting in an attenuation of acid secretion

  9. Effects of nicotine on cellular proliferation, macromolecular synthesis and cell cycle phase distribution in human and murine cells

    SciTech Connect

    Konno, S.; Chiao, J.; Rossi, J.; Wang, C.H.; Wu, J.M.

    1986-05-01

    Addition of nicotine causes a dose- and time-dependent inhibition of cell growth in established human and murine cells. In the human promyelocytic HL-60 leukemic cells, 3 mM nicotine results in a 50% inhibition of cellular proliferation after 80 h. Nicotine was also found to affect the cell cycle distribution of HL-60 cells. Treatment with 4 mM nicotine for 20 h causes an increase in proportion of Gl-phase cells (from 49% to 57%) and a significant decrease in the proportion of S-phase cells (from 41% to 32%). These results suggest that nicotine causes cell arrest in the Gl-phase which may in part account for its effects on cell growth. To determine whether nicotine has a primary effect on the uptake/transport of macromolecular precursors into cells, HL-60 cells were treated with 2-6 mM nicotine for 30 h/sub 3/ at the end of which time cells were labeled with (/sup 3/H)thymidine, (/sup 3/H)uridine, (/sup 14/C)lysine and (/sup 35/S)methionine, the trichloroacetic acid (TCA) soluble and insoluble radioactivities from each of the labeling conditions were determined. These studies show that nicotine primarily affect the synthesis of proteins.

  10. Nicotine prevents the apoptosis induced by menadione in human lung cancer cells

    SciTech Connect

    Zhang Tao; Lu Heng; Shang Xuan; Tian Yihao; Zheng Congyi; Wang Shiwen; Cheng Hanhua . E-mail: hhcheng@whu.edu.cn; Zhou Rongjia . E-mail: rjzhou@whu.edu.cn

    2006-04-14

    Approximately 50% of long-term cigarette smokers die prematurely from the adverse effects of smoking, including on lung cancer and other illnesses. Nicotine is a main component in tobacco and has been implicated as a potential factor in the pathogenesis of human lung cancer. However, the mechanism of nicotine action in the development of lung cancer remains largely unknown. In the present study, we designed a nicotine-apoptosis system, by pre-treatment of nicotine making lung cancer cell A549 to be in a physiological nicotine environment, and observed that nicotine promoted cell proliferation and prevented the menadione-induced apoptosis, and exerts its role of anti-apoptosis by shift of apoptotic stage induced by menadione from late apoptotic stage to early apoptotic stage, in which NF-{kappa}B was up-regulated. Interference analysis of NF-{kappa}B in A549 cells showed that knock down of NF-{kappa}B resulted in apoptosis promotion and counteracted the protective effect of nicotine. The findings suggest that nicotine has potential effect in lung cancer genesis, especially in patients with undetectable early tumor development and development of specific NF-{kappa}B inhibitors would represent a potentially exciting new pharmacotherapy for tobacco-related lung cancer.

  11. Functional interaction between Lypd6 and nicotinic acetylcholine receptors.

    PubMed

    Arvaniti, Maria; Jensen, Majbrit M; Soni, Neeraj; Wang, Hong; Klein, Anders B; Thiriet, Nathalie; Pinborg, Lars H; Muldoon, Pretal P; Wienecke, Jacob; Imad Damaj, M; Kohlmeier, Kristi A; Gondré-Lewis, Marjorie C; Mikkelsen, Jens D; Thomsen, Morten S

    2016-09-01

    Nicotinic acetylcholine receptors (nAChRs) affect multiple physiological functions in the brain and their functions are modulated by regulatory proteins of the Lynx family. Here, we report for the first time a direct interaction of the Lynx protein LY6/PLAUR domain-containing 6 (Lypd6) with nAChRs in human brain extracts, identifying Lypd6 as a novel regulator of nAChR function. Using protein cross-linking and affinity purification from human temporal cortical extracts, we demonstrate that Lypd6 is a synaptically enriched membrane-bound protein that binds to multiple nAChR subtypes in the human brain. Additionally, soluble recombinant Lypd6 protein attenuates nicotine-induced hippocampal inward currents in rat brain slices and decreases nicotine-induced extracellular signal-regulated kinase phosphorylation in PC12 cells, suggesting that binding of Lypd6 is sufficient to inhibit nAChR-mediated intracellular signaling. We further show that perinatal nicotine exposure in rats (4 mg/kg/day through minipumps to dams from embryonic day 7 to post-natal day 21) significantly increases Lypd6 protein levels in the hippocampus in adulthood, which did not occur after exposure to nicotine in adulthood only. Our findings suggest that Lypd6 is a versatile inhibitor of cholinergic signaling in the brain, and that Lypd6 is dysregulated by nicotine exposure during early development. Regulatory proteins of the Lynx family modulate the function of nicotinic receptors (nAChRs). We report for the first time that the Lynx protein Lypd6 binds to nAChRs in human brain extracts, and that recombinant Lypd6 decreases nicotine-induced ERK phosphorylation and attenuates nicotine-induced hippocampal inward currents. Our findings suggest that Lypd6 is a versatile inhibitor of cholinergic signaling in the brain. PMID:27344019

  12. Opioid and nicotine receptors affect growth regulation of human lung cancer cell lines

    SciTech Connect

    Maneckjee, R.; Minna, J.D. Uniformed Services Univ. of the Health Sciences, Bethesda, MD )

    1990-05-01

    Using specific radioactively-labeled ligands, the authors find that lung cancer cell lines of diverse histologic types express multiple, high-affinity membrane receptors for {mu}, {delta}, and {kappa} opioid agonists and for nicotine and {alpha}-bungarotoxin. These receptors are biologically active because cAMP levels decreased in lung cancer cells after opioid and nicotine application. Nicotine at concentrations found in the blood of smokers had no effect on in vitro lung cancer cell growth, whereas {mu}, {delta}, and {kappa} opioid agonists at low concentrations inhibited lung cancer growth in vitro. They also found that lung cancer cells expressed various combinations of immunoreactive opioid peptides ({beta}-endorphin, enkephalin, or dynorphin), suggesting the participation of opioids in a negative autocrine loop or tumor-suppressing system. Due to the almost universal exposure of patients with lung cancer to nicotine, they tested whether nicotine affected the response of lung cancer cell growth to opioids and found that nicotine at concentrations of 100-200 nM partially or totally reversed opioid-induced growth inhibition in 9/14 lung cancer cell lines. These in vitro results for lung cancer cells suggest that opioids could function as part of a tumor suppressor system and that nicotine can function to circumvent this system in the pathogenesis of lung cancer.

  13. Islet-1 Controls the Differentiation of Retinal Bipolar and Cholinergic Amacrine Cells

    PubMed Central

    Elshatory, Yasser; Everhart, Drew; Deng, Min; Xie, Xiaoling; Barlow, Robert B.; Gan, Lin

    2010-01-01

    Whereas the mammalian retina possesses a repertoire of factors known to establish general retinal cell types, these factors alone cannot explain the vast diversity of neuronal subtypes. In other CNS regions, the differentiation of diverse neuronal pools is governed by coordinately acting LIM-homeodomain proteins including the Islet-class factor Islet-1 (Isl1). We report that deletion of Isl1 profoundly disrupts retinal function as assessed by electroretinograms and vision as assessed by optomotor behavior. These deficits are coupled with marked reductions in mature ON- and OFF-bipolar (>76%), cholinergic amacrine (93%), and ganglion (71%) cells. Mosaic deletion of Isl1 permitted a chimeric analysis of “wild-type” cells in a predominantly Isl1-null environment, demonstrating a cell-autonomous role for Isl1 in rod bipolar and cholinergic amacrine development. Furthermore, the effects on bipolar cell development appear to be dissociable from the preceding retinal ganglion cell loss, because Pou4f2-null mice are devoid of similar defects in bipolar cell marker expression. Expression of the ON- and OFF-bipolar cell differentiation factors Bhlhb4 and Vsx1, respectively, requires the presence of Isl1, whereas the early bipolar cell marker Prox1 initially did not. Thus, Isl1 is required for engaging bipolar differentiation pathways but not for general bipolar cell specification. Spatiotemporal expression analysis of additional LIM-homeobox genes identifies a LIM-homeobox gene network during bipolar cell development that includes Lhx3 and Lhx4. We conclude that Isl1 has an indispensable role in retinal neuron differentiation within restricted cell populations and this function may reflect a broader role for other LIM-homeobox genes in retinal development, and perhaps in establishing neuronal subtypes. PMID:18003851

  14. Multiple roles of nicotine on cell proliferation and inhibition of apoptosis: implications on lung carcinogenesis.

    PubMed

    Catassi, A; Servent, D; Paleari, L; Cesario, A; Russo, P

    2008-01-01

    The genotoxic effects of tobacco carcinogens have long been recognized, the contribution of tobacco components to cancerogenesis by cell surface receptor signaling is relatively unexplored. Nicotine, the principal tobacco alkaloid, acts through nicotinic acetylcholine receptor (nAChR). nAChR are functionally present on human lung airway epithelial cells, on lung carcinoma [SCLC and NSCLC] and on mesothelioma and build a part of an autocrine-proliferative network that facilitates the growth of neoplastic cells. Different nAChR subunit gene expression patterns are expressed between NSCLC from smokers and non-smokers. Although there is no evidence that nicotine itself could induce cancer, different studies established that nicotine promotes in vivo the growth of cancer cells and the proliferation of endothelial cells suggesting that nicotine might contribute to the progression of tumors already initiated. These observations led to the hypothesis that nicotine might be playing a direct role in the promotion and progression of human lung cancers. Here, we briefly overview the role and the effects of nicotine on pulmonary cell growth and physiology and its feasible implications in lung carcinogenesis. PMID:18495523

  15. Modulation of spontaneous intracellular Ca²⁺ fluctuations and spontaneous cholinergic transmission in rat chromaffin cells in situ by endogenous GABA acting on GABAA receptors.

    PubMed

    Tzitzitlini, Alejandre-García; Pedro, Segura-Chama; Martha, Pérez-Armendáriz E; Rodolfo, Delgado-Lezama; Arturo, Hernández-Cruz

    2016-02-01

    Using fluorescence [Ca(2+)]i imaging in rat adrenal slices, we characterized the effects of agonists and antagonists of the GABAA receptor (GABAA-R) on resting intracellular Ca(2+) ([Ca(2+)]i) and spontaneous [Ca(2+)]i fluctuations (SCFs) in hundreds of individual chromaffin cells (CCs) recorded simultaneously in situ. Muscimol, a GABAA-R agonist (20 μM; 25 s), induced an increase of resting [Ca(2+)]i in 43 ± 3 % of CCs, a decrease in 26 ± 2 %, and no response in 30 ± 5 %. In Ca(2+)-free external medium, SCFs ceased completely and muscimol failed to elicit [Ca(2+)]i rises. All muscimol-induced [Ca(2+)]i changes were blocked by the GABAA-R antagonist bicuculline, suggesting that they result from changes in membrane potential depending on the cell's Cl(-) equilibrium potential. Unexpectedly, bicuculline increased the amplitude and frequency of SCFs in 54 % of CCs, revealing a tonic inhibition of SCFs by ambient GABA acting through GABAA-R. Mecamylamine (a specific nicotinic cholinergic blocker) decreased basal SCF activity in 18 % of CCs and inhibited bicuculline-induced SCF intensification, suggesting that spontaneous acetylcholine (ACh) release from nerve endings contributes to SCF generation in CCs in situ and that blockade of presynaptic GABAA-Rs intensifies SCFs in part through the disinhibition of spontaneous cholinergic transmission. Electrophysiological experiments confirmed that spontaneous excitatory postsynaptic currents recorded from CCs in situ were enhanced by bicuculline. To our knowledge, this is the first description of a regulatory effect of endogenous GABA on synaptic currents and SCFs of adrenal CCs. These findings denote a novel GABA-mediated presynaptic and postsynaptic regulatory mechanism of CC activity which may participate in the control of catecholamine secretion. PMID:26490458

  16. Basic and clinical aspects of non-neuronal acetylcholine: overview of non-neuronal cholinergic systems and their biological significance.

    PubMed

    Kawashima, Koichiro; Fujii, Takeshi

    2008-02-01

    Acetylcholine (ACh) is a phylogenetically ancient molecule involved in cell-to-cell signaling in almost all life-forms on earth. Cholinergic components, including ACh, choline acetyltransferase, acetylcholinesterase, and muscarinic and nicotinic ACh receptors (mAChRs and nAChRs, respectively) have been identified in numerous non-neuronal cells and tissues, including keratinocytes, cancer cells, immune cells, urinary bladder, airway epithelial cells, vascular endothelial cells, and reproductive organs, among many others. Stimulation of the mAChRs and nAChRs elicits cell-specific functional and biochemical effects. These findings support the notion that non-neuronal cholinergic systems are expressed in certain cells and tissues and are involved in the regulation of their function and that cholinergic dysfunction is related to the pathophysiology of certain diseases. They also provide clues for development of drugs with novel mechanisms of action. PMID:18285657

  17. Nicotine Directly Induces Endoplasmic Reticulum Stress Response in Rat Placental Trophoblast Giant Cells.

    PubMed

    Wong, Michael K; Holloway, Alison C; Hardy, Daniel B

    2016-05-01

    Nicotine exposure during pregnancy leads to placental insufficiency impairing both fetal and neonatal development. Previous studies from our laboratory have demonstrated that in rats, nicotine augmented endoplasmic reticulum (ER) stress in association with placental insufficiency; however, the underlying mechanisms remain elusive. Therefore, we sought to investigate the possible direct effect of nicotine on ER stress in Rcho-1 rat placental trophoblast giant (TG) cells during differentiation. Protein and/or mRNA expression of markers involved in ER stress (eg, phosphorylated PERK, eIF2α, CHOP, and BiP/GRP78) and TG cell differentiation and function (eg, Pl-1, placental growth factor [Pgf], Hsd11b1, and Hsd11b2) were quantified via Western blot or real-time polymerase chain reaction. Nicotine treatment led to dose-dependent increases in the phosphorylation of PERK[Thr981] and eIF2α[Ser51], whereas pretreatment with a nicotinic acetylcholine receptor (nAChR) antagonist (mecamylamine hydrochloride) blocked the induction of PERK phosphorylation, verifying the direct involvement of nicotine and nAChR binding. We next investigated select target genes known to play essential roles in placental TG cell differentiation and function (Pl-1, Pgf, Hsd11b1, and Hsd11b2), and found that nicotine significantly augmented the mRNA levels of Hsd11b1 in a dose-dependent manner. Furthermore, using tauroursodeoxycholic acid, a safe bile acid known to improve protein chaperoning and folding, we were able to prevent nicotine-induced increases in both PERK phosphorylation and Hsd11b1 mRNA levels, revealing a potential novel therapeutic approach to reverse the deleterious effects of nicotine exposure in pregnancy. Collectively, these results implicate that nicotine, acting through its receptor, can directly augment ER stress and impair placental function. PMID:26803847

  18. Effects of Nicotine on Streptococcus gordonii Growth, Biofilm Formation, and Cell Aggregation.

    PubMed

    Huang, R; Li, M; Ye, M; Yang, K; Xu, X; Gregory, R L

    2014-12-01

    Streptococcus gordonii is a commensal species of human oral flora. It initiates dental biofilm formation and provides binding sites for later colonizers to attach to and generate mature biofilm. Smoking is the second highest risk factor for periodontal disease, and cigarette smoke extract has been reported to facilitate Porphyromonas gingivalis-S. gordonii dual-species biofilm formation. Our hypothesis is that nicotine, one of the most important and active components of tobacco, stimulates S. gordonii multiplication and aggregation. In the present study, S. gordonii planktonic cell growth (kinetic absorbance and CFU), biofilm formation (crystal violet stain and confocal laser scanning microscopy [CLSM]), aggregation with/without sucrose, and 11 genes that encode binding proteins or regulators of gene expression were investigated. Results demonstrated planktonic cell growth was stimulated by 1 to 4 mg/ml nicotine treatment. Biofilm formation was increased at 0.5 to 4 mg/ml nicotine. CLSM indicated bacterial cell mass was increased by 2 and 4 mg/ml nicotine, but biofilm extracellular polysaccharide was not significantly affected by nicotine. Cell aggregation was upregulated by 4, 8, and 16 mg/ml nicotine with sucrose and by 16 mg/ml nicotine without sucrose. Quantitative reverse transcriptase PCR indicated S. gordonii abpA, scaA, ccpA, and srtA were upregulated in planktonic cells by 2 mg/ml nicotine. In conclusion, nicotine stimulates S. gordonii planktonic cell growth, biofilm formation, aggregation, and gene expression of binding proteins. Those effects may promote later pathogen attachment to tooth surfaces, the accumulation of tooth calculus, and the development of periodontal disease in cigarette smokers. PMID:25217021

  19. Modulation of secretion by dopamine involves decreases in calcium and nicotinic currents in bovine chromaffin cells.

    PubMed Central

    Sontag, J M; Sanderson, P; Klepper, M; Aunis, D; Takeda, K; Bader, M F

    1990-01-01

    1. Catecholamine secretion from cultured bovine adrenal chromaffin cells was decreased in a dose-dependent manner by the D2 dopamine agonists apomorphine and LY 17 1555. 2. 45Ca2+ uptake was similarly inhibited and whole-cell Ca2+ currents were reduced by apomorphine. 3. These inhibitory effects of D2 agonists depended on the secretagogue used, being much more pronounced for nicotine-evoked responses compared to high K+ stimulation, indicating another possible site of action of apomorphine up-stream of Ca2+ entry. 4. Inhibition by apomorphine of nicotine-evoked responses could not be explained by competitive antagonism against nicotine or DMPP (1,1-dimethyl-4-phenyl-piperazinium iodide). 5. Apomorphine caused reductions of inward whole-cell nicotinic current evoked by ACh and nicotine. 6. Inhibition of nicotine-evoked secretion and 22Na+ influx by apomorphine were not affected by tetrodotoxin, and voltage-dependent, whole-cell Na+ currents were unaltered by apomorphine. 7. No evidence was obtained for increases in K+ conductance by apomorphine. 8. Action potentials recorded in whole-cell current clamp were blocked by apomorphine when they were triggered by nicotinic depolarization but not when they were elicited by direct electrical stimulation. 9. Inclusion of GDP-beta-S in the pipette internal solution did not affect apomorphine-dependent inhibition of nicotinic-evoked responses, while the decrease in whole-cell Ca2+ current induced by apomorphine was completely inhibited in the presence of GDP-beta-S. 10. Increases in cyclic AMP caused by cholera toxin and forskolin did not change the apomorphine-dependent inhibitory effects on nicotine-evoked secretion, indicating that changes in cyclic AMP levels caused by dopamine receptor stimulation are probably not involved. PMID:2170637

  20. Cholinergic afferent stimulation induces axonal function plasticity in adult hippocampal granule cells.

    PubMed

    Martinello, Katiuscia; Huang, Zhuo; Lujan, Rafael; Tran, Baouyen; Watanabe, Masahiko; Cooper, Edward C; Brown, David A; Shah, Mala M

    2015-01-21

    Acetylcholine critically influences hippocampal-dependent learning. Cholinergic fibers innervate hippocampal neuron axons, dendrites, and somata. The effects of acetylcholine on axonal information processing, though, remain unknown. By stimulating cholinergic fibers and making electrophysiological recordings from hippocampal dentate gyrus granule cells, we show that synaptically released acetylcholine preferentially lowered the action potential threshold, enhancing intrinsic excitability and synaptic potential-spike coupling. These effects persisted for at least 30 min after the stimulation paradigm and were due to muscarinic receptor activation. This caused sustained elevation of axonal intracellular Ca(2+) via T-type Ca(2+) channels, as indicated by two-photon imaging. The enhanced Ca(2+) levels inhibited an axonal KV7/M current, decreasing the spike threshold. In support, immunohistochemistry revealed muscarinic M1 receptor, CaV3.2, and KV7.2/7.3 subunit localization in granule cell axons. Since alterations in axonal signaling affect neuronal firing patterns and neurotransmitter release, this is an unreported cellular mechanism by which acetylcholine might, at least partly, enhance cognitive processing. PMID:25578363

  1. Acute and long-term exposure to chlorpyrifos induces cell death of basal forebrain cholinergic neurons through AChE variants alteration.

    PubMed

    del Pino, Javier; Moyano, Paula; Anadon, María José; García, José Manuel; Díaz, María Jesús; García, Jimena; Frejo, María Teresa

    2015-10-01

    Chlorpyrifos (CPF) is one of the most widely used organophosphates insecticides that has been reported to induce cognitive disorders both after acute and repeated administration similar to those induced in Alzheimer's disease (AD). However, the mechanisms through which it induces these effects are unknown. On the other hand, the cholinergic system, mainly basal forebrain cholinergic neurons, is involved in learning and memory regulation, and an alteration of cholinergic transmission or/and cholinergic cell loss could induce these effects. In this regard, it has been reported that CPF can affect cholinergic transmission, and alter AChE variants, which have been shown to be related with basal forebrain cholinergic neuronal loss. According to these data, we hypothesized that CPF could induce basal forebrain cholinergic neuronal loss through cholinergic transmission and AChE variants alteration. To prove this hypothesis, we evaluated in septal SN56 basal forebrain cholinergic neurons, the CPF toxic effects after 24h and 14 days exposure on neuronal viability and the cholinergic mechanisms related to it. This study shows that CPF impaired cholinergic transmission, induced AChE inhibition and, only after long-term exposure, increased CHT expression, which suggests that acetylcholine levels alteration could be mediated by these actions. Moreover, CPF induces, after acute and long-term exposure, cell death in cholinergic neurons in the basal forebrain and this effect is independent of AChE inhibition and acetylcholine alteration, but was mediated partially by AChE variants alteration. Our present results provide a new understanding of the mechanisms contributing to the harmful effects of CPF on neuronal function and viability, and the possible relevance of CPF in the pathogenesis of neurodegenerative diseases. PMID:26210949

  2. Acetylcholine-induced potassium current of guinea pig outer hair cells: its dependence on a calcium influx through nicotinic-like receptors.

    PubMed

    Blanchet, C; Eróstegui, C; Sugasawa, M; Dulon, D

    1996-04-15

    The cholinergic efferent inhibition of mammalian outer hair cells (OHCs) is mediated by a hyperpolarizing K+ current. We have made whole-cell tight-seal recordings from single OHCs isolated from the guinea pig cochlea to characterize the mechanism by which acetylcholine (ACh) activates K+ channels. After ACh application, OHCs exhibited a biphasic response: an early depolarizing current preceding the predominant hyperpolarizing K+ current. The current-voltage (I-V) relationship of the ACh-induced response displayed an N-shape, suggesting the involvement of Ca2+ influx. When whole-cell recording was combined with confocal calcium imaging, we simultaneously observed the ACh-induced K+ current (IK(ACh)) and a Ca2+ response restricted to the synaptic area of the cell. This IK(ACh) could be prevented by loading OHCs with 10 mM of the fast Ca2+ buffer bis(2-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid (or BAPTA), therefore allowing the observation of the ACh-induced early current in isolation. This early current revealed nicotinic features because it activated with an intrinsic delay in the millisecond range, reversed nearly in between potassium and sodium equilibrium potentials, and was blocked by curare. However, it was strongly reduced in the absence of external Ca2+, and its I-V relationship displayed an unusual outward rectification at positive membrane potentials and an inward rectification below -60 mV. The results indicate that the cholinergic response of mammalian OHCs involves a "nicotinic-like" nonspecific cation channel through which Ca2+ enters and triggers activation of nearby Ca2+-dependent K+ channels. PMID:8786433

  3. Cholinergic inhibition of short (outer) hair cells of the chick's cochlea.

    PubMed

    Fuchs, P A; Murrow, B W

    1992-03-01

    Cochlear hair cells are thought to be inhibited by the release of ACh from efferent neurons. Several studies have implicated Ca2+ as a postsynaptic intermediary in hair cell inhibition, but its role remains unproven. We have made whole-cell, tight-seal recordings from single short hair cells (the avian analog of outer hair cells in the mammalian cochlea), isolated from the chick's cochlea, to determine the mechanism of cholinergic inhibition. These cells hyperpolarized upon exposure to ACh, although a brief depolarization preceded the much larger, longer-lasting hyperpolarization. In voltage clamp ACh evoked an outward current that reversed in sign near the K+ equilibrium potential. A small, transient inward current preceded the predominant outward current. The ACh-evoked K+ current depended on Ca2+ in the external saline, or could be prevented when the cell was dialyzed with the rapid Ca2+ buffer BAPTA. In BAPTA-loaded cells a residual inward current was seen. This activated with very little delay upon exposure of the cell to ACh and reversed near 0 mV membrane potential. Thus, the hair cell ACh receptor appears to be a nonspecific cation channel through which Ca2+ enters and triggers the opening of nearby Ca(2+)-activated K+ channels. However, the ACh-evoked K+ channels are not the same as the "maxi" K+ channels activated by Ca2+ influx through voltage-gated Ca2+ channels in these same cells. PMID:1545240

  4. Fetal chlorpyrifos exposure: adverse effects on brain cell development and cholinergic biomarkers emerge postnatally and continue into adolescence and adulthood.

    PubMed Central

    Qiao, Dan; Seidler, Frederic J; Tate, Charlotte A; Cousins, Mandy M; Slotkin, Theodore A

    2003-01-01

    Fetal and childhood exposures to widely used organophosphate pesticides, especially chlorpyrifos (CPF), have raised concerns about developmental neurotoxicity. Previously, biomarkers for brain cell number, cell packing density, and cell size indicated that neonatal rats were more sensitive to CPF than were fetal rats, yet animals exposed prenatally still developed behavioral deficits in adolescence and adulthood. In the present study, we administered CPF to pregnant rats on gestational days 17-20, using regimens devoid of overt fetal toxicity. We then examined subsequent development of acetylcholine systems in forebrain regions involved in cognitive function and compared the effects with those on general biomarkers of cell development. Choline acetyltransferase, a constitutive marker for cholinergic nerve terminals, showed only minor CPF-induced changes during the period of rapid synaptogenesis. In contrast, hemicholinium-3 binding to the presynaptic choline transporter, which is responsive to nerve impulse activity, displayed marked suppression in the animals exposed to CPF; despite a return to nearly normal values by weaning, deficits were again apparent in adolescence and adulthood. There was no compensatory up-regulation of cholinergic receptors, as m2-muscarinic cholinergic receptor binding was unchanged. CPF also elicited delayed-onset alterations in biomarkers for general aspects of cell integrity, with reductions in cell packing density, increases in relative cell size, and contraction of neuritic extensions; however, neither the magnitude nor timing of these changes was predictive of the cholinergic defects. The present findings indicate a wide window of vulnerability of cholinergic systems to CPF, extending from prenatal through postnatal periods, occurring independently of adverse effects on general cellular neurotoxicity. PMID:12676612

  5. Central Insulin Action Activates Kupffer Cells by Suppressing Hepatic Vagal Activation via the Nicotinic Alpha 7 Acetylcholine Receptor.

    PubMed

    Kimura, Kumi; Tanida, Mamoru; Nagata, Naoto; Inaba, Yuka; Watanabe, Hitoshi; Nagashimada, Mayumi; Ota, Tsuguhito; Asahara, Shun-ichiro; Kido, Yoshiaki; Matsumoto, Michihiro; Toshinai, Koji; Nakazato, Masamitsu; Shibamoto, Toshishige; Kaneko, Shuichi; Kasuga, Masato; Inoue, Hiroshi

    2016-03-15

    Central insulin action activates hepatic IL-6/STAT3 signaling, which suppresses the gene expression of hepatic gluconeogenic enzymes. The vagus nerve plays an important role in this centrally mediated hepatic response; however, the precise mechanism underlying this brain-liver interaction is unclear. Here, we present our findings that the vagus nerve suppresses hepatic IL-6/STAT3 signaling via α7-nicotinic acetylcholine receptors (α7-nAchR) on Kupffer cells, and that central insulin action activates hepatic IL-6/STAT3 signaling by suppressing vagal activity. Indeed, central insulin-mediated hepatic IL-6/STAT3 activation and gluconeogenic gene suppression were impeded in mice with hepatic vagotomy, pharmacological cholinergic blockade, or α7-nAchR deficiency. In high-fat diet-induced obese and insulin-resistant mice, control of the vagus nerve by central insulin action was disturbed, inducing a persistent increase of inflammatory cytokines. These findings suggest that dysregulation of the α7-nAchR-mediated control of Kupffer cells by central insulin action may affect the pathogenesis of chronic hepatic inflammation in obesity. PMID:26947072

  6. Nicotine-mediated signals modulate cell death and survival of T lymphocytes

    SciTech Connect

    Oloris, Silvia C.S.; Frazer-Abel, Ashley A.; Jubala, Cristan M.; Fosmire, Susan P.; Helm, Karen M.; Robinson, Sally R.; Korpela, Derek M.; Duckett, Megan M.; Baksh, Shairaz; Modiano, Jaime F.

    2010-02-01

    The capacity of nicotine to affect the behavior of non-neuronal cells through neuronal nicotinic acetylcholine receptors (nAChRs) has been the subject of considerable recent attention. Previously, we showed that exposure to nicotine activates the nuclear factor of activated T cells (NFAT) transcription factor in lymphocytes and endothelial cells, leading to alterations in cellular growth and vascular endothelial growth factor production. Here, we extend these studies to document effects of nicotine on lymphocyte survival. The data show that nicotine induces paradoxical effects that might alternatively enforce survival or trigger apoptosis, suggesting that depending on timing and context, nicotine might act both as a survival factor or as an inducer of apoptosis in normal or transformed lymphocytes, and possibly other non-neuronal cells. In addition, our results show that, while having overlapping functions, low and high affinity nAChRs also transmit signals that promote distinct outcomes in lymphocytes. The sum of our data suggests that selective modulation of nAChRs might be useful to regulate lymphocyte activation and survival in health and disease.

  7. Global actions of nicotine on the striatal microcircuit

    PubMed Central

    Plata, Víctor; Duhne, Mariana; Pérez-Ortega, Jesús; Hernández-Martinez, Ricardo; Rueda-Orozco, Pavel; Galarraga, Elvira; Drucker-Colín, René; Bargas, José

    2013-01-01

    The question to solve in the present work is: what is the predominant action induced by the activation of cholinergic-nicotinic receptors (nAChrs) in the striatal network given that nAChrs are expressed by several elements of the circuit: cortical terminals, dopamine terminals, and various striatal GABAergic interneurons. To answer this question some type of multicellular recording has to be used without losing single cell resolution. Here, we used calcium imaging and nicotine. It is known that in the presence of low micromolar N-Methyl-D-aspartate (NMDA), the striatal microcircuit exhibits neuronal activity consisting in the spontaneous synchronization of different neuron pools that interchange their activity following determined sequences. The striatal circuit also exhibits profuse spontaneous activity in pathological states (without NMDA) such as dopamine depletion. However, in this case, most pathological activity is mostly generated by the same neuron pool. Here, we show that both types of activity are inhibited during the application of nicotine. Nicotine actions were blocked by mecamylamine, a non-specific antagonist of nAChrs. Interestingly, inhibitory actions of nicotine were also blocked by the GABAA-receptor antagonist bicuculline, in which case, the actions of nicotine on the circuit became excitatory and facilitated neuronal synchronization. We conclude that the predominant action of nicotine in the striatal microcircuit is indirect, via the activation of networks of inhibitory interneurons. This action inhibits striatal pathological activity in early Parkinsonian animals almost as potently as L-DOPA. PMID:24223538

  8. Interaction of IFN-γ with Cholinergic Agonists to Modulate Rat and Human Goblet Cell Function

    PubMed Central

    García-Posadas, L; Hodges, RR; Li, D; Shatos, MA; Storr-Paulsen, T; Diebold, Y; Dartt, DA

    2015-01-01

    Goblet cells populate wet-surfaced mucosa including the conjunctiva of the eye, intestine, and nose, among others. These cells function as part of the innate immune system by secreting high molecular weight mucins that interact with environmental constituents including pathogens, allergens, and particulate pollutants. Herein we determined whether IFN-γ, a Th1 cytokine increased in dry eye, alters goblet cell function. Goblet cells from rat and human conjunctiva were cultured. Changes in intracellular [Ca2+] ([Ca2+]i), high molecular weight glycoconjugate secretion, and proliferation were measured after stimulation with IFN-γ with or without the cholinergic agonist carbachol. IFN-γ itself increased [Ca2+]i in rat and human goblet cells and prevented the increase in [Ca2+]i caused by carbachol. Carbachol prevented IFN-γ-mediated increase in [Ca2+]i. This cross-talk between IFN-γ and muscarinic receptors may be partially due to use of the same Ca2+i reservoirs, but also from interaction of signaling pathways proximal to the increase in [Ca2+]i. IFN-γ blocked carbachol-induced high molecular weight glycoconjugate secretion and reduced goblet cell proliferation. We conclude that increased levels of IFN-γ in dry eye disease could explain the lack of goblet cells and mucin deficiency typically found in this pathology. IFN-γ could also function similarly in respiratory and gastrointestinal tracts. PMID:26129651

  9. Prenatal and lactation nicotine exposure affects Sertoli cell and gonadotropin levels in rats.

    PubMed

    Paccola, C C; Miraglia, S M

    2016-02-01

    Nicotine is largely consumed in the world as a component of cigarettes. It can cross the placenta and reach the milk of smoking mothers. This drug induces apoptosis, affects sex hormone secretion, and leads to male infertility. To investigate the exposure to nicotine during the whole intrauterine and lactation phases in Sertoli cells, pregnant rats received nicotine (2 mg/kg per day) through osmotic minipumps. Male offsprings (30, 60, and 90 days old) had blood collected for hormonal analysis (FSH and LH) and their testes submitted for histophatological study, analysis of the frequency of the stages of seminiferous epithelium cycle, immunolabeling of apoptotic epithelial cells (TUNEL and Fas/FasL), analysis of the function and structure of Sertoli cells (respectively using transferrin and vimentin immunolabeling), and analysis of Sertoli-germ cell junctional molecule (β-catenin immunolabeling). The exposure to nicotine increased the FSH and LH plasmatic levels in adult rats. Although nicotine had not changed the number of apoptotic cells, neither in Fas nor FasL expression, it provoked an intense sloughing of epithelial cells and also altered the frequency of some stages of the seminiferous epithelium cycle. Transferrin and β-catenin expressions were not changed, but vimentin was significantly reduced in the early stages of the seminiferous cycle of the nicotine-exposed adult rats. Thus, we concluded that nicotine exposure during all gestational and lactation periods affects the structure of Sertoli cells by events causing intense germ cell sloughing observed in the tubular lumen and can compromise the fertility of the offspring. PMID:26556892

  10. Nicotine recruits glutamate receptors to postsynaptic sites.

    PubMed

    Duan, Jing-Jing; Lozada, Adrian F; Gou, Chen-Yu; Xu, Jing; Chen, Yuan; Berg, Darwin K

    2015-09-01

    Cholinergic neurons project throughout the nervous system and activate nicotinic receptors to modulate synaptic function in ways that shape higher order brain function. The acute effects of nicotinic signaling on long-term synaptic plasticity have been well-characterized. Less well understood is how chronic exposure to low levels of nicotine, such as those encountered by habitual smokers, can alter neural connections to promote addiction and other lasting behavioral effects. We show here that chronic exposure of hippocampal neurons in culture to low levels of nicotine recruits AMPA and NMDA receptors to the cell surface and sequesters them at postsynaptic sites. The receptors include GluA2-containing AMPA receptors, which are responsible for most of the excitatory postsynaptic current mediated by AMPA receptors on the neurons, and include NMDA receptors containing GluN1 and GluN2B subunits. Moreover, we find that the nicotine treatment also increases expression of the presynaptic component synapsin 1 and arranges it in puncta juxtaposed to the additional AMPA and NMDA receptor puncta, suggestive of increases in synaptic contacts. Consistent with increased synaptic input, we find that the nicotine treatment leads to an increase in the excitatory postsynaptic currents mediated by AMPA and NMDA receptors. Further, the increases skew the ratio of excitatory-to-inhibitory input that the cell receives, and this holds both for pyramidal neurons and inhibitory neurons in the hippocampal CA1 region. The GluN2B-containing NMDA receptor redistribution at synapses is associated with a significant increase in GluN2B phosphorylation at Tyr1472, a site known to prevent GluN2B endocytosis. These results suggest that chronic exposure to low levels of nicotine not only alters functional connections but also is likely to change excitability levels across networks. Further, it may increase the propensity for synaptic plasticity, given the increase in synaptic NMDA receptors. PMID

  11. Heterogeneity of phasic cholinergic signaling in neocortical neurons.

    PubMed

    Gulledge, Allan T; Park, Susanna B; Kawaguchi, Yasuo; Stuart, Greg J

    2007-03-01

    Acetylcholine (ACh) is a neurotransmitter critical for normal cognition. Here we demonstrate heterogeneity of cholinergic signaling in neocortical neurons in the rat prefrontal, somatosensory, and visual cortex. Focal ACh application (100 muM) inhibited layer 5 pyramidal neurons in all cortical areas via activation of an apamin-sensitive SK-type calcium-activated potassium conductance. Cholinergic inhibition was most robust in prefrontal layer 5 neurons, where it relies on the same signal transduction mechanism (M1-like receptors, IP(3)-dependent calcium release, and SK-channels) as exists in somatosensory pyramidal neurons. Pyramidal neurons in layer 2/3 were less responsive to ACh, but substantial apamin-sensitive inhibitory responses occurred in deep layer 3 neurons of the visual cortex. ACh was only inhibitory when presented near the somata of layer 5 pyramidal neurons, where repetitive ACh applications generated discrete inhibitory events at frequencies of up to approximately 0.5 Hz. Fast-spiking (FS) nonpyramidal neurons in all cortical areas were unresponsive to ACh. When applied to non-FS interneurons in layers 2/3 and 5, ACh generated mecamylamine-sensitive nicotinic responses (38% of cells), apamin-insensitive hyperpolarizing responses, with or without initial nicotinic depolarization (7% of neurons), or no response at all (55% of cells). Responses in interneurons were similar across cortical layers and regions but were correlated with cellular physiology and the expression of biochemical markers associated with different classes of nonpyramidal neurons. Finally, ACh generated nicotinic responses in all layer 1 neurons tested. These data demonstrate that phasic cholinergic input can directly inhibit projection neurons throughout the cortex while sculpting intracortical processing, especially in superficial layers. PMID:17122323

  12. Global Analysis of Protein Expression and Phosphorylation Levels in Nicotine-Treated Pancreatic Stellate Cells.

    PubMed

    Paulo, Joao A; Gaun, Aleksandr; Gygi, Steven P

    2015-10-01

    Smoking is a risk factor in pancreatic disease; however, the biochemical mechanisms correlating smoking with pancreatic dysfunction remain poorly understood. Strategies using multiplexed isobaric tag-based mass spectrometry facilitate the study of drug-induced perturbations on biological systems. Here, we present the first large-scale analysis of the proteomic and phosphoproteomic alterations in pancreatic stellate cells following treatment with two nicotinic acetylcholine receptor (nAChR) ligands: nicotine and α-bungarotoxin. We treated cells with nicotine or α-bungarotoxin for 12 h in triplicate and compared alterations in protein expression and phosphorylation levels to mock-treated cells using a tandem mass tag (TMT9plex)-based approach. Over 8100 proteins were quantified across all nine samples, of which 46 were altered in abundance upon treatment with nicotine. Proteins with increased abundance included those associated with neurons, defense mechanisms, indicators of pancreatic disease, and lysosomal proteins. In addition, we measured differences for ∼16 000 phosphorylation sites across all nine samples using a titanium dioxide-based strategy, of which 132 sites were altered with nicotine and 451 with α-bungarotoxin treatment. Many altered phosphorylation sites were involved in nuclear function and transcriptional events. This study supports the development of future targeted investigations to establish a better understanding for the role of nicotine and associated receptors in pancreatic disease. PMID:26265067

  13. Global analysis of protein expression and phosphorylation levels in nicotine-treated pancreatic stellate cells

    PubMed Central

    Paulo, Joao A.; Gaun, Aleksandr; Gygi, Steven P.

    2016-01-01

    Smoking is a risk factor in pancreatic disease, however, the biochemical mechanisms correlating smoking with pancreatic dysfunction remain poorly understood. Strategies using multiplexed isobaric tag-based mass spectrometry facilitate the study of drug-induced perturbations on biological systems. Here, we present the first large scale analysis of the proteomic and phosphoproteomic alterations in pancreatic stellate cells following treatment with two nicotinic acetylcholine receptor (nAChR) ligands: nicotine and α-bungarotoxin. We treated cells with nicotine or α-bungarotoxin for 12hr in triplicate and compared alterations in protein expression and phosphorylation levels to mock treated cells using a tandem mass tag (TMT9plex)-based approach. Over 8,100 proteins were quantified across all nine samples of which 46 were altered in abundance upon treatment with nicotine. Proteins with increased abundance included those associated with neurons, defense mechanisms, indicators of pancreatic disease and lysosomal proteins. In addition, we measured differences for ∼16,000 phosphorylation sites across all nine samples using a titanium dioxide-based strategy, of which 132 sites were altered with nicotine and 451 with α-bungarotoxin treatment. Many altered phosphorylation sites were involved in nuclear function and transcriptional events. This study supports the development of future targeted investigations to establish a better understanding for the role of nicotine and associated receptors in pancreatic disease. PMID:26265067

  14. Cell-surface translational dynamics of nicotinic acetylcholine receptors

    PubMed Central

    Barrantes, Francisco J.

    2014-01-01

    Synapse efficacy heavily relies on the number of neurotransmitter receptors available at a given time. In addition to the equilibrium between the biosynthetic production, exocytic delivery and recycling of receptors on the one hand, and the endocytic internalization on the other, lateral diffusion and clustering of receptors at the cell membrane play key roles in determining the amount of active receptors at the synapse. Mobile receptors traffic between reservoir compartments and the synapse by thermally driven Brownian motion, and become immobilized at the peri-synaptic region or the synapse by: (a) clustering mediated by homotropic inter-molecular receptor–receptor associations; (b) heterotropic associations with non-receptor scaffolding proteins or the subjacent cytoskeletal meshwork, leading to diffusional “trapping,” and (c) protein-lipid interactions, particularly with the neutral lipid cholesterol. This review assesses the contribution of some of these mechanisms to the supramolecular organization and dynamics of the paradigm neurotransmitter receptor of muscle and neuronal cells -the nicotinic acetylcholine receptor (nAChR). Currently available information stemming from various complementary biophysical techniques commonly used to interrogate the dynamics of cell-surface components is critically discussed. The translational mobility of nAChRs at the cell surface differs between muscle and neuronal receptors in terms of diffusion coefficients and residence intervals at the synapse, which cover an ample range of time regimes. A peculiar feature of brain α7 nAChR is its ability to spend much of its time confined peri-synaptically, vicinal to glutamatergic (excitatory) and GABAergic (inhibitory) synapses. An important function of the α7 nAChR may thus be visiting the territories of other neurotransmitter receptors, differentially regulating the dynamic equilibrium between excitation and inhibition, depending on its residence time in each domain. PMID

  15. Nicotine Promotes Acquisition of Stem Cell and Epithelial-to-Mesenchymal Properties in Head and Neck Squamous Cell Carcinoma

    PubMed Central

    Rahimy, Elham; Haas, Martin; Yu, Vicky; Ellies, Lesley G.; Chen, Jing; Fan, Jian-Bing; Brumund, Kevin T.; Weisman, Robert A.; Ongkeko, Weg M.

    2012-01-01

    The ability of nicotine to enhance the malignancy of cancer cells is known; however, the possibility that nicotine could regulate a cancer stem cell phenotype remains to be well-established. In this study we sought to determine whether long-term exposure to nicotine could promote cancer stem cell-like properties in two head and neck squamous cell carcinoma cell lines, UMSCC-10B and HN-1. Nicotine treatment induced epithelial-to-mesenchymal transition (EMT) in both cell lines by repressing E-cadherin expression, and led to the induction of stem cell markers Oct-4, Nanog, CD44 and BMI-1, which was reversed upon ectopic re-expression of E-cadherin. Nicotine-treated cells formed spheres at a higher efficiency than non-treated cells, formed larger tumors when injected into mice, and formed tumors with 4-fold greater efficiency compared to control cells when injected at limiting doses. Consistent with previous literature, nicotine-treated cells demonstrated a greater capacity for survival and also a higher tendency to invade. Comparison of microRNA profiles between nicotine and control cells revealed the upregulation of miR-9, a repressor of E-cadherin, and the downregulation of miR-101, a repressor of EZH2. Taken together, these results suggest that nicotine may play a critical role in the development of tobacco-induced cancers by regulating cancer stem cell characteristics, and that these effects are likely mediated through EMT-promoting, microRNA-mediated pathways. Further characterization of such pathways remains a promising avenue for the understanding and treatment of tobacco-related cancers. PMID:23300583

  16. Nicotine mediates oxidative stress and apoptosis through cross talk between NOX1 and Bcl-2 in lung epithelial cells.

    PubMed

    Zanetti, Filippo; Giacomello, Marta; Donati, Yves; Carnesecchi, Stephanie; Frieden, Maud; Barazzone-Argiroffo, Constance

    2014-11-01

    Nicotine contributes to the onset and progression of several pulmonary diseases. Among the various pathophysiological mechanisms triggered by nicotine, oxidative stress and cell death are reported in several cell types. We found that chronic exposure to nicotine (48h) induced NOX1-dependent oxidative stress and apoptosis in primary pulmonary cells. In murine (MLE-12) and human (BEAS-2B) lung epithelial cell lines, nicotine acted as a sensitizer to cell death and synergistically enhanced apoptosis when cells were concomitantly exposed to hyperoxia. The precise signaling pathway was investigated in MLE-12 cells in which NOX1 was abrogated by a specific inhibitor or stably silenced by shRNA. In the early phase of exposure (1h), nicotine mediated intracellular Ca(2+) fluxes and activation of protein kinase C, which in its turn activated NOX1, leading to cellular and mitochondrial oxidative stress. The latter triggered the intrinsic apoptotic machinery by modulating the expression of Bcl-2 and Bax. Overexpression of Bcl-2 completely prevented nicotine's detrimental effects, suggesting Bcl-2as a downstream key regulator in nicotine/NOX1-induced cell damage. These results suggest that NOX1 is a major contributor to the generation of intracellular oxidative stress induced by nicotine and might be an important molecule to target in nicotine-related lung pathologies. PMID:25151121

  17. Cholinergic microvillous cells in the mouse main olfactory epithelium and effect of acetylcholine on olfactory sensory neurons and supporting cells

    PubMed Central

    Ogura, Tatsuya; Szebenyi, Steven A.; Krosnowski, Kurt; Sathyanesan, Aaron; Jackson, Jacqueline

    2011-01-01

    The mammalian olfactory epithelium is made up of ciliated olfactory sensory neurons (OSNs), supporting cells, basal cells, and microvillous cells. Previously, we reported that a population of nonneuronal microvillous cells expresses transient receptor potential channel M5 (TRPM5). Using transgenic mice and immunocytochemical labeling, we identify that these cells are cholinergic, expressing the signature markers of choline acetyltransferase (ChAT) and the vesicular acetylcholine transporter. This result suggests that acetylcholine (ACh) can be synthesized and released locally to modulate activities of neighboring supporting cells and OSNs. In Ca2+ imaging experiments, ACh induced increases in intracellular Ca2+ levels in 78% of isolated supporting cells tested in a concentration-dependent manner. Atropine, a muscarinic ACh receptor (mAChR) antagonist suppressed the ACh responses. In contrast, ACh did not induce or potentiate Ca2+ increases in OSNs. Instead ACh suppressed the Ca2+ increases induced by the adenylyl cyclase activator forskolin in some OSNs. Supporting these results, we found differential expression of mAChR subtypes in supporting cells and OSNs using subtype-specific antibodies against M1 through M5 mAChRs. Furthermore, we found that various chemicals, bacterial lysate, and cold saline induced Ca2+ increases in TRPM5/ChAT-expressing microvillous cells. Taken together, our data suggest that TRPM5/ChAT-expressing microvillous cells react to certain chemical or thermal stimuli and release ACh to modulate activities of neighboring supporting cells and OSNs via mAChRs. Our studies reveal an intrinsic and potentially potent mechanism linking external stimulation to cholinergic modulation of activities in the olfactory epithelium. PMID:21676931

  18. Nicotine exposure induces bronchial epithelial cell apoptosis and senescence via ROS mediated autophagy-impairment.

    PubMed

    Bodas, Manish; Van Westphal, Colin; Carpenter-Thompson, Rhett; K Mohanty, Dillip; Vij, Neeraj

    2016-08-01

    Waterpipe smoking and e-cigarette vaping, the non-combustible sources of inhaled nicotine exposure are increasingly becoming popular and marketed as safer alternative to cigarette smoking. Hence, this study was designed to investigate the impact of inhaled nicotine exposure on disease causing COPD-emphysema mechanisms. For in vitro studies, human bronchial epithelial cells (Beas2b) were treated with waterpipe smoke extract (WPSE, 5%), nicotine (5mM), and/or cysteamine (250μM, an autophagy inducer and anti-oxidant drug), for 6hrs. We observed significantly (p<0.05) increased ubiquitinated protein-accumulation in the insoluble protein fractions of Beas2b cells treated with WPSE or nicotine that could be rescued by cysteamine treatment, suggesting aggresome-formation and autophagy-impairment. Moreover, our data also demonstrate that both WPSE and nicotine exposure significantly (p<0.05) elevates Ub-LC3β co-localization to aggresome-bodies while inducing Ub-p62 co-expression/accumulation, verifying autophagy-impairment. We also found that WPSE and nicotine exposure impacts Beas2b cell viability by significantly (p<0.05) inducing cellular apoptosis/senescence via ROS-activation, as it could be controlled by cysteamine, which is known to have an anti-oxidant property. For murine studies, C57BL/6 mice were administered with inhaled nicotine (intranasal, 500μg/mouse/day for 5 days), as an experimental model of non-combustible nicotine exposure. The inhaled nicotine exposure mediated oxidative-stress induces autophagy-impairment in the murine lungs as seen by significant (p<0.05, n=4) increase in the expression levels of nitrotyrosine protein-adduct (oxidative-stress marker, soluble-fraction) and Ub/p62/VCP (impaired-autophagy marker, insoluble-fraction). Overall, our data shows that nicotine, a common component of WPS, e-cigarette vapor and cigarette smoke, induces bronchial epithelial cell apoptosis and senescence via ROS mediated autophagy-impairment as a potential

  19. Nicotine enhances invasion and metastasis of human colorectal cancer cells through the nicotinic acetylcholine receptor downstream p38 MAPK signaling pathway.

    PubMed

    Xiang, Tao; Fei, Rushan; Wang, Zhe; Shen, Zhonglei; Qian, Jing; Chen, Wenbin

    2016-01-01

    Nicotine as a cigarette component is an established risk factor for colorectal cancer tumorigenesis. The downstream signaling pathways of nicotinic acetylcholine receptors (nAchRs) are believed to be responsible for the cellular effects. In the present study, we evaluated the effects and novel mechanisms for nicotine on the capacity for colorectal cancer cell invasion and metastasis. LOVO and SW620 colorectal cancer cells were stimulated with nicotine in vitro. A Transwell chamber model was applied to detect the capacity for tumor cell invasion. Assays for gelatin zymography and western blotting were applied to detect the activity and expression of metastasis-related matrix metalloproteinases (MMPs), respectively. Signal transduction was assessed by immunoblotting for the phosphorylation of relevant signal molecules and the application of pharmaceutical inhibitors. We showed that nicotine increased LOVO and SW620 colorectal cancer cell invasion along with enhanced activity and expression of MMP-1, -2 and -9. Nicotine increased phosphorylation of p38, ERK, Akt and PI3K p85 but had no effect on phosphorylation of JNK, or NF-κB. Of the pharmaceutical inhibitors of U0126 (ERK1/2 inhibitor), LY294002 (Akt activation inhibitor), SB239063 (p38 MAPK activation inhibitor) and hexamethonium (Hex) (nAchRs inhibitor), the cellular and molecular effects were reduced by the applications of SB239063 and Hex. We concluded that nicotine stimulates the invasion and metastasis of colon cancer cells in vitro via activation of the nAchRs and the p38 MAPK downstream signaling pathway. Therefore, p38 MAPK may have potential as a therapeutic target for smoking-related human colorectal cancer metastasis. PMID:26530054

  20. Further proof of the existence of a non-neuronal cholinergic system in the human Achilles tendon: Presence of the AChRα7 receptor in tendon cells and cells in the peritendinous tissue.

    PubMed

    Forsgren, Sture; Alfredson, Håkan; Andersson, Gustav

    2015-11-01

    Human tendon cells have the capacity for acetylcholine (ACh) production. It is not known if the tendon cells also have the potential for ACh breakdown, nor if they show expression of the nicotinic acetylcholine receptor AChRα7 (α7nAChR). Therefore, tendon tissue specimens from patients with midportion Achilles tendinopathy/tendinosis and from normal midportion Achilles tendons were examined. Reaction for the degradative enzyme acetylcholinesterase (AChE) was found in some tenocytes in only a few tendinopathy tendons, and was never found in those of control tendons. Tenocytes displayed more regularly α7nAChR immunoreactivity. However, there was a marked heterogeneity in the degree of this reaction within and between the specimens. α7nAChR immunoreactivity was especially pronounced for tenocytes showing an oval/widened appearance. There was a tendency that the magnitude of α7nAChR immunoreactivity was higher in tendinopathy tendons as compared to control tendons. A stronger α7nAChR immunoreactivity than seen for tenocytes was observed for the cells in the peritendinous tissue. It is likely that the α7nAChR may be an important part of an auto-and paracrine loop of non-neuronal ACh that is released from the tendon cells. The effects may be related to proliferative and blood vessel regulatory functions as well as features related to collagen deposition. ACh can furthermore be of importance in leading to anti-inflammatory effects in the peritendinous tissue, a tissue nowadays considered to be of great relevance for the tendinopathy process. Overall, the findings show that tendon tissue, a tissue known to be devoid of cholinergic innervation, is a tissue in which there is a marked non-neuronal cholinergic system. PMID:25981114

  1. Protective Effects of Nicotine Against Aminochrome-Induced Toxicity in Substantia Nigra Derived Cells: Implications for Parkinson’s Disease

    PubMed Central

    Muñoz, Patricia; Huenchuguala, Sandro; Paris, Irmgard; Cuevas, Carlos; Villa, Monica; Caviedes, Pablo; Segura-Aguilar, Juan

    2013-01-01

    Parkinson’s disease is a debilitating progressive neurodegenerative disorder that results from the loss of or damage to dopaminergic cells containing neuromelanin in the substantia nigra (SN). The underlying neurodegenerative mechanism(s), however, remain elusive. Aminochrome, the precursor of neuromelanin is an endogenous substance capable of inducing selective neurotoxicity to dopaminergic neurons in SN. Nicotine, on the other hand, may offer protective effects against dopaminergic cell damage induced by various neurotoxins including MPTP and salsolinol. In this study, we sought to determine whether nicotine may also protect against aminochrome-induced toxicity in SN derived RCSN-3 cells. Exposure of RCSN-3 cells to a combination of aminochrome (50 μM) and dicoumarol (50 μM) for 48 h induced approximately 70 % cell death. Pretreatment with nicotine, dose-dependently blocked this toxicity. The effects of nicotine in turn were dose-dependently blocked by mecamylamine, a non-selective nicotinic receptor antagonist. These results suggest involvement of nicotinic receptors in protective effects of nicotine against aminochrome-induced toxicity and provide further evidence for possible therapeutic effects of nicotine or nicotinic agonists in Parkinson’s disease. PMID:22528249

  2. COMPARISON OF WEEKLY EXPOSURES TO ANATOXIN-A AND NICOTINE ON THE MOTOR ACTIVITY OF RATS.

    EPA Science Inventory

    Anatoxin-a is a nicotinic cholinergic agonist that is produced by several genera of cyanobacteria, and has been implicated in several poisoning episodes of wildlife, livestock, domestic animals and people. Previous research on nicotine has obtained tolerance and sensitization ...

  3. Nicotine-mediated cell proliferation and angiogenesis: new twists to an old story.

    PubMed

    Dasgupta, Piyali; Chellappan, Srikumar P

    2006-10-01

    Tobacco smoking is one of the major etiologic factors associated with cancer. While there are many carcinogenic compounds present in tobacco smoke, its main addictive component, nicotine, is not carcinogenic by itself. The addictive properties of nicotine are achieved through the nicotinic acetylcholine receptors (nAChRs) that are widely distributed in the brain and neuromuscular junctions; at the same time, they were found to be expressed in a variety of non-neuronal tissues in the body including those of the lung. Recent studies show that these non-neuronal nAChRs can induce cell proliferation and angiogenesis. Analysis of the molecular mechanisms underlying nicotine-mediated cell proliferation showed the involvement of Src kinase and the scaffolding protein beta-arrestin-1. Further, nAChRs were found to activate the basic components of the cell cycle machinery similar to growth factor receptors. This involved increased binding of Raf-1 kinase to the Rb protein, activation of cyclins D and E as well as induction of proliferative promoters. This article describes pathway involved in nicotine-induced cell proliferation and angiogenesis and the potential steps that are amenable for developing novel anti-cancer therapies. PMID:17102610

  4. Culture conditions affect the cholinergic development of an isolated subpopulation of chick mesencephalic neural crest cells.

    PubMed

    Barald, K F

    1989-10-01

    Although neural crest cells are known to be very responsive to environmental cues during their development, recent evidence indicates that at least some subpopulations may be committed to a specific differentiation program prior to migration. Because the neural crest is composed of a heterogeneous mixture of cells that contributes to many vertebrate cell lineages, assessing the properties of specific subpopulations and the effect of the environment on their development has been difficult. To address this problem, we have isolated a pure subpopulation of chick mesencephalic neural crest cells by fluorescence no-flow cytometry after labeling them with monoclonal antibodies (Mabs) to a 75-kDa cell surface antigen that is associated with high affinity choline uptake. When cultures of chick mesencephalic neural crest cells are labeled with these Mabs and a fluorescent second step antibody, approximately 5% of the cells are antigen-positive (A+). After sorting, 100% of the resulting cultured mesencephalic neural crest cells are A+. The Mabs we used also label all of the neurons of the embryonic chick and quail ciliary ganglion in vivo and in vitro. We have compared the effect of various cell culture media on the isolated neural crest subpopulation and the heterogeneous chick mesencephalic neural crest from which it was derived. A+ cells were passaged and grown in a variety of media, each of which differently affected its characteristics and development. A+ cells proliferated in the presence of 15% fetal bovine serum (FBS) and high concentrations (10-15%) of chick embryo extract, but did not differentiate, although they retained basal levels of choline acetyltransferase (ChAT) activity. However, in chick serum and high (25 mM as opposed to 7 mM) K+, and heart-, iris-, or lung-conditioned medium, all of which are known to promote survival and/or cholinergic development of ciliary ganglion neurons, the cells ceased to proliferate and all of the cells in the culture became

  5. Alpha5 nicotinic acetylcholine receptor mediates nicotine-induced HIF-1α and VEGF expression in non-small cell lung cancer

    SciTech Connect

    Ma, Xiaoli; Jia, Yanfei; Zu, Shanshan; Li, Ruisheng; Jia, Ying; Zhao, Yun; Xiao, Dongjie; Dang, Ningning; Wang, Yunshan

    2014-07-15

    By binding to nicotinic acetylcholine receptors (nAChRs), nicotine induces the proliferation and apoptosis of non-small cell lung cancer (NSCLC). Previous studies have indicated that α5-nAChR is highly associated with lung cancer risk and nicotine dependence. However, the mechanisms through which α5-nAChRs may influence lung carcinogenesis are far from clear. In the present study, we investigated the roles of α5-nAChR in the nicotine-induced expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF). Immunohistochemistry was used to detect the expression of α5-nAChR and HIF-1α in 60 specimens of lung cancer and para-carcinoma tissue. The correlations between the expression levels of α5-nAChR and HIF-1α and other clinicopathological data were analyzed. In a cell line that highly expressed α5-nAChR, the loss of α5-nAChR function by siRNA was used to study whether α5-nAChR is involved in the nicotine-induced expression of HIF-1α and VEGF through the activation of the ERK1/2 and PI3K/Akt signaling pathways. Cell growth was detected using the cell counting kit-8 (CCK-8). α5-nAChR (78.3%) and HIF-1α (88.3%) were both overexpressed in NSCLC, and their expression levels were found to be correlated with each other (P < 0.05). In the A549 cell line, α5-nAChR and HIF-1α were found to be expressed under normal conditions, and their expression levels were significantly increased in response to nicotine treatment. The silencing of α5-nAChR significantly inhibited the nicotine-induced cell proliferation compared with the control group and attenuated the nicotine-induced upregulation of HIF-1α and VEGF, and these effects required the cooperation of the ERK1/2 and PI3K/Akt signaling pathways. These results show that the α5-nAChR/HIF-1α/VEGF axis is involved in nicotine-induced tumor cell proliferation, which suggests that α5-nAChR may serve as a potential anticancer target in nicotine-associated lung cancer. - Highlights

  6. Nicotine-induced resistance of non-small cell lung cancer to treatment--possible mechanisms.

    PubMed

    Czyżykowski, Rafał; Połowinczak-Przybyłek, Joanna; Potemski, Piotr

    2016-01-01

    Cigarette smoking is the leading risk factor of lung cancer. Data from several clinical studies suggest that continuation of smoking during therapy of tobacco-related cancers is associated with lower response rates to chemotherapy and/or radiotherapy, and even with decreased survival. Although nicotine--an addictive component of tobacco--is not a carcinogen, it may influence cancer development and progression or effectiveness of anti-cancer therapy. Several in vitro and in vivo trials have evaluated the influence of nicotine on lung cancer cells. The best known mechanisms by which nicotine impacts cancer biology involve suppression of apoptosis induced by certain drugs or radiation, promotion of proliferation, angiogenesis, invasion and migration of cancer cells. This effect is mainly mediated by membranous nicotinic acetylcholine receptors whose stimulation leads to sustained activation of such intracellular pathways as PI3K/Akt/mTOR, RAS/RAF/MEK/ERK and JAK/STAT, induction of NF-κB activity, enhanced transcription of mitogenic promoters, inhibition of the mitochondrial death pathway or stimulation of pro-angiogenic factors. We herein summarize the mechanisms underlying nicotine's influence on biology of lung cancer cells and the effectiveness of anti-cancer therapy. PMID:26943316

  7. Transplantation of NSC-derived cholinergic neuron-like cells improves cognitive function in APP/PS1 transgenic mice.

    PubMed

    Gu, G; Zhang, W; Li, M; Ni, J; Wang, P

    2015-04-16

    The ability to selectively control the differentiation of neural stem cells (NSCs) into cholinergic neurons in vivo would be an important step toward cell replacement therapy. First, green fluorescent protein (GFP)-NSCs were induced to differentiate into cholinergic neuron-like cells (CNLs) with retinoic acid (RA) pre-induction followed by nerve growth factor (NGF) induction. Then, these CNLs were transplanted into bilateral hippocampus of APP/PS1 transgenic mice. Behavioral parameters showed by Morris water maze (MWM) tests and the percentages of GFP-labeled cholinergic neurons of CNL transplanted mice were compared with those of controls. Brain levels of choline acetyltransferase (ChAT) mRNA and proteins were analyzed by quantitative real-time PCR and Western blotting, ChAT activity and acetylcholine (ACh) concentration were also evaluated by ChAT activity and ACh concentration assay kits. Immunofluorescence analysis showed that 80.3±1.5% NSCs differentiated into CNLs after RA pre-induction followed by NGF induction in vitro. Three months after transplantation, 82.4±6.3% CNLs differentiated into cholinergic neurons in vivo. APP/PS1 mice transplanted with CNLs showed a significant improvement in learning and memory ability compared with control groups at different time points. Furthermore, CNLs transplantation dramatically increased in the expressions of ChAT mRNA and protein, as well ChAT activity and ACh concentration in APP/PS1 mice. Our findings support the prospect of using NSC-derived CNLs in developing therapies for Alzheimer's disease (AD). PMID:25681520

  8. The role of cholinergic and GABAergic medial septal/diagonal band cell populations in the emergence of diencephalic amnesia.

    PubMed

    Roland, J J; Savage, L M

    2009-04-21

    The septohippocampal pathway, which is mostly composed of cholinergic and GABAergic projections between the medial septum/diagonal band (MS/DB) and the hippocampus, has an established role in learning, memory and disorders of cognition. In Wernicke-Korsakoff's syndrome (WKS) and the animal model of the disorder, pyrithiamine-induced thiamine deficiency (PTD), there is both diencephalic damage and basal forebrain cell loss that could contribute to the amnesic state. In the current experiment, we used the PTD animal model to access both cholinergic (choline acetyltransferase [ChAT] immunopositive) and GABAergic (parvalbumin [PV]; calbindin [CaBP]) neuronal loss in the MS/DB in relationship to midline-thalamic pathology. In addition, to gain an understanding about the role of such neuropathology in behavioral dysfunction, animals were tested on a non-rewarded spontaneous alternation task and behavioral performance was correlated to neuropathology. Unbiased stereological assessment of neuronal populations revealed that ChAT-positive neurons were significantly reduced in PTD rats, relative to control pair-fed rats, and thalamic mass and behavioral performance correlated with ChAT neuronal estimates. In contrast, both the PV- and CaBP-positive neurons in the MS/DB were not affected by PTD treatment. These results support an interactive role of both thalamic pathology and cholinergic cell loss in diencephalic amnesia. PMID:19264109

  9. The Role of Cholinergic and GABAergic Medial Septal/Diagonal Band Cell Populations in the Emergence of Diencephalic amnesia

    PubMed Central

    Roland, Jessica J.; Savage, Lisa M.

    2010-01-01

    The septohippocampal pathway, which is mostly comprised of cholinergic and GABAergic projections between the medial septum/diagonal band (MS/DB) and the hippocampus, has an established role in learning, memory and disorders of cognition. In Wernicke-Korsakoff’s syndrome (WKS) and the animal model of the disorder, pyrithiamine-induced thiamine deficiency (PTD), there is both diencephalic damage and basal forebrain cell loss that could contribute to the amnesic state. In the current experiment, we used the PTD animal model to access both cholinergic (choline acetyltransferase [ChAT] immunopositive) and GABAergic (parvalbumin [PV]; calbindin [CaBP]) neuronal loss in the MS/DB in relationship to midline-thalamic pathology. In addition, to gain an understanding about the role of such neuropathology in behavioral dysfunction, animals were tested on a non-rewarded spontaneous alternation task and behavioral performance was correlated to neuropathology. Unbiased stereological assessment of neuronal populations revealed that ChAT-positive neurons were significantly reduced in PTD rats, relative to control pair-fed rats, and thalamic mass and behavioral performance correlated with ChAT neuronal estimates. In contrast, both the PV- and CaBP-positive neurons in the MS/DB were not affected by PTD treatment. These results support an interactive role of both thalamic pathology and cholinergic cell loss in diencephalic amnesia. PMID:19264109

  10. Cholinergic receptor pathways involved in apoptosis, cell proliferation and neuronal differentiation

    PubMed Central

    Resende, Rodrigo R; Adhikari, Avishek

    2009-01-01

    Acetylcholine (ACh) has been shown to modulate neuronal differentiation during early development. Both muscarinic and nicotinic acetylcholine receptors (AChRs) regulate a wide variety of physiological responses, including apoptosis, cellular proliferation and neuronal differentiation. However, the intracellular mechanisms underlying these effects of AChR signaling are not fully understood. It is known that activation of AChRs increase cellular proliferation and neurogenesis and that regulation of intracellular calcium through AChRs may underlie the many functions of ACh. Intriguingly, activation of diverse signaling molecules such as Ras-mitogen-activated protein kinase, phosphatidylinositol 3-kinase-Akt, protein kinase C and c-Src is modulated by AChRs. Here we discuss the roles of ACh in neuronal differentiation, cell proliferation and apoptosis. We also discuss the pathways involved in these processes, as well as the effects of novel endogenous AChRs agonists and strategies to enhance neuronal-differentiation of stem and neural progenitor cells. Further understanding of the intracellular mechanisms underlying AChR signaling may provide insights for novel therapeutic strategies, as abnormal AChR activity is present in many diseases. PMID:19712465

  11. Intracerebellar behavioral interactions between nicotine, cotinine and ethanol in mice

    SciTech Connect

    Dar, M.S.; Li, C. )

    1992-02-26

    Using ethanol-induced motor incoordination as the test response as evaluated by rotorod, possible behavioral interactions between ethanol and (-)-nicotine in the cerebellum, one of the key motor area, were investigated. (-)-Nicotine, 5, 1.25, 0.625 ng/100nL intracerebellarly significantly attenuated motor incoordination due to ethanol in a dose-dependent manner. Similarly, (-)-cotinine, a major metabolite of nicotine, 5, 2.5, and 1.25 ng/100nL, significantly but less marked compared to (-)-nicotine attenuated ethanol-induced motor incoordination. The highest, 5 ng/100nL, dose of (-)-nicotine or (-)-cotinine followed by saline instead of ethanol did not alter normal motor coordination. The attenuation of ethanol-induced motor incoordination by (-)-nicotine and (-)- cotinine was blocked by intracerebellar hexamethonium 1 ug/100nL, a purported nicotinic cholinergic antagonist. The data obtained strongly suggest participation of cerebellar nicotinic cholinergic receptor in the ethanol-induced motor incoordination.

  12. Differentiation of LA-N-5 neuroblastoma cells into cholinergic neurons: methods for differentiation, immunohistochemistry and reporter gene introduction.

    PubMed

    Hill, D P; Robertson, K A

    1998-03-01

    The use of model systems derived from cell lines has been a valuable tool in understanding the molecules and cellular processes that govern differentiation processes (T.R. Breitman, S.E. Selonick, S.J. Collins, Induction of differentiation of the human promyelocytic leukemia cell line (HL-60) by retinoic acid, Proc. Natl. Acad. Sci. USA 77 (1980) 2936-2940 [2]; N. Gomez, S. Traverse, P. Cohen, Identification of a MAP kinase in phaeochromocytoma (PC12) cells, FEBS Lett. 314 (1992) 461-465 [4]). The use of such systems provides an inexpensive, quick and simple way to identify and test molecules that can be further studied in more complex in vivo experiments. Some cell lines such as embryonic stem cells can be induced to differentiate in vitro, however, the differentiation is difficult to control and most often leads to the generation of a wide variety of cell types. Cell lines derived from sources committed to a restricted cell fate provide an opportunity to examine cell growth and differentiation within a specific cell type (G.M. Keller, In vitro differentiation of embryonic stem cells, Curr. Opin. Cell Biol. 7 (1995) 862-869 [10]). In this article we describe a simple system for the differentiation of the human neuroblastoma cell line LA-N-5 into cholinergic neurons using all-trans retinoic acid (G. Han, B. Chang, M.J. Connor, N. Sidell, Enhanced potency of 9-cis versus all-trans retinoic acid to induce the differentiation of human neuroblastoma cells, Differentiation, 59 (1995) 61-69 [5]; D.P. Hill, K.R. Robertson, Characterization of the cholinergic neuronal differentiation of the human neuroblastoma cell line LA-N-5 after treatment with retinoic acid, Dev. Brain Res. 102 (1997) 53-67 [6]; J.A. Robson, N. Sidell, Ultrastructural features of a human neuroblastoma cell line treated with retinoic acid, Neuroscience 14 (1985) 1149-1162 [12]; N. Sidell, C.A. Lucas, G.W. Kreutzberg, Regulation of acetylcholinesterase activity by retinoic acid in a human neuroblastoma

  13. Analgesic and Antineuropathic Drugs Acting Through Central Cholinergic Mechanisms

    PubMed Central

    Bartolini, Alessandro; Cesare Mannelli, Lorenzo Di; Ghelardini, Carla

    2011-01-01

    The role of muscarinic and nicotinic cholinergic receptors in analgesia and neuropathic pain relief is relatively unknown. This review describes how such drugs induce analgesia or alleviate neuropathic pain by acting on the central cholinergic system. Several pharmacological strategies are discussed which increase synthesis and release of acetylcholine (ACh) from cholinergic neurons. The effects of their acute and chronic administration are described. The pharmacological strategies which facilitate the physiological functions of the cholinergic system without altering the normal modulation of cholinergic signals are highlighted. It is proposed that full agonists of muscarinic or nicotinic receptors should be avoided. Their activation is too intense and un-physiological because neuronal signals are distorted when these receptors are constantly activated. Good results can be achieved by using agents that are able to a) increase ACh synthesis, b) partially inhibit cholinesterase activity c) selectively block the autoreceptor or heteroreceptor feedback mechanisms. Activation of M1 subtype muscarinic receptors induces analgesia. Chronic stimulation of nicotinic (N1) receptors has neuronal protective effects. Recent experimental results indicate a relationship between repeated cholinergic stimulation and neurotrophic activation of the glial derived neurotrophic factor (GDNF) family. At least 9 patents covering novel chemicals for cholinergic system modulation and pain control are discussed. PMID:21585331

  14. Striatal cholinergic cell ablation attenuates L-DOPA induced dyskinesia in Parkinsonian mice.

    PubMed

    Won, Lisa; Ding, Yunmin; Singh, Pardeep; Kang, Un Jung

    2014-02-19

    3,4-Dihydroxyphenyl-L-alanine (L-DOPA)-induced dyskinesia (LID) is a debilitating side effect of long-term dopamine replacement therapy in Parkinson's Disease. At present, there are few therapeutic options for treatment of LID and mechanisms contributing to the development and maintenance of these drug-induced motor complications are not well understood. We have previously shown that pharmacological reduction of cholinergic tone attenuates the expression of LID in parkinsonian mice with established dyskinesia after chronic L-DOPA treatment. The present study was undertaken to provide anatomically specific evidence for the role of striatal cholinergic interneurons by ablating them before initiation of L-DOPA treatment and determining whether it decreases LID. We used a novel approach to ablate striatal cholinergic interneurons (ChIs) via Cre-dependent viral expression of the diphtheria toxin A subunit (DT-A) in hemiparkinsonian transgenic mice expressing Cre recombinase under control of the choline acetyltransferase promoter. We show that Cre recombinase-mediated DT-A ablation selectively eliminated ChIs when injected into striatum. The depletion of ChIs markedly attenuated LID without compromising the therapeutic efficacy of L-DOPA. These results provide evidence that ChIs play a key and selective role in LID and that strategies to reduce striatal cholinergic tone may represent a promising approach to decreasing L-DOPA-induced motor complications in Parkinson's disease. PMID:24553948

  15. Generation, Release, and Uptake of the NAD Precursor Nicotinic Acid Riboside by Human Cells.

    PubMed

    Kulikova, Veronika; Shabalin, Konstantin; Nerinovski, Kirill; Dölle, Christian; Niere, Marc; Yakimov, Alexander; Redpath, Philip; Khodorkovskiy, Mikhail; Migaud, Marie E; Ziegler, Mathias; Nikiforov, Andrey

    2015-11-01

    NAD is essential for cellular metabolism and has a key role in various signaling pathways in human cells. To ensure proper control of vital reactions, NAD must be permanently resynthesized. Nicotinamide and nicotinic acid as well as nicotinamide riboside (NR) and nicotinic acid riboside (NAR) are the major precursors for NAD biosynthesis in humans. In this study, we explored whether the ribosides NR and NAR can be generated in human cells. We demonstrate that purified, recombinant human cytosolic 5'-nucleotidases (5'-NTs) CN-II and CN-III, but not CN-IA, can dephosphorylate the mononucleotides nicotinamide mononucleotide and nicotinic acid mononucleotide (NAMN) and thus catalyze NR and NAR formation in vitro. Similar to their counterpart from yeast, Sdt1, the human 5'-NTs require high (millimolar) concentrations of nicotinamide mononucleotide or NAMN for efficient catalysis. Overexpression of FLAG-tagged CN-II and CN-III in HEK293 and HepG2 cells resulted in the formation and release of NAR. However, NAR accumulation in the culture medium of these cells was only detectable under conditions that led to increased NAMN production from nicotinic acid. The amount of NAR released from cells engineered for increased NAMN production was sufficient to maintain viability of surrounding cells unable to use any other NAD precursor. Moreover, we found that untransfected HeLa cells produce and release sufficient amounts of NAR and NR under normal culture conditions. Collectively, our results indicate that cytosolic 5'-NTs participate in the conversion of NAD precursors and establish NR and NAR as integral constituents of human NAD metabolism. In addition, they point to the possibility that different cell types might facilitate each other's NAD supply by providing alternative precursors. PMID:26385918

  16. Nicotine-Mediated Regulation of Nicotinic Acetylcholine Receptors in Non-Small Cell Lung Adenocarcinoma by E2F1 and STAT1 Transcription Factors

    PubMed Central

    Schaal, Courtney; Chellappan, Srikumar

    2016-01-01

    Cigarette smoking is the major risk factor for non-small cell lung cancer (NSCLC), which accounts for 80% of all lung cancers. Nicotine, the addictive component of tobacco smoke, can induce proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), angiogenesis, and survival in NSCLC cell lines, as well as growth and metastasis of NSCLC in mice. This nicotine-mediated tumor progression is facilitated through activation of nicotinic acetylcholine receptors (nAChRs), specifically the α7 subunit; however, how the α7 nAChR gene is regulated in lung adenocarcinoma is not fully clear. Here we demonstrate that the α7 nAChR gene promoter is differentially regulated by E2F and STAT transcription factors through a competitive interplay; E2F1 induces the promoter, while STAT transcription factors repress it by binding to an overlapping site at a region -294 through -463bp upstream of the transcription start site. Treatment of cells with nicotine induced the mRNA and protein levels of α7 nAChR; this could be abrogated by treatment with inhibitors targeting Src, PI3K, MEK, α7 nAChR, CDK4/6 or a disruptor of the Rb-Raf-1 interaction. Further, nicotine–mediated induction of α7 nAChR was reduced when E2F1 was depleted and in contrast elevated when STAT1 was depleted by siRNAs. Interestingly, extracts from e-cigarettes, which have recently emerged as healthier alternatives to traditional cigarette smoking, can also induce α7 nAChR expression in a manner similar to nicotine. These results suggest an autoregulatory feed-forward loop that induces the levels of α7 nAChR upon exposure to nicotine, which enhances the strength of the signal. It can be imagined that such an induction of α7 nAChR contributes to the tumor-promoting functions of nicotine. PMID:27228072

  17. Nicotine: abused substance and therapeutic agent.

    PubMed Central

    Le Houezec, J

    1998-01-01

    Tobacco dependence is a complex phenomenon that is not fully understood. Nicotine is the main alkaloid in tobacco and the addictive compound of tobacco. It can improve both mood and cognitive functioning; these positive effects are strong reinforcements for smokers and contribute to their addiction. Opposite results also have been reported, however, and the effects of nicotine remain controversial. Recent epidemiological and empirical studies have indicated that smoking or nicotine or both may have protective effects against certain diseases. These findings have suggested that nicotine may be used as a therapeutic agent. However, because a variety of nicotinic cholinergic receptors are present in the brain, new agonist compounds may prove to be more effective than nicotine for therapeutic purposes. Studies are reviewed and the suggestion made that nicotine may prove useful as a tool to help us understand normal and pathological brain functioning. PMID:9549250

  18. Additive protective effects of donepezil and nicotine against salsolinol-induced cytotoxicity in SH-SY5Y cells.

    PubMed

    Das, Jharna R; Tizabi, Yousef

    2009-10-01

    Although the etiology of Parkinson's disease (PD) remains elusive, a number of toxins including elevated salsolinol, an endogenous metabolite of dopamine may contribute to its pathology. It was reported recently that nicotine may have protective effects against salsolinol-induced toxicity in human neuroblastoma derived SH-SY5Y cells and that these effects of nicotine are mediated by nicotinic receptors. Donepezil (Aricept) is a reversible non-competitive acetylcholinesterase inhibitor that is approved for use in mild to moderate Alzheimer's disease. The increase in acetylcholine concentrations is believed to be the major contributory factor in donepezil's therapeutic efficacy. However, cholinesterase inhibitors may also directly interact with nicotinic receptors and possess neuroprotective properties. In this study, we sought to determine whether donepezil may have protective effects against salsolinol-induced toxicity in SH-SY5Y cells and whether the combination of donepezil and nicotine may result in additive protection. Moreover, it was of interest to elucidate the role of nicotinic receptors as well as cell cycle and apoptosis in mechanism of action of these compounds. SH-SY5Y cells were exposed to 0.6 mM salsolinol with and without various drug pretreatments for 48 h. Nicotine (50 muM) resulted in approximately 54% protection and donepezil (5 muM) resulted in approximately 40% protection, and the combination of the two resulted in an additive (approximately 93%) protection against salsolinol-induced toxicity. Salsolinol caused an arrest of the cells in G(1)-phase of cell cycle and an increase in apoptotic indices that were blocked by the combination of donepezil and nicotine. Mecamylamine, a non-selective nicotinic receptor antagonist completely blocked the effects of nicotine and partially attenuated the effects of donepezil. A combination of atropine, a muscarinic receptor antagonist and mecamylamine completely blocked the effects of donepezil, indicating

  19. Is the input to a GABAergic or cholinergic synapse the sole asymmetry in rabbit's retinal directional selectivity?

    PubMed

    Grzywacz, N M; Tootle, J S; Amthor, F R

    1997-01-01

    We examined contrast, direction of motion, and concentration dependencies of the effects of GABAergic and cholinergic antagonists, and anticholinesterases on responses to movement of On-Off directionally selective (DS) ganglion cells of the rabbit's retina. The drugs tested were curare and hexamethonium bromide (cholinergic antagonists), physostigmine (anticholinesterase), and picrotoxin (GABAergic antagonist). They all reduced the cells' directional selectivity, while maintaining their preferred-null axis. However, cholinergic antagonists did not block directional selectivity completely even at saturating concentrations. The failure to eliminate directional selectivity was probably not due to an incomplete blockade of cholinergic receptors. In a extension of a Masland and Ames (1976) experiment, saturating concentrations of antagonists blocked the effects of exogenous acetylcholine or nicotine applied during synaptic blockade. Consequently, a noncholinergic pathway may be sufficient to account for at least some directional selectivity. This putative pathway interacts with the cholinergic pathway before spike generation, since physostigmine eliminated directional selectivity at contrasts lower than those saturating responses. This elimination apparently resulted from cholinergic-induced saturation, since reduction of contrast restored directional selectivity. Under picrotoxin, directional selectivity was lost in 33% of the cells regardless of contrast. However, 47% maintained their preferred direction despite saturating concentrations of picrotoxin, and 20% reversed the preferred and null directions. Therefore, models based solely on a GABAergic implementation of Barlow and Levick's asymmetric-inhibition model or solely on a cholinergic implementation of asymmetric-excitation models are not complete models of directional selectivity in the rabbit. We propose an alternate model for this retinal property. PMID:9057267

  20. Otilonium: a potent blocker of neuronal nicotinic ACh receptors in bovine chromaffin cells.

    PubMed Central

    Gandía, L.; Villarroya, M.; Lara, B.; Olmos, V.; Gilabert, J. A.; López, M. G.; Martínez-Sierra, R.; Borges, R.; García, A. G.

    1996-01-01

    1. Otilonium, a clinically useful spasmolytic, behaves as a potent blocker of neuronal nicotinic acetylcholine receptors (AChR) as well as a mild wide-spectrum Ca2+ channel blocker in bovine adrenal chromaffin cells. 2. 45Ca2+ uptake into chromaffin cells stimulated with high K+ (70 mM, 1 min) was blocked by otilonium with an IC50 of 7.6 microM. The drug inhibited the 45Ca2+ uptake stimulated by the nicotinic AChR agonist, dimethylphenylpiperazinium (DMPP) with a 79 fold higher potency (IC50 = 0.096 microM). 3. Whole-cell Ba2+ currents (IBa) through Ca2+ channels of voltage-clamped chromaffin cells were blocked by otilonium with an IC50 of 6.4 microM, very close to that of K(+)-evoked 45Ca2+ uptake. Blockade developed in 10-20 s, almost as a single step and was rapidly and almost fully reversible. 4. Whole-cell nicotinic AChR-mediated currents (250 ms pulses of 100 microM DMPP) applied at 30 s intervals were blocked by otilonium in a concentration-dependent manner, showing an IC50 of 0.36 microM. Blockade was induced in a step-wise manner. Wash out of otilonium allowed a slow recovery of the current, also in discrete steps. 5. In experiments with recordings in the same cells of whole-cell IDMPP, Na+ currents (INa) and Ca2+ currents (ICa), 1 microM otilonium blocked 87% IDMPP, 7% INa and 13% ICa. 6. Otilonium inhibited the K(+)-evoked catecholamine secretory response of superfused bovine chromaffin cells with an IC50 of 10 microM, very close to the IC50 for blockade of K(+)-induced 45Ca2+ uptake and IBa. 7. Otilonium inhibited the secretory responses induced by 10 s pulses of 50 microM DMPP with an IC50 of 7.4 nM. Hexamethonium blocked the DMPP-evoked responses with an IC50 of 29.8 microM, 4,000 fold higher than that of otilonium. 8. In conclusion, otilonium is a potent blocker of nicotinic AChR-mediated responses. The drugs also blocked various subtypes of neuronal voltage-dependent Ca2+ channels at a considerably lower potency. Na+ channels were unaffected by

  1. Cholinergic Machinery as Relevant Target in Acute Lymphoblastic T Leukemia

    PubMed Central

    Dobrovinskaya, Oxana; Valencia-Cruz, Georgina; Castro-Sánchez, Luis; Bonales-Alatorre, Edgar O.; Liñan-Rico, Liliana; Pottosin, Igor

    2016-01-01

    Various types of non-neuronal cells, including tumors, are able to produce acetylcholine (ACh), which acts as an autocrine/paracrine growth factor. T lymphocytes represent a key component of the non-neuronal cholinergic system. T cells-derived ACh is involved in a stimulation of their activation and proliferation, and acts as a regulator of immune response. The aim of the present work was to summarize the data about components of cholinergic machinery in T lymphocytes, with an emphasis on the comparison of healthy and leukemic T cells. Cell lines derived from acute lymphoblastic leukemias of T lineage (T-ALL) were found to produce a considerably higher amount of ACh than healthy T lymphocytes. Additionally, ACh produced by T-ALL is not efficiently hydrolyzed, because acetylcholinesterase (AChE) activity is drastically decreased in these cells. Up-regulation of muscarinic ACh receptors was also demonstrated at expression and functional level, whereas nicotinic ACh receptors seem to play a less important role and not form functional channels in cells derived from T-ALL. We hypothesized that ACh over-produced in T-ALL may act as an autocrine growth factor and play an important role in leukemic clonal expansion through shaping of intracellular Ca2+ signals. We suggest that cholinergic machinery may be attractive targets for new drugs against T-ALL. Specifically, testing of high affinity antagonists of muscarinic ACh receptors as well as antagomiRs, which interfere with miRNAs involved in the suppression of AChE expression, may be the first choice options.

  2. Nicotine induces self-renewal of pancreatic cancer stem cells via neurotransmitter-driven activation of sonic hedgehog signalling.

    PubMed

    Al-Wadei, Mohammed H; Banerjee, Jheelam; Al-Wadei, Hussein A N; Schuller, Hildegard M

    2016-01-01

    A small subpopulation of pancreatic cancer cells with characteristics of stem cells drive tumour initiation, progression and metastasis. A better understanding of the regulation of cancer stem cells may lead to more effective cancer prevention and therapy. We have shown that the proliferation and migration of pancreatic cancer cell lines is activated by the nicotinic receptor-mediated release of stress neurotransmitters, responses reversed by γ-aminobutyric acid (GABA). However, the observed cancer inhibiting effects of GABA will only succeed clinically if GABA inhibits pancreatic cancer stem cells (PCSCs) in addition to the more differentiated cancer cells that comprise the majority of cancer tissues and cell lines. Using PCSCs isolated from two pancreatic cancer patients by cell sorting and by spheroid formation assay from pancreatic cancer cell line Panc-1, we tested the hypothesis that nicotine induces the self-renewal of PCSCs. Nicotinic acetylcholine receptors (nAChRs) α3, α4, α5 and α7 were expressed and chronic exposure to nicotine increased the protein expression of these receptors. Immunoassays showed that PCSCs produced the stress neurotransmitters epinephrine and norepinephrine and the inhibitory neurotransmitter GABA. Chronic nicotine significantly increased the production of stress neurotransmitters and sonic hedgehog (SHH) while inducing Gli1 protein and decreasing GABA. GABA treatment inhibited the induction of SHH and Gli1. Spheroid formation and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide assays showed significant nicotine-induced increases in self renewal and cell proliferation, responses blocked by GABA. Our data suggest that nicotine increases the SHH-mediated malignant potential of PCSCs and that GABA prevents these effects. PMID:26689865

  3. Mutual Control of Cholinergic and Low-Threshold Spike Interneurons in the Striatum

    PubMed Central

    Elghaba, Rasha; Vautrelle, Nicolas; Bracci, Enrico

    2016-01-01

    The striatum is the largest nucleus of the basal ganglia and is crucially involved in action selection and reward processing. Cortical and thalamic inputs to the striatum are processed by local networks in which several classes of interneurons play an important, but still poorly understood role. Here we investigated the interactions between cholinergic and low-threshold spike (LTS) interneurons. LTS interneurons were hyperpolarized by co-application of muscarinic and nicotinic receptor antagonists (atropine and mecamylamine, respectively). Mecamylamine alone also caused hyperpolarizations, while atropine alone caused depolarizations and increased firing. LTS interneurons were also under control of tonic GABA, as application of the GABAA receptor antagonist picrotoxin caused depolarizations and increased firing. Frequency of spontaneous GABAergic events in LTS interneurons was increased by co-application of atropine and mecamylamine or by atropine alone, but reduced by mecamylamine alone. In the presence of picrotoxin and tetrodotoxin (TTX), atropine and mecamylamine depolarized the LTS interneurons. We concluded that part of the excitatory effects of tonic acetylcholine (ACh) on LTS interneurons were due to cholinergic modulation of tonic GABA. We then studied the influence of LTS interneurons on cholinergic interneurons. Application of antagonists of somatostatin or neuropeptide Y (NPY) receptors or of an inhibitor of nitric oxide synthase (L-NAME) did not cause detectable effects in cholinergic interneurons. However, prolonged synchronized depolarizations of LTS interneurons (elicited with optogenetics tools) caused slow-onset depolarizations in cholinergic interneurons, which were often accompanied by strong action potential firing and were fully abolished by L-NAME. Thus, a mutual excitatory influence exists between LTS and cholinergic interneurons in the striatum, providing an opportunity for sustained activation of the two cell types. This activation may

  4. Basic and modern concepts on cholinergic receptor: A review

    PubMed Central

    Tiwari, Prashant; Dwivedi, Shubhangi; Singh, Mukesh Pratap; Mishra, Rahul; Chandy, Anish

    2013-01-01

    Cholinergic system is an important system and a branch of the autonomic nervous system which plays an important role in memory, digestion, control of heart beat, blood pressure, movement and many other functions. This article serves as both structural and functional sources of information regarding cholinergic receptors and provides a detailed understanding of the determinants governing specificity of muscarinic and nicotinic receptor to researchers. The study helps to give overall information about the fundamentals of the cholinergic system, its receptors and ongoing research in this field.

  5. Nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone induce cyclooxygenase-2 activity in human gastric cancer cells: Involvement of nicotinic acetylcholine receptor (nAChR) and {beta}-adrenergic receptor signaling pathways

    SciTech Connect

    Shin, Vivian Yvonne; Jin, H.C.; Ng, Enders K.O.; Yu Jun; Leung, W.K.; Cho, C.H.; Sung, J.J.Y.

    2008-12-01

    Induction of cyclooxygenase-2 (COX-2) associates with cigarette smoke exposure in many malignancies. Nicotine and its derivative, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are the two important components in cigarette smoke that contributes to cancer development. However, the molecular mechanism(s) by which nicotine or NNK promotes gastric carcinogenesis remains largely unknown. We found that nicotine and NNK significantly enhanced cell proliferation in AGS cells that expressed both alpha7 nicotinic acetylcholine receptor ({alpha}7 nAChR) and {beta}-adrenergic receptors. Treatment of cells with {alpha}-bungarotoxin ({alpha}-BTX, {alpha}7nAChR antagonist) or propranolol ({beta}-adrenergic receptor antagonist) blocked NNK-induced COX-2/PGE{sub 2} and cell proliferation, while nicotine-mediated cell growth and COX-2/PGE{sub 2} induction can only be suppressed by propranolol, but not {alpha}-BTX. Moreover, in contrast to the dependence of growth promoting effect of nicotine on Erk activation, inhibitor of p38 mitogen-activated protein kinase (MAPK) repressed NNK-induced COX-2 upregulation and resulted in suppression of cell growth. In addition, nicotine and NNK mediated COX-2 induction via different receptors to modulate several G1/S transition regulatory proteins and promote gastric cancer cell growth. Selective COX-2 inhibitor (SC-236) caused G1 arrest and abrogated nicotine/NNK-induced cell proliferation. Aberrant expression of cyclin D1 and other G1 regulatory proteins are reversed by blockade of COX-2. These results pointed to the importance of adrenergic and nicotinic receptors in gastric tumor growth through MAPK/COX-2 activation, which may perhaps provide a chemoprevention strategy for cigarette smoke-related gastric carcinogenesis.

  6. Nicotine inhibits collagen synthesis and alkaline phosphatase activity, but stimulates DNA synthesis in osteoblast-like cells

    SciTech Connect

    Ramp, W.K.; Lenz, L.G.; Galvin, R.J. )

    1991-05-01

    Use of smokeless tobacco is associated with various oral lesions including periodontal damage and alveolar bone loss. This study was performed to test the effects of nicotine on bone-forming cells at concentrations that occur in the saliva of smokeless tobacco users. Confluent cultures of osteoblast-like cells isolated from chick embryo calvariae were incubated for 2 days with nicotine added to the culture medium (25-600 micrograms/ml). Nicotine inhibited alkaline phosphatase in the cell layer and released to the medium, whereas glycolysis (as indexed by lactate production) was unaffected or slightly elevated. The effects on medium and cell layer alkaline phosphatase were concentration dependent with maximal inhibition occurring at 600 micrograms nicotine/ml. Nicotine essentially did not affect the noncollagenous protein content of the cell layer, but did inhibit collagen synthesis (hydroxylation of ({sup 3}H)proline and collagenase-digestible protein) at 100, 300, and 600 micrograms/ml. Release of ({sup 3}H)hydroxyproline to the medium was also decreased in a dose-dependent manner, as was the collagenase-digestible protein for both the medium and cell layer. In contrast, DNA synthesis (incorporation of ({sup 3}H)thymidine) was more than doubled by the alkaloid, whereas total DNA content was slightly inhibited at 600 micrograms/ml, suggesting stimulated cell turnover. Morphologic changes occurred in nicotine-treated cells including rounding up, detachment, and the occurrence of numerous large vacuoles. These results suggest that steps to reduce the salivary concentration of nicotine in smokeless tobacco users might diminish damaging effects of this product on alveolar bone.

  7. Intracellular ion concentrations and cell volume during cholinergic stimulation of eccrine secretory coil cells

    SciTech Connect

    Takemura, T.; Sato, F.; Saga, K.; Suzuki, Y.; Sato, K. )

    1991-02-01

    Methacholine (MCh)-induced changes in intracellular concentrations of Na, K, and Cl (( Na)i, (K)i, and (Cl)i, respectively) and in cellular dry mass (a measure of cell shrinkage) were examined in isolated monkey eccrine sweat secretory coils by electron probe X-ray microanalysis using the peripheral standard method. To further confirm the occurrence of cell shrinkage during MCh stimulation, the change in cell volume of dissociated clear and dark cells were directly determined under a light microscope equipped with differential interference contrast (DIC) optics. X-ray microanalysis revealed a biphasic increase in cellular dry mass in clear cells during continuous MCh stimulation; an initial increase of dry mass to 158% (of control) followed by a plateau at 140%, which correspond to the decrease in cell volume of 37 and 29%, respectively. The latter agrees with the MCh-induced cell shrinkage of 29% in dissociated clear cells. The MCh-induced increase in dry mass in myoepithelial cells was less than half that of clear cells. During the steady state of MCh stimulation, both (K+)i and (Cl)i of clear cells decreased by about 45%, whereas (Na)i increased in such a way to maintain the sum of (Na) i + (K)i constant. There was a small (12-15 mM) increase in (Na)i and a decrease in (K)i in myoepithelial cells during stimulation with MCh. Dissociated dark cells failed to significantly shrink during MCh stimulation. The decrease in (Cl)i in the face of constant (Na)i + (K)i suggests the accumulation of unknown anion(s) inside the clear cell during MCh stimulation.

  8. 6-hydroxy-nicotine-inducible multilevel transgene control in mammalian cells.

    PubMed

    Malphettes, Laetitia; Schoenmakers, Ronald G; Fussenegger, Martin

    2006-11-01

    The precise control of transgene expression is essential for biopharmaceutical manufacturing, gene therapy and tissue engineering. We have designed a novel conditional transcription technology, which enables reversible induction, repression and adjustment of desired transgene expression using the clinically inert 6-hydroxy-nicotine (6HNic). The 6-hydroxy-nicotine oxidase (6HNO) repressor (HdnoR), which manages nicotine metabolism in Arthrobacter nicotinovorans pAO1 by binding to a specific operator of the 6-hydroxy-nicotine oxidase (O(NIC)), was fused to the Krueppel-associated box protein of the human kox-1 gene (KRAB) to create a synthetic 6HNic-dependent transsilencer (NS) that controls chimeric mammalian promoters, which are assembled by cloning tandem O(NIC) operators 3' of a constitutive promoter. In the absence of 6HNic, NS binds to O(NIC) and silences the constitutive promoter, which otherwise drives high-level transgene expression when the NS-O(NIC) interaction stops in the presence of 6HNic. Generic NICE(ON) technology was compatible with a variety of constitutive viral and mammalian housekeeping promoters, each of which enabled specific induced, repressed, adjusted and reversible transgene expression profiles in Chinese hamster ovary (CHO-K1), baby hamster kidney (BHK-21) as well as in human fibrosarcoma (HT-1080) cells. NICE(ON) also proved successful in controlling multicistronic expression units for coordinated transcription of up to three transgenes and in the fine-tuning of transcription-translation networks, in which RNA polymerase II- and III-dependent promoters, engineered for 6HNic responsiveness, drove expression of siRNAs that triggered specific transgene knockdown. NICE(ON) represents a robust and versatile technology for the precise tuning of transgene expression in mammalian cells. PMID:16962351

  9. Maternal antioxidants prevent beta cell apoptosis and promote formation of dual hormone-expressing endocrine cells in male offspring following fetal and neonatal nicotine exposure

    PubMed Central

    BRUIN, Jennifer E; WOYNILLOWICZ, Amanda K; HETTINGA, Bart P; TARNOPOLSKY, Mark A; MORRISON, Katherine M; GERSTEIN, Hertzel C; HOLLOWAY, Alison C

    2013-01-01

    Aim Fetal and neonatal nicotine exposure causes beta cell oxidative stress and apoptosis in neonates, leading to adult-onset dysglycemia. The goal of this study was to determine whether an antioxidant intervention could prevent nicotine-induced beta cell loss. Methods Nulliparous female Wistar rats received daily subcutaneous injections of either saline or nicotine bitartrate (1.0 mg/kg/d) for 2 weeks prior to mating until weaning. Nicotine-exposed dams received either normal chow or diet containing antioxidants (1000 IU/kg vitamin E, 0.25% w/w coenzyme Q10 and 0.1% w/w alpha-lipoic acid) during mating, pregnancy and lactation; saline-exposed dams received normal chow. Pancreas tissue was collected from male offspring at 3 weeks of age to measure beta cell fraction, apoptosis, proliferation and the presence of cells co-expressing insulin and glucagon. Results The birth weight of the offspring born to nicotine-exposed dams receiving dietary antioxidants was significantly reduced. Most interestingly, the antioxidant intervention to nicotine-exposed dams prevented the beta cell loss and apoptosis observed in nicotine exposed male offspring whose mothers did not receive antioxidants. Male pups born to nicotine-treated mothers receiving antioxidants also had a trend towards increased beta cell proliferation and a significant increase in islets containing insulin/glucagon bi-hormonal cells relative to the other two treatment groups. Conclusion This study demonstrates that exposure to maternal antioxidants protects beta cells from the damaging effects of nicotine thus preserving beta cell mass. PMID:22385833

  10. Increase in cholinergic modulation with pyridostigmine induces anti-inflammatory cell recruitment soon after acute myocardial infarction in rats.

    PubMed

    Rocha, Juraci Aparecida; Ribeiro, Susan Pereira; França, Cristiane Miranda; Coelho, Otávio; Alves, Gisele; Lacchini, Silvia; Kallás, Esper Georges; Irigoyen, Maria Cláudia; Consolim-Colombo, Fernanda M

    2016-04-15

    We tested the hypothesis that an increase in the anti-inflammatory cholinergic pathway, when induced by pyridostigmine (PY), may modulate subtypes of lymphocytes (CD4+, CD8+, FOXP3+) and macrophages (M1/M2) soon after myocardial infarction (MI) in rats. Wistar rats, randomly allocated to receive PY (40 mg·kg(-1)·day(-1)) in drinking water or to stay without treatment, were followed for 4 days and then were subjected to ligation of the left coronary artery. The groups-denominated as the pyridostigmine-treated infarcted (IP) and infarcted control (I) groups-were submitted to euthanasia 3 days after MI; the heart was removed for immunohistochemistry, and the peripheral blood and spleen were collected for flow cytometry analysis. Noninfarcted and untreated rats were used as controls (C Group). Echocardiographic measurements were registered on the second day after MI, and heart rate variability was measured on the third day after MI. The infarcted groups had similar MI areas, degrees of systolic dysfunction, blood pressures, and heart rates. Compared with the I Group, the IP Group showed a significant higher parasympathetic modulation and a lower sympathetic modulation, which were associated with a small, but significant, increase in diastolic function. The IP Group showed a significant increase in M2 macrophages and FOXP3(+)cells in the infarcted and peri-infarcted areas, a significantly higher frequency of circulating Treg cells (CD4(+)CD25(+)FOXP3(+)), and a less extreme decrease in conventional T cells (CD25(+)FOXP3(-)) compared with the I Group. Therefore, increasing cholinergic modulation with PY induces greater anti-inflammatory cell recruitment soon after MY in rats. PMID:26791829

  11. Nicotine induces cell proliferation in association with cyclin D1 up-regulation and inhibits cell differentiation in association with p53 regulation in a murine pre-osteoblastic cell line

    SciTech Connect

    Sato, Tsuyoshi Abe, Takahiro; Nakamoto, Norimichi; Tomaru, Yasuhisa; Koshikiya, Noboru; Nojima, Junya; Kokabu, Shoichiro; Sakata, Yasuaki; Kobayashi, Akio; Yoda, Tetsuya

    2008-12-05

    Recent studies have suggested that nicotine critically affects bone metabolism. Many studies have examined the effects of nicotine on proliferation and differentiation, but the underlying molecular mechanisms remain unclear. We examined cell cycle regulators involved in the proliferation and differentiation of MC3T3-E1 cells. Nicotine induced cell proliferation in association with p53 down-regulation and cyclin D1 up-regulation. In differentiated cells, nicotine reduced alkaline phosphatase activity and mineralized nodule formation in dose-dependent manners. Furthermore, p53 expression was sustained in nicotine-treated cells during differentiation. These findings indicate that nicotine promotes the cell cycle and inhibits differentiation in association with p53 regulation in pre-osteoblastic cells.

  12. The Pro-Proliferative Effects of Nicotine and Its Underlying Mechanism on Rat Airway Smooth Muscle Cells

    PubMed Central

    He, Fang; Li, Bing; Zhao, Zhuxiang; Zhou, Yumin; Hu, Guoping; Zou, Weifeng; Hong, Wei; Zou, Yimin; Jiang, Changbin; Zhao, Dongxing; Ran, Pixin

    2014-01-01

    Recent studies have shown that nicotine, a major component of cigarette smoke, can stimulate the proliferation of non-neuronal cells. Cigarette smoking can promote a variety of pulmonary and cardiovascular diseases, such as chronic obstructive pulmonary disease (COPD), atherosclerosis, and cancer. A predominant feature of COPD is airway remodeling, which includes increased airway smooth muscle (ASM) mass. The mechanisms underlying ASM remodeling in COPD have not yet been fully elucidated. Here, we show that nicotine induces a profound and time-dependent increase in DNA synthesis in rat airway smooth muscle cells (RASMCs) in vitro. Nicotine also significantly increased the number of RASMCs, which was associated with the increased expression of Cyclin D1, phosphorylation of the retinoblastoma protein (RB) and was dependent on the activation of Akt. The activation of Akt by nicotine occurred within minutes and depended upon the nicotinic acetylcholine receptors (nAchRs). Activated Akt increased the phosphorylation of downstream substrates such as GSK3β. Our data suggest that the binding of nicotine to the nAchRs on RASMCs can regulate cellular proliferation by activating the Akt pathway. PMID:24690900

  13. Cholinergic Responses and Intrinsic Membrane Properties of Developing Thalamic Parafascicular Neurons

    PubMed Central

    Ye, Meijun; Hayar, Abdallah; Garcia-Rill, Edgar

    2009-01-01

    Parafascicular (Pf) neurons receive cholinergic input from the pedunculopontine nucleus (PPN), which is active during waking and REM sleep. There is a developmental decrease in REM sleep in humans between birth and puberty and 10–30 days in rat. Previous studies have established an increase in muscarinic and 5-HT1 serotonergic receptor–mediated inhibition and a transition from excitatory to inhibitory GABAA responses in the PPN during the developmental decrease in REM sleep. However, no studies have been conducted on the responses of Pf cells to the cholinergic input from the PPN during development, which is a major target of ascending cholinergic projections and may be an important mechanism for the generation of rhythmic oscillations in the cortex. Whole cell patch-clamp recordings were performed in 9- to 20-day-old rat Pf neurons in parasagittal slices, and responses to the cholinergic agonist carbachol (CAR) were determined. Three types of responses were identified: inhibitory (55.3%), excitatory (31.1%), and biphasic (fast inhibitory followed by slow excitatory, 6.8%), whereas 6.8% of cells showed no response. The proportion of CAR-inhibited Pf neurons increased with development. Experiments using cholinergic antagonists showed that M2 receptors mediated the inhibitory response, whereas excitatory modulation involved M1, nicotinic, and probably M3 or M5 receptors, and the biphasic response was caused by the activation of multiple types of muscarinic receptors. Compared with CAR-inhibited cells, CAR-excited Pf cells showed 1) a decreased membrane time constant, 2) higher density of hyperpolarization-activated channels (Ih), 3) lower input resistance (Rin), 4) lower action potential threshold, and 5) shorter half-width duration of action potentials. Some Pf cells exhibited spikelets, and all were excited by CAR. During development, we observed decreases in Ih density, Rin, time constant, and action potential half-width. These results suggest that cholinergic

  14. Cholinergic responses and intrinsic membrane properties of developing thalamic parafascicular neurons.

    PubMed

    Ye, Meijun; Hayar, Abdallah; Garcia-Rill, Edgar

    2009-08-01

    Parafascicular (Pf) neurons receive cholinergic input from the pedunculopontine nucleus (PPN), which is active during waking and REM sleep. There is a developmental decrease in REM sleep in humans between birth and puberty and 10-30 days in rat. Previous studies have established an increase in muscarinic and 5-HT1 serotonergic receptor-mediated inhibition and a transition from excitatory to inhibitory GABA(A) responses in the PPN during the developmental decrease in REM sleep. However, no studies have been conducted on the responses of Pf cells to the cholinergic input from the PPN during development, which is a major target of ascending cholinergic projections and may be an important mechanism for the generation of rhythmic oscillations in the cortex. Whole cell patch-clamp recordings were performed in 9- to 20-day-old rat Pf neurons in parasagittal slices, and responses to the cholinergic agonist carbachol (CAR) were determined. Three types of responses were identified: inhibitory (55.3%), excitatory (31.1%), and biphasic (fast inhibitory followed by slow excitatory, 6.8%), whereas 6.8% of cells showed no response. The proportion of CAR-inhibited Pf neurons increased with development. Experiments using cholinergic antagonists showed that M2 receptors mediated the inhibitory response, whereas excitatory modulation involved M1, nicotinic, and probably M3 or M5 receptors, and the biphasic response was caused by the activation of multiple types of muscarinic receptors. Compared with CAR-inhibited cells, CAR-excited Pf cells showed 1) a decreased membrane time constant, 2) higher density of hyperpolarization-activated channels (I(h)), 3) lower input resistance (R(in)), 4) lower action potential threshold, and 5) shorter half-width duration of action potentials. Some Pf cells exhibited spikelets, and all were excited by CAR. During development, we observed decreases in I(h) density, R(in), time constant, and action potential half-width. These results suggest that

  15. CYTOKINE-INDUCED ALTERATIONS OF α7 NICOTINIC RECEPTOR IN COLONIC CD4 T CELLS MEDIATE DICHOTOMOUS RESPONSE TO NICOTINE IN MURINE MODELS OF Th1/Th17 VS. Th2-MEDIATED COLITIS

    PubMed Central

    Galitovskiy, Valentin; Qian, Jing; Chernyavsky, Alexander I.; Marchenko, Steve; Gindi, Vivian; Edwards, Robert A.; Grando, Sergei A.

    2014-01-01

    Ulcerative colitis (UC) and Crohn’s disease (CD) are two forms of chronic inflammatory bowel disease. CD4 T cells play a central role in the pathogenesis of both diseases. Smoking affects both UC and CD but with opposite effects, ameliorating UC and worsening CD. We hypothesized that the severity of gut inflammation could be modulated through T-cell nicotinic acetylcholine receptors (nAChRs) and that the exact clinical outcome would depend on the repertoire of nAChRs on CD4 T cells mediating each form of colitis. We measured clinical and immunologic outcomes of treating BALB/c mice with oxazolone- and TNBS-induced colitides by nicotine. Nicotine attenuated oxazolone colitis, which was associated with increased percentage of colonic Tregs and a reduction of Th17 cells. TCR stimulation of naïve CD4+CD62L+ T cells in the presence of nicotine upregulated expression of Foxp3. In marked contrast, nicotine worsened TNBS colitis, and this was associated with increased Th17 cells among colonic CD4 T cells. Nicotine upregulated IL-10 and inhibited IL-17 production, which could be abolished by exogenous IL-12 that also abolished the nicotine-dependent upregulation of Tregs. The dichotomous action of nicotine resulted from the up- and downregulation of anti-inflammatory α7 nAChR on colonic CD4 T cells induced by cytokines characteristic of the inflammatory milieu in oxazolone (IL-4), and TNBS (IL-12) colitis, respectively. These findings help explain the dichotomous effect of smoking in patients with UC and CD, and underscore the potential for nicotinergic drugs in regulating colonic inflammation. PMID:21784975

  16. Harmful effects of nicotine

    PubMed Central

    Mishra, Aseem; Chaturvedi, Pankaj; Datta, Sourav; Sinukumar, Snita; Joshi, Poonam; Garg, Apurva

    2015-01-01

    With the advent of nicotine replacement therapy, the consumption of the nicotine is on the rise. Nicotine is considered to be a safer alternative of tobacco. The IARC monograph has not included nicotine as a carcinogen. However there are various studies which show otherwise. We undertook this review to specifically evaluate the effects of nicotine on the various organ systems. A computer aided search of the Medline and PubMed database was done using a combination of the keywords. All the animal and human studies investigating only the role of nicotine were included. Nicotine poses several health hazards. There is an increased risk of cardiovascular, respiratory, gastrointestinal disorders. There is decreased immune response and it also poses ill impacts on the reproductive health. It affects the cell proliferation, oxidative stress, apoptosis, DNA mutation by various mechanisms which leads to cancer. It also affects the tumor proliferation and metastasis and causes resistance to chemo and radio therapeutic agents. The use of nicotine needs regulation. The sale of nicotine should be under supervision of trained medical personnel. PMID:25810571

  17. Harmful effects of nicotine.

    PubMed

    Mishra, Aseem; Chaturvedi, Pankaj; Datta, Sourav; Sinukumar, Snita; Joshi, Poonam; Garg, Apurva

    2015-01-01

    With the advent of nicotine replacement therapy, the consumption of the nicotine is on the rise. Nicotine is considered to be a safer alternative of tobacco. The IARC monograph has not included nicotine as a carcinogen. However there are various studies which show otherwise. We undertook this review to specifically evaluate the effects of nicotine on the various organ systems. A computer aided search of the Medline and PubMed database was done using a combination of the keywords. All the animal and human studies investigating only the role of nicotine were included. Nicotine poses several health hazards. There is an increased risk of cardiovascular, respiratory, gastrointestinal disorders. There is decreased immune response and it also poses ill impacts on the reproductive health. It affects the cell proliferation, oxidative stress, apoptosis, DNA mutation by various mechanisms which leads to cancer. It also affects the tumor proliferation and metastasis and causes resistance to chemo and radio therapeutic agents. The use of nicotine needs regulation. The sale of nicotine should be under supervision of trained medical personnel. PMID:25810571

  18. Targeting leukemic side population cells by isatin derivatives of nicotinic acid amide.

    PubMed

    Naglah, A M; Shinwari, Z; Bhat, M A; Al-Tahhan, M; Al-Omar, M A; Al-Dhfyan, A

    2016-01-01

    Side population (SP) cells mediate chemoresistance in leukemia. However, chemical inhibition approach to target SP cells has been poorly studied. Herein, we report the discovery of isatin derivatives of nicotinic acid amide as potent side population cell inhibitors. The selected derivatives showed superior potency over the reference drug verapamil. Furthermore, the treatment increased chemosensitivity and inhibited the cell proliferation on three different leukemic cell lines, K562, THP-1 and U937, suggesting that both SP and the bulk of leukemic cells are affected. Moreover, treatment with the most potent compound Nic9 reduced the expression of ABCG2, demonstrating that side population inhibition effect of the target derivatives is at least via ABCG2 inhibition. Importantly, the target derivatives induced erythrocyte/dendritic differentiation to leukemic cells mainly through Musashi/Numb pathway modulation. PMID:27358121

  19. Nicotine stimulates urokinase-type plasminogen activator receptor expression and cell invasiveness through mitogen-activated protein kinase and reactive oxygen species signaling in ECV304 endothelial cells

    SciTech Connect

    Khoi, Pham Ngoc; Park, Jung Sun; Kim, Nam Ho; Jung, Young Do

    2012-03-01

    Urokinase-type plasminogen activator receptor (uPAR) expression is elevated during inflammation, tissue remodeling and in many human cancers. This study investigated the effect of nicotine, a major alkaloid in tobacco, on uPAR expression and cell invasiveness in ECV304 endothelial cells. Nicotine stimulated uPAR expression in a dose-dependent manner and activated extracellular signal-regulated kinases-1/2 (Erk-1/2), c-Jun amino-terminal kinase (JNK) and p38 mitogen activated protein kinase (MAPK). Specific inhibitors of MEK-1 (PD98059) and JNK (SP600125) inhibited the nicotine-induced uPAR expression, while the p38 MAPK inhibitor SB203580 did not. Expression vectors encoding dominant negative MEK-1 (pMCL-K97M) and JNK (TAM67) also prevented nicotine-induced uPAR promoter activity. The intracellular hydrogen peroxide (H{sub 2}O{sub 2}) content was increased by nicotine treatment. The antioxidant N-acetylcysteine prevented nicotine-activated production of reactive oxygen species (ROS) and uPAR expression. Furthermore, exogenous H{sub 2}O{sub 2} increased uPAR mRNA expression. Deleted and site-directed mutagenesis demonstrated the involvement of the binding sites of transcription factor nuclear factor-kappaB (NF-κB) and activator protein (AP)-1 in the nicotine-induced uPAR expression. Studies with expression vectors encoding mutated NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the nicotine-stimulated uPAR expression. MAPK (Erk-1/2 and JNK) and ROS functioned as upstream signaling molecules in the activation of AP-1 and NF-κB, respectively. In addition, ECV304 endothelial cells treated with nicotine displayed markedly enhanced invasiveness, which was partially abrogated by uPAR neutralizing antibodies. The data indicate that nicotine induces uPAR expression via the MAPK/AP-1 and ROS/NF-κB signaling pathways and, in turn, stimulates invasiveness in human ECV304 endothelial cells. -- Highlights: ► Endothelial cells

  20. Central cholinergic control of vasopressin release in conscious rats

    SciTech Connect

    Iitake, K.; Share, L.; Ouchi, Y.; Crofton, J.T.; Brooks, D.P.

    1986-08-01

    Intracerebroventricular (icv) administration of carbachol into conscious rats evoked a substantial increase in vasopressin secretion and blood pressure in a dose-dependent manner. These effects were blocked by pretreatment with the muscarinic blocker, atropine (10 g icv), but not by the nicotinic blocker, hexamethonium (10 g icv). Hexamethonium did, however, block the increase in blood pressure, the decrease in heart rate, and they very small elevation in the plasma vasopressin concentration induced by nicotine (10 g icv). These results indicate that stimulation of either central nicotinic or muscarinic receptors can affect the cardiovascular system and suggest that the cholinergic stimulation of vasopressin secretion may involve primarily muscarinic receptors in the conscious rat.

  1. Nicotine and the adolescent brain

    PubMed Central

    Yuan, Menglu; Cross, Sarah J; Loughlin, Sandra E; Leslie, Frances M

    2015-01-01

    Adolescence encompasses a sensitive developmental period of enhanced clinical vulnerability to nicotine, tobacco, and e-cigarettes. While there are sociocultural influences, data at preclinical and clinical levels indicate that this adolescent sensitivity has strong neurobiological underpinnings. Although definitions of adolescence vary, the hallmark of this period is a profound reorganization of brain regions necessary for mature cognitive and executive function, working memory, reward processing, emotional regulation, and motivated behavior. Regulating critical facets of brain maturation are nicotinic acetylcholine receptors (nAChRs). However, perturbations of cholinergic systems during this time with nicotine, via tobacco or e-cigarettes, have unique consequences on adolescent development. In this review, we highlight recent clinical and preclinical data examining the adolescent brain's distinct neurobiology and unique sensitivity to nicotine. First, we discuss what defines adolescence before reviewing normative structural and neurochemical alterations that persist until early adulthood, with an emphasis on dopaminergic systems. We review how acute exposure to nicotine impacts brain development and how drug responses differ from those seen in adults. Finally, we discuss the persistent alterations in neuronal signaling and cognitive function that result from chronic nicotine exposure, while highlighting a low dose, semi-chronic exposure paradigm that may better model adolescent tobacco use. We argue that nicotine exposure, increasingly occurring as a result of e-cigarette use, may induce epigenetic changes that sensitize the brain to other drugs and prime it for future substance abuse. PMID:26018031

  2. Light microscopic distribution of some cholinergic markers in the rat and rabbit locus coeruleus and the nucleus angularis grisea periventricularis of the domestic pig (Sus scrofa): a correlative electron microscopic investigation of cholinergic receptor proteins in the rabbit.

    PubMed

    Caffé, A R

    1994-10-15

    Cholinergic modulation of locus coeruleus (LC) neurons evokes a variety of neuronal and behavioural effects. In an attempt to understand the LC cholinergic circuit, several markers has been investigated and compared. (Immuno)-histochemical and autoradiographic methods have been used on rat, rabbit, and pig tissue. To identify the boundaries of the LC in each of these species, sections through the entire brainstem have been stained for tyrosine hydroxylase. The results indicate that the pig does not possess a LC proper that conforms to the accepted features of this cell group. However, in this location fusiform cells reminiscent of LC interneurons are still present. This group of fusiform neurons has been named the nucleus angularis grisea periventricularis (NAGP). LC cells of the rat and rabbit show strong acetylcholinesterase (AChE) activity. In the pig the NAGP is markedly free from AChE staining. Muscarinic binding sites are densely distributed over the rabbit LC and adjacent region. The rat and rabbit LC neurons synthesise both muscarinic (mAChR) and nicotinic receptor protein (nAChR). In the pig NAGP region mAChR and nAChR positive cell bodies are almost absent, while some nAChR immunoreactive dendrites are present. The light microscopic data in the rabbit have been confirmed by electron microscopic analysis. It is concluded that the general concept of a noradrenergic LC that is present throughout mammals is questionable. At present, choline acetyltransferase immunoreactive terminals that closely correspond to the other cholinergic components in the rat or rabbit LC have not been observed. However, in these species the cholinergic sensitivity of LC cells is mediated via both muscarinic and nicotinic receptors on somata and dendrites. PMID:7849322

  3. Nicotinate-Curcumin Impedes Foam Cell Formation from THP-1 Cells through Restoring Autophagy Flux

    PubMed Central

    Gu, Hong-Feng; Li, Hai-Zhe; Tang, Ya-Ling; Tang, Xiao-Qing; Zheng, Xi-Long; Liao, Duan-Fang

    2016-01-01

    Our previous studies have indicated that a novel curcumin derivate nicotinate-curcumin (NC) has beneficial effects on the prevention of atherosclerosis, but the precise mechanisms are not fully understood. Given that autophagy regulates lipid metabolism, the present study was designed to investigate whether NC decreases foam cell formation through restoring autophagy flux in oxidized low-density lipoprotein (ox-LDL)-treated THP-1 cells. Our results showed that ox-LDL (100 μg/ml) was accumulated in THP-1 cells and impaired autophagy flux. Ox-LDL-induced impairment of autophagy was enhanced by treatment with the autophagy inhibitor chloroquine (CQ) and rescued by the autophagy inducer rapamycin. The aggregation of ox-LDL was increased by CQ, but decreased by rapamycin. In addition, colocalization of lipid droplets with LC3-II was remarkably reduced in ox-LDL group. In contrast, NC (10 μM) rescued the impaired autophagy flux by significantly increasing level of LC3-II, the number of autophagolysosomes, and the degradation of p62 in ox-LDL-treated THP-1 cells. Inhibition of the PI3K-Akt-mTOR signaling was required for NC-rescued autophagy flux. Notably, our results showed that NC remarkably promoted the colocalization of lipid droplets with autophagolysosomes, increased efflux of cholesterol, and reduced ox-LDL accumulation in THP-1 cells. However, treatment with 3-methyladenine (3-MA) or CQ reduced the protective effects of NC on lipid accumulation. Collectively, the findings suggest that NC decreases lipid accumulation in THP-1 cells through restoring autophagy flux, and further implicate that NC may be a potential therapeutic reagent to reverse atherosclerosis. PMID:27128486

  4. Nicotinate-Curcumin Impedes Foam Cell Formation from THP-1 Cells through Restoring Autophagy Flux.

    PubMed

    Gu, Hong-Feng; Li, Hai-Zhe; Tang, Ya-Ling; Tang, Xiao-Qing; Zheng, Xi-Long; Liao, Duan-Fang

    2016-01-01

    Our previous studies have indicated that a novel curcumin derivate nicotinate-curcumin (NC) has beneficial effects on the prevention of atherosclerosis, but the precise mechanisms are not fully understood. Given that autophagy regulates lipid metabolism, the present study was designed to investigate whether NC decreases foam cell formation through restoring autophagy flux in oxidized low-density lipoprotein (ox-LDL)-treated THP-1 cells. Our results showed that ox-LDL (100 μg/ml) was accumulated in THP-1 cells and impaired autophagy flux. Ox-LDL-induced impairment of autophagy was enhanced by treatment with the autophagy inhibitor chloroquine (CQ) and rescued by the autophagy inducer rapamycin. The aggregation of ox-LDL was increased by CQ, but decreased by rapamycin. In addition, colocalization of lipid droplets with LC3-II was remarkably reduced in ox-LDL group. In contrast, NC (10 μM) rescued the impaired autophagy flux by significantly increasing level of LC3-II, the number of autophagolysosomes, and the degradation of p62 in ox-LDL-treated THP-1 cells. Inhibition of the PI3K-Akt-mTOR signaling was required for NC-rescued autophagy flux. Notably, our results showed that NC remarkably promoted the colocalization of lipid droplets with autophagolysosomes, increased efflux of cholesterol, and reduced ox-LDL accumulation in THP-1 cells. However, treatment with 3-methyladenine (3-MA) or CQ reduced the protective effects of NC on lipid accumulation. Collectively, the findings suggest that NC decreases lipid accumulation in THP-1 cells through restoring autophagy flux, and further implicate that NC may be a potential therapeutic reagent to reverse atherosclerosis. PMID:27128486

  5. Striatal cholinergic interneuron regulation and circuit effects

    PubMed Central

    Lim, Sean Austin O.; Kang, Un Jung; McGehee, Daniel S.

    2014-01-01

    The striatum plays a central role in motor control and motor learning. Appropriate responses to environmental stimuli, including pursuit of reward or avoidance of aversive experience all require functional striatal circuits. These pathways integrate synaptic inputs from limbic and cortical regions including sensory, motor and motivational information to ultimately connect intention to action. Although many neurotransmitters participate in striatal circuitry, one critically important player is acetylcholine (ACh). Relative to other brain areas, the striatum contains exceptionally high levels of ACh, the enzymes that catalyze its synthesis and breakdown, as well as both nicotinic and muscarinic receptor types that mediate its postsynaptic effects. The principal source of striatal ACh is the cholinergic interneuron (ChI), which comprises only about 1–2% of all striatal cells yet sends dense arbors of projections throughout the striatum. This review summarizes recent advances in our understanding of the factors affecting the excitability of these neurons through acute effects and long term changes in their synaptic inputs. In addition, we discuss the physiological effects of ACh in the striatum, and how changes in ACh levels may contribute to disease states during striatal dysfunction. PMID:25374536

  6. Regulation of Prostate Development and Benign Prostatic Hyperplasia by Autocrine Cholinergic Signaling via Maintaining the Epithelial Progenitor Cells in Proliferating Status.

    PubMed

    Wang, Naitao; Dong, Bai-Jun; Quan, Yizhou; Chen, Qianqian; Chu, Mingliang; Xu, Jin; Xue, Wei; Huang, Yi-Ran; Yang, Ru; Gao, Wei-Qiang

    2016-05-10

    Regulation of prostate epithelial progenitor cells is important in prostate development and prostate diseases. Our previous study demonstrated a function of autocrine cholinergic signaling (ACS) in promoting prostate cancer growth and castration resistance. However, whether or not such ACS also plays a role in prostate development is unknown. Here, we report that ACS promoted the proliferation and inhibited the differentiation of prostate epithelial progenitor cells in organotypic cultures. These results were confirmed by ex vivo lineage tracing assays and in vivo renal capsule recombination assays. Moreover, we found that M3 cholinergic receptor (CHRM3) was upregulated in a large subset of benign prostatic hyperplasia (BPH) tissues compared with normal tissues. Activation of CHRM3 also promoted the proliferation of BPH cells. Together, our findings identify a role of ACS in maintaining prostate epithelial progenitor cells in the proliferating state, and blockade of ACS may have clinical implications for the management of BPH. PMID:27167157

  7. Effects of amyloid-beta on cholinergic and acetylcholinesterase-positive cells in cultured basal forebrain neurons of embryonic rat brain.

    PubMed

    Kasa, Peter; Papp, Henrietta; Kasa, Peter; Pakaski, Magdolna; Balaspiri, Lajos

    2004-02-13

    The neurotoxic effects of amyloid-beta(1-42) and amyloid-beta(25-35) (A beta) on cholinergic and acetylcholinesterase-positive neurons were investigated in primary cultures derived from embryonic 18-day-old rat basal forebrain. After various time intervals, the cultures were treated with 1, 5, 10 or 20 microM A beta for different time periods. The cholinergic neurons and their axon terminals were revealed by vesicular acetylcholine transporter immunohistochemistry and the cholinoceptive cells by acetylcholinesterase histochemical staining. To assess the toxic effects of these A beta peptides on the cholinergic neurons, image analysis was applied for quantitative determination of the numbers of axon varicosities/terminals and cells. The results demonstrate that, following treatment with 1 or 5 microM A beta for 5, 10, 30, 60 or 120 min, no changes in vesicular acetylcholine transporter immunohistochemical staining were observed. However, after treatment for 30 min with 10 or 20 microM A beta, the number of stained axon varicosities was reduced, and treatment for 2 h they had disappeared. In contrast, vesicular acetylcholine transporter-positivity could be seen in some of the neuronal perikarya even after 3 days after treatment. The acetylcholinesterase staining was homogeneously distributed in the control neurons. After A beta treatment, the histochemical reaction end-product was detected in some of the neuronal perikarya or in the dendritic processes near to the soma. It is concluded that the neurotoxic effects of A beta appear more rapidly in the cholinergic axon terminals than in the cholinergic and acetylcholinesterase-positive neuronal perikarya. PMID:14725970

  8. Novel aspects of cholinergic regulation of colonic ion transport.

    PubMed

    Bader, Sandra; Diener, Martin

    2015-06-01

    Nicotinic receptors are not only expressed by excitable tissues, but have been identified in various epithelia. One aim of this study was to investigate the expression of nicotinic receptors and their involvement in the regulation of ion transport across colonic epithelium. Ussing chamber experiments with putative nicotinic agonists and antagonists were performed at rat colon combined with reverse transcription polymerase chain reaction (RT-PCR) detection of nicotinic receptor subunits within the epithelium. Dimethylphenylpiperazinium (DMPP) and nicotine induced a tetrodotoxin-resistant anion secretion leading to an increase in short-circuit current (I sc) across colonic mucosa. The response was suppressed by the nicotinic receptor antagonist hexamethonium. RT-PCR experiments revealed the expression of α2, α4, α5, α6, α7, α10, and β4 nicotinic receptor subunits in colonic epithelium. Choline, the product of acetylcholine hydrolysis, is known for its affinity to several nicotinic receptor subtypes. As a strong acetylcholinesterase activity was found in colonic epithelium, the effect of choline on I sc was examined. Choline induced a concentration-dependent, tetrodotoxin-resistant chloride secretion which was, however, resistant against hexamethonium, but was inhibited by atropine. Experiments with inhibitors of muscarinic M1 and M3 receptors revealed that choline-evoked secretion was mainly due to a stimulation of epithelial M3 receptors. Although choline proved to be only a partial agonist, it concentration-dependently desensitized the response to acetylcholine, suggesting that it might act as a modulator of cholinergically induced anion secretion. Thus the cholinergic regulation of colonic ion transport - up to now solely explained by cholinergic submucosal neurons stimulating epithelial muscarinic receptors - is more complex than previously assumed. PMID:26236483

  9. Novel aspects of cholinergic regulation of colonic ion transport

    PubMed Central

    Bader, Sandra; Diener, Martin

    2015-01-01

    Nicotinic receptors are not only expressed by excitable tissues, but have been identified in various epithelia. One aim of this study was to investigate the expression of nicotinic receptors and their involvement in the regulation of ion transport across colonic epithelium. Ussing chamber experiments with putative nicotinic agonists and antagonists were performed at rat colon combined with reverse transcription polymerase chain reaction (RT-PCR) detection of nicotinic receptor subunits within the epithelium. Dimethylphenylpiperazinium (DMPP) and nicotine induced a tetrodotoxin-resistant anion secretion leading to an increase in short-circuit current (Isc) across colonic mucosa. The response was suppressed by the nicotinic receptor antagonist hexamethonium. RT-PCR experiments revealed the expression of α2, α4, α5, α6, α7, α10, and β4 nicotinic receptor subunits in colonic epithelium. Choline, the product of acetylcholine hydrolysis, is known for its affinity to several nicotinic receptor subtypes. As a strong acetylcholinesterase activity was found in colonic epithelium, the effect of choline on Isc was examined. Choline induced a concentration-dependent, tetrodotoxin-resistant chloride secretion which was, however, resistant against hexamethonium, but was inhibited by atropine. Experiments with inhibitors of muscarinic M1 and M3 receptors revealed that choline-evoked secretion was mainly due to a stimulation of epithelial M3 receptors. Although choline proved to be only a partial agonist, it concentration-dependently desensitized the response to acetylcholine, suggesting that it might act as a modulator of cholinergically induced anion secretion. Thus the cholinergic regulation of colonic ion transport – up to now solely explained by cholinergic submucosal neurons stimulating epithelial muscarinic receptors – is more complex than previously assumed. PMID:26236483

  10. Medial Habenula Output Circuit Mediated by α5 Nicotinic Receptor-Expressing GABAergic Neurons in the Interpeduncular Nucleus

    PubMed Central

    Hsu, Yun-Wei A.; Tempest, Lynne; Quina, Lely A.; Wei, Aguan D.; Zeng, Hongkui

    2013-01-01

    The Chrna5 gene encodes the α5 nicotinic acetylcholine receptor subunit, an “accessory” subunit of pentameric nicotinic receptors, that has been shown to play a role in nicotine-related behaviors in rodents and is genetically linked to smoking behavior in humans. Here we have used a BAC transgenic mouse line, α5GFP, to examine the cellular phenotype, connectivity, and function of α5-expressing neurons. Although the medial habenula (MHb) has been proposed as a site of α5 function, α5GFP is not detectable in the MHb, and α5 mRNA is expressed there only at very low levels. However, α5GFP is strongly expressed in a subset of neurons in the interpeduncular nucleus (IP), median raphe/paramedian raphe (MnR/PMnR), and dorsal tegmental area (DTg). Double-label fluorescence in situ hybridization reveals that these neurons are exclusively GABAergic. Transgenic and conventional tract tracing show that α5GFP neurons in the IP project principally to the MnR/PMnR and DTg/interfascicular dorsal raphe, both areas rich in serotonergic neurons. The α5GFP neurons in the IP are located in a region that receives cholinergic fiber inputs from the ventral MHb, and optogenetically assisted circuit mapping demonstrates a monosynaptic connection between these cholinergic neurons and α5GFP IP neurons. Selective inhibitors of both α4β2- and α3β4-containing nicotinic receptors were able to reduce nicotine-evoked inward currents in α5GFP neurons in the IP, suggesting a mixed nicotinic receptor profile in these cells. Together, these findings show that the α5-GABAergic interneurons form a link from the MHb to serotonergic brain centers, which is likely to mediate some of the behavioral effects of nicotine. PMID:24227714

  11. Medial habenula output circuit mediated by α5 nicotinic receptor-expressing GABAergic neurons in the interpeduncular nucleus.

    PubMed

    Hsu, Yun-Wei A; Tempest, Lynne; Quina, Lely A; Wei, Aguan D; Zeng, Hongkui; Turner, Eric E

    2013-11-13

    The Chrna5 gene encodes the α5 nicotinic acetylcholine receptor subunit, an "accessory" subunit of pentameric nicotinic receptors, that has been shown to play a role in nicotine-related behaviors in rodents and is genetically linked to smoking behavior in humans. Here we have used a BAC transgenic mouse line, α5(GFP), to examine the cellular phenotype, connectivity, and function of α5-expressing neurons. Although the medial habenula (MHb) has been proposed as a site of α5 function, α5(GFP) is not detectable in the MHb, and α5 mRNA is expressed there only at very low levels. However, α5(GFP) is strongly expressed in a subset of neurons in the interpeduncular nucleus (IP), median raphe/paramedian raphe (MnR/PMnR), and dorsal tegmental area (DTg). Double-label fluorescence in situ hybridization reveals that these neurons are exclusively GABAergic. Transgenic and conventional tract tracing show that α5(GFP) neurons in the IP project principally to the MnR/PMnR and DTg/interfascicular dorsal raphe, both areas rich in serotonergic neurons. The α5(GFP) neurons in the IP are located in a region that receives cholinergic fiber inputs from the ventral MHb, and optogenetically assisted circuit mapping demonstrates a monosynaptic connection between these cholinergic neurons and α5(GFP) IP neurons. Selective inhibitors of both α4β2- and α3β4-containing nicotinic receptors were able to reduce nicotine-evoked inward currents in α5(GFP) neurons in the IP, suggesting a mixed nicotinic receptor profile in these cells. Together, these findings show that the α5-GABAergic interneurons form a link from the MHb to serotonergic brain centers, which is likely to mediate some of the behavioral effects of nicotine. PMID:24227714

  12. Effects of diazinon on the lymphocytic cholinergic system of Nile tilapia fish (Oreochromis niloticus).

    PubMed

    Toledo-Ibarra, G A; Díaz-Resendiz, K J G; Pavón-Romero, L; Rojas-García, A E; Medina-Díaz, I M; Girón-Pérez, M I

    2016-08-01

    Fish rearing under intensive farming conditions can be easily disturbed by pesticides, substances that have immunotoxic properties and may predispose to infections. Organophosphorus pesticides (OPs) are widely used in agricultural activities; however, the mechanism of immunotoxicity of these substances is unclear. The aim of this study was to evaluate the effect of diazinon pesticides (OPs) on the cholinergic system of immune cells as a possible target of OP immunotoxicity. We evaluated ACh levels and cholinergic (nicotinic and muscarinic) receptor concentration. Additionally, AChE activity was evaluated in mononuclear cells of Nile tilapia (Oreochromis niloticus), a freshwater fish mostly cultivated in tropical regions around the world. The obtained results indicate that acute exposure to diazinon induces an increase in ACh concentration and a decrease in nAChR and mAChR concentrations and AChE activity in fish immune cells, This suggests that the non-neuronal lymphocytic cholinergic system may be the main target in the mechanism of OP immunotoxicity. This study contributes to the understanding of the mechanisms of immunotoxicity of pollutants and may help to take actions for animal health improvement. PMID:27260186

  13. Nicotine, acetylcholine and bombesin are trophic growth factors in neuroendocrine cell lines derived from experimental hamster lung tumors

    SciTech Connect

    Schueller, H.M.; Nylen, E.; Park, P.; Becker, K.L. George Washington Univ., Washington, DC )

    1990-01-01

    Neuroendocrine hamster lung tumors, induced by exposure to 60% hyperoxia and subcutaneous administration of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) for 12 weeks, were placed in cell culture. By subsequent selective transfer of epithelial cells and maintenance in an atmosphere of 8% CO{sub 2}, cell lines with characteristics of neuroendocrine cells were established. The neuroendocrine markers expressed by these cell lines included electron dense neuroendocrine secretion granules as well as secretion of calcitonin and mammalian bombesin. In keeping with data previously reported for a human neuroendocrine lung tumor cell line, nicotine, acetylcholien, and mammalian bombesin (MB) acted as strongrowth factors in these neuroendocrine hamster tumor lines. The mitogenic effect of nicotine an acetylcholine was abolished by nicotinic receptor inhibition while the effects of mammalian bombesin were inhibited by an antagonist of MB receptors. Our data suggest that a receptor-mediated mitogenic effect of nicotine on neuroendocrine lung cells may be instrumental in the induction of smoking-associated small cell lung cancer.

  14. Nicotine Inhibits Cisplatin-Induced Apoptosis via Regulating α5-nAChR/AKT Signaling in Human Gastric Cancer Cells.

    PubMed

    Jia, Yanfei; Sun, Haiji; Wu, Hongqiao; Zhang, Huilin; Zhang, Xiuping; Xiao, Dongjie; Ma, Xiaoli; Wang, Yunshan

    2016-01-01

    Gastric cancer incidence demonstrates a strong etiologic association with smoking. Nicotine, the major component in tobacco, is a survival agonist that inhibits apoptosis induced by certain chemotherapeutic agents, but the precise mechanisms involved remain largely unknown. Recently studies have indicated that α5-nicotinic acetylcholine receptor (α5-nAChR) is highly associated with lung cancer risk and nicotine dependence. Nevertheless, no information has been available about whether nicotine also affects proliferation of human gastric cancer cells through regulation of α5-nAChR. To evaluate the hypothesis that α5-nAChR may play a role in gastric cancer, we investigated its expression in gastric cancer tissues and cell lines. The expression of α5-nAChR increased in gastric cancer tissue compared with para-carcinoma tissues. In view of the results, we proceeded to investigate whether nicotine inhibits cisplatin-induced apoptosis via regulating α5-nAChR in gastric cancer cell. The results showed that nicotine significantly promoted cell proliferation in a dose and time-dependent manner through α5-nAChR activation in human gastric cells. Furthermore, nicotine inhibited apoptosis induced by cisplatin. Silence of α5-nAChR ablated the protective effects of nicotine. However, when co-administrating LY294002, an inhibitor of PI3K/AKT pathway, an increased apoptosis was observed. This effect correlated with the induction of Bcl-2, Bax, Survivin and Caspase-3 by nicotine in gastric cell lines. These results suggest that exposure to nicotine might negatively impact the apoptotic potential of chemotherapeutic drugs and that α5-nAChR/AKT signaling plays a key role in the anti-apoptotic activity of nicotine induced by cisplatin. PMID:26909550

  15. Polymer-encapsulated cells genetically modified to secrete human nerve growth factor promote the survival of axotomized septal cholinergic neurons.

    PubMed Central

    Winn, S R; Hammang, J P; Emerich, D F; Lee, A; Palmiter, R D; Baetge, E E

    1994-01-01

    Effective treatments for neurodegenerative disorders are limited by our inability to alter the progression of the diseases. A number of proteins have specific neuroprotective activities in vitro; however, the delivery of these factors into the central nervous system over the long term at therapeutic levels has been difficult to achieve. BHK cells engineered to express and release human nerve growth factor were encapsulated in an immunoisolation polymeric device and transplanted into both fimbria-fornix-lesioned rat brains and naive controls. In the lesioned rat brain, chronic delivery of human nerve growth factor by the encapsulated BHK cells provided nearly complete protection of axotomized medial septal cholinergic neurons. Human nerve growth factor continued to be released by encapsulated cells upon removal from the aspirative site after 3 weeks or from normal rat striatum after 3 and 6 months in vivo. Long-term encapsulated cell survival was confirmed by histologic analysis. This encapsulated xenogeneic system may provide therapeutically effective amounts of a number of neurotrophic factors, alone or in combination, to virtually any site within the body. Images PMID:8134395

  16. Cadmium-induced cell death of basal forebrain cholinergic neurons mediated by muscarinic M1 receptor blockade, increase in GSK-3β enzyme, β-amyloid and tau protein levels.

    PubMed

    Del Pino, Javier; Zeballos, Gabriela; Anadón, María José; Moyano, Paula; Díaz, María Jesús; García, José Manuel; Frejo, María Teresa

    2016-05-01

    Cadmium is a neurotoxic compound which induces cognitive alterations similar to those produced by Alzheimer's disease (AD). However, the mechanism through which cadmium induces this effect remains unknown. In this regard, we described in a previous work that cadmium blocks cholinergic transmission and induces a more pronounced cell death on cholinergic neurons from basal forebrain which is partially mediated by AChE overexpression. Degeneration of basal forebrain cholinergic neurons, as happens in AD, results in memory deficits attributable to the loss of cholinergic modulation of hippocampal synaptic circuits. Moreover, cadmium has been described to activate GSK-3β, induce Aβ protein production and tau filament formation, which have been related to a selective loss of basal forebrain cholinergic neurons and development of AD. The present study is aimed at researching the mechanisms of cell death induced by cadmium on basal forebrain cholinergic neurons. For this purpose, we evaluated, in SN56 cholinergic mourine septal cell line from basal forebrain region, the cadmium toxic effects on neuronal viability through muscarinic M1 receptor, AChE splice variants, GSK-3β enzyme, Aβ and tau proteins. This study proves that cadmium induces cell death on cholinergic neurons through blockade of M1 receptor, overexpression of AChE-S and GSK-3β, down-regulation of AChE-R and increase in Aβ and total and phosphorylated tau protein levels. Our present results provide new understanding of the mechanisms contributing to the harmful effects of cadmium on cholinergic neurons and suggest that cadmium could mediate these mechanisms by M1R blockade through AChE splices altered expression. PMID:26026611

  17. Role of [Na+]i and [Ca2+]i in nicotine-induced norepinephrine release from bovine adrenal chromaffin cells.

    PubMed

    Gerber, S H; Haunstetter, A; Krüger, C; Kaufmann, A; Nobiling, R; Haass, M

    1995-09-01

    Intracellular free sodium ([Na+]i) and calcium ([Ca2+]i) concentrations were determined by sodium-binding benzofuran isophthalate (SBFI) and fura 2 microfluorimetry, respectively, in bovine adrenal chromaffin cells (BCC). Validation of SBFI microfluorimetry by in vitro and in vivo calibration revealed a reliable assessment of [Na+]i within a range of 1-30 mM in single BCC. Nicotine (0.1-10 microM) induced concentration-dependent increases of both [Na+]i (from 3.3 +/- 0.1 to 25.6 +/- 0.4 mM, n = 76, P < 0.001) and [Ca2+]i (from 64 +/- 1 to 467 +/- 16 nM, n = 87, P < 0.001), which were accompanied by an increase in [3H]norepinephrine (NE) release. Consistent with an exocytotic release mechanism, nicotine-induced increments of [Ca2+]i and [3H]NE release were reduced under calcium-free conditions and by gadolinium chloride (40 microM), whereas [Na+]i was not affected. In contrast, a parallel attenuation of nicotine-evoked changes in [Na+]i, [Ca2+]i, and [3H]NE release was observed during reduction of the extracellular sodium concentration. The nicotine-evoked responses were neutralized by the nicotinic receptor antagonist hexamethonium (100 microM) but not by blockade of voltage-dependent sodium channels (1 microM tetrodotoxin). In conclusion, the nicotine-induced exocytotic release of [3H]NE is triggered by an increase in [Ca2+]i, which is facilitated by sodium influx through the nicotinic receptor ionophore. PMID:7573386

  18. Nicotine and tobacco

    MedlinePlus

    Withdrawal from nicotine; Smoking - nicotine addiction and withdrawal; Smokeless tobacco - nicotine addiction; Cigar smoking; Pipe smoking; Smokeless snuff; Tobacco use; Chewing tobacco; Nicotine addiction and tobacco

  19. Synaptic modulation of excitatory synaptic transmission by nicotinic acetylcholine receptors in spinal ventral horn neurons.

    PubMed

    Mine, N; Taniguchi, W; Nishio, N; Izumi, N; Miyazaki, N; Yamada, H; Nakatsuka, T; Yoshida, M

    2015-04-01

    Nicotinic acetylcholine receptors (nAChRs) are distributed widely in the central nervous system and play important roles in higher brain functions, including learning, memory, and recognition. However, functions of the cholinergic system in spinal motoneurons remain poorly understood. In this study, we investigated the actions of presynaptic and postsynaptic nAChRs in spinal ventral horn neurons by performing whole-cell patch-clamp recordings on lumbar slices from male rats. The application of nicotine or acetylcholine generated slow inward currents and increased the frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs). Slow inward currents by acetylcholine or nicotine were not inhibited by tetrodotoxin (TTX) or glutamate receptor antagonists. In the presence of TTX, the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) were also increased by acetylcholine or nicotine. A selective α4β2 nicotinic receptor antagonist, dihydro-β-erythroidine hydrobromide (DhβE), significantly decreased nicotine-induced inward currents without affecting the enhancement of sEPSCs and mEPSCs. In addition, a selective α7 nicotinic receptor antagonist, methyllycaconitine, did not affect either nicotine-induced inward currents or the enhancement of sEPSCs and mEPSCs. These results suggest that α4β2 AChRs are localized at postsynaptic sites in the spinal ventral horn, non-α4β2 and non-α7 nAChRs are located presynaptically, and nAChRs enhance excitatory synaptic transmission in the spinal ventral horn. PMID:25613686

  20. Epigallocatechin-3-gallate inhibits nicotine-induced migration and invasion by the suppression of angiogenesis and epithelial-mesenchymal transition in non-small cell lung cancer cells.

    PubMed

    Shi, Jingli; Liu, Fei; Zhang, Wenzhang; Liu, Xin; Lin, Bihua; Tang, Xudong

    2015-06-01

    Epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea extract, has been found to have anticancer activities in various types of cancer. However, the underlying mechanisms are not completely clear. In the present study, the effects of EGCG on migration, invasion, angiogenesis and epithelial-mesenchymal transition (EMT) induced by nicotine in A549 non-small cell lung cancer (NSCLC) cells were investigated, and the underlying molecular mechanisms were preliminarily examined. The results showed that different concentrations of EGCG significantly inhibited nicotine-induced migration and invasion. Moreover, EGCG reversed the upregulation of HIF-1α, vascular endothelial growth factor (VEGF), COX-2, p-Akt, p-ERK and vimentin protein levels and the downregulation of p53 and β-catenin protein levels mediated by nicotine in A549 cells, but had no significant effect on their mRNA levels. Furthermore, EGCG markedly inhibited HIF-1α-dependent angiogenesis induced by nicotine in vitro and in vivo, and suppressed HIF-1α and VEGF protein expression induced by nicotine in A549 xenografts of nude mice. Taken together, the results indicated that EGCG inhibited nicotine-induced angiogenesis and EMT, leading to migration and invasion in A549 cells. The results of the present study suggested that EGCG can be developed into a potential agent for the prevention and treatment of smoking-associated NSCLC. PMID:25845434

  1. Activation of the cholinergic anti-inflammatory system in peripheral blood mononuclear cells from patients with borderline personality disorder.

    PubMed

    Díaz-Marsá, Marina; Macdowell, Karina S; Guemes, Itziar; Rubio, Víctor; Carrasco, José L; Leza, Juan C

    2012-12-01

    A case-control study including patients (n = 20) with Borderline Personality Disorder (BPD) and healthy controls (n = 33) was carried out. To avoid interferences of other clinical conditions on biological findings, patients were free of current major depressive episodes or substance dependence disorders, and had no life history of schizophrenia, bipolar or neuropsychiatric disorders. Patients were free of medication for at least two weeks at the time of the study. Studies carried out in peripheral mononuclear blood cells and plasma evidence a systemic inflammatory condition in unstable-impulsive BPD patients. Specifically, a significant increase in some intracellular components of two main pro-inflammatory pathways such as iNOS and COX-2, as well as an increase in the plasma levels of the inflammatory cytokine IL1β. Interestingly, patients have an increase in the protein expression of the anti-inflammatory subtype of nicotinic receptor α7nAChR. This finding may reflect a possible mechanism trying to maintain intracellular inflammation pathways under control. All together, these results describe an imbalanced, pro-inflammatory and oxidant phenotype in BPD patients independent of plasma cotinine levels. Although more scientific evidence is needed, the determination of multiple components of pro- and anti-inflammatory cellular pathways have interesting potential as biological markers for BPD and other generalized impulsive syndromes, specially data obtained with α7nAChR and its lack of correlation with plasma levels of nicotine metabolites. Their pharmacological modulation with receptor modulators can be a promising therapeutic target to take into account in mental health conditions associated with inflammatory or oxido/nitrosative consequences. Also, identifying at-risk individuals would be of importance for early detection and intervention in adolescent subjects before they present severe behavioural problems. PMID:23083519

  2. Preferential entry of botulinum neurotoxin A Hc domain through intestinal crypt cells and targeting to cholinergic neurons of the mouse intestine.

    PubMed

    Couesnon, Aurélie; Molgó, Jordi; Connan, Chloé; Popoff, Michel R

    2012-01-01

    Botulism, characterized by flaccid paralysis, commonly results from botulinum neurotoxin (BoNT) absorption across the epithelial barrier from the digestive tract and then dissemination through the blood circulation to target autonomic and motor nerve terminals. The trafficking pathway of BoNT/A passage through the intestinal barrier is not yet fully understood. We report that intralumenal administration of purified BoNT/A into mouse ileum segment impaired spontaneous muscle contractions and abolished the smooth muscle contractions evoked by electric field stimulation. Entry of BoNT/A into the mouse upper small intestine was monitored with fluorescent HcA (half C-terminal domain of heavy chain) which interacts with cell surface receptor(s). We show that HcA preferentially recognizes a subset of neuroendocrine intestinal crypt cells, which probably represent the entry site of the toxin through the intestinal barrier, then targets specific neurons in the submucosa and later (90-120 min) in the musculosa. HcA mainly binds to certain cholinergic neurons of both submucosal and myenteric plexuses, but also recognizes, although to a lower extent, other neuronal cells including glutamatergic and serotoninergic neurons in the submucosa. Intestinal cholinergic neuron targeting by HcA could account for the inhibition of intestinal peristaltism and secretion observed in botulism, but the consequences of the targeting to non-cholinergic neurons remains to be determined. PMID:22438808

  3. Cholinergic modulation of fast inhibitory and excitatory transmission to pedunculopontine thalamic projecting neurons.

    PubMed

    Ye, Meijun; Hayar, Abdallah; Strotman, Beau; Garcia-Rill, Edgar

    2010-05-01

    The pedunculopontine nucleus (PPN) is part of the cholinergic arm of the reticular activating system, which is mostly active during waking and rapid-eye movement sleep. The PPN projects to the thalamus and receives cholinergic inputs from the laterodorsal tegmental nucleus and contralateral PPN. We employed retrograde labeling and whole cell recordings to determine the modulation of GABAergic, glycinergic, and glutamatergic transmission to PPN thalamic projecting neurons, and their postsynaptic responses to the nonspecific cholinergic agonist carbachol. M2 and M4 muscarinic receptor-modulated inhibitory postsynaptic responses were observed in 73% of PPN output neurons; in 12.9%, M1 and nicotinic receptor-mediated excitation was detected; and muscarinic and nicotinic-modulated fast inhibitory followed by slow excitatory biphasic responses were evident in 6.7% of cells. A significant increase in the frequency of spontaneous excitatory postsynaptic currents (EPSCs) and inhibitory postsynaptic currents during carbachol application was observed in 66.2% and 65.2% of efferent neurons, respectively. This effect was blocked by a M1 antagonist or nonselective muscarinic blocker, indicating that glutamatergic, GABAergic, and/or glycinergic neurons projecting to PPN output neurons are excited through muscarinic receptors. Decreases in the frequency of miniature EPSCs, and amplitude of electrical stimulation-evoked EPSCs, were blocked by a M2 antagonist, suggesting the presence of M2Rs at terminals of presynaptic glutamatergic neurons. Carbachol-induced multiple types of postsynaptic responses, enhancing both inhibitory and excitatory fast transmission to PPN thalamic projecting neurons through muscarinic receptors. These results provide possible implications for the generation of different frequency oscillations in PPN thalamic projecting neurons during distinct sleep-wake states. PMID:20181729

  4. Quinuclidine compounds differently act as agonists of Kenyon cell nicotinic acetylcholine receptors and induced distinct effect on insect ganglionic depolarizations.

    PubMed

    Mathé-Allainmat, Monique; Swale, Daniel; Leray, Xavier; Benzidane, Yassine; Lebreton, Jacques; Bloomquist, Jeffrey R; Thany, Steeve H

    2013-12-01

    We have recently demonstrated that a new quinuclidine benzamide compound named LMA10203 acted as an agonist of insect nicotinic acetylcholine receptors. Its specific pharmacological profile on cockroach dorsal unpaired median neurons (DUM) helped to identify alpha-bungarotoxin-insensitive nAChR2 receptors. In the present study, we tested its effect on cockroach Kenyon cells. We found that it induced an inward current demonstrating that it bounds to nicotinic acetylcholine receptors expressed on Kenyon cells. Interestingly, LMA10203-induced currents were completely blocked by the nicotinic antagonist α-bungarotoxin. We suggested that LMA10203 effect occurred through the activation of α-bungarotoxin-sensitive receptors and did not involve α-bungarotoxin-insensitive nAChR2, previously identified in DUM neurons. In addition, we have synthesized two new compounds, LMA10210 and LMA10211, and compared their effects on Kenyon cells. These compounds were members of the 3-quinuclidinyl benzamide or benzoate families. Interestingly, 1 mM LMA10210 was not able to induce an inward current on Kenyon cells compared to LMA10211. Similarly, we did not find any significant effect of LMA10210 on cockroach ganglionic depolarization, whereas these three compounds were able to induce an effect on the central nervous system of the third instar M. domestica larvae. Our data suggested that these three compounds could bind to distinct cockroach nicotinic acetylcholine receptors. PMID:23884575

  5. Nicotinic Mechanisms Modulate Ethanol Withdrawal and Modify Time Course and Symptoms Severity of Simultaneous Withdrawal from Alcohol and Nicotine.

    PubMed

    Perez, Erika; Quijano-Cardé, Natalia; De Biasi, Mariella

    2015-09-01

    Alcohol and nicotine are among the top causes of preventable death in the United States. Unfortunately, people who are dependent on alcohol are more likely to smoke than individuals in the general population. Similarly, smokers are more likely to abuse alcohol. Alcohol and nicotine codependence affects health in many ways and leads to poorer treatment outcomes in subjects who want to quit. This study examined the interaction of alcohol and nicotine during withdrawal and compared abstinence symptoms during withdrawal from one of the two drugs only vs both. Our results indicate that simultaneous withdrawal from alcohol and nicotine produces physical symptoms that are more severe and last longer than those experienced during withdrawal from one of the two drugs alone. In animals experiencing withdrawal after chronic ethanol treatment, acute nicotine exposure was sufficient to prevent abstinence symptoms. Similarly, symptoms were prevented when alcohol was injected acutely in mice undergoing nicotine withdrawal. These experiments provide evidence for the involvement of the nicotinic cholinergic system in alcohol withdrawal. Furthermore, the outcomes of intracranial microinfusions of mecamylamine, a nonselective nicotinic receptor antagonist, highlight a major role for the nicotinic receptors expressed in medial habenula and interpeduncular nucleus during withdrawal. Overall, the data support the notion that modulating the nicotinic cholinergic system might help to maintain long-term abstinence from alcohol. PMID:25790020

  6. Enhancement of cancer stem-like and epithelial−mesenchymal transdifferentiation property in oral epithelial cells with long-term nicotine exposure: Reversal by targeting SNAIL

    SciTech Connect

    Yu, Cheng-Chia; Chang, Yu-Chao

    2013-02-01

    Cigarette smoking is one of the major risk factors in the development and further progression of tumorigenesis, including oral squamous cell carcinoma (OSCC). Recent studies suggest that interplay cancer stem-like cells (CSCs) and epithelial−mesenchymal transdifferentiation (EMT) properties are responsible for the tumor maintenance and metastasis in OSCC. The aim of the present study was to investigate the effects of long-term exposure with nicotine, a major component in cigarette, on CSCs and EMT characteristics. The possible reversal regulators were further explored in nicotine-induced CSCs and EMT properties in human oral epithelial (OE) cells. Long-term exposure with nicotine was demonstrated to up-regulate ALDH1 population in normal gingival and primary OSCC OE cells dose-dependently. Moreover, long-term nicotine treatment was found to enhance the self-renewal sphere-forming ability and stemness gene signatures expression and EMT regulators in OE cells. The migration/cell invasiveness/anchorage independent growth and in vivo tumor growth by nude mice xenotransplantation assay was enhanced in long-term nicotine-stimulated OE cells. Knockdown of Snail in long-term nicotine-treated OE cells was found to reduce their CSCs properties. Therapeutic delivery of Si-Snail significantly blocked the xenograft tumorigenesis of long-term nicotine-treated OSCC cells and largely significantly improved the recipient survival. The present study demonstrated that the enrichment of CSCs coupled EMT property in oral epithelial cells induced by nicotine is critical for the development of OSCC tumorigenesis. Targeting Snail might offer a new strategy for the treatment of OSCC patients with smoking habit. -- Highlights: ► Sustained nicotine treatment induced CSCs properties of oral epithelial cells. ► Long-term nicotine treatment enhance EMT properties of oral epithelial cells. ► Long-term nicotine exposure increased tumorigenicity of oral epithelial cells. ► Si

  7. cGMP/cGMP-dependent protein kinase pathway modulates nicotine-induced currents through the activation of α-bungarotoxin-insensitive nicotinic acetylcholine receptors from insect neurosecretory cells.

    PubMed

    Mannai, Safa; Bitri, Lofti; Thany, Steeve H

    2016-06-01

    Insect neurosecretory cells, called dorsal unpaired median neurons, are known to express two α-bungarotoxin-insensitive nicotinic acetylcholine receptor (nAChR) subtypes, nAChR1 and nAChR2. It was demonstrated that nAChR1 was sensitive to cAMP/cAMP-dependent protein kinase (PKA) regulation, resulting in a modulation of nicotine currents. In this study, we show that cyclic guanosine monophosphate (cGMP)/cGMP-dependent protein kinase (PKG) pathway modulates nicotine-induced currents, as increased cGMP affects the second compound of the biphasic current-voltage curve, corresponding to the nAChR2 receptors. Indeed, maintaining the guanosine triphosphate level with 100 μM guanosine triphosphate-γ-S increased nicotine currents through nAChR2. We also demonstrated that inhibition of PKG activity with 0.2 μM (8R,9S,11S)-(-)-9-methoxy-carbamyl-8-methyl-2,3,9,10-tetrahydro-8,11-epoxy-1H,8H,11H-2,7b,11a-trizadibenzo-(a,g)-cycloocta-(c,d,e)-trinden-1-one (KT5823), a PKG specific inhibitor, reduced nicotine-induced current amplitudes. KT5823 effect on nicotine currents is associated with calcium (Ca(2+) ) activity because inhibition of Ca(2+) concentration with cadmium chloride (CdCl2 ) abolished KT5823-induced inhibition mediated by nAChR2. However, specific inhibition of nitric oxide-guanylyl cyclase (GC) complex by 10 μM 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) significantly increased nicotine-induced current amplitudes on both nAChR1 and nAChR2. These results suggest that nicotine-induced currents mediated by both α-bungarotoxin-insensitive nAChR1 and nAChR2 are coupled to the cGMP/PKG pathway. We propose that nicotinic acetylcholine receptor activation induces an increase in intracellular calcium (Ca(2+) ) concentration. Elevation of intracellular Ca(2+) results in the formation of Ca(2+) -calmodulin (CaM) complex, which activates guanylyl cyclase (GC) and/or adenylyl cyclase (AC). Ca(2+) -CaM complex could activate Ca(2+) calmodulin kinase II which

  8. Dynamics of cholinergic function

    SciTech Connect

    Hanin, I.

    1986-01-01

    This book presents information on the following topics; cholinergic pathways - anatomy of the central nervous system; aging, DSAT and other clinical conditions; cholinergic pre- and post-synaptic receptors; acetylcholine release; cholinesterases, anticholinesterases and reactivators; acetylcholine synthesis, metabolism and precursors; second messenger messenger mechanisms; interaction of acetylcholine with other neurotransmitter systems; cholinergic mechanisms in physiological function, including cardiovascular events; and neurotoxic agents and false transmitters.

  9. Binding of /sup 3/H-acetylcholine to cholinergic receptors in bovine cerebral arteries

    SciTech Connect

    Shimohama, S.; Tsukahara, T.; Taniguchi, T.; Fujiwara, M.

    1985-11-18

    Cholinergic receptor sites in bovine cerebral arteries were analyzed using radioligand binding techniques with the cholinergic agonist, /sup 3/H-acetylcholine (ACh), as the ligand. Specific binding of /sup 3/H-ACh to membrane preparations of bovine cerebral arteries was saturable, of two binding sites, with dissociation constant (K/sub D/) values of 0.32 and 23.7 nM, and maximum binding capacity (Bmax) values of 67 and 252 fmol/mg protein, respectively. Specific binding of /sup 3/H-ACh was displaced effectively by muscarinic cholinergic agents and less effectively by nicotinic cholinergic agents. IC/sub 50/ values of cholinergic drugs for /sup 3/H-ACh binding were as follows: atropine, 38.5 nM; ACh, 59.8 nM; oxotremorine, 293 nM; scopolamine 474 nM; carbamylcholine, 990 nM. IC/sub 50/ values of nicotinic cholinergic agents such as nicotine, cytisine and ..cap alpha..-bungarotoxin exceeded 50 ..mu..M. Choline acetyltransferase activity was 1.09 nmol/mg protein/hour in the cerebral arteries. These findings suggest that the cholinergic nerves innervate the bovine cerebral arteries and that there are at least two classes of ACh binding sites of different affinities on muscarinic reporters in these arteries. 18 references, 2 figures, 2 tables.

  10. Direct muscarinic and nicotinic receptor-mediated excitation of rat medial vestibular nucleus neurons in vitro

    NASA Technical Reports Server (NTRS)

    Phelan, K. D.; Gallagher, J. P.

    1992-01-01

    We have utilized intracellular recording techniques to investigate the cholinoceptivity of rat medial vestibular nucleus (MVN) neurons in a submerged brain slice preparation. Exogenous application of the mixed cholinergic agonists, acetylcholine (ACh) or carbachol (CCh), produced predominantly membrane depolarization, induction of action potential firing, and decreased input resistance. Application of the selective muscarinic receptor agonist muscarine (MUSC), or the selective nicotinic receptor agonists nicotine (NIC) or 1,1-dimethyl-4-phenylpiperazinium (DMPP) also produced membrane depolarizations. The MUSC-induced depolarization was accompanied by decreased conductance, while an increase in conductance appeared to underlie the NIC- and DMPP-induced depolarizations. The muscarinic and nicotinic receptor mediated depolarizations persisted in tetrodotoxin and/or low Ca2+/high Mg2+ containing media, suggesting direct postsynaptic receptor activation. The MUSC-induced depolarization could be reversibly blocked by the selective muscarinic-receptor antagonist, atropine, while the DMPP-induced depolarization could be reversibly suppressed by the selective ganglionic nicotinic-receptor antagonist, mecamylamine. Some neurons exhibited a transient membrane hyperpolarization during the depolarizing response to CCh or MUSC application. This transient inhibition could be reversibly blocked by the gamma-aminobutyric acid (GABA) antagonist, bicuculline, suggesting that the underlying hyperpolarization results indirectly from the endogenous release of GABA acting at GABA receptors. This study confirms the cholinoceptivity of MVN neurons and establishes that individual MVN cells possess muscarinic as well as nicotinic receptors. The data provide support for a prominent role of cholinergic mechanisms in the direct and indirect regulation of the excitability of MVN neurons.

  11. Cholinergic Functioning in Stimulant Addiction: Implications for Medications Development

    PubMed Central

    Sofuoglu, Mehmet; Mooney, Marc

    2009-01-01

    Acetylcholine (ACh), the first neurotransmitter discovered, participates in many CNS functions including sensory and motor processing, sleep, nociception, mood, stress response, attention, arousal, memory, motivation and reward. These diverse cholinergic effects are mediated by nicotinic (nAChR) and muscarinic (mAChR) type cholinergic receptors. The goal of this review is to synthesize a growing literature that supports the potential role of ACh as a treatment target for stimulant addiction. ACh interacts with the dopaminergic reward system in the ventral tegmental area (VTA), nucleus accumbens (NAc) and prefrontal cortex (PFC). In the VTA, both nAChR and mAChR stimulate the dopaminergic system. In the NAc, cholinergic interneurons integrate cortical and subcortical information related to reward. In the PFC, the cholinergic system contributes to the cognitive aspects of addiction. Preclinical studies support a facilitative role of nicotinic agonists in the development of stimulant addiction. Muscarinic agonists seem to have an inhibitory role depending on the subtype of mAChR. In human studies acetylcholine esterase (AChE) inhibitors, which increase synaptic ACh levels, have shown promise for the treatment of stimulant addiction. Further studies testing the efficacy of cholinergic medications for stimulant addiction are warranted. PMID:19845415

  12. Endogenous Cholinergic Neurotransmission Contributes to Behavioral Sensitization to Morphine

    PubMed Central

    Bajic, Dusica; Soiza-Reilly, Mariano; Spalding, Allegra L.; Berde, Charles B.; Commons, Kathryn G.

    2015-01-01

    Neuroplasticity in the mesolimbic dopaminergic system is critical for behavioral adaptations associated with opioid reward and addiction. These processes may be influenced by cholinergic transmission arising from the laterodorsal tegmental nucleus (LDTg), a main source of acetylcholine to mesolimbic dopaminergic neurons. To examine this possibility we asked if chronic systemic morphine administration affects expression of genes in ventral and ventrolateral periaqueductal gray at the level of the LDTg using rtPCR. Specifically, we examined gene expression changes in the area of interest using Neurotransmitters and Receptors PCR array between chronic morphine and saline control groups. Analysis suggested that chronic morphine administration led to changes in expression of genes associated, in part, with cholinergic neurotransmission. Furthermore, using a quantitative immunofluorescent technique, we found that chronic morphine treatment produced a significant increase in immunolabeling of the cholinergic marker (vesicular acetylcholine transporter) in neurons of the LDTg. Finally, systemic administration of the nonselective and noncompetitive neuronal nicotinic antagonist mecamylamine (0.5 or 2 mg/kg) dose-dependently blocked the expression, and to a lesser extent the development, of locomotor sensitization. The same treatment had no effect on acute morphine antinociception, antinociceptive tolerance or dependence to chronic morphine. Taken together, the results suggest that endogenous nicotinic cholinergic neurotransmission selectively contributes to behavioral sensitization to morphine and this process may, in part, involve cholinergic neurons within the LDTg. PMID:25647082

  13. Positive allosteric modulation of alpha-7 nicotinic receptors promotes cell death by inducing Ca(2+) release from the endoplasmic reticulum.

    PubMed

    Guerra-Álvarez, María; Moreno-Ortega, Ana J; Navarro, Elisa; Fernández-Morales, José Carlos; Egea, Javier; López, Manuela G; Cano-Abad, María F

    2015-05-01

    Positive allosteric modulation of α7 isoform of nicotinic acetylcholine receptors (α7-nAChRs) is emerging as a promising therapeutic approach for central nervous system disorders such as schizophrenia or Alzheimer's disease. However, its effect on Ca(2+) signaling and cell viability remains controversial. This study focuses on how the type II positive allosteric modulator (PAM II) PNU120596 affects intracellular Ca(2+) signaling and cell viability. We used human SH-SY5Y neuroblastoma cells overexpressing α7-nAChRs (α7-SH) and their control (C-SH). We monitored cytoplasmic and endoplasmic reticulum (ER) Ca(2+) with Fura-2 and the genetically encoded cameleon targeting the ER, respectively. Nicotinic inward currents were measured using patch-clamp techniques. Viability was assessed using methylthiazolyl blue tetrazolium bromide or propidium iodide staining. We observed that in the presence of a nicotinic agonist, PNU120596 (i) reduced viability of α7-SH but not of C-SH cells; (ii) significantly increased inward nicotinic currents and cytosolic Ca(2+) concentration; (iii) released Ca(2+) from the ER by a Ca(2+) -induced Ca(2+) release mechanism only in α7-SH cells; (iv) was cytotoxic in rat organotypic hippocampal slice cultures; and, lastly, all these effects were prevented by selective blockade of α7-nAChRs, ryanodine receptors, or IP3 receptors. In conclusion, positive allosteric modulation of α7-nAChRs with the PAM II PNU120596 can lead to dysregulation of ER Ca(2+) , overloading of intracellular Ca(2+) , and neuronal cell death. This study focuses on how the type II positive allosteric modulator PNU120596 (PAM II PNU12) affects intracellular Ca(2+) signaling and cell viability. Using SH-SY5Y neuroblastoma cells overexpressing α7-nAChRs (α7-SH) and their control (C-SH), we find that PAM of α7-nAChRs with PNU120596: (i) increases inward calcium current (ICa ) and cytosolic Ca(2+) concentration ([Ca(2+) ]cyt ); (ii) releases Ca(2+) from the ER ([Ca(2

  14. New Etiology of Cholinergic Urticaria.

    PubMed

    Tokura, Yoshiki

    2016-01-01

    Cholinergic urticaria (CholU) is characterized by pinpoint-sized, highly pruritic wheals occurring upon sweating. Both direct and indirect theories in the interaction of acetylcholine (ACh) with mast cells have been put forward in the sweating-associated histamine release from mast cells. In the mechanism of indirect involvement of ACh, patients are hypersensitive to sweat antigen(s) and develop wheals in response to sweat substances leaking from the syringeal ducts to the dermis, possibly by obstruction of the ducts. Some patients with CholU exhibit a positive reaction to intradermal injection of their own diluted sweat, representing 'sweat allergy (hypersensitivity)'. Regarding the direct interaction theory between ACh and mast cells, we found that CholU with anhidrosis and hypohidrosis lacks cholinergic receptor M3 (CHRM3) expression in eccrine sweat gland epithelial cells. The expression of CHRM3 is completely absent in the anhidrotic areas and lowly expressed in the hypohidrotic areas. In the hypohidrotic area, where CholU occurs, it is hypothesized that ACh released from nerves cannot be completely trapped by cholinergic receptors of eccrine glands and overflows to the adjacent mast cells, leading to wheals. PMID:27584968

  15. Short-term plasticity and modulation of synaptic transmission at mammalian inhibitory cholinergic olivocochlear synapses

    PubMed Central

    Katz, Eleonora; Elgoyhen, Ana Belén

    2014-01-01

    The organ of Corti, the mammalian sensory epithelium of the inner ear, has two types of mechanoreceptor cells, inner hair cells (IHCs) and outer hair cells (OHCs). In this sensory epithelium, vibrations produced by sound waves are transformed into electrical signals. When depolarized by incoming sounds, IHCs release glutamate and activate auditory nerve fibers innervating them and OHCs, by virtue of their electromotile property, increase the amplification and fine tuning of sound signals. The medial olivocochlear (MOC) system, an efferent feedback system, inhibits OHC activity and thereby reduces the sensitivity and sharp tuning of cochlear afferent fibers. During neonatal development, IHCs fire Ca2+ action potentials which evoke glutamate release promoting activity in the immature auditory system in the absence of sensory stimuli. During this period, MOC fibers also innervate IHCs and are thought to modulate their firing rate. Both the MOC-OHC and the MOC-IHC synapses are cholinergic, fast and inhibitory and mediated by the α9α10 nicotinic cholinergic receptor (nAChR) coupled to the activation of calcium-activated potassium channels that hyperpolarize the hair cells. In this review we discuss the biophysical, functional and molecular data which demonstrate that at the synapses between MOC efferent fibers and cochlear hair cells, modulation of transmitter release as well as short term synaptic plasticity mechanisms, operating both at the presynaptic terminal and at the postsynaptic hair-cell, determine the efficacy of these synapses and shape the hair cell response pattern. PMID:25520631

  16. Neuronal-type alpha-bungarotoxin receptors and the alpha 5-nicotinic receptor subunit gene are expressed in neuronal and nonneuronal human cell lines.

    PubMed Central

    Chini, B; Clementi, F; Hukovic, N; Sher, E

    1992-01-01

    alpha-Bungarotoxin (alpha Bgtx) is a toxin known to interact with muscle nicotinic receptors and with some neuronal nicotinic receptors. We show that alpha Bgtx binding sites are also expressed in nonmuscle and nonneuronal human cells, including small cell lung carcinoma and several epithelial cell lines. These receptors are immunologically related to the alpha Bgtx receptors of unknown function described in the nervous system and in the IMR32 neuroblastoma cell line and are distinct from muscle nicotinic receptors. We have also cloned from IMR32 cells the human alpha 5-nicotinic receptor subunit, which is supposed to participate in the formation of alpha Bgtx receptors. Transcripts corresponding to the alpha 5-subunit gene were found not only in neuroblastoma cells but also in all the cell lines expressing alpha Bgtx receptors, with the exception of the TE671 cell line, whose nicotinic receptor subunits are of the muscle type. We conclude that both alpha Bgtx receptors and the alpha 5-nicotinic subunit gene are not neuron-specific, as previously thought, but are expressed in a number of human cell lines of various origin. Images PMID:1542648

  17. Cirri of the stalked crinoid Metacrinus rotundus: neural elements and the effect of cholinergic agonists on mechanical properties.

    PubMed Central

    Birenheide, R; Yokoyama, K; Motokawa, T

    2000-01-01

    Sea lilies are enigmatic animals due to their scarcity and their biology is comparatively neglected. Cirri, arranged in whorls of five along the sea lily stalk, anchor and support the animal. They consist of ossicles interconnected by collagenous ligaments and by a central canal. Cirri have a well-developed nervous system but lack muscular cells. A light and electron microscopic study was performed to clarify the morphology of the nervous system of the cirri. Two cellular networks were found, one of neuron-like cells and one of cells filled with bullet-shaped organelles. Both networks ramify throughout the cirral ossicles up to the interossicle ligaments. Mechanical tests were performed to analyse the influence of cholinergic agonists on the mechanical properties of these ligaments. In the tests, the cirral ligaments softened after the application of acetylcholine, muscarinic agonists and nicotinic agonists. The reaction time to muscarinic agonists was much slower than to acetylcholine and nicotinic agonists. At low concentrations, muscarinic agonists caused active development of force. No reaction to stimuli was observed in anaesthetized cirri. The data clearly establish the existence of catch connective tissue which can change its mechanical properties under nervous control mediated via nerves with cholinergic receptors. The possible sources of the observed force production are discussed and it is concluded that active contraction of collagenous ligaments causes movement of cirri. PMID:10670946

  18. Purinergic and Cholinergic Drugs Mediate Hyperventilation in Zebrafish: Evidence from a Novel Chemical Screen.

    PubMed

    Rahbar, Saman; Pan, Wen; Jonz, Michael G

    2016-01-01

    A rapid test to identify drugs that affect autonomic responses to hypoxia holds therapeutic and ecologic value. The zebrafish (Danio rerio) is a convenient animal model for investigating peripheral O2 chemoreceptors and respiratory reflexes in vertebrates; however, the neurotransmitters and receptors involved in this process are not adequately defined. The goals of the present study were to demonstrate purinergic and cholinergic control of the hyperventilatory response to hypoxia in zebrafish, and to develop a procedure for screening of neurochemicals that affect respiration. Zebrafish larvae were screened in multi-well plates for sensitivity to the cholinergic receptor agonist, nicotine, and antagonist, atropine; and to the purinergic receptor antagonists, suramin and A-317491. Nicotine increased ventilation frequency (fV) maximally at 100 μM (EC50 = 24.5 μM). Hypoxia elevated fV from 93.8 to 145.3 breaths min-1. Atropine reduced the hypoxic response only at 100 μM. Suramin and A-317491 maximally reduced fV at 50 μM (EC50 = 30.4 and 10.8 μM) and abolished the hyperventilatory response to hypoxia. Purinergic P2X3 receptors were identified in neurons and O2-chemosensory neuroepithelial cells of the gills using immunohistochemistry and confocal microscopy. These studies suggest a role for purinergic and nicotinic receptors in O2 sensing in fish and implicate ATP and acetylcholine in excitatory neurotransmission, as in the mammalian carotid body. We demonstrate a rapid approach for screening neuroactive chemicals in zebrafish with implications for respiratory medicine and carotid body disease in humans; as well as for preservation of aquatic ecosystems. PMID:27100625

  19. Purinergic and Cholinergic Drugs Mediate Hyperventilation in Zebrafish: Evidence from a Novel Chemical Screen

    PubMed Central

    Rahbar, Saman; Pan, Wen; Jonz, Michael G.

    2016-01-01

    A rapid test to identify drugs that affect autonomic responses to hypoxia holds therapeutic and ecologic value. The zebrafish (Danio rerio) is a convenient animal model for investigating peripheral O2 chemoreceptors and respiratory reflexes in vertebrates; however, the neurotransmitters and receptors involved in this process are not adequately defined. The goals of the present study were to demonstrate purinergic and cholinergic control of the hyperventilatory response to hypoxia in zebrafish, and to develop a procedure for screening of neurochemicals that affect respiration. Zebrafish larvae were screened in multi-well plates for sensitivity to the cholinergic receptor agonist, nicotine, and antagonist, atropine; and to the purinergic receptor antagonists, suramin and A-317491. Nicotine increased ventilation frequency (fV) maximally at 100 μM (EC50 = 24.5 μM). Hypoxia elevated fV from 93.8 to 145.3 breaths min-1. Atropine reduced the hypoxic response only at 100 μM. Suramin and A-317491 maximally reduced fV at 50 μM (EC50 = 30.4 and 10.8 μM) and abolished the hyperventilatory response to hypoxia. Purinergic P2X3 receptors were identified in neurons and O2-chemosensory neuroepithelial cells of the gills using immunohistochemistry and confocal microscopy. These studies suggest a role for purinergic and nicotinic receptors in O2 sensing in fish and implicate ATP and acetylcholine in excitatory neurotransmission, as in the mammalian carotid body. We demonstrate a rapid approach for screening neuroactive chemicals in zebrafish with implications for respiratory medicine and carotid body disease in humans; as well as for preservation of aquatic ecosystems. PMID:27100625

  20. Promoter polymorphisms and transcript levels of nicotinic receptor CHRNA5.

    PubMed

    Falvella, Felicia S; Galvan, Antonella; Colombo, Francesca; Frullanti, Elisa; Pastorino, Ugo; Dragani, Tommaso A

    2010-09-01

    Chromosomal locus 15q25, implicated in lung cancer risk and nicotine dependence, shows extensive linkage disequilibrium that complicates identification of causal variation. Cholinergic receptor nicotinic alpha5 (CHRNA5) has been identified as a lung cancer risk factor. We identified by sequence analysis three haplotypes (delTTC, insATC, and insTGG) in the 5' promoter region and three at the 3'-untranslated region of CHRNA5. Linkage disequilibrium analysis of the 5' variants showed that the insTGG haplotype is associated with three tightly linked risk alleles (nicotine dependence, lung cancer, and chronic obstructive pulmonary disease). The three CHRNA5 promoter haplotypes were statistically significantly associated with lung CHRNA5 transcript levels, determined by real-time polymerase chain reaction. In nontumor lung parenchyma from 68 patients who underwent lung lobectomy, the delTTC haplotype was associated with the highest CHRNA5 transcript levels (relative quantification units = 1.82), whereas the insTGG haplotype was associated with the lowest (0.88 units, P(diff) < .001, Welch t test; all statistical tests were two-sided). Luciferase reporter assays in human lung cancer cell lines A549, H460, H520, and H596 also showed that the 5' region haplotypes were statistically significantly associated with changes in CHRNA5 promoter activity, whereas the 3'-untranslated region variants were not. PMID:20733116

  1. Chemical coding and chemosensory properties of cholinergic brush cells in the mouse gastrointestinal and biliary tract

    PubMed Central

    Schütz, Burkhard; Jurastow, Innokentij; Bader, Sandra; Ringer, Cornelia; von Engelhardt, Jakob; Chubanov, Vladimir; Gudermann, Thomas; Diener, Martin; Kummer, Wolfgang; Krasteva-Christ, Gabriela; Weihe, Eberhard

    2015-01-01

    The mouse gastro-intestinal and biliary tract mucosal epithelia harbor choline acetyltransferase (ChAT)-positive brush cells with taste cell-like traits. With the aid of two transgenic mouse lines that express green fluorescent protein (EGFP) under the control of the ChAT promoter (EGFPChAT) and by using in situ hybridization and immunohistochemistry we found that EGFPChAT cells were clustered in the epithelium lining the gastric groove. EGFPChAT cells were numerous in the gall bladder and bile duct, and found scattered as solitary cells along the small and large intestine. While all EGFPChAT cells were also ChAT-positive, expression of the high-affinity choline transporter (ChT1) was never detected. Except for the proximal colon, EGFPChAT cells also lacked detectable expression of the vesicular acetylcholine transporter (VAChT). EGFPChAT cells were found to be separate from enteroendocrine cells, however they were all immunoreactive for cytokeratin 18 (CK18), transient receptor potential melastatin-like subtype 5 channel (TRPM5), and for cyclooxygenases 1 (COX1) and 2 (COX2). The ex vivo stimulation of colonic EGFPChAT cells with the bitter substance denatonium resulted in a strong increase in intracellular calcium, while in other epithelial cells such an increase was significantly weaker and also timely delayed. Subsequent stimulation with cycloheximide was ineffective in both cell populations. Given their chemical coding and chemosensory properties, EGFPChAT brush cells thus may have integrative functions and participate in induction of protective reflexes and inflammatory events by utilizing ACh and prostaglandins for paracrine signaling. PMID:25852573

  2. Chemical coding and chemosensory properties of cholinergic brush cells in the mouse gastrointestinal and biliary tract.

    PubMed

    Schütz, Burkhard; Jurastow, Innokentij; Bader, Sandra; Ringer, Cornelia; von Engelhardt, Jakob; Chubanov, Vladimir; Gudermann, Thomas; Diener, Martin; Kummer, Wolfgang; Krasteva-Christ, Gabriela; Weihe, Eberhard

    2015-01-01

    The mouse gastro-intestinal and biliary tract mucosal epithelia harbor choline acetyltransferase (ChAT)-positive brush cells with taste cell-like traits. With the aid of two transgenic mouse lines that express green fluorescent protein (EGFP) under the control of the ChAT promoter (EGFP (ChAT) ) and by using in situ hybridization and immunohistochemistry we found that EGFP (ChAT) cells were clustered in the epithelium lining the gastric groove. EGFP (ChAT) cells were numerous in the gall bladder and bile duct, and found scattered as solitary cells along the small and large intestine. While all EGFP (ChAT) cells were also ChAT-positive, expression of the high-affinity choline transporter (ChT1) was never detected. Except for the proximal colon, EGFP (ChAT) cells also lacked detectable expression of the vesicular acetylcholine transporter (VAChT). EGFP (ChAT) cells were found to be separate from enteroendocrine cells, however they were all immunoreactive for cytokeratin 18 (CK18), transient receptor potential melastatin-like subtype 5 channel (TRPM5), and for cyclooxygenases 1 (COX1) and 2 (COX2). The ex vivo stimulation of colonic EGFP (ChAT) cells with the bitter substance denatonium resulted in a strong increase in intracellular calcium, while in other epithelial cells such an increase was significantly weaker and also timely delayed. Subsequent stimulation with cycloheximide was ineffective in both cell populations. Given their chemical coding and chemosensory properties, EGFP (ChAT) brush cells thus may have integrative functions and participate in induction of protective reflexes and inflammatory events by utilizing ACh and prostaglandins for paracrine signaling. PMID:25852573

  3. Cholinergic imaging in dementia spectrum disorders.

    PubMed

    Roy, Roman; Niccolini, Flavia; Pagano, Gennaro; Politis, Marios

    2016-07-01

    The multifaceted nature of the pathology of dementia spectrum disorders has complicated their management and the development of effective treatments. This is despite the fact that they are far from uncommon, with Alzheimer's disease (AD) alone affecting 35 million people worldwide. The cholinergic system has been found to be crucially involved in cognitive function, with cholinergic dysfunction playing a pivotal role in the pathophysiology of dementia. The use of molecular imaging such as SPECT and PET for tagging targets within the cholinergic system has shown promise for elucidating key aspects of underlying pathology in dementia spectrum disorders, including AD or parkinsonian dementias. SPECT and PET studies using selective radioligands for cholinergic markers, such as [(11)C]MP4A and [(11)C]PMP PET for acetylcholinesterase (AChE), [(123)I]5IA SPECT for the α4β2 nicotinic acetylcholine receptor and [(123)I]IBVM SPECT for the vesicular acetylcholine transporter, have been developed in an attempt to clarify those aspects of the diseases that remain unclear. This has led to a variety of findings, such as cortical AChE being significantly reduced in Parkinson's disease (PD), PD with dementia (PDD) and AD, as well as correlating with certain aspects of cognitive function such as attention and working memory. Thalamic AChE is significantly reduced in progressive supranuclear palsy (PSP) and multiple system atrophy, whilst it is not affected in PD. Some of these findings have brought about suggestions for the improvement of clinical practice, such as the use of a thalamic/cortical AChE ratio to differentiate between PD and PSP, two diseases that could overlap in terms of initial clinical presentation. Here, we review the findings from molecular imaging studies that have investigated the role of the cholinergic system in dementia spectrum disorders. PMID:26984612

  4. The Regulatory Role of Rolipram on Inflammatory Mediators and Cholinergic/Adrenergic Stimulation-Induced Signals in Isolated Primary Mouse Submandibular Gland Cells

    PubMed Central

    Lee, Dong Un; Shin, Dong Min; Hong, Jeong Hee

    2016-01-01

    Exposure to bacterial lipopolysaccharides (LPS) induces inflammatory signals in salivary glands. We investigated the regulatory role of phosphodiesterase 4 (PDE4) inhibitor rolipram on inflammatory mediators and cholinergic/adrenergic stimulation-induced intracellular Ca2+ signaling in salivary acinar and ductal cells. Submandibular gland (SMG) expressed PDE4A through 4D mRNA and PDE4 was localized in the luminal membrane of SMG. LPS induced Ca2+ signaling and ROS production in SMG. Treatment with rolipram blocked LPS-induced Ca2+ increase and ROS production. The application of histamine evoked Ca2+ signals and ROS production, which were attenuated by rolipram in SMG cells. Moreover, LPS-induced NLRP3 inflammasome and cleaved caspase-1 were inhibited by rolipram. The inhibitory role of rolipram in ROS-induced Ca2+ signaling was mainly observed in acinar cells and not in ductal cells. Rolipram also protected SMG acinar but not ductal cells from LPS-induced cell membrane damage. In the case of cholinergic/adrenergic stimulation, carbachol/isoproterenol-induced Ca2+ signals were upregulated by the treatment of rolipram in SMG. In the case of cAMP-dependent ductal bicarbonate secretion by rolipram, no effect was observed on the modulation of ductal chloride/bicarbonate exchange activity. Rolipram could suppress the inflammatory signals and could be a potential therapeutic strategy against LPS-induced inflammation to protect the salivary gland cells. PMID:27143817

  5. [Probable mechanism of recognition of cholinergic ligands by acetylcholine receptors].

    PubMed

    Demushkin, V P; Kotelevtsev, Iu V; Pliashkevich, Iu G; Khramtsov, N V

    1982-01-01

    Dryding's models were used for the conformational analysis of compounds affecting muscarin-specific acetylcholine receptor and nicotin-specific acetylcholine receptor. Ammonium group and ether oxygen (3.6 A apart from the ammonium group) specifically oriented to each other were shown to be necessary structural elements to reveal muscarin-type cholinergic activity. Ammonium group along with carbonyl oxygen or its substituent (5 A distance) are the necessary structural units providing nicotin-type cholinergic activity. The presence of two hydrophobic substituents (one in the ammonium area and the other neighbouring the second active grouping) is the additional factor. The developed principles were justified by the use of a series of synthetic samples. The compounds were obtained likely favouring affinitive modification of acetylcholine receptor (dissociation constants of acetylcholine receptor complexes equalling to 10(-4)--10(-7) M-1). PMID:7070378

  6. Chronic Nicotine Exposure In Vivo and In Vitro Inhibits Vitamin B1 (Thiamin) Uptake by Pancreatic Acinar Cells

    PubMed Central

    Srinivasan, Padmanabhan; Thrower, Edwin C.; Loganathan, Gopalakrishnan; Balamurugan, A. N.; Subramanian, Veedamali S.; Gorelick, Fred S.; Said, Hamid M.

    2015-01-01

    Thiamin (vitamin B1), a member of the water-soluble family of vitamins, is essential for normal cellular functions; its deficiency results in oxidative stress and mitochondrial dysfunction. Pancreatic acinar cells (PAC) obtain thiamin from the circulation using a specific carrier-mediated process mediated by both thiamin transporters -1 and -2 (THTR-1 and THTR-2; encoded by the SLC19A2 and SLC19A3 genes, respectively). The aim of the current study was to examine the effect of chronic exposure of mouse PAC in vivo and human PAC in vitro to nicotine (a major component of cigarette smoke that has been implicated in pancreatic diseases) on thiamin uptake and to delineate the mechanism involved. The results showed that chronic exposure of mice to nicotine significantly inhibits thiamin uptake in murine PAC, and that this inhibition is associated with a marked decrease in expression of THTR-1 and THTR-2 at the protein, mRNA and hnRNAs level. Furthermore, expression of the important thiamin-metabolizing enzyme, thiamin pyrophosphokinase (TPKase), was significantly reduced in PAC of mice exposed to nicotine. Similarly, chronic exposure of cultured human PAC to nicotine (0.5 μM, 48 h) significantly inhibited thiamin uptake, which was also associated with a decrease in expression of THTR-1 and THTR-2 proteins and mRNAs. This study demonstrates that chronic exposure of PAC to nicotine impairs the physiology and the molecular biology of the thiamin uptake process. Furthermore, the study suggests that the effect is, in part, mediated through transcriptional mechanism(s) affecting the SLC19A2 and SLC19A3 genes. PMID:26633299

  7. Chronic Nicotine Exposure In Vivo and In Vitro Inhibits Vitamin B1 (Thiamin) Uptake by Pancreatic Acinar Cells.

    PubMed

    Srinivasan, Padmanabhan; Thrower, Edwin C; Loganathan, Gopalakrishnan; Balamurugan, A N; Subramanian, Veedamali S; Gorelick, Fred S; Said, Hamid M

    2015-01-01

    Thiamin (vitamin B1), a member of the water-soluble family of vitamins, is essential for normal cellular functions; its deficiency results in oxidative stress and mitochondrial dysfunction. Pancreatic acinar cells (PAC) obtain thiamin from the circulation using a specific carrier-mediated process mediated by both thiamin transporters -1 and -2 (THTR-1 and THTR-2; encoded by the SLC19A2 and SLC19A3 genes, respectively). The aim of the current study was to examine the effect of chronic exposure of mouse PAC in vivo and human PAC in vitro to nicotine (a major component of cigarette smoke that has been implicated in pancreatic diseases) on thiamin uptake and to delineate the mechanism involved. The results showed that chronic exposure of mice to nicotine significantly inhibits thiamin uptake in murine PAC, and that this inhibition is associated with a marked decrease in expression of THTR-1 and THTR-2 at the protein, mRNA and hnRNAs level. Furthermore, expression of the important thiamin-metabolizing enzyme, thiamin pyrophosphokinase (TPKase), was significantly reduced in PAC of mice exposed to nicotine. Similarly, chronic exposure of cultured human PAC to nicotine (0.5 μM, 48 h) significantly inhibited thiamin uptake, which was also associated with a decrease in expression of THTR-1 and THTR-2 proteins and mRNAs. This study demonstrates that chronic exposure of PAC to nicotine impairs the physiology and the molecular biology of the thiamin uptake process. Furthermore, the study suggests that the effect is, in part, mediated through transcriptional mechanism(s) affecting the SLC19A2 and SLC19A3 genes. PMID:26633299

  8. Comparative non-cholinergic neurotoxic effects of paraoxon and diisopropyl fluorophosphate (DFP) on human neuroblastoma and astrocytoma cell lines

    SciTech Connect

    Qian Yongchang; Venkatraj, Jijayanagaram; Barhoumi, Rola; Pal, Ranadip; Datta, Aniruddha; Wild, James R.; Tiffany-Castiglioni, Evelyn . E-mail: ecastiglioni@cvm.tamu.edu

    2007-03-15

    The objective of this study was to evaluate the comparative non-cholinergic neurotoxic effects of paraoxon, which is acutely neurotoxic, and diisopropyl fluorophosphate (DFP), which induces OPIDN, in the human neuroblastoma SY5Y and the human astrocytoma cell line CCF-STTG1. SY5Y cells have been studied extensively as a model for OP-induced neurotoxicity, but CCF cells have not previously been studied. We conducted a preliminary human gene array assay of OP-treated SY5Y cells in order to assess at the gene level whether these cells can distinguish between OP compounds that do and do not cause OPIDN. Paraoxon and DFP induced dramatically different profiles of gene expression. Two genes were upregulated and 13 downregulated by at least 2-fold in paraoxon-treated cells. In contrast, one gene was upregulated by DFP and none was downregulated at the 2-fold threshold. This finding is consistent with current and previous observations that SY5Y cells can distinguish between OPs that do or do not induce OPIDN. We also examined gene array results for possible novel target proteins or metabolic pathways for OP neurotoxicity. Protein levels of glucose regulated protein 78 (GRP78) revealed that paraoxon exposure at 3 {mu}M for 24 h significantly reduced GRP78 levels by 30% in neuroblastoma cells, whereas DFP treatment had no effect. In comparison with SY5Y neuroblastoma cells, paraoxon and DFP (3 {mu}M for 24 h) each significantly increased GRP78 levels by 23-24% in CCF astrocytoma cells. As we have previously evaluated intracellular changes in Ca{sup 2+} levels in SY5Y cells, we investigated the effects of paraoxon and DFP on cellular Ca{sup 2+} homeostasis in CCF by studying cytosolic and mitochondrial basal calcium levels. A significant decrease in the ratio of mitochondrial to cytosolic Ca{sup 2+} fluorescence was detected in CCF cultures treated for either 1 or 3 days with 1, 3, 10, or 30 {mu}M paraoxon. In contrast, treatment with DFP for 1 day had no significant effect

  9. Memory-Relevant Mushroom Body Output Synapses Are Cholinergic

    PubMed Central

    Barnstedt, Oliver; Owald, David; Felsenberg, Johannes; Brain, Ruth; Moszynski, John-Paul; Talbot, Clifford B.; Perrat, Paola N.; Waddell, Scott

    2016-01-01

    Summary Memories are stored in the fan-out fan-in neural architectures of the mammalian cerebellum and hippocampus and the insect mushroom bodies. However, whereas key plasticity occurs at glutamatergic synapses in mammals, the neurochemistry of the memory-storing mushroom body Kenyon cell output synapses is unknown. Here we demonstrate a role for acetylcholine (ACh) in Drosophila. Kenyon cells express the ACh-processing proteins ChAT and VAChT, and reducing their expression impairs learned olfactory-driven behavior. Local ACh application, or direct Kenyon cell activation, evokes activity in mushroom body output neurons (MBONs). MBON activation depends on VAChT expression in Kenyon cells and is blocked by ACh receptor antagonism. Furthermore, reducing nicotinic ACh receptor subunit expression in MBONs compromises odor-evoked activation and redirects odor-driven behavior. Lastly, peptidergic corelease enhances ACh-evoked responses in MBONs, suggesting an interaction between the fast- and slow-acting transmitters. Therefore, olfactory memories in Drosophila are likely stored as plasticity of cholinergic synapses. PMID:26948892

  10. Counting Bungarotoxin Binding Sites of Nicotinic Acetylcholine Receptors in Mammalian Cells with High Signal/Noise Ratios

    PubMed Central

    Simonson, Paul D.; DeBerg, Hannah A.; Ge, Pinghua; Alexander, John K.; Jeyifous, Okunola; Green, William N.; Selvin, Paul R.

    2010-01-01

    Nicotinic acetylcholine receptors are some of the most studied synaptic proteins; however, many questions remain that can only be answered using single molecule approaches. Here we report our results from single α7 and neuromuscular junction type nicotinic acetylcholine receptors in mammalian cell membranes. By labeling the receptors with fluorophore-labeled bungarotoxin, we can image individual receptors and count the number of bungarotoxin-binding sites in receptors expressed in HEK 293 cells. Our results indicate that there are two bungarotoxin-binding sites in neuromuscular junction receptors, as expected, and five in α7 receptors, clarifying previous uncertainty. This demonstrates a valuable technique for counting subunits in membrane-bound proteins at the single molecule level, with nonspecialized optics and with higher signal/noise ratios than previous fluorescent protein-based techniques. PMID:21081055

  11. Pu-erh Tea Extract Attenuates Nicotine-Induced Foam Cell Formation in Primary Cultured Monocytes: An in Vitro Mechanistic Study.

    PubMed

    Tu, Shih-Hsin; Chen, Ming-Yao; Chen, Li-Ching; Mao, Yi-Ting; Ho, Chi-Hou; Lee, Wen-Jui; Lin, Yen-Kuang; Pan, Min-Hsiung; Lo, Chih-Yu; Chen, Chi-Long; Yen, Yun; Whang-Peng, Jacqueline; Ho, Chi-Tang; Wu, Chih-Hsiung; Ho, Yuan-Soon

    2016-04-27

    In this study, the mechanisms by which pu-erh tea extract (PETE) attenuates nicotine-induced foam cell formation were investigated. Monocytes were purified from healthy individuals using commercial antibodies coated with magnetic beads. We found that the nicotine-induced (1-10 μM) expression of oxidized low-density lipoprotein receptors (ox-LDLRs) and α9-nAchRs in monocytes was significantly attenuated by 24 h of PETE (10 μg/mL; ∗, p < 0.05) cotreatment. Nicotine (1 μM for 24 h) significantly induced the expression of the surface adhesion molecule ICAM-1 and the monocyte integrin adhesion molecule (CD11b) by human umbilical vein endothelial cells (HUVECs) and triggered monocytes to differentiate into macrophages via interactions with the endothelium. After treatment with nicotine (0.1-10 μM for 24 h), the HUVECs released chemotactic factors (IL-8) to attract monocytes into the tunica intima of the artery, and the monocytes then transformed into foam cells. We demonstrated that PETE treatment (>1 μg/mL for 24 h; ∗, p < 0.05) significantly attenuates nicotine-induced (1 μM) monocyte migration toward HUVECs and foam cell formation. This study suggests that tea components effectively attenuate the initial step (foam cell formation) of nicotine-induced atherosclerosis in circulating monocytes. PMID:27001463

  12. Striatal cholinergic neurotransmission requires VGLUT3.

    PubMed

    Nelson, Alexandra B; Bussert, Timothy G; Kreitzer, Anatol C; Seal, Rebecca P

    2014-06-25

    It is now clear that many neuronal populations release more than one classical neurotransmitter, yet in most cases the functional role of corelease is unknown. Striatal cholinergic interneurons release both glutamate and acetylcholine, and vesicular loading of glutamate has been shown to enhance acetylcholine content. Using a combination of optogenetics and whole-cell recordings in mice, we now provide physiological evidence that optogenetic stimulation of cholinergic interneurons triggers monosynaptic glutamate- and acetylcholine-mediated currents in striatal fast-spiking interneurons (FSIs), both of which depend on the expression of the vesicular glutamate transporter 3 (VGLUT3). In contrast to corticostriatal glutamatergic inputs onto FSIs, which are mediated primarily by AMPA-type glutamate receptors, glutamate release by cholinergic interneurons activates both AMPA- and NMDA-type glutamate receptors, suggesting a unique role for these inputs in the modulation of FSI activity. Importantly, we find that the loss of VGLUT3 not only markedly attenuates glutamatergic and cholinergic inputs on FSIs, but also significantly decreases disynaptic GABAergic input onto medium spiny neurons (MSNs), the major output neurons of the striatum. Our data demonstrate that VGLUT3 is required for normal cholinergic signaling onto FSIs, as well as for acetylcholine-dependent disynaptic inhibition of MSNs. Thus, by supporting fast glutamatergic transmission as well as by modulating the strength of cholinergic signaling, VGLUT3 has the capacity to exert widespread influence on the striatal network. PMID:24966377

  13. Striatal Cholinergic Neurotransmission Requires VGLUT3

    PubMed Central

    Nelson, Alexandra B.; Bussert, Timothy G.

    2014-01-01

    It is now clear that many neuronal populations release more than one classical neurotransmitter, yet in most cases the functional role of corelease is unknown. Striatal cholinergic interneurons release both glutamate and acetylcholine, and vesicular loading of glutamate has been shown to enhance acetylcholine content. Using a combination of optogenetics and whole-cell recordings in mice, we now provide physiological evidence that optogenetic stimulation of cholinergic interneurons triggers monosynaptic glutamate- and acetylcholine-mediated currents in striatal fast-spiking interneurons (FSIs), both of which depend on the expression of the vesicular glutamate transporter 3 (VGLUT3). In contrast to corticostriatal glutamatergic inputs onto FSIs, which are mediated primarily by AMPA-type glutamate receptors, glutamate release by cholinergic interneurons activates both AMPA- and NMDA-type glutamate receptors, suggesting a unique role for these inputs in the modulation of FSI activity. Importantly, we find that the loss of VGLUT3 not only markedly attenuates glutamatergic and cholinergic inputs on FSIs, but also significantly decreases disynaptic GABAergic input onto medium spiny neurons (MSNs), the major output neurons of the striatum. Our data demonstrate that VGLUT3 is required for normal cholinergic signaling onto FSIs, as well as for acetylcholine-dependent disynaptic inhibition of MSNs. Thus, by supporting fast glutamatergic transmission as well as by modulating the strength of cholinergic signaling, VGLUT3 has the capacity to exert widespread influence on the striatal network. PMID:24966377

  14. Evidence of Nicotine-Induced, Curare-Insensitive, Behavior in Planarians.

    PubMed

    Pagán, Oné R; Montgomery, Erica; Deats, Sean; Bach, Daniel; Baker, Debra

    2015-10-01

    Planarians are rapidly developing into very useful research subjects in pharmacology and neuroscience research. Here we report that curare, a cholinergic nicotinic receptor antagonist, alleviates the nicotine-induced planarian seizure-like movements (pSLM) by up to 50 % at equimolar concentrations of nicotine and curare (1 mM), while curare alone does not induce significant pSLMs. The simplest interpretation of our data is that there are nicotine induced behaviors insensitive to curare in our experimental organism. To the best of our knowledge, this is the first report on curare-insensitive, nicotine-induced effects in any organism. PMID:25614180

  15. Alzheimer's Disease: Targeting the Cholinergic System

    PubMed Central

    Ferreira-Vieira, Talita H.; Guimaraes, Isabella M.; Silva, Flavia R.; Ribeiro, Fabiola M.

    2016-01-01

    Acetylcholine (ACh) has a crucial role in the peripheral and central nervous systems. The enzyme choline acetyltransferase (ChAT) is responsible for synthesizing ACh from acetyl-CoA and choline in the cytoplasm and the vesicular acetylcholine transporter (VAChT) uptakes the neurotransmitter into synaptic vesicles. Following depolarization, ACh undergoes exocytosis reaching the synaptic cleft, where it can bind its receptors, including muscarinic and nicotinic receptors. ACh present at the synaptic cleft is promptly hydrolyzed by the enzyme acetylcholinesterase (AChE), forming acetate and choline, which is recycled into the presynaptic nerve terminal by the high-affinity choline transporter (CHT1). Cholinergic neurons located in the basal forebrain, including the neurons that form the nucleus basalis of Meynert, are severely lost in Alzheimer’s disease (AD). AD is the most ordinary cause of dementia affecting 25 million people worldwide. The hallmarks of the disease are the accumulation of neurofibrillary tangles and amyloid plaques. However, there is no real correlation between levels of cortical plaques and AD-related cognitive impairment. Nevertheless, synaptic loss is the principal correlate of disease progression and loss of cholinergic neurons contributes to memory and attention deficits. Thus, drugs that act on the cholinergic system represent a promising option to treat AD patients. PMID:26813123

  16. Nicotine-induced exocytotic norepinephrine release in guinea-pig heart, human atrium and bovine adrenal chromaffin cells: modulation by single components of ischaemia.

    PubMed

    Krüger, C; Haunstetter, A; Gerber, S; Serf, C; Kaufmann, A; Kübler, W; Haass, M

    1995-08-01

    The influence of single components of myocardial ischaemia, such as anoxia, substrate withdrawal, hyperkalemia and extracellular acidosis, on nicotine-induced norepinephrine (NE) release was investigated in the isolated perfused guinea-pig heart, in incubated human atrial tissue and in cultured bovine adrenal chromaffin cells (BCC). In normoxia, nicotine (1-1000 mumol/l) evoked a concentration-dependent release of NE (determined by high pressure liquid chromatography and electrochemical detection) from guinea-pig heart and human atrium. In contrast to selective anoxia (Po2 < 5 mmHg) or glucose withdrawal, respectively, anoxia in combination with glucose withdrawal (5-40 min) markedly potentiated nicotine-induced NE release both in guinea-pig heart and human atrium. The sensitization of cardiac sympathetic nerve endings to nicotine was characterized by a lower threshold concentration and an approximate two-fold increase of maximum NE release, peaking after 10 min of anoxia and glucose withdrawal. Cyanide intoxication (1 mmol/l) combined with glucose withdrawal resulted in a similar increase of nicotine-induced sympathetic transmitter release both in guinea-pig heart and human atrium. In contrast, the nicotine-induced (10 mumol/l) NE overflow was only slightly potentiated by 10 min of global ischaemia in guinea-pig heart. Both hyperkalemia ([K+] 16 mmol/l) and acidosis (pH 6.8-6.0) distinctly attenuated the stimulatory effect of nicotine in guinea-pig heart and human atrium under normoxic conditions. Consistent with an exocytotic release mechanism, NE release was dependent on the presence of extracellular calcium under all conditions tested. Furthermore, NE overflow from guinea-pig heart was accompanied by a release of the exocytosis marker neuropeptide Y (NPY; determined by radioimmunoassay). In BCC, nicotine (1-10 mumol/l) evoked a release of NE and NPY and a transient rise of [Ca2+]i (determined with fura-2) during normoxia which were both dependent on the

  17. The α7-nicotinic acetylcholine receptor mediates the sensitivity of gastric cancer cells to taxanes.

    PubMed

    Tu, Chao-Chiang; Huang, Chien-Yu; Cheng, Wan-Li; Hung, Chin-Sheng; Uyanga, Batzorig; Wei, Po-Li; Chang, Yu-Jia

    2016-04-01

    Gastric cancer is difficult to cure because most patients are diagnosed at an advanced disease stage. Systemic chemotherapy remains an important therapy for gastric cancer, but both progression-free survival and disease-free survival associated with various combination regimens are limited because of refractoriness and chemoresistance. Accumulating evidence has revealed that the homomeric α7-nicotinic acetylcholine receptor (A7-nAChR) promotes human gastric cancer by driving cancer cell proliferation, migration, and metastasis. Therefore, A7-nAChR may serve as a potential therapeutic target for gastric cancer. However, the role of A7-nAChR in taxane therapy for gastric cancer was unclear. Cells were subjected to A7-nAChR knockdown (A7-nAChR KD) using short interfering RNA (siRNA). The anti-proliferative effects of taxane were assessed via 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL), and cell cycle distribution assays. A7-nAChR-KD cells exhibited low resistance to docetaxel and paclitaxel treatment, as measured by the MTT assay. Following paclitaxel treatment, the proportion of apoptotic cells was higher among A7-nAChR-KD cells than among scrambled control cells, as measured by cell cycle distribution and TUNEL assays. Further molecular analyses showed a reduction in the pAKT levels and a dramatic increase in the Bad levels in paclitaxel-treated A7-nAChR-KD cells but not in scrambled control cells. Following paclitaxel treatment, the level of Bax was slightly increased in both cell populations, whereas Poly (ADP-ribose) polymerase (PARP) cleavage was increased only in A7-nAChR-KD cells. These findings indicate that A7-nAChR-KD cells are more sensitive to paclitaxel treatment. We conclude that A7-nAChR may be a key biomarker for assessing the chemosensitivity of gastric cancer cells to taxane. PMID:26499946

  18. Purification of L-( sup 3 H) Nicotine eliminates low affinity binding

    SciTech Connect

    Romm, E.; Marks, M.J.; Collins, A.C. ); Lippiello, P.M. )

    1990-01-01

    Some studies of L-({sup 3}H) nicotine binding to rodent and human brain tissue have detected two binding sites as evidenced by nonlinear Scatchard plots. Evidence presented here indicated that the low affinity binding site is not stereospecific, is not inhibited by low concentrations of cholinergic agonists and is probably due to breakdown products of nicotine since purification of the L-({sup 3}H)nicotine eliminates the low affinity site.

  19. Basal ganglia cholinergic and dopaminergic function in progressive supranuclear palsy.

    PubMed

    Warren, Naomi M; Piggott, Margaret A; Greally, Elizabeth; Lake, Michelle; Lees, Andrew J; Burn, David J

    2007-08-15

    Progressive Supranuclear Palsy (PSP) is a progressive neurodegenerative disorder. In contrast to Parkinson's disease (PD) and dementia with Lewy bodies (DLB), replacement therapy with dopaminergic and cholinergic agents in PSP has been disappointing. The neurochemical basis for this is unclear. Our objective was to measure dopaminergic and cholinergic receptors in the basal ganglia of PSP and control brains. We measured, autoradiographically, dopaminergic (dopamine transporter, 125I PE2I and dopamine D2 receptors, 125I epidepride) and cholinergic (nicotinic alpha4beta2 receptors, 125I 5IA85380 and muscarinic M1 receptors, 3H pirenzepine) parameters in the striatum and pallidum of pathologically confirmed PSP cases (n=15) and controls (n=32). In PSP, there was a marked loss of dopamine transporter and nicotinic alpha4beta2 binding in the striatum and pallidum, consistent with loss of nigrostriatal neurones. Striatal D2 receptors were increased in the caudate and muscarinic M1 receptors were unchanged compared with controls. These results do not account for the poor response to dopaminergic and cholinergic replacement therapies in PSP, and suggest relative preservation of postsynaptic striatal projection neurones bearing D2/M1 receptors. PMID:17534953

  20. Where attention falls: Increased risk of falls from the converging impact of cortical cholinergic and midbrain dopamine loss on striatal function.

    PubMed

    Sarter, Martin; Albin, Roger L; Kucinski, Aaron; Lustig, Cindy

    2014-07-01

    Falls are a major source of hospitalization, long-term institutionalization, and death in older adults and patients with Parkinson's disease (PD). Limited attentional resources are a major risk factor for falls. In this review, we specify cognitive-behavioral mechanisms that produce falls and map these mechanisms onto a model of multi-system degeneration. Results from PET studies in PD fallers and findings from a recently developed animal model support the hypothesis that falls result from interactions between loss of basal forebrain cholinergic projections to the cortex and striatal dopamine loss. Striatal dopamine loss produces inefficient, low-vigor gait, posture control, and movement. Cortical cholinergic deafferentation impairs a wide range of attentional processes, including monitoring of gait, posture and complex movements. Cholinergic cell loss reveals the full impact of striatal dopamine loss on motor performance, reflecting loss of compensatory attentional supervision of movement. Dysregulation of dorsomedial striatal circuitry is an essential, albeit not exclusive, mediator of falls in this dual-system model. Because cholinergic neuromodulatory activity influences cortical circuitry primarily via stimulation of α4β2* nicotinic acetylcholine receptors, and because agonists at these receptors are known to benefit attentional processes in animals and humans, treating PD fallers with such agonists, as an adjunct to dopaminergic treatment, is predicted to reduce falls. Falls are an informative behavioral endpoint to study attentional-motor integration by striatal circuitry. PMID:24805070

  1. Optical methods in modeling nicotine effect on the surface water of cell membranes

    NASA Astrophysics Data System (ADS)

    Alexandrova, Tatyana V.; Rogacheva, Svetlana M.; Kuznetsov, Pavel E.; Gubina, Tamara I.

    2005-06-01

    Fluorescence and spectrophotometric methods have been used for investigation of nicotine action on the state and mobility of the surface water. The surfaces of membranes and proteins were simulated with the help of liposomes and ultradispersive diamonds consequently. Nicotine was shown to reduce the stability of liposomes and to change the aggregative ability of ultradispersive diamonds. The wave-like curves for the nicotine concentration dependences of the pointed features were observed. Such shape of responses was suggested to be due to the changing in structure and dynamics of water hydrogen bonds net near the surface of the model systems induced by nicotine molecules. The surface water phase was supposed to be one of signal elements ofthe ligand receptor recognition process.

  2. Nicotine Withdrawal

    PubMed Central

    McLaughlin, Ian; Dani, John A.; De Biasi, Mariella

    2015-01-01

    An aversive abstinence syndrome manifests 4–24 h following cessation of chronic use of nicotine-containing products. Symptoms peak on approximately the 3rd day and taper off over the course of the following 3–4 weeks. While the severity of withdrawal symptoms is largely determined by how nicotine is consumed, certain short nucleotide polymorphisms (SNPs) have been shown to predispose individuals to consume larger amounts of nicotine more frequently—as well as to more severe symptoms of withdrawal when trying to quit. Additionally, rodent behavioral models and transgenic mouse models have revealed that specific nicotinic acetylcholine receptor (nAChR) subunits, cellular components, and neuronal circuits are critical to the expression of withdrawal symptoms. Consequently, by continuing to map neuronal circuits and nAChR subpopulations that underlie the nicotine withdrawal syndrome—and by continuing to enumerate genes that predispose carriers to nicotine addiction and exacerbated withdrawal symptoms—it will be possible to pursue personalized therapeutics that more effectively treat nicotine addiction. PMID:25638335

  3. Chlorpyrifos promotes colorectal adenocarcinoma H508 cell growth through the activation of EGFR/ERK1/2 signaling pathway but not cholinergic pathway.

    PubMed

    Suriyo, Tawit; Tachachartvanich, Phum; Visitnonthachai, Daranee; Watcharasit, Piyajit; Satayavivad, Jutamaad

    2015-12-01

    Aside from the effects on neuronal cholinergic system, epidemiological studies suggest an association between chlorpyrifos (CPF) exposure and cancer risk. This in vitro study examined the effects of CPF and its toxic metabolite, chlorpyrifos oxon (CPF-O), on the growth of human colorectal adenocarcinoma H508, colorectal adenocarcinoma HT-29, normal colon epithelial CCD841, liver hepatocellular carcinoma HepG2, and normal liver hepatocyte THLE-3 cells. The results showed that CPF (5-100 μM) concentration-dependently increased viability of H508 and CCD841 cells in serum-free conditions. This increasing trend was not found in HT-29, HepG2 and THLE-3 cells. In contrast, CPF-O (50-100 μM) reduced the viability of all cell lines. Cell cycle analysis showed the induction of cells in the S phase, and EdU incorporation assay revealed the induction of DNA synthesis in CPF-treated H508 cells indicating that CPF promotes cell cycle progression. Despite the observation of acetylcholinesterase activity inhibition and reactive oxygen species (ROS) generation, atropine (a non-selective muscarinic acetylcholine receptor antagonist) and N-acetylcysteine (a potent antioxidant) failed to inhibit the growth-promoting effect of CPF. CPF increased the phosphorylation of epidermal growth factor receptor (EGFR) and its downstream effector, extracellular signal regulated kinase (ERK1/2), in H508 cells. AG-1478 (a specific EGFR tyrosine kinase inhibitor) and U0126 (a specific MEK inhibitor) completely mitigated the growth promoting effect of CPF. Altogether, these results suggest that EGFR/ERK1/2 signaling pathway but not cholinergic pathway involves in CPF-induced colorectal adenocarcinoma H508 cell growth. PMID:26514924

  4. Glutamatergic synapse formation is promoted by α7-containing nicotinic acetylcholine receptors.

    PubMed

    Lozada, Adrian F; Wang, Xulong; Gounko, Natalia V; Massey, Kerri A; Duan, Jingjing; Liu, Zhaoping; Berg, Darwin K

    2012-05-30

    Glutamate is the primary excitatory transmitter in adult brain, acting through synapses on dendritic spines and shafts. Early in development, however, when glutamatergic synapses are only beginning to form, nicotinic cholinergic excitation is already widespread; it is mediated by acetylcholine activating nicotinic acetylcholine receptors (nAChRs) that generate waves of activity across brain regions. A major class of nAChRs contributing at this time is a species containing α7 subunits (α7-nAChRs). These receptors are highly permeable to calcium, influence a variety of calcium-dependent events, and are diversely distributed throughout the developing CNS. Here we show that α7-nAChRs unexpectedly promote formation of glutamatergic synapses during development. The dependence on α7-nAChRs becomes clear when comparing wild-type (WT) mice with mice constitutively lacking the α7-nAChR gene. Ultrastructural analysis, immunostaining, and patch-clamp recording all reveal synaptic deficits when α7-nAChR input is absent. Similarly, nicotinic activation of α7-nAChRs in WT organotypic culture, as well as cell culture, increases the number of glutamatergic synapses. RNA interference demonstrates that the α7-nAChRs must be expressed in the neuron being innervated for normal innervation to occur. Moreover, the deficits persist throughout the developmental period of major de novo synapse formation and are still fully apparent in the adult. GABAergic synapses, in contrast, are undiminished in number under such conditions. As a result, mice lacking α7-nAChRs have an altered balance in the excitatory/inhibitory input they receive. This ratio represents a fundamental feature of neural networks and shows for the first time that endogenous nicotinic cholinergic signaling plays a key role in network construction. PMID:22649244

  5. Estrogen down-regulates nicotine-induced adhesion molecule expression via nongenomic signal pathway in endothelial cells.

    PubMed

    Wang, Yajing; Wang, Zhaoxia; Wang, Lianyun; Zhou, Ying; Zhao, Yangxing; Liu, Liming; Yao, Chenjiang; Qiao, Zhongdong

    2006-06-01

    Although gonadal hormone mostly causes genotropic actions through the members of nuclear receptor family, it also can regulate these actions via membrane receptor. To explore the possibility of plasma membrane estrogen receptors (mER) mediating genotropic events, we have investigated estrogen's effect on nicotine-stimulated adhesion molecule expression and evaluated whether this effect depends on calcium, MAPK signal pathway. Fluorescence Spectroscopy analysis of Ca2+ from human umbilical vein endothelial cells (HUVECs) showed through mER, estrogen induced a rapid rise of intracellular free Ca2+ concentration and this rise could not be inhibited by tamoxifen (classic ER inhibitor). In the context of nicotine stimulating, however, estrogen attenuated phosphorylation of mitogen-activated protein kinase (MAPK) family members, extracellular signal regulated kinase 1/2 (ERK1/2), p38 but not c-Jun-N-terminal kinase (JNK) in HUVECs and this effect could not still be prevented by tamoxifen. In the meantime, estrogen also down-regulated surface/soluble vascular cell adhesion molecule (VCAM-1, sVCAM-1) and endothelial selectin (E-selectin, sE-selectin) levels, which was not abolished by tamoxifen either. Moreover, calcium chelator BAPTA, ERK1/2 inhibitor PD98059, p38 inhibitor SB203580 significantly reduced the production of nicotine-activated surface/soluble VCAM-1 and E-selectin and both of the remained levels were no longer regulated by estrogen. Our study here provides the information of decrease effect of mER-mediated estrogen through Ca2+ and ERK1/2, p38 MAPK signaling pathway on nicotine-stimulated expression of surface/soluble VCAM-1 and E-selectin in HUVECs. PMID:16644474

  6. Brain Region–Specific Alterations in the Gene Expression of Cytokines, Immune Cell Markers and Cholinergic System Components during Peripheral Endotoxin–Induced Inflammation

    PubMed Central

    Silverman, Harold A; Dancho, Meghan; Regnier-Golanov, Angelique; Nasim, Mansoor; Ochani, Mahendar; Olofsson, Peder S; Ahmed, Mohamed; Miller, Edmund J; Chavan, Sangeeta S; Golanov, Eugene; Metz, Christine N; Tracey, Kevin J; Pavlov, Valentin A

    2014-01-01

    Inflammatory conditions characterized by excessive peripheral immune responses are associated with diverse alterations in brain function, and brain-derived neural pathways regulate peripheral inflammation. Important aspects of this bidirectional peripheral immune–brain communication, including the impact of peripheral inflammation on brain region–specific cytokine responses, and brain cholinergic signaling (which plays a role in controlling peripheral cytokine levels), remain unclear. To provide insight, we studied gene expression of cytokines, immune cell markers and brain cholinergic system components in the cortex, cerebellum, brainstem, hippocampus, hypothalamus, striatum and thalamus in mice after an intraperitoneal lipopolysaccharide injection. Endotoxemia was accompanied by elevated serum levels of interleukin (IL)-1β, IL-6 and other cytokines and brain region–specific increases in Il1b (the highest increase, relative to basal level, was in cortex; the lowest increase was in cerebellum) and Il6 (highest increase in cerebellum; lowest increase in striatum) mRNA expression. Gene expression of brain Gfap (astrocyte marker) was also differentially increased. However, Iba1 (microglia marker) mRNA expression was decreased in the cortex, hippocampus and other brain regions in parallel with morphological changes, indicating microglia activation. Brain choline acetyltransferase (Chat ) mRNA expression was decreased in the striatum, acetylcholinesterase (Ache) mRNA expression was decreased in the cortex and increased in the hippocampus, and M1 muscarinic acetylcholine receptor (Chrm1) mRNA expression was decreased in the cortex and the brainstem. These results reveal a previously unrecognized regional specificity in brain immunoregulatory and cholinergic system gene expression in the context of peripheral inflammation and are of interest for designing future antiinflammatory approaches. PMID:25299421

  7. Developmental exposure of aflatoxin B1 reversibly affects hippocampal neurogenesis targeting late-stage neural progenitor cells through suppression of cholinergic signaling in rats.

    PubMed

    Tanaka, Takeshi; Mizukami, Sayaka; Hasegawa-Baba, Yasuko; Onda, Nobuhiko; Sugita-Konishi, Yoshiko; Yoshida, Toshinori; Shibutani, Makoto

    2015-10-01

    To elucidate the maternal exposure effects of aflatoxin B1 (AFB1) and its metabolite aflatoxin M1, which is transferred into milk, on postnatal hippocampal neurogenesis, pregnant Sprague-Dawley rats were provided a diet containing AFB1 at 0, 0.1, 0.3, or 1.0 ppm from gestational day 6 to day 21 after delivery on weaning. Offspring were maintained through postnatal day (PND) 77 without AFB1 exposure. Following exposure to 1.0 ppm AFB1, offspring showed no apparent systemic toxicity at weaning, whereas dams showed increased liver weight and DNA repair gene upregulation in the liver. In the hippocampal dentate gyrus of male PND 21 offspring, the number of doublecortin(+) progenitor cells were decreased, which was associated with decreased proliferative cell population in the subgranular zone at ≥ 0.3 ppm, although T-box brain 2(+) cells, tubulin beta III(+) cells, gamma-H2A histone family, member X(+) cells, and cyclin-dependent kinase inhibitor 1A(+) cells did not fluctuate in number. AFB1 exposure examined at 1.0 ppm also resulted in transcript downregulation of the cholinergic receptor subunit Chrna7 and dopaminergic receptor Drd2 in the dentate gyrus, although there was no change in transcript levels of DNA repair genes. In the hippocampal dentate hilus, interneurons expressing CHRNA7 or phosphorylated tropomyosin receptor kinase B (TRKB) decreased at ≥ 0.3 ppm. On PND 77, there were no changes in neurogenesis-related parameters. These results suggested that maternal AFB1 exposure reversibly affects hippocampal neurogenesis targeting type-3 progenitor cells. This mechanism likely involves suppression of cholinergic signals on hilar GABAergic interneurons and brain-derived neurotrophic factor-TRKB signaling from granule cells. The no-observed-adverse-effect level for offspring neurogenesis was determined to be 0.1 ppm (7.1-13.6 mg/kg body weight/day). PMID:26260870

  8. MicroRNA-124 mediates the cholinergic anti-inflammatory action through inhibiting the production of pro-inflammatory cytokines

    PubMed Central

    Sun, Yang; Li, Qi; Gui, Huan; Xu, Dong-Ping; Yang, Yi-Li; Su, Ding-Feng; Liu, Xia

    2013-01-01

    The vagus nerve can control inflammatory response through a 'cholinergic anti-inflammatory pathway', which is mediated by the α7-nicotinic acetylcholine receptor (α7nAChR) on macrophages. However, the intracellular mechanisms that link α7nAChR activation and pro-inflammatory cytokine production remain not well understood. In this study, we found that miR-124 is upregulated by cholinergic agonists in LPS-exposed cells and mice. Utilizing miR-124 mimic and siRNA knockdown, we demonstrated that miR-124 is a critical mediator for the cholinergic anti-inflammatory action. Furthermore, our data indicated that miR-124 modulates LPS-induced cytokine production by targeting signal transducer and activator of transcription 3 (STAT3) to decrease IL-6 production and TNF-α converting enzyme (TACE) to reduce TNF-α release. These results also indicate that miR-124 is a potential therapeutic target for the treatment of inflammatory diseases. PMID:23979021

  9. Nicotine Gum

    MedlinePlus

    ... gum is used to help people stop smoking cigarettes. Nicotine chewing gum should be used together with ... by your doctor.If you smoke your first cigarette more than 30 minutes after waking up, use ...

  10. Transient Cholesterol Effects on Nicotinic Acetylcholine Receptor Cell-Surface Mobility

    PubMed Central

    Almarza, Gonzalo; Sánchez, Francisco; Barrantes, Francisco J.

    2014-01-01

    To what extent do cholesterol-rich lipid platforms modulate the supramolecular organization of the nicotinic acetylcholine receptor (AChR)? To address this question, the dynamics of AChR particles at high density and its cholesterol dependence at the surface of mammalian cells were studied by combining total internal reflection fluorescence microscopy and single-particle tracking. AChR particles tagged with a monovalent ligand, fluorescent α-bungarotoxin (αBTX), exhibited two mobile pools: i) a highly mobile one undergoing simple Brownian motion (16%) and ii) one with restricted motion (∼50%), the rest being relatively immobile (∼44%). Depletion of membrane cholesterol by methyl-α-cyclodextrin increased the fraction of the first pool to 22% and 33% after 15 and 40 min, respectively; the pool undergoing restricted motion diminished from 50% to 44% and 37%, respectively. Monoclonal antibody binding results in AChR crosslinking-internalization after 2 h; here, antibody binding immobilized within minutes ∼20% of the totally mobile AChR. This proportion dramatically increased upon cholesterol depletion, especially during the initial 10 min (83.3%). Thus, antibody crosslinking and cholesterol depletion exhibited a mutually synergistic effect, increasing the average lifetime of cell-surface AChRs∼10 s to ∼20 s. The instantaneous (microscopic) diffusion coefficient D2–4 of the AChR obtained from the MSD analysis diminished from ∼0.001 µm2 s−1 to ∼0.0001–0.00033 µm2 s−1 upon cholesterol depletion, ∼30% of all particles falling into the stationary mode. Thus, muscle-type AChR exhibits heterogeneous motional regimes at the cell surface, modulated by the combination of intrinsic (its supramolecular organization) and extrinsic (membrane cholesterol content) factors. PMID:24971757

  11. Opioid Analgesics and Nicotine: More Than Blowing Smoke.

    PubMed

    Yoon, Jin H; Lane, Scott D; Weaver, Michael F

    2015-09-01

    Practitioners are highly likely to encounter patients with concurrent use of nicotine products and opioid analgesics. Smokers present with more severe and extended chronic pain outcomes and have a higher frequency of prescription opioid use. Current tobacco smoking is a strong predictor of risk for nonmedical use of prescription opioids. Opioid and nicotinic-cholinergic neurotransmitter systems interact in important ways to modulate opioid and nicotine effects: dopamine release induced by nicotine is dependent on facilitation by the opioid system, and the nicotinic-acetylcholine system modulates self-administration of several classes of abused drugs-including opioids. Nicotine can serve as a prime for the use of other drugs, which in the case of the opioid system may be bidirectional. Opioids and compounds in tobacco, including nicotine, are metabolized by the cytochrome P450 enzyme system, but the metabolism of opioids and tobacco products can be complicated. Accordingly, drug interactions are possible but not always clear. Because of these issues, asking about nicotine use in patients taking opioids for pain is recommended. When assessing patient tobacco use, practitioners should also obtain information on products other than cigarettes, such as cigars, pipes, smokeless tobacco, and electronic nicotine delivery systems (ENDS, or e-cigarettes). There are multiple forms of behavioral therapy and pharmacotherapy available to assist patients with smoking cessation, and opioid agonist maintenance and pain clinics represent underutilized opportunities for nicotine intervention programs. PMID:26375198

  12. Schizophrenia and the alpha7 nicotinic acetylcholine receptor.

    PubMed

    Martin, Laura F; Freedman, Robert

    2007-01-01

    In addition to the devastating symptoms of psychosis, many people with schizophrenia also suffer from cognitive impairment. These cognitive symptoms lead to marked dysfunction and can impact employability, treatment adherence, and social skills. Deficits in P50 auditory gating are associated with attentional impairment and may contribute to cognitive symptoms and perceptual disturbances. This nicotinic cholinergic-mediated inhibitory process represents a potential new target for therapeutic intervention in schizophrenia. This chapter will review evidence implicating the nicotinic cholinergic, and specifically, the alpha7 nicotinic receptor system in the pathology of schizophrenia. Impaired auditory sensory gating has been linked to the alpha7 nicotinic receptor gene on the chromosome 15q14 locus. A majority of persons with schizophrenia are heavy smokers. Although nicotine can acutely reverse diminished auditory sensory gating in people with schizophrenia, this effect is lost on a chronic basis due to receptor desensitization. The alpha7 nicotinic agonist 3-(2,4 dimethoxy)benzylidene-anabaseine (DMXBA) can also enhance auditory sensory gating in animal models. DMXBA is well tolerated in humans and a new study in persons with schizophrenia has found that DMXBA enhances both P50 auditory gating and cognition. alpha7 Nicotinic acetylcholine receptor agonists appear to be viable candidates for the treatment of cognitive disturbances in schizophrenia. PMID:17349863

  13. Induction of cognitive deficits by immunization with cholinergic cell bodies: the influence of age and integrity of the blood-brain barrier.

    PubMed

    Alroy, G; Chapman, J; Feldon, J; Michaelson, D M

    1991-01-01

    We have recently shown that prolonged immunization of young rats for one year with cholinergic cell bodies (perikarya, PK) purified from Torpedo electric lobe results in the accumulation of IgG in specific brain areas such as the hippocampus and induces behavioral deficits in spatial orientation and short term memory /1, 7/. We presently studied the rate of development of the cognitive deficit in older (12 months old) Sprague Dawley rats which were immunized for periods of up to one year with either Torpedo cholinergic PK or adjuvant (controls). T-maze alternation and Morris swim maze tests revealed a small deficit in the performance of the PK immunized rats after 6 months whereas significant deficits were observed after 12 months of immunization. These results suggest that the duration of immunization is a more significant factor than the age of the animals in the development of the behavioral deficit. In order to examine whether permeability of the blood-brain barrier to IgG influences the rate of development of the cognitive deficit, we disrupted the blood-brain barrier of PK immunized rats by hypercapnia. This treatment repeated weekly for 2 months was found not to accelerate the rate of appearance of deficits in performance of the rats in the T-maze alternation and Morris swim test. These results suggest that penetration of IgG via the blood-brain barrier does not determine the rate of appearance of the cognitive deficits. PMID:1797094

  14. Nicotinic Regulation of Energy Homeostasis

    PubMed Central

    2012-01-01

    Introduction: The ability of nicotine, the primary psychoactive substance in tobacco smoke, to regulate appetite and body weight is one of the factors cited by smokers that prevents them from quitting and is the primary reason for smoking initiation in teenage girls. The regulation of feeding and metabolism by nicotine is complex, and recent studies have begun to identify nicotinic acetylcholine receptor (nAChR) subtypes and circuits or cell types involved in this regulation. Discussion: We will briefly describe the primary anatomical and functional features of the input, output, and central integration structures of the neuroendocrine systems that regulate energy homeostasis. Then, we will describe the nAChR subtypes expressed in these structures in mammals to identify the possible molecular targets for nicotine. Finally, we will review the effects of nicotine and its withdrawal on feeding and energy metabolism and attribute them to potential central and peripheral cellular targets. PMID:22990212

  15. Cholinergic Modulation during Acquisition of Olfactory Fear Conditioning Alters Learning and Stimulus Generalization in Mice

    ERIC Educational Resources Information Center

    Pavesi, Eloisa; Gooch, Allison; Lee, Elizabeth; Fletcher, Max L.

    2013-01-01

    We investigated the role of cholinergic neurotransmission in olfactory fear learning. Mice receiving pairings of odor and foot shock displayed fear to the trained odor the following day. Pretraining injections of the nicotinic antagonist mecamylamine had no effect on subsequent freezing, while the muscarinic antagonist scopolamine significantly…

  16. Cannabinoid CB2 Receptor Mediates Nicotine-Induced Anti-Inflammation in N9 Microglial Cells Exposed to β Amyloid via Protein Kinase C

    PubMed Central

    Jia, Ji; Peng, Jie; Li, Zhaoju; Wu, Youping; Wu, Qunlin; Tu, Weifeng; Wu, Mingchun

    2016-01-01

    Background. Reducing β amyloid- (Aβ-) induced microglial activation is considered to be effective in treating Alzheimer's disease (AD). Nicotine attenuates Aβ-induced microglial activation; the mechanism, however, is still elusive. Microglia could be activated into classic activated state (M1 state) or alternative activated state (M2 state); the former is cytotoxic and the latter is neurotrophic. In this investigation, we hypothesized that nicotine attenuates Aβ-induced microglial activation by shifting microglial M1 to M2 state, and cannabinoid CB2 receptor and protein kinase C mediate the process. Methods. We used Aβ1–42 to activate N9 microglial cells and observed nicotine-induced effects on microglial M1 and M2 biomarkers by using western blot, immunocytochemistry, and enzyme-linked immunosorbent assay (ELISA). Results. We found that nicotine reduced the levels of M1 state markers, including inducible nitric oxide synthase (iNOS) expression and tumor necrosis factor α (TNF-α) and interleukin- (IL-) 6 releases; meanwhile, it increased the levels of M2 state markers, including arginase-1 (Arg-1) expression and brain-derived neurotrophic factor (BDNF) release, in the Aβ-stimulated microglia. Coadministration of cannabinoid CB2 receptor antagonist or protein kinase C (PKC) inhibitor partially abolished the nicotine-induced effects. Conclusion. These findings indicated that cannabinoid CB2 receptor mediates nicotine-induced anti-inflammation in microglia exposed to Aβ via PKC. PMID:26884647

  17. Effect of nicotine in matrix mineralization by human bone marrow and Saos-2 cells cultured on the surface of plasma-sprayed titanium implants.

    PubMed

    Pereira, M L; Carvalho, J C; Peres, F; Fernandes, M H

    2009-01-01

    Smoking has an established negative impact in the clinical outcome of dental implants. This work analyses the response of human osteoblastic cells to nicotine, at the surface of plasma-sprayed commercial titanium implants. Human bone marrow (HBM) and Saos-2 cells, seeded on the surface of titanium implants and cultured in experimental conditions favoring osteoblastic differentiation, were exposed continuously to nicotine (0.0001 to 0.5 mg mL(-1)) and characterized for cell proliferation and function. Exposure of HBM cells resulted in increased cell proliferation, higher alkaline phosphatase (ALP) activity, and earlier onset of matrix mineralization at levels up to 0.2 mg mL(-1), an initial inhibitory effect in cell growth and functional activity followed by a recovery in the presence of 0.3 mg mL(-1) and a dose-dependent deleterious effect at higher levels. By contrast, exposure to nicotine did not affect cell proliferation of Saos-2 cells at levels up to 0.2 mg mL(-1), and caused only a small positive effect in ALP activity in the presence of 0.05 and 0.1 mg mL(-1); however, matrix mineralization by Saos-2 cells also occurred earlier in the cultures exposed to levels of nicotine up to 0.1 mg mL(-1). Higher concentrations caused dose-dependent inhibitory effects. Considering the high diffusion potential of nicotine, results suggest a local role of nicotine in modulating bone formation events at the implant surface. PMID:18260147

  18. Historical and Current Perspective on Tobacco use and Nicotine Addiction

    PubMed Central

    Dani, John A.; Balfour, David J.K.

    2011-01-01

    Although the addictive influence of tobacco was recognized very early, the modern concepts of nicotine addiction have relied on knowledge of cholinergic neurotransmission and nicotinic acetylcholine receptors (nAChRs). The discovery of the “receptive substance” by Langley, that would turn out to be nAChRs, and “Vagusstoff” (acetylcholine) by Loewi, coincided with an exciting time when the concept of chemical synaptic transmission was being formulated. More recently, the application of more powerful techniques and the study of animal models that replicate key features of nicotine dependence have led to important advancements in our understanding of molecular, cellular, and systems mechanisms of nicotine addiction. In this Review, we present a historical perspective and overview of the research that has led to our present understanding of nicotine addiction. PMID:21696833

  19. Nicotinic alteration of functional thalamocortical topography.

    PubMed

    Lee, Charles C; Yanagawa, Yuchio; Imaizumi, Kazuo

    2015-08-19

    The thalamocortical pathways form highly topographic connections from the primary sensory thalamic nuclei to the primary cortical areas. The synaptic properties of these thalamocortical connections are modifiable by activation from various neuromodulators, such as acetylcholine. Cholinergic activation can alter functional properties in both the developing and the mature nervous system. Moreover, environmental factors, such as nicotine, can activate these receptors, although the circuit-level alterations resulting from such nicotinic activation of sensory neural circuits remain largely unexplored. Therefore, we examined alterations to the functional topography of thalamocortical circuits in the developing sensory pathways of the mouse. Photostimulation by uncaging of glutamate was used to map these functional thalamocortical alterations in response to nicotinic receptor activation. As a result, we found that activation of forebrain nicotinic acetylcholine receptors results in an expansion and enhancement of functional thalamocortical topographies as assessed in brain slice preparations using laser-scanning photostimulation by uncaging of glutamate. These physiological changes were correlated with the neuroanatomical expression of nicotinic acetylcholine receptor subtypes (α7 and β2). These circuit-level alterations may provide a neural substrate underlying the plastic development and reshaping of thalamocortical circuitry in response to nicotinic receptor activation. PMID:26164456

  20. MESOPONTINE CHOLINERGIC PROJECTIONS TO THE HYPOGLOSSAL MOTOR NUCLEUS

    PubMed Central

    Rukhadze, Irma; Kubin, Leszek

    2007-01-01

    Mesopontine cholinergic (ACh) neurons have increased discharge during wakefulness, rapid eye movement (REM) sleep, or both. Hypoglossal (12) motoneurons, which play an important role in the control of upper airway patency, are postsynaptically excited by stimulation of nicotinic receptors, whereas muscarinic receptors presynaptically inhibit inputs to 12 motoneurons. These data suggest that ACh contributes to sleep/wake-related changes in the activity of 12 motoneurons by acting within the hypoglossal motor nucleus (Mo12), but the origins of ACh projections to Mo12 are not well established. We used retrograde tracers to assess the projections of ACh neurons of the mesopontine pedinculopontine tegmental (PPT) and laterodorsal tegmental (LDT) nuclei to the Mo12. In six Sprague-Dawley rats, Fluorogold or B subunit of cholera toxin, were pressure injected (5-20 nl) into the Mo12. Retrogradely labeled neurons, identified as ACh using nitric oxide synthase (NOS) immunohistochemistry, were found bilaterally in discrete subregions of both PPT and LDT nuclei. Most retrogradely labeled PPT cells (96%) were located in the PPT pars compacta region adjacent to the ventrolateral tip of the superior cerebellar peduncle. In the LDT, retrogradely labeled neurons were located exclusively in its pars alpha region. Over twice as many ACh neurons projecting to the Mo12 were located in the PPT than LDT. The results demonstrate direct mesopontine ACh projections to the Mo12. These projections may contribute to the characteristic of wakefulness and REM sleep increases, as well as REM sleep-related decrements, of 12 motoneuronal activity. PMID:17174027

  1. Reductions in (/sup 3/H)nicotinic acetylcholine binding in Alzheimer's disease and Parkinson's disease: an autoradiographic study

    SciTech Connect

    Whitehouse, P.J.; Martino, A.M.; Wagster, M.V.; Price, D.L.; Mayeux, R.; Atack, J.R.; Kellar, K.J.

    1988-05-01

    In Alzheimer's disease (AD) and Parkinson's disease (PD), dysfunction in the basal forebrain cholinergic system is accompanied by a consistent loss of presynaptic cholinergic markers in cortex, but changes in cholinergic receptor binding sites are poorly understood. In the present study, we used receptor autoradiography to map the distribution of nicotinic (/sup 3/H)acetylcholine binding sites in cortices of individuals with AD and PD and matched control subjects. In both diseases, a profound loss of nicotinic receptors occurs in all cortical layers, particularly the deepest layers.

  2. Oxidative and pro-inflammatory impact of regular and denicotinized cigarettes on blood brain barrier endothelial cells: is smoking reduced or nicotine-free products really safe?

    PubMed Central

    2014-01-01

    Background Both active and passive tobacco smoke (TS) potentially impair the vascular endothelial function in a causative and dose-dependent manner, largely related to the content of reactive oxygen species (ROS), nicotine, and pro-inflammatory activity. Together these factors can compromise the restrictive properties of the blood–brain barrier (BBB) and trigger the pathogenesis/progression of several neurological disorders including silent cerebral infarction, stroke, multiple sclerosis and Alzheimer’s disease. Based on these premises, we analyzed and assessed the toxic impact of smoke extract from a range of tobacco products (with varying levels of nicotine) on brain microvascular endothelial cell line (hCMEC/D3), a well characterized human BBB model. Results Initial profiling of TS showed a significant release of reactive oxygen (ROS) and reactive nitrogen species (RNS) in full flavor, nicotine-free (NF, “reduced-exposure” brand) and ultralow nicotine products. This release correlated with increased oxidative cell damage. In parallel, membrane expression of endothelial tight junction proteins ZO-1 and occludin were significantly down-regulated suggesting the impairment of barrier function. Expression of VE-cadherin and claudin-5 were also increased by the ultralow or nicotine free tobacco smoke extract. TS extract from these cigarettes also induced an inflammatory response in BBB ECs as demonstrated by increased IL-6 and MMP-2 levels and up-regulation of vascular adhesion molecules, such as VCAM-1 and PECAM-1. Conclusions In summary, our results indicate that NF and ultralow nicotine cigarettes are potentially more harmful to the BBB endothelium than regular tobacco products. In addition, this study demonstrates that the TS-induced toxicity at BBB ECs is strongly correlated to the TAR and NO levels in the cigarettes rather than the nicotine content. PMID:24755281

  3. Luminal cholinergic signalling in airway lining fluid: a novel mechanism for activating chloride secretion via Ca2+-dependent Cl− and K+ channels

    PubMed Central

    Hollenhorst, Monika I; Lips, Katrin S; Wolff, Miriam; Wess, Jürgen; Gerbig, Stefanie; Takats, Zoltan; Kummer, Wolfgang; Fronius, Martin

    2012-01-01

    BACKGROUND AND PURPOSE Recent studies detected the expression of proteins involved in cholinergic metabolism in airway epithelial cells, although the function of this non-neuronal cholinergic system is not known in detail. Thus, this study focused on the effect of luminal ACh as a regulator of transepithelial ion transport in epithelial cells. EXPERIMENTAL APPROACH RT-PCR experiments were performed using mouse tracheal epithelial cells for ChAT and organic cation transporter (OCT) transcripts. Components of tracheal airway lining fluid were analysed with desorption electrospray ionization (DESI) MS. Effects of nicotine on mouse tracheal epithelial ion transport were examined with Ussing-chamber experiments. KEY RESULTS Transcripts encoding ChAT and OCT1–3 were detected in mouse tracheal epithelial cells. The DESI experiments identified ACh in the airway lining fluid. Luminal ACh induced an immediate, dose-dependent increase in the transepithelial ion current (EC50: 23.3 µM), characterized by a transient peak and sustained plateau current. This response was not affected by the Na+-channel inhibitor amiloride. The Cl−-channel inhibitor niflumic acid or the K+-channel blocker Ba2+ attenuated the ACh effect. The calcium ionophore A23187 mimicked the ACh effect. Luminal nicotine or muscarine increased the ion current. Experiments with receptor gene-deficient animals revealed the participation of muscarinic receptor subtypes M1 and M3. CONCLUSIONS AND IMPLICATIONS The presence of luminal ACh and activation of transepithelial ion currents by luminal ACh receptors identifies a novel non-neuronal cholinergic pathway in the airway lining fluid. This pathway could represent a novel drug target in the airways. PMID:22300281

  4. Nicotinic modulation of serotonergic activity in the dorsal raphe nucleus.

    PubMed

    Hernandez-Lopez, Salvador; Garduño, Julieta; Mihailescu, Stefan

    2013-01-01

    Cholinergic signaling mediated by nicotinic receptors has been associated to a large number of physiological and behavioral processes such as learning, memory, attention, food-intake and mood disorders. Although it is well established that many nicotinic actions are mediated through an increase in serotonin (5-HT) release, the physiological mechanisms by which nicotine produces these effects are still unclear. The dorsal raphe nucleus (DRN) contains the major amount of 5-HT neurons projecting to different parts of the brain. DRN also contains nicotinic acetylcholine receptors (nAChRs) located at somatic and presynaptic elements. Nicotine produces both inhibitory and excitatory effects on different subpopulations of 5-HT DRN neurons. In this review, we describe the presynaptic and postsynaptic mechanisms by which nicotine increases the excitability of DRN neurons as well as the subtypes of nAChRs involved. We also describe the inhibitory effects of nicotine and the role of 5-HT1A receptors in this effect. These nicotinic actions modulate the activity of different neuronal subpopulations in the DRN, changing the 5-HT tone in the brain areas where these groups of neurons project. Some of the physiological implications of nicotine-induced 5-HT release are discussed. PMID:24021594

  5. Cholinergic dysfunction in Parkinson's disease.

    PubMed

    Müller, Martijn L T M; Bohnen, Nicolaas I

    2013-09-01

    There is increasing interest in the clinical effects of cholinergic basal forebrain and tegmental pedunculopontine complex (PPN) projection degeneration in Parkinson's disease (PD). Recent evidence supports an expanded role beyond cognitive impairment, including effects on olfaction, mood, REM sleep behavior disorder, and motor functions. Cholinergic denervation is variable in PD without dementia and may contribute to clinical symptom heterogeneity. Early in vivo imaging evidence that impaired cholinergic integrity of the PPN associates with frequent falling in PD is now confirmed by human post-mortem evidence. Brainstem cholinergic lesioning studies in primates confirm the role of the PPN in mobility impairment. Degeneration of basal forebrain cholinergic projections correlates with decreased walking speed. Cumulatively, these findings provide evidence for a new paradigm to explain dopamine-resistant features of mobility impairments in PD. Recognition of the increased clinical role of cholinergic system degeneration may motivate new research to expand indications for cholinergic therapy in PD. PMID:23943367

  6. Functional role of the nicotinic arm of the acetylcholine regulatory axis in human B-cell lines

    PubMed Central

    Arredondo, Juan; Omelchenko, Denys; Chernyavsky, Alexander I; Qian, Jing; Skok, Maryna; Grando, Sergei A

    2009-01-01

    We studied the involvement of nicotinic acetylcholine receptors (nAChRs) in the inflammation-related activity of human B-cell lines. Activation of nAChRs in Daudi cells with epibatidine abolished the pansorbin-dependent upregulation of the pro-inflammatory marker Cox-2 both at the mRNA and protein levels, indicating that the nicotinergic signaling suppresses B-cell activation. While the anti-inflammatory action on B-cells was mediated predominantly through α7 nAChR, as could be judged from abolishing epibatidine effects with methyllycaconitine, both α7 and non-α7 nAChRs, such as α2-containing receptors, were involved in regulation of B-cell apoptosis. The net effect was antiapoptotic. To determine the role of nAChRs in regulating B-cell activation/plasmacytic differentiation, we measured changes in the CD38, CD138 and Bcl-6 gene expression. Epibatidine significantly (P < 0.05) upregulated CD38 at the transcriptional level and CD138 and Bcl-6 – at the translational levels. AR-R17779 significantly (P < 0.05) increased the protein levels of CD38 and CD138. In both cases, the effect of epibatidine was abolished with Mec, and that of AR-R17779 – by MLA, demonstrating a functional role of nAChRs in regulating Daudi cell differentiation. The obtained results revealed distinct contributions of α7 and non-α7 nAChRs to regulation of B-cell activation/differentiation, and suggested that signaling through the nicotinic arm of acetylcholine regulatory axis is important for B-cell involvement in inflammation.

  7. Nicotine Lozenges

    MedlinePlus

    ... is stopped and to reduce the urge to smoke. ... often than prescribed by your doctor.If you smoke your first cigarette within 30 minutes of waking ... should use 4-mg nicotine lozenges. If you smoke your first cigarette more than 30 minutes after ...

  8. Electrophysiology-Based Assays to Detect Subtype-Selective Modulation of Human Nicotinic Acetylcholine Receptors

    PubMed Central

    Kirsch, Glenn E.; Fedorov, Nikolai B.; Kuryshev, Yuri A.; Liu, Zhiqi; Orr, Michael S.

    2016-01-01

    Abstract The Family Smoking Prevention and Tobacco Control Act of 2009 (Public Law 111-31) gave the US Food and Drug Administration (FDA) the responsibility for regulating tobacco products. Nicotine is the primary addictive component of tobacco and its effects can be modulated by additional ingredients in manufactured products. Nicotine acts by mimicking the neurotransmitter acetylcholine on neuronal nicotinic acetylcholine receptors (nAChRs), which function as ion channels in cholinergic modulation of neurotransmission. Subtypes within the family of neuronal nAChRs are defined by their α- and β-subunit composition. The subtype-selective profiles of tobacco constituents are largely unknown, but could be essential for understanding the physiological effects of tobacco products. In this report, we report the development and validation of electrophysiology-based high-throughput screens (e-HTS) for human nicotinic subtypes, α3β4, α3β4α5, α4β2, and α7 stably expressed in Chinese Hamster Ovary cells. Assessment of agonist sensitivity and acute desensitization gave results comparable to those obtained by conventional manual patch clamp electrophysiology assays. The potency of reference antagonists for inhibition of the receptor channels and selectivity of positive allosteric modulators also were very similar between e-HTS and conventional manual patch voltage clamp data. Further validation was obtained in pilot screening of a library of FDA-approved drugs that identified α7 subtype-selective positive allosteric modulation by novel compounds. These assays provide new tools for profiling of nicotinic receptor selectivity. PMID:27505073

  9. Electrophysiology-Based Assays to Detect Subtype-Selective Modulation of Human Nicotinic Acetylcholine Receptors.

    PubMed

    Kirsch, Glenn E; Fedorov, Nikolai B; Kuryshev, Yuri A; Liu, Zhiqi; Armstrong, Lucas C; Orr, Michael S

    2016-08-01

    The Family Smoking Prevention and Tobacco Control Act of 2009 (Public Law 111-31) gave the US Food and Drug Administration (FDA) the responsibility for regulating tobacco products. Nicotine is the primary addictive component of tobacco and its effects can be modulated by additional ingredients in manufactured products. Nicotine acts by mimicking the neurotransmitter acetylcholine on neuronal nicotinic acetylcholine receptors (nAChRs), which function as ion channels in cholinergic modulation of neurotransmission. Subtypes within the family of neuronal nAChRs are defined by their α- and β-subunit composition. The subtype-selective profiles of tobacco constituents are largely unknown, but could be essential for understanding the physiological effects of tobacco products. In this report, we report the development and validation of electrophysiology-based high-throughput screens (e-HTS) for human nicotinic subtypes, α3β4, α3β4α5, α4β2, and α7 stably expressed in Chinese Hamster Ovary cells. Assessment of agonist sensitivity and acute desensitization gave results comparable to those obtained by conventional manual patch clamp electrophysiology assays. The potency of reference antagonists for inhibition of the receptor channels and selectivity of positive allosteric modulators also were very similar between e-HTS and conventional manual patch voltage clamp data. Further validation was obtained in pilot screening of a library of FDA-approved drugs that identified α7 subtype-selective positive allosteric modulation by novel compounds. These assays provide new tools for profiling of nicotinic receptor selectivity. PMID:27505073

  10. Cholinergic inhibition of adrenergic neurosecretion in the rabbit iris-ciliary body

    SciTech Connect

    Jumblatt, J.E.; North, G.T.

    1988-04-01

    The prejunctional effects of cholinergic agents on release of norepinephrine from sympathetic nerve endings were investigated in the isolated, superfused rabbit iris-ciliary body. Stimulation-evoked release of /sup 3/H-norepinephrine was inhibited by the cholinergic agonists methacholine, oxotremorine, muscarine, carbamylcholine and acetylcholine (plus eserine), but was unmodified by pilocarpine or nicotine. Agonist-induced inhibition was antagonized selectively by atropine, indicating a muscarinic response. Atropine alone markedly enhanced norepinephrine release, revealing considerable tonic activation of prejunctional cholinergic receptors in this system. Prejunctional inhibition by carbamylcholine was found to completely override the facilitative action of forskolin or 8-bromo-cyclic AMP on neurotransmitter release. Cholinergic and alpha 2-adrenergic effects on neurosecretion were non-additive, suggesting that the underlying receptors coexist at neurotransmitter release sites.

  11. Prenatal nicotine exposure enhances Cx43 and Panx1 unopposed channel activity in brain cells of adult offspring mice fed a high-fat/cholesterol diet

    PubMed Central

    Orellana, Juan A.; Busso, Dolores; Ramírez, Gigliola; Campos, Marlys; Rigotti, Attilio; Eugenín, Jaime; von Bernhardi, Rommy

    2014-01-01

    Nicotine, the most important neuroteratogen of tobacco smoke, can reproduce brain and cognitive disturbances per se when administered prenatally. However, it is still unknown if paracrine signaling among brain cells participates in prenatal nicotine-induced brain impairment of adult offspring. Paracrine signaling is partly mediated by unopposed channels formed by connexins hemichannels (HCs) and pannexins serving as aqueous pores permeable to ions and small signaling molecules, allowing exchange between the intra- and extracellular milieus. Our aim was to address whether prenatal nicotine exposure changes the activity of those channels in adult mice offspring under control conditions or subjected to a second challenge during young ages: high-fat/cholesterol (HFC) diet. To induce prenatal exposure to nicotine, osmotic minipumps were implanted in CF1 pregnant mice at gestational day 5 to deliver nicotine bitartrate or saline (control) solutions. After weaning, offspring of nicotine-treated or untreated pregnant mice were fed ad libitum with chow or HFC diets for 8 weeks. The functional state of connexin 43 (Cx43) and pannexin 1 (Panx1) unopposed channels was evaluated by dye uptake experiments in hippocampal slices from 11-week-old mice. We found that prenatal nicotine increased the opening of Cx43 HCs in astrocytes, and Panx1 channels in microglia and neurons only if offspring mice were fed with HFC diet. Blockade of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX2) and prostaglandin E receptor 1 (EP1), ionotropic ATP receptor type 7 (P2X7) and NMDA receptors, showed differential inhibition of prenatal nicotine-induced channel opening in glial cells and neurons. Importantly, inhibition of the above mentioned enzymes and receptors, or blockade of Cx43 and Panx1 unopposed channels greatly reduced adenosine triphosphate (ATP) and glutamate release from hippocampal slices of prenatally nicotine-exposed offspring. We propose that unregulated gliotransmitter

  12. Cholinergic modulation of food and drug satiety and withdrawal.

    PubMed

    Avena, Nicole M; Rada, Pedro V

    2012-06-01

    Although they comprise only a small portion of the neurons in the region, cholinergic interneurons in the dorsal striatum appear to play an important role in the regulation of various appetitive behaviors, in part, through their interactions with mesolimbic dopamine (DA) systems. In this review, we describe studies that suggest that the activity of cholinergic interneurons in the nucleus accumbens (NAc) and cholinergic projections to the ventral tegmental area (VTA) affect feeding behavior. In vivo microdialysis studies in rats have revealed that the cessation of a meal is associated with a rise in acetylcholine (ACh) levels in the NAc. ACh activation will suppress feeding, and this is also associated with an increase in synaptic accumulation of ACh. Further, we discuss how, in addition to their role in the ending of a meal, cholinergic interneurons in the NAc play an integral role in the cessation of drug use. Another cholinergic system involved in different aspects of appetitive behavior is the projection from the pedunculpontine nuclei directly to the VTA. Activation of this system enhances behaviors through activation of the mesolimbic DA system, and antagonism of ACh receptors in the VTA can reduce drug self-administration. Finally, we discuss the role of accumbens ACh in both drug and palatable food withdrawal. Studies reveal that accumbens ACh is increased during withdrawal from several different drugs of abuse (including cocaine, nicotine and morphine). This rise in extracellular levels of ACh, coupled with a decrease in extracellular levels of DA, is believed to contribute to an aversive state, which can manifest as behaviors associated with drug withdrawal. This theory has also been applied to studies of overeating and/or "food addiction," and the findings suggest a similar imbalance in DA/ACh levels, which is associated with behavioral indications of drug-like withdrawal. In summary, cholinergic neurons play an important role in the modulation of both

  13. Interaction between the antioxidant activity of curcumin and cholinergic system on memory retention in adult male Wistar rats

    PubMed Central

    Sarlak, Zeynab; Oryan, Shahrbanoo; Moghaddasi, Mehrnoush

    2015-01-01

    Objective(s): The cholinergic system plays an important role in learning and memory. This study investigated the effects of curcumin (turmeric extract) and the cholinergic system and their interaction on memory retention of passive avoidance learning in adult male Wistar rats. Materials and Methods: At first, an injection cannula was implanted in right ventricles of the animals. One week after the surgery, the animals were trained with a shuttle box set up. Post-training, injections were performed in all experiments. Administration of curcumin increased memory retention. Also administrations of nicotine and pilocarpine, the cholinergic receptor agonists, increased memory retention, while it is decreased by succinylcholine and scopolamine, the cholinergic receptor antagonists. Then co-administration of curcumin and cholinergic drugs were performed. Intraperitoneal and intracerebroventricular injections were applied for the curcumin and cholinergic drugs, respectively. Results: Co-administration of curcumin (45 mg/kg) with a low dose of nicotine (0.1 µg/rat) or pilocarpine (0.5 µg/rat) increased memory retention significantly. Effects of succinylcholine (0.01, 0.1 and 0.5 µg/rat) or scopolamine (0.1, 1 and 5 µg/rat) were attenuated by curcumin markedly (45 mg/kg). Conclusion: The results suggest that curcumin has a close interaction with cholinergic system in memory retention process. PMID:26019804

  14. Nicotine Transdermal Patch

    MedlinePlus

    ... patches are used to help people stop smoking cigarettes. They provide a source of nicotine that reduces ... cause harm to the fetus.do not smoke cigarettes or use other nicotine products while using nicotine ...

  15. The catecholaminergic-cholinergic balance hypothesis of bipolar disorder revisited

    PubMed Central

    van Enkhuizen, Jordy; Janowsky, David S; Olivier, Berend; Minassian, Arpi; Perry, William; Young, Jared W; Geyer, Mark A

    2014-01-01

    Bipolar disorder is a unique illness characterized by fluctuations between mood states of depression and mania. Originally, an adrenergic-cholinergic balance hypothesis was postulated to underlie these different affective states. In this review, we update this hypothesis with recent findings from human and animal studies, suggesting that a catecholaminergic-cholinergic hypothesis may be more relevant. Evidence from neuroimaging studies, neuropharmacological interventions, and genetic associations support the notion that increased cholinergic functioning underlies depression, whereas increased activations of the catecholamines (dopamine and norepinephrine) underlie mania. Elevated functional acetylcholine during depression may affect both muscarinic and nicotinic acetylcholine receptors in a compensatory fashion. Increased functional dopamine and norepinephrine during mania on the other hand may affect receptor expression and functioning of dopamine reuptake transporters. Despite increasing evidence supporting this hypothesis, a relationship between these two neurotransmitter systems that could explain cycling between states of depression and mania is missing. Future studies should focus on the influence of environmental stimuli and genetic susceptibilities that may affect the catecholaminergic-cholinergic balance underlying cycling between the affective states. Overall, observations from recent studies add important data to this revised balance theory of bipolar disorder, renewing interest in this field of research. PMID:25107282

  16. Calcium entry through nicotinic receptor channels and calcium channels in cultured rat superior cervical ganglion cells.

    PubMed Central

    Trouslard, J; Marsh, S J; Brown, D A

    1993-01-01

    1. Patch-clamp techniques in conjunction with indo-1 fluorescent measurements were used to measure increases in intracellular free calcium concentration and membrane conductance induced by the activation of nicotinic and calcium channels in cultured rat sympathetic neurons. 2. Under voltage-clamp conditions, pressure application of the nicotinic agonist DMPP (1,1-dimethyl-4-phenylpiperazinium iodide, 100 microM, 100 ms) increased [Ca2+]i by 193 +/- 26 nM at a clamp potential of -60 mV. This was accompanied by an inward current of -4.53 +/- 0.89 nA, giving a mean ratio of the delta (Ca2+]i to the total inward charge transfer of 42.7 nmoles per litre of free calcium per nanocoulomb of charge (M/q ratio). 3. The DMPP-induced current and associated delta [Ca2+]i were reduced by mecamylamine (100 nM-10 microM) but were unaffected by alpha-bungarotoxin (100 nM) or cadmium (100 microM). 4. The M/q ratio was not affected by the holding potential (from -80 to -40 mV) but was a function of the external calcium concentration. 5. The M/q ratio was reduced by increasing the intracellular calcium buffering capacity and increased by heparin but not affected by ryanodine or by depletion of the caffeine-sensitive calcium store. 6. Under the same recording conditions, we quantified the increase in [Ca2+]i associated with activation of the voltage-dependent calcium current. On average at -60 mV, the M/q ratio of this highly calcium-selective permeability was 1961 mM nC-1, which is 46 times that obtained for the nicotinic channel. 7. Assuming constant-field theory, ion-substitution experiments suggest that in 2.5 mM external calcium, the permeability sequence for the nicotinic conductance was Cs+ < Li+ < Na+ < K+ < Ca2+. 8. We conclude that the nicotinic channels in rat sympathetic neurones are significantly permeant to Ca2+ and that the influx of Ca2+ through these channels is the principal cause of the rise in [Ca2+]i seen under voltage clamp. PMID:8254522

  17. Nematode cholinergic pharmacology

    SciTech Connect

    Segerberg, M.A.

    1989-01-01

    Nematode acetylcholine (ACh) receptors were characterized using both biochemical and electrophysiological techniques, including: (1) receptor binding studies in crude homogenates of the free-living nematode Caenorhabditis elegans and the parasitic nematode Ascaris lumbricoides with the high-affinity probe ({sup 3}H)N-methylscopolamine (({sup 3}H)NMS) which binds to muscarinic receptors in many vertebrate and invertebrate tissues (2) measurement of depolarization and contraction induced by a variety of cholinergic agents, including N-methylscopolamine (NMS), in an innervated dorsal muscle strip preparation of Ascaris; (3) examination of the antagonistic actions of d-tubocurarine (dTC) and NMS at dorsal neuromuscular junction; (4) measurement of input resistance changes in Ascaris commissural motorneurons induced by ACh, dTC, NMS, pilocarpine and other cholinergic drugs.

  18. Nicotinic acetylcholine receptor-mediated responses in medial vestibular and prepositus hypoglossi nuclei neurons showing distinct neurotransmitter phenotypes.

    PubMed

    Zhang, Yue; Yanagawa, Yuchio; Saito, Yasuhiko

    2016-06-01

    Cholinergic transmission in both the medial vestibular nucleus (MVN) and prepositus hypoglossi nucleus (PHN) plays an important role in horizontal eye movements. We previously demonstrated that the current responses mediated via nicotinic acetylcholine receptors (nAChRs) were larger than those mediated via muscarinic acetylcholine receptors (mAChRs) in cholinergic MVN and PHN neurons that project to the cerebellum. In this study, to clarify the predominant nAChR responses and the expression patterns of nAChRs in MVN and PHN neurons that exhibit distinct neurotransmitter phenotypes, we identified cholinergic, inhibitory, and glutamatergic neurons using specific transgenic rats and investigated current responses to the application of acetylcholine (ACh) using whole cell recordings in brain stem slices. ACh application induced larger nAChR-mediated currents than mAChR-mediated currents in every neuronal phenotype. In the presence of an mAChR antagonist, we found three types of nAChR-mediated currents that exhibited different rise and decay times and designated these as fast (F)-, slow (S)-, and fast and slow (FS)-type currents. F-type currents were the predominant response in inhibitory MVN neurons, whereas S-type currents were observed in the majority of glutamatergic MVN and PHN neurons. No dominant response type was observed in cholinergic neurons. Pharmacological analyses revealed that the F-, S-, and FS-type currents were mainly mediated by α7, non-α7, and both α7 and non-α7 nAChRs, respectively. These findings suggest that cholinergic responses in the major neuronal populations of the MVN and PHN are predominantly mediated by nAChRs and that the expression of α7 and non-α7 nAChRs differ among the neuronal phenotypes. PMID:26936981

  19. Acetylcholine release in mouse hippocampal CA1 preferentially activates inhibitory-selective interneurons via α4β2* nicotinic receptor activation

    PubMed Central

    Bell, L. Andrew; Bell, Karen A.; McQuiston, A. Rory

    2015-01-01

    Acetylcholine (ACh) release onto nicotinic receptors directly activates subsets of inhibitory interneurons in hippocampal CA1. However, the specific interneurons activated and their effect on the hippocampal network is not completely understood. Therefore, we investigated subsets of hippocampal CA1 interneurons that respond to ACh release through the activation of nicotinic receptors and the potential downstream effects this may have on hippocampal CA1 network function. ACh was optogenetically released in mouse hippocampal slices by expressing the excitatory optogenetic protein oChIEF-tdTomato in medial septum/diagonal band of Broca cholinergic neurons using Cre recombinase-dependent adeno-associated viral mediated transfection. The actions of optogenetically released ACh were assessed on both pyramidal neurons and different interneuron subtypes via whole cell patch clamp methods. Vasoactive intestinal peptide (VIP)-expressing interneurons that selectively innervate other interneurons (VIP/IS) were excited by ACh through the activation of nicotinic receptors containing α4 and β2 subunits (α4β2*). ACh release onto VIP/IS was presynaptically inhibited by M2 muscarinic autoreceptors. ACh release produced spontaneous inhibitory postsynaptic current (sIPSC) barrages blocked by dihydro-β-erythroidine in interneurons but not pyramidal neurons. Optogenetic suppression of VIP interneurons did not inhibit these sIPSC barrages suggesting other interneuron-selective interneurons were also excited by α4β2* nicotinic receptor activation. In contrast, interneurons that innervate pyramidal neuron perisomatic regions were not activated by ACh release onto nicotinic receptors. Therefore, we propose ACh release in CA1 facilitates disinhibition through activation of α4β2* nicotinic receptors on interneuron-selective interneurons whereas interneurons that innervate pyramidal neurons are less affected by nicotinic receptor activation. PMID:25918499

  20. Psychoactive drugs and pilot performance: a comparison of nicotine, donepezil, and alcohol effects.

    PubMed

    Mumenthaler, Martin S; Yesavage, Jerome A; Taylor, Joy L; O'Hara, Ruth; Friedman, Leah; Lee, Hana; Kraemer, Helena C

    2003-07-01

    The cholinergic system plays a major role in cognitive abilities that are essential to piloting an aircraft: attention, learning, and memory. In previous studies, drugs that enhance the cholinergic system through different pharmacologic mechanisms have shown beneficial effects on cognition; but dissimilar cognitive measures were used and samples were not comparable. A comparison within the same cognitive tasks, within comparable samples appears desirable. Toward this aim, we compared effect sizes (ES) of performance-enhancing doses of nicotine (a nicotinic receptor agonist) and donepezil (an acetylcholinesterase inhibitor) as found in our prior work on pilot performance. We also compared cholinergic ES to those of performance-impairing doses of alcohol. In three randomized, placebo-controlled trials, we assessed the flight performance of aircraft pilots in a Frasca 141 simulator, testing I: the acute effects of nicotine gum 2 mg; II: the effects of administration of 5 mg donepezil/day for 30 days; and III: the acute and 8 h-carryover effects of alcohol after a target peak BAC of 0.10%. We calculated the ES of nicotine, donepezil, and alcohol on a flight summary score and on four flight component scores. Compared to placebo, nicotine and donepezil significantly improved, while alcohol significantly impaired overall flight performance: ES (nicotine)=0.80; ES (donepezil)=1.02; ES (alcohol acute)=-3.66; ES (alcohol 8 h)=-0.82. Both cholinergic drugs showed the largest effects on flight tasks requiring sustained visual attention. Although the two tested cholinergic drugs have different pharmacologic mechanisms, their effects on flight performance were similar in kind and size. The beneficial effects of the cholinergic drugs on overall flight performance were large and the absolute (ie nondirectional) sizes were about one-fourth of the absolute ES of acute alcohol intoxication and roughly the same as the absolute 8 h-carryover ES of alcohol. PMID:12784106

  1. Cholinergic receptors as target for cancer therapy in a systems medicine perspective.

    PubMed

    Russo, P; Del Bufalo, A; Milic, M; Salinaro, G; Fini, M; Cesario, A

    2014-01-01

    Epithelial cells not innervated by cholinergic neurons express nicotinic and muscarinic acetylcholine (ACh) receptors (nAChR, mAChR). nAChR and mAChR are components of the auto-/paracrine-regulatory loop of non-neuronal ACh release. The cholinergic control of non-neuronal cells may be mediated by different effects (synergistic, additive, or reciprocal) triggered by these receptors. The ionic events (Ca(+2) influx) are generated by the ACh-opening of nAChR channels, while the metabolic events by ACh-binding to G-proteincoupled mAChR. Effective inter- and intracellular signaling is crucial for valuable cancer cells proliferation and survival. Depending on cancer cell type, different AChR have been identified. The proliferation of airways epithelial cancer cells and pancreatic cancer cells may be under the control of α7-nAChR and M3-mAChR, while breast cancer cells and colon cancer cells are regulated by α9-nAChR, and M3-mAChR, respectively. In turn, these receptors may activate different pathways (Ras-Raf-1-Erk-AKT) as well as other receptors (β- adrenergicR). nAChR or mAChR antagonists may inhibit cancer growth. Inhibition of M3 by antisense or antagonists (Darifenacin, Tiotropium) reduces lung or colon cancer proliferation, as well as inhibition of α9- nAChR [polyphenol (-)-epigallocatechin-3-gallate] diminishes breast cancer cells growth. α7-nAChR silencing inhibits lung cancer proliferation. Moreover, inhibition of the nAChR-β-adrenergicR pathway (β-blockers) could be also useful. This review will describe the future translational perspectives of cholinergic receptors druginhibition in a complex disease such as cancer that poses compelling treatment challenges. Cancer happens as consequence of disease-perturbed molecular networks in relevant organ cells that change during progression. The framework for approaching these challenges is a systems approach. PMID:25324001

  2. Actions of cholinergic drugs in the nematode Ascaris suum. Complex pharmacology of muscle and motorneurons

    PubMed Central

    1993-01-01

    The cholinergic agonists acetylcholine (ACh), nicotine, and pilocarpine produced depolarizations and contractions of muscle of the nematode Ascaris suum. Dose-dependent depolarization and contraction by ACh were suppressed by about two orders of magnitude by 100 microM d- tubocurarine (dTC), a nicotinic antagonist, but only about fivefold by 100 microM N-methyl-scopolamine (NMS), a muscarinic antagonist. NMS itself depolarized both normal and synaptically isolated muscle cells. The muscle depolarizing action of pilocarpine was not consistently antagonized by either NMS or dTC. ACh receptors were detected on motorneuron classes DE1, DE2, DI, and VI as ACh-induced reductions in input resistance. These input resistance changes were reversed by washing in drug-free saline or by application of dTC. NMS applied alone lowered input resistance in DE1, but not in DE2, DI, or VI motorneurons. In contrast to the effect of ACh, the action of NMS in DE1 was not reversed by dTC, suggesting that NMS-sensitive sites may not respond to ACh. Excitatory synaptic responses in muscle evoked by depolarizing current injections into DE1 and DE2 motorneurons were antagonized by dTC; however, NMS antagonized the synaptic output of only the DE1 and DE3 classes of motorneurons, an effect that was more likely to have been produced by motorneuron conduction failure than by pharmacological blockade of receptor. The concentration of NMS required to produce these changes in muscle polarization and contraction, ACh antagonism, input resistance reduction, and synaptic antagonism was 100 microM, or more than five orders of magnitude higher than the binding affinity for [3H]NMS in larval Ascaris homogenates and adult Caenorhabditis elegans (Segerberg, M. A. 1989. Ph.D. thesis. University of Wisconsin-Madison, Madison, WI). These results describe a nicotinic- like pharmacology, but muscle and motorneurons also have unusual responses to muscarinic agents. PMID:8455017

  3. Nicotine Dependence Reveals Distinct Responses from Neurons and Their Resident Nicotinic Receptors in Medial Habenula.

    PubMed

    Shih, Pei-Yu; McIntosh, J Michael; Drenan, Ryan M

    2015-12-01

    Nicotinic acetylcholine receptors (nAChRs) are the molecular target of nicotine. nAChRs in the medial habenula (MHb) have recently been shown to play a role in nicotine dependence, but it is not clear which nAChR subtypes or MHb neuron types are most important. To identify MHb nAChRs and/or cell types that play a role in nicotine dependence, we studied these receptors and cells with brain slice electrophysiology using both acute and chronic nicotine application. Cells in the ventroinferior (MHbVI) and ventrolateral MHb (MHbVL) subregions expressed functional nAChRs with different pharmacology. Further, application of nicotine to cells in these subregions led to different action potential firing patterns. The latter result was correlated with a differing ability of nicotine to induce nAChR desensitization. Chronic nicotine caused functional upregulation of nAChRs selectively in MHbVI cells, but did not change nAChR function in MHbVL. Importantly, firing responses were also differentially altered in these subregions following chronic nicotine. MHbVI neurons treated chronically with nicotine exhibited enhanced basal pacemaker firing but a blunted nicotine-induced firing response. MHbVL neurons did not change their firing properties in response to chronic nicotine. Together, these results suggest that acute and chronic nicotine differentially affect nAChR function and output of cells in MHb subregions. Because the MHb extensively innervates the interpeduncular nucleus, an area critical for both affective and somatic signs of withdrawal, these results could reflect some of the neurophysiological changes thought to occur in the MHb to the interpeduncular nucleus circuit in human smokers. PMID:26429939

  4. Liang-Ge-San, a classic traditional Chinese medicine formula, protects against lipopolysaccharide-induced inflammation through cholinergic anti-inflammatory pathway.

    PubMed

    Liu, Jun-Shan; Wei, Xi-Duan; Lu, Zi-Bin; Xie, Pei; Zhou, Hong-Ling; Chen, Yu-Yao; Ma, Jia-Mei; Yu, Lin-Zhong

    2016-04-19

    Liang-Ge-San (LGS) is a classic formula in traditional Chinese medicine, which is widely used to treat acute lung injury (ALI), pharyngitis and amygdalitis in clinic. However, the underlying mechanisms remain poorly defined. In this study, we discovered that LGS exerted potent anti-inflammatory effects in lipopolysaccharide (LPS)-induced inflammation. We found that LGS significantly depressed the production of IL-6 and TNF-α in LPS-stimulated RAW 264.7 macrophage cells. The degradation and phosphorylation of IκBα and the nuclear translocation of NF-κB p65 were also inhibited. Moreover, LGS activated α7 nicotinic cholinergic receptor (α7nAchR). The blockage of α7nAchR by selective inhibitor methyllycaconitine (MLA) or α7nAchR siRNA attenuated the inhibitory effects of LGS on IκBα, NF-κB p65, IL-6 and TNF-α. Critically, LGS significantly inhibited inflammation in LPS-induced ALI rats through the activation of NF-κB signaling pathway. However, these protective effects could be counteracted by the treatment of MLA. Taken together, we first demonstrated anti-inflammatory effects of LGS both in vitro and in vivo through cholinergic anti-inflammatory pathway. The study provides a rationale for the clinical application of LGS as an anti-inflammatory agent and supports the critical role of cholinergic anti-inflammatory pathway in inflammation. PMID:27034013

  5. Liang-Ge-San, a classic traditional Chinese medicine formula, protects against lipopolysaccharide-induced inflammation through cholinergic anti-inflammatory pathway

    PubMed Central

    Xie, Pei; Zhou, Hong-Ling; Chen, Yu-Yao; Ma, Jia-Mei; Yu, Lin-Zhong

    2016-01-01

    Liang-Ge-San (LGS) is a classic formula in traditional Chinese medicine, which is widely used to treat acute lung injury (ALI), pharyngitis and amygdalitis in clinic. However, the underlying mechanisms remain poorly defined. In this study, we discovered that LGS exerted potent anti-inflammatory effects in lipopolysaccharide (LPS)-induced inflammation. We found that LGS significantly depressed the production of IL-6 and TNF-α in LPS-stimulated RAW 264.7 macrophage cells. The degradation and phosphorylation of IκBα and the nuclear translocation of NF-κB p65 were also inhibited. Moreover, LGS activated α7 nicotinic cholinergic receptor (α7nAchR). The blockage of α7nAchR by selective inhibitor methyllycaconitine (MLA) or α7nAchR siRNA attenuated the inhibitory effects of LGS on IκBα, NF-κB p65, IL-6 and TNF-α. Critically, LGS significantly inhibited inflammation in LPS-induced ALI rats through the activation of NF-κB signaling pathway. However, these protective effects could be counteracted by the treatment of MLA. Taken together, we first demonstrated anti-inflammatory effects of LGS both in vitro and in vivo through cholinergic anti-inflammatory pathway. The study provides a rationale for the clinical application of LGS as an anti-inflammatory agent and supports the critical role of cholinergic anti-inflammatory pathway in inflammation. PMID:27034013

  6. Okadaic acid induced neurotoxicity leads to central cholinergic dysfunction in rats.

    PubMed

    Kamat, Pradeep Kumar; Tota, Santoshkumar; Rai, Shivika; Shukla, Rakesh; Ali, Shakir; Najmi, Abul Kalam; Nath, Chandishwar

    2012-09-01

    Central cholinergic system is involved in regulation of memory and disturbances in these results in memory loss. Previously, we examined the effect of okadaic acid, OKA (200ng, i.c.v.) on memory impairment and mitochondrial dysfunction in rats. In the present study, we investigated effect of OKA (i.c.v) on cholinergic function by observing acetylcholine level (ACh), acetylcholinestrase (AChE) activity, and mRNA expression of acetylcholinestrase and α7nicotinic receptor (α7-nAChR) as a cholinergic markers in brain areas (cerebellum, striatum cortex and hippocampus). In present work OKA, caused a significant decrease in acetylcholine level, acetylcholinestrase activity and mRNA expression of acetylcholinestrase and α7-nicotinic receptor in rat but these changes were mainly observed in cortex and hippocampus. Further, histopathological study by cresyl violet staining showed neuronal loss in cortex and hippocampus after OKA administration indicating neurotoxicity. Pretreatment with anti-dementic drugs donepezil (AChE inhibitor; 5mg/kg, p.o) and memantine (NMDA receptor antagonist; 10mg/kg, p.o) daily for 13 day prevented cholinergic dysfunction and neuronal loss in cortex and hippocampus of OKA treated rat. Daily per se treatment for 13 day with donepezil decreased acetylcholinestrase activity and increased mRNA expression of acetylcholinestrase and α7-nicotinic receptor. Whereas, per se treatment with memantine daily for 13 day did not affect acetylcholinestrase activity, mRNA expression of acetylcholinestrase and α7-nicotinic receptor. Findings of this work shows that OKA (i.c.v.), apart from memory impairment and mitochondrial dysfunction, as our previous study showed, also induced cholinergic dysfunction and neuronal loss, which can be addressed by antidementic drugs like donepezil and memantine. PMID:22749976

  7. Inhibition of PaCaMKII-E isoform in the dorsal unpaired median neurosecretory cells of cockroach reduces nicotine- and clothianidin-induced currents.

    PubMed

    List, Olivier; Calas-List, Delphine; Taillebois, Emiliane; Juchaux, Marjorie; Heuland, Emilie; Thany, Steeve H

    2014-08-01

    Cellular responses to Ca(2+) require intermediary proteins such as calcium/calmodulin-dependent protein kinase II (CaMKII), which transduces the signal into downstream effects. We recently demonstrated that the cockroach genome encodes five different CaMKII isoforms, and only PaCaMKII-E isoform is specifically expressed in the dorsal unpaired median neurosecretory cells. In the present study, using antisense oligonucleotides, we demonstrated that PaCaMKII-E isoform inhibition reduced nicotine-induced currents through α-bungarotoxin-sensitive and -insensitive nicotinic acetylcholine receptor subtypes. Specifically, PaCaMKII-E isoform is sufficient to repress nicotinic current amplitudes as a result of its depression by antisense oligonucleotides. Similar results were found using the neonicotinoid insecticide clothianidin, which acted as a full agonist of dorsal unpaired median neuron nicotinic acetylcholine receptors. Clothianidin current amplitudes are strongly reduced under bath application of PaCaMKII-E antisense oligonucleotides but no significant results are found with α-bungarotoxin co-applied, demonstrating that CaMKII-E isoform affects nicotine currents through α-bungarotoxin-sensitive and -insensitive receptor subtypes whereas clothianidin currents are reduced via α-bungarotoxin-insensitive receptors. In addition, we found that intracellular calcium increase induced by nicotine and clothianidin were reduced by PaCaMKII-E antisense oligonucleotides, demonstrating that intracellular calcium increase induced by nicotine and clothianidin are affected by PaCaMKII-E inhibition. Cellular responses to Ca(2+) require intermediary proteins such as calcium/calmodulin-dependent protein kinase II (CaMKII). We recently demonstrated that the cockroach genome encodes five different CaMKII isoforms and only PaCaMKII-E isoform was specifically expressed in the dorsal unpaired median neurosecretory cells. Here we show that specific inhibition of PaCaMKII-E isoform is

  8. Unequal neuroprotection afforded by the acetylcholinesterase inhibitors galantamine, donepezil, and rivastigmine in SH-SY5Y neuroblastoma cells: role of nicotinic receptors.

    PubMed

    Arias, Esperanza; Gallego-Sandín, Sonia; Villarroya, Mercedes; García, Antonio G; López, Manuela G

    2005-12-01

    Donepezil, rivastigmine, and galantamine are three drugs with acetylcholinesterase (AChE)-inhibiting activity that are currently being used to treat patients suffering from Alzheimer's disease. We have studied the neuroprotective effects of these drugs, in comparison with nicotine, on cell death caused by beta-amyloid (Abeta) and okadaic acid, two models that are relevant to Alzheimer's pathology, in the human neuroblastoma cell line SH-SY5Y. Galantamine and donepezil showed a U-shaped neuroprotective curve against okadaic acid toxicity; maximum protection was achieved at 0.3 microM galantamine and at 1 microM donepezil; at higher concentrations, protection was diminished. Rivastigmine showed a concentration-dependent effect; maximum protection was achieved at 3 microM. When apoptosis was induced by Abeta25-35, galantamine, donepezil, and rivastigmine showed maximum protection at the same concentrations: 0.3, 1, and 3 microM, respectively. Nicotine also afforded protection against Abeta- and okadaic acid-induced toxicity. The neuroprotective effects of galantamine, donepezil, and nicotine were reversed by the alpha7 nicotinic antagonist methyllycaconitine but not by the alpha4beta2 nicotinic antagonist dihydro-beta-erythroidine. The phosphoinositide 3-kinase (PI3K)-Akt blocker 2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride (LY294002) reversed the protective effects of galantamine, donepezil, and nicotine but not that of rivastigmine. In contrast, the bcl-2 antagonist ethyl[2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)]-4H-chromene-3-carboxylate (HA 14-1) reversed the protective effects of the three AChE inhibitors and that of nicotine. Our results show that galantamine, donepezil, and rivastigmine afford neuroprotection through a mechanism that is likely unrelated to AChE inhibition. Such neuroprotection seemed to be linked to alpha7 nicotinic receptors and the PI3K-Akt pathway in the case of galantamine and donepezil but not for rivastigmine

  9. CHRNA5 as negative regulator of nicotine signaling in normal and cancer bronchial cells: effects on motility, migration and p63 expression.

    PubMed

    Krais, Annette M; Hautefeuille, Agnès H; Cros, Marie-Pierre; Krutovskikh, Vladimir; Tournier, Jean-Marie; Birembaut, Philippe; Thépot, Amélie; Paliwal, Anupam; Herceg, Zdenko; Boffetta, Paolo; Brennan, Paul; Hainaut, Pierre L

    2011-09-01

    Genome-wide association studies have linked lung cancer risk with a region of chromosome 15q25.1 containing CHRNA3, CHRNA5 and CHRNB4 encoding α3, α5 and β4 subunits of nicotinic acetylcholine receptors (nAChR), respectively. One of the strongest associations was observed for a non-silent single-nucleotide polymorphism at codon 398 in CHRNA5. Here, we have used pharmacological (antagonists) or genetic (RNA interference) interventions to modulate the activity of CHRNA5 in non-transformed bronchial cells and in lung cancer cell lines. In both cell types, silencing CHRNA5 or inhibiting receptors containing nAChR α5 with α-conotoxin MII exerted a nicotine-like effect, with increased motility and invasiveness in vitro and increasing calcium influx. The effects on motility were enhanced by addition of nicotine but blocked by inhibiting CHRNA7, which encodes the homopentameric receptor α7 subunit. Silencing CHRNA5 also decreased the expression of cell adhesion molecules P120 and ZO-1 in lung cancer cells as well as the expression of DeltaNp63α in squamous cell carcinoma cell lines. These results demonstrate a role for CHRNA5 in modulating adhesion and motility in bronchial cells, as well as in regulating p63, a potential oncogene in squamous cell carcinoma. PMID:21586512

  10. CHRNA5 as negative regulator of nicotine signaling in normal and cancer bronchial cells: effects on motility, migration and p63 expression

    PubMed Central

    Krais, Annette M.; Hautefeuille, Agnès H.; Cros, Marie-Pierre; Krutovskikh, Vladimir; Tournier, Jean-Marie; Birembaut, Philippe; Thépot, Amélie; Paliwal, Anupam; Herceg, Zdenko; Boffetta, Paolo; Brennan, Paul; Hainaut, Pierre L.

    2011-01-01

    Genome-wide association studies have linked lung cancer risk with a region of chromosome 15q25.1 containing CHRNA3, CHRNA5 and CHRNB4 encoding α3, α5 and β4 subunits of nicotinic acetylcholine receptors (nAChR), respectively. One of the strongest associations was observed for a non-silent single-nucleotide polymorphism at codon 398 in CHRNA5. Here, we have used pharmacological (antagonists) or genetic (RNA interference) interventions to modulate the activity of CHRNA5 in non-transformed bronchial cells and in lung cancer cell lines. In both cell types, silencing CHRNA5 or inhibiting receptors containing nAChR α5 with α-conotoxin MII exerted a nicotine-like effect, with increased motility and invasiveness in vitro and increasing calcium influx. The effects on motility were enhanced by addition of nicotine but blocked by inhibiting CHRNA7, which encodes the homopentameric receptor α7 subunit. Silencing CHRNA5 also decreased the expression of cell adhesion molecules P120 and ZO-1 in lung cancer cells as well as the expression of DeltaNp63α in squamous cell carcinoma cell lines. These results demonstrate a role for CHRNA5 in modulating adhesion and motility in bronchial cells, as well as in regulating p63, a potential oncogene in squamous cell carcinoma. PMID:21586512

  11. Toxicological Analysis of Low-Nicotine and Nicotine-Free Cigarettes

    PubMed Central

    Chen, Jinguo; Higby, Richard; Tian, Defa; Tan, Duanjun; Johnson, Michael D.; Xiao, Yingxian; Kellar, Kenneth J; Feng, Shibao; Shields, Peter G.

    2008-01-01

    Low-nicotine and nicotine-free cigarettes are commercially available under the brand-name Quest®. Some consumers may believe that these are safer cigarettes, and they may smoke more cigarettes or inhale more smoke to compensate for low nicotine yields. Thus, we have studied the toxicological effects of these two cigarettes and compared them with the Kentucky reference cigarette 2R4F. Also, the availability of nicotine-free cigarettes allows for the assessing the role of nicotine in cigarette smoke. In addition to nicotine, some tobacco-specific nitrosamines, aldehydes, and volatile organic compounds were also reduced in the Quest® cigarettes compared to the 2R4F. However, aromatic amines were higher in the nicotine-free compared with low nicotine cigarettes. The Ames test revealed that cigarette smoke condensates from the nicotinefree (CSC-F), low nicotine (CSC-L) and 2R4F (CSC-R) cigarettes had a similar mutagenic potency. Exposure to any CSC caused a similar dose-dependent LDH leakage from normal human bronchial epithelial cells. However, CSC-F had more inhibitory effects on the cell growth than CSC-L and CSC-R. Adding nicotine to the CSC-F attenuated this inhibition. Both Quest® CSCs decreased gap junction intercellular communication and caused cell cycle arrest. CSC exposure increased cytoplasmic nucleosomes, sub-G1/G0 population and apoptotic comet tails. Proapoptotic protein Bax increased independent of p53 induction after exposure to CSC-F. In conclusion, these studies are not consistent with a perception that low-nicotine or nicotine-free cigarettes may have less toxicity in human cells. Nicotine, as it exists in CSC, attenuates cytotoxicity possibly in part through inhibition of apoptotic pathways. PMID:18599178

  12. Integration of inhibitory and excitatory effects of α7 nicotinic acetylcholine receptor activation in the prelimbic cortex regulates network activity and plasticity.

    PubMed

    Udakis, Matthew; Wright, Victoria Louise; Wonnacott, Susan; Bailey, Christopher Philip

    2016-06-01

    Cognitive and attentional processes governed by the prefrontal cortex (PFC) are influenced by cholinergic innervation. Here we have explored the role of α7 nicotinic acetylcholine receptors (nAChRs) as mediators of cholinergic signalling in the dorsomedial (prelimbic) PFC, using mouse brain slice electrophysiology. Activation of α7 nAChRs located on glutamatergic terminals and cell soma of GABAergic interneurons increased excitation and inhibition, respectively, in layer V of the prelimbic cortex. These actions were distinguished by their differential dependence on local acetylcholine (ACh): potentiation of endogenous cholinergic signalling with the positive allosteric modulator, PNU-120596, enhanced spontaneous excitatory events, an effect that was further increased by inhibition of acetylcholinesterase. In contrast, α7 nicotinic modulation of inhibitory signalling required addition of exogenous agonist (PNU-282987) as well as PNU-120596, and was unaffected by acetylcholinesterase inhibition. Thus α7 nAChRs can bi-directionally regulate network activity in the prelimbic cortex, depending on the magnitude and localisation of cholinergic signalling. This bidirectional influence is manifest in dual effects of α7 nAChRs on theta-burst-induced long-term potentiation (LTP) in layer V of the prelimbic cortex. Antagonism of α7 nAChRs significantly decreased LTP implicating a contribution from endogenous ACh, consistent with the ability of local ACh to enhance glutamatergic signalling. Exogenous agonist plus potentiator also decreased LTP, indicative of the influence of this drug combination on inhibitory signalling. Thus α7 nAChRs make a complex contribution to network activity and synaptic plasticity in the prelimbic cortex. PMID:26921769

  13. Characterization of nicotine binding in mouse brain and comparison with the binding of alpha-bungarotoxin and quinuclidinyl benzilate

    SciTech Connect

    Marks, M.J.; Collins, A.C.

    1982-11-01

    The binding of (/sup 3/H)nicotine to mouse brain has been measured and subsequently compared with the binding of (/sup 125/I)alpha-bungarotoxin (alpha-BTX) and L-(/sup 3/H)quinuclidinyl benzilate (QNB). The binding of nicotine was saturable, reversible, and stereospecific. The average KD and Bmax were 59 nM and 88 fmoles/mg of protein, respectively. Although the rates of association and dissociation of nicotine were temperature-dependent, the incubation temperature had no effect on either KD or Bmax. When measured at 20 degrees or 37 degrees, nicotine appeared to bind to a single class of binding sites, but a second, very low-affinity, binding site was observed at 4 degrees. Nicotine binding was unaffected by the addition of NaCl, KCl, CaCl/sub 2/, or MgSO/sub 4/ to the incubation medium. Nicotinic cholinergic agonists were potent inhibitors of nicotine binding; however, nicotinic antagonists were poor inhibitors. The regional distribution of binding was not uniform: midbrain and striatum contained the highest number of receptors, whereas cerebellum had the fewest. Differences in site densities, regional distribution, inhibitor potencies, and thermal denaturation indicated that nicotine binding was not the same as either QNB or alpha-BTX binding, and therefore that receptors for nicotine may represent a unique population of cholinergic receptors.

  14. Nicotine and periodontal tissues

    PubMed Central

    Malhotra, Ranjan; Kapoor, Anoop; Grover, Vishakha; Kaushal, Sumit

    2010-01-01

    Tobacco use has been recognized to be a significant risk factor for the development and progression of periodontal disease. Its use is associated with increased pocket depths, loss of periodontal attachment, alveolar bone and a higher rate of tooth loss. Nicotine, a major component and most pharmacologically active agent in tobacco is likely to be a significant contributing factor for the exacerbation of periodontal diseases. Available literature suggests that nicotine affects gingival blood flow, cytokine production, neutrophil and other immune cell function; connective tissue turnover, which can be the possible mechanisms responsible for overall effects of tobacco on periodontal tissues. Inclusion of tobacco cessation as a part of periodontal therapy encourages dental professionals to become more active in tobacco cessation counseling. This will have far reaching positive effects on our patients’ oral and general health. PMID:20922084

  15. Nicotine Inhibits Clostridium difficile Toxin A-Induced Colitis but Not Ileitis in Rats

    PubMed Central

    Vigna, Steven R.

    2016-01-01

    Nicotine is protective in ulcerative colitis but not Crohn's disease of the small intestine, but little is known about the effects of nicotine on Clostridium difficile toxin A-induced enteritis. Isolated ileal or colonic segments in anesthetized rats were pretreated with nicotine bitartrate or other pharmacological agents before intraluminal injection of toxin A. After 3 hours, the treated segments were removed and inflammation was assessed. Nicotine biphasically inhibited toxin A colitis but not ileitis. Pretreatment with the nicotinic receptor antagonist, hexamethonium, blocked the effects of nicotine. Pretreating the colonic segments with hexamethonium before toxin A administration resulted in more inflammation than seen with toxin A alone, suggesting that a tonic nicotinic anti-inflammatory condition exists in the colon. Nicotine also inhibited toxin A-induced increased colonic concentrations of the TRPV1 (transient receptor potential vanilloid subtype 1) agonist, leukotriene B4 (LTB4), and release of the proinflammatory neuropeptide, substance P. Pretreatment with nicotine did not protect against direct TRPV1-mediated colitis caused by intraluminal capsaicin. Nicotinic cholinergic receptors tonically protect the colon against inflammation and nicotine inhibits toxin A colitis but not toxin A ileitis in rats in part by inhibition of toxin A-induced activation of TRPV1 by endogenous TRPV1 agonists such as LTB4. PMID:26881175

  16. Nicotine contributes to the neural stem cells fate against toxicity of microglial-derived factors induced by Aβ via the Wnt/β-catenin pathway.

    PubMed

    Jiang, De-Qi; Wei, Mei-Dan; Wang, Ke-Wan; Lan, Yan-Xian; Zhu, Ning; Wang, Yong

    2016-01-01

    Recent studies have demonstrated that the molecules secreted from microglias play important roles in the cell fate determination of neural stem cells (NSCs), and nicotinic acetylcholine receptor agonist treatment could reduce neuroinflammation in some neurodegenerative disease models, such as Alzheimer's disease (AD). However, it is not clear how nicotine plays a neuroprotective role in inflammation-mediated central nervous diseases, and its possible mechanisms in the process remain largely elusive. The aim of this study is to improve the survival microenvironment of NSCs co-cultured with microglias in vitro by weakening inflammation that mediated by accumulation of β-amyloid peptide (Aβ). The viability, proliferation, differentiation, apoptosis of NSCs and underlying mechanisms associated with Wnt signaling pathway were investigated. The results showed that Aβ could directly damage NSCs. Furthermore, concomitant to elevated levels of TNF-α, IL-1β derived from microglias, the NSCs had been damaged more severely with the upregulation of Axin 2, p-β-catenin and the downregulation of β-catenin, p-GSK-3β, microtubule-associated protein-2, choline acetyltransferase. However, addition of 10 μmol/L nicotine before microglias treated with Aβ was beneficial to protect the NSCs against neurotoxicity of microglial-derived factors induced by Aβ, which partially rescued proliferation, differentiation and inhibited apoptosis of NSCs via activation of Wnt/β-catenin pathway. Taken together, these data imply that low concentration nicotine attenuates NSCs injury induced by microglial-derived factors via Wnt signaling pathway. Thus, treatment with nicotinic acetylcholine receptor agonist provides a promising research field for neural stem cell fate and therapeutic intervention in neuroinflammation diseases. PMID:26001208

  17. Expression and Functional Role of α7 Nicotinic Receptor in Human Cytokine-stimulated Natural Killer (NK) Cells.

    PubMed

    Zanetti, Samanta R; Ziblat, Andrea; Torres, Nicolás I; Zwirner, Norberto W; Bouzat, Cecilia

    2016-08-01

    The homomeric α7 nicotinic receptor (nAChR) is one of the most abundant nAChRs in the central nervous system where it contributes to cognition, attention, and working memory. α7 nAChR is also present in lymphocytes, dendritic cells (DCs), and macrophages and it is emerging as an important drug target for intervention in inflammation and sepsis. Natural killer (NK) cells display cytotoxic activity against susceptible target cells and modulate innate and adaptive immune responses through their interaction with DCs. We here show that human NK cells also express α7 nAChR. α7 nAChR mRNA is detected by RT-PCR and cell surface expression of α7 nAChR is detected by confocal microscopy and flow cytometry using α-bungarotoxin, a specific antagonist. Both mRNA and protein levels increase during NK stimulation with cytokines (IL-12, IL-18, and IL-15). Exposure of cytokine-stimulated NK cells to PNU-282987, a specific α7 nAChR agonist, increases intracellular calcium concentration ([Ca(2+)]i) mainly released from intracellular stores, indicating that α7 nAChR is functional. Moreover, its activation by PNU-282987 plus a specific positive allosteric modulator greatly enhances the Ca(2+) responses in NK cells. Stimulation of NK cells with cytokines and PNU-282987 decreases NF-κB levels and nuclear mobilization, down-regulates NKG2D receptors, and decreases NKG2D-dependent cell-mediated cytotoxicity and IFN-γ production. Also, such NK cells are less efficient to trigger DC maturation. Thus, our results demonstrate the anti-inflammatory role of α7 nAChR in NK cells and suggest that modulation of its activity in these cells may constitute a novel target for regulation of the immune response. PMID:27284006

  18. Binding, uptake, and release of nicotine by human gingival fibroblasts

    SciTech Connect

    Hanes, P.J.; Schuster, G.S.; Lubas, S. )

    1991-02-01

    Previous studies of the effects of nicotine on fibroblasts have reported an altered morphology and attachment of fibroblasts to substrates and disturbances in protein synthesis and secretion. This altered functional and attachment response may be associated with changes in the cell membrane resulting from binding of the nicotine, or to disturbances in cell metabolism as a result of high intracellular levels of nicotine. The purpose of the present study, therefore, was to (1) determine whether gingival fibroblasts bound nicotine and if any binding observed was specific or non-specific in nature; (2) determine whether gingival fibroblasts internalized nicotine, and if so, at what rate; (3) determine whether gingival fibroblasts also released nicotine back into the extracellular environment; and (4) if gingival fibroblasts release nicotine intact or as a metabolite. Cultures of gingival fibroblasts were prepared from gingival connective tissue biopsies. Binding was evaluated at 4{degree}C using a mixture of {sup 3}H-nicotine and unlabeled nicotine. Specific binding was calculated as the difference between {sup 3}H-nicotine bound in the presence and absence of unlabeled nicotine. The cells bound 1.44 (+/- 0.42) pmols/10(6) cells in the presence of unlabeled nicotine and 1.66 (+/- 0.55) pmols/10(6) cells in the absence of unlabeled nicotine. The difference was not significant. Uptake of nicotine was measured at 37{degree}C after treating cells with {sup 3}H-nicotine for time periods up to 4 hours. Uptake in pmols/10(6) cells was 4.90 (+/- 0.34) at 15 minutes, 8.30 (+/- 0.75) at 30 minutes, 12.28 (+/- 2.62) at 1 hour and 26.31 (+/- 1.15) at 4 hours.

  19. Prostate stem cell antigen is an endogenous lynx1-like prototoxin that antagonizes alpha7 containing nicotinic receptors and prevents programmed cell death of parasympathetic neurons

    PubMed Central

    Hruska, Martin; Keefe, Julie; Wert, David; Tekinay, Ayse Begum; Hulce, Jonathan J.; Ibanez-Tallon, Ines; Nishi, Rae

    2010-01-01

    Vertebrate α–bungarotoxin-like molecules of the Ly-6 super family have been implicated as balancers of activity and survival in the adult nervous system. To determine whether a member of this family could be involved in the development of the avian ciliary ganglion, we identified 6 Gallus genes by their homology in structure to mouse lynx1 and lynx2. One of these genes, an ortholog of prostate stem cell antigen (PSCA), is barely detectable at embryonic day 8, prior to neuronal cell loss in the ciliary ganglion, but increases over 100-fold as the number of neurons begins to decline between E9 and E14. PSCA is highly expressed in chicken and mouse telencephalon and peripheral ganglia and correlates with expression of α7-containing nicotinic acetylcholine receptors (α7-nAChRs). Misexpressing PSCA prior to cell death in the ciliary ganglion blocks α7-nAChR activation by nicotine and rescues the choroid subpopulation from dying. Thus, PSCA, a molecule previously identified as a marker of prostate cancer, is a member of the Ly-6 neurotoxin-like family in the nervous system, and is likely to play a role as a modulator of α7 signaling induced cell death during development. PMID:19940180

  20. Impact of prenatal nicotine on the structure of midbrain dopamine regions in the rat.

    PubMed

    Omelchenko, Natalia; Roy, Priya; Balcita-Pedicino, Judith Joyce; Poloyac, Samuel; Sesack, Susan R

    2016-05-01

    In utero exposure of rats to nicotine (NIC) provides a useful animal model for studying the impact of smoking during pregnancy on human offspring. Certain sequelae of prenatal NIC exposure suggest an impact on the development of the midbrain dopamine (DA) system, which receives a robust cholinergic innervation from the mesopontine tegmentum. We therefore investigated whether prenatal NIC induced structural changes in cells and synapses within the midbrain that persisted into adulthood. Osmotic minipumps delivering either sodium bitartrate (vehicle; VEH) or NIC bitartrate at 2 mg/kg/day were implanted into nine timed-pregnant dams at E4. At birth, rat pups were culled to litters of six males each, and the litters were cross-fostered. Plasma levels of NIC and cotinine from killed pups provided evidence of NIC exposure in utero. Pups separated from dams at weaning showed a trend toward reduced locomotor activity at this time point but not when tested again in adulthood. Adult rats were killed for anatomical studies. Estimates of brain size and volume did not vary with NIC treatment. Midbrain sections stained for Nissl or by immunoperoxidase for tyrosine hydroxylase and analyzed using unbiased stereology revealed no changes in volume or cell number in the substantia nigra compacta or ventral tegmental area as a result of NIC exposure. Within the ventral tegmental area, electron microscopic physical disector analysis showed no significant differences in the number of axon terminals or the number of asymmetric (putative excitatory) or symmetric (putative inhibitory) synapses. Although too infrequent to estimate by unbiased stereology, no obvious difference in the proportion of cholinergic axons was noted in NIC- versus VEH-treated animals. These data suggest that activation of nicotinic receptors during prenatal development induces no significant modifications in the structure of cells in the ventral midbrain when assessed in adulthood. PMID:25716298

  1. Nicotinic acetylcholine receptors induce c-Kit ligand/Stem Cell Factor and promote stemness in an ARRB1/ β-arrestin-1 dependent manner in NSCLC

    PubMed Central

    Perumal, Deepak; Pillai, Smitha; Nguyen, Jonathan; Schaal, Courtney; Coppola, Domenico; Chellappan, Srikumar P.

    2014-01-01

    Lung cancer remains the leading cause of cancer-related deaths worldwide. β-arrestin-1 (ARRB1), a scaffolding protein involved in the desensitization of signals arising from activated G-protein-coupled receptors (GPCRs), has been shown to play a role in invasion and proliferation of cancer cells, including nicotine-induced proliferation of human non–small cell lung cancers (NSCLCs). In this study, we identified genes that are differentially regulated by nicotine in an ARRB1/β-arrestin-1 dependent manner in NSCLC cells by microarray analysis. Among the identified genes, SCF (Stem cell factor) strongly differentiated smokers from non-smokers in the Director's Challenge Set expression data and its high expression correlated with poor prognosis. SCF, a major cytokine is the ligand for the c-Kit proto-oncogene and was found to be over expressed in human lung adenocarcinomas, but not squamous cell carcinomas. Data presented here show that transcription factor E2F1 can induce SCF expression at the transcriptional level and depletion of E2F1 or ARRB1/β-arrestin-1 could not promote self-renewal of SP cells. These studies suggest that nicotine might be promoting NSCLC growth and metastasis by inducing the secretion of SCF, and raise the possibility that targeting signalling cascades that activate E2F1 might be an effective way to combat NSCLC. PMID:25401222

  2. ID1 facilitates the growth and metastasis of non-small cell lung cancer in response to nicotinic acetylcholine receptor and epidermal growth factor receptor signaling.

    PubMed

    Pillai, Smitha; Rizwani, Wasia; Li, Xueli; Rawal, Bhupendra; Nair, Sajitha; Schell, Michael J; Bepler, Gerold; Haura, Eric; Coppola, Domenico; Chellappan, Srikumar

    2011-07-01

    Expression of ID1 (inhibitor of differentiation) has been correlated with the progression of a variety of cancers, but little information is available on its role in non-small cell lung cancer (NSCLC). Here we show that ID1 is induced by nicotinic acetylcholine receptor (nAChR) and epidermal growth factor receptor (EGFR) signaling in a panel of NSCLC cell lines and primary cells from the lung. ID1 induction was Src dependent and mediated through the α7 subunit of nAChR; transfection of K-Ras or EGFR to primary cells induced ID1. ID1 depletion prevented nicotine- and EGF-induced proliferation, migration, and invasion of NSCLC cells and angiogenic tubule formation of human microvascular endothelial cells from lungs (HMEC-Ls). ID1 could induce the expression of mesenchymal markers such as vimentin and fibronectin by downregulating ZBP-89, a zinc finger repressor protein. ID1 levels were elevated in tumors from mice that were exposed to nicotine. Further, human lung tissue microarrays (TMAs) showed elevated levels of ID1 in NSCLC samples, with maximal levels in metastatic lung cancers. Quantitative reverse transcription-PCR (RT-PCR) performed on patient lung tumors showed that ID1 levels were elevated in advanced stages of NSCLC and correlated with elevated expression of vimentin and fibronectin, irrespective of smoking history. PMID:21606196

  3. Nicotinic receptors in addiction pathways.

    PubMed

    Leslie, Frances M; Mojica, Celina Y; Reynaga, Daisy D

    2013-04-01

    Neuronal nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that consist of pentameric combinations of α and β subunits. These receptors are widely distributed throughout the brain and are highly expressed in addiction circuitry. The role of nAChRs in regulating neuronal activity and motivated behavior is complex and varies both in and among brain regions. The rich diversity of central nAChRs has hampered the characterization of their structure and function with use of classic pharmacological techniques. However, recent molecular approaches using null mutant mice with specific regional lentiviral re-expression, in combination with neuroanatomical and electrophysiological techniques, have allowed the elucidation of the influence of different nAChR types on neuronal circuit activity and behavior. This review will address the influence of nAChRs on limbic dopamine circuitry and the medial habenula-interpeduncular nucleus complex, which are critical mediators of reinforced behavior. Characterization of the mechanisms underlying regulation of addiction pathways by endogenous cholinergic transmission and by nicotine may lead to the identification of new therapeutic targets for treating tobacco dependence and other addictions. PMID:23247824

  4. Functional interactions between the SK2 channel and the nicotinic acetylcholine receptor in enteric neurons of the guinea pig ileum.

    PubMed

    Nakajima, Hidemitsu; Goto, Hiroto; Azuma, Yasu-Taka; Fujita, Akikazu; Takeuchi, Tadayoshi

    2007-12-01

    The neurotransmitter acetylcholine (ACh) plays a critical role in gastrointestinal function. The role of the small conductance Ca2+-activated K+ (SK) channel in ACh release was examined using myenteric plexus preparations of guinea pig ileum. Apamin, an inhibitor of the SK channel, significantly enhanced nicotine-induced ACh release, but neither electrical field stimulation- nor 5-hydroxytryptamine-induced ACh release, suggesting that SK channels might be selectively involved in the regulation of nicotine-induced ACh release. Therefore, we investigated the distribution of SK2 and SK3 subunits and the interaction between SK2 channels and nicotinic ACh receptors (nAChRs) in the guinea pig ileum. The immunoreactivity of SK2 subunits was located in enteric neuronal cells. Furthermore, SK2-immunoreactive cells stained with an antibody for choline acetyltransferase, a marker for cholinergic neurons, and with an antibody for the alpha3/5 subunits of nAChR. In contrast, immunoreactivity of SK3 subunits was not found in enteric neurons. A co-immunoprecipitation assay with Triton X-100-soluble membrane fractions prepared from the ileum revealed an association of the SK2 subunit with the alpha3/5 subunits of nAChR. These results suggest that SK2 channels negatively regulate the excitation of enteric neurons via functional interactions with nAChRs. PMID:17953675

  5. Innate Immunity and Inflammation Post-Stroke: An α7-Nicotinic Agonist Perspective

    PubMed Central

    Neumann, Silke; Shields, Nicholas J.; Balle, Thomas; Chebib, Mary; Clarkson, Andrew N.

    2015-01-01

    Stroke is one of the leading causes of death and long-term disability, with limited treatment options available. Inflammation contributes to damage tissue in the central nervous system across a broad range of neuropathologies, including Alzheimer’s disease, pain, Schizophrenia, and stroke. While the immune system plays an important role in contributing to brain damage produced by ischemia, the damaged brain, in turn, can exert a powerful immune-suppressive effect that promotes infections and threatens the survival of stroke patients. Recently the cholinergic anti-inflammatory pathway, in particular its modulation using α7-nicotinic acetylcholine receptor (α7-nAChR) ligands, has shown potential as a strategy to dampen the inflammatory response and facilitate functional recovery in stroke patients. Here we discuss the current literature on stroke-induced inflammation and the effects of α7-nAChR modulators on innate immune cells. PMID:26690125

  6. Differential inhibition of tumour cell-induced platelet aggregation by the nicotinate aspirin prodrug (ST0702) and aspirin

    PubMed Central

    Medina, Carlos; Harmon, Shona; Inkielewicz, Iwona; Santos-Martinez, Maria Jose; Jones, Michael; Cantwell, Paula; Bazou, Despina; Ledwidge, Mark; Radomski, Marek W; Gilmer, John F

    2012-01-01

    BACKGROUND AND PURPOSE Tumour cell-induced platelet aggregation (TCIPA) facilitates cancer cell invasion, angiogenesis and the formation of metastatic foci. TCIPA can be modulated by pharmacological inhibitors of MMP-2 and ADP; however, the COX inhibitor aspirin did not prevent TCIPA. In this study, we have tested the pharmacological effects of a new group of isosorbide-based aspirin prodrugs on TCIPA. EXPERIMENTAL APPROACH TCIPA was induced in human platelets by mixing with human adenocarcinoma or fibrosarcoma cells under no flow and flow conditions. The release of gelatinases and P-selectin expression during TCIPA were studied by zymography and flow cytometry respectively. KEY RESULTS Tumour cells caused platelet aggregation. This aggregation resulted in the release of MMP-2 and a significant up-regulation of P-selectin on platelets, indicative of platelet activation. Pharmacological modulation of TCIPA revealed that ST0702, one of the aspirin prodrugs, down-regulated TCIPA while aspirin was ineffective. The deacetylated metabolite of ST0702, 5-nicotinate salicylate (ST0702 salicylate), down-regulated both ADP-stimulated platelet aggregation and TCIPA. CONCLUSIONS AND IMPLICATIONS Our results show that ST0702 was an effective inhibitor of TCIPA in vitro. Its deacetylated metabolite may contribute to the effects of ST0702 by inhibiting ADP-mediated TCIPA. PMID:22122360

  7. Cholinergic ligand interactions with acetylcholine receptor proteins and solvent interactions with N,N-dialkylnicotinamides

    SciTech Connect

    Bean, J.W.

    1987-01-01

    A dual-chambered flow dialysis nuclear counting apparatus was used to monitor cholinergic ligand induced displacement of {sup 155}Eu{sup 3+} from acetylcholine receptor proteins. Acetylcholine, nicotine and carbamylcholine induced similar rates of displacement of {sup 155}Eu{sup 3+} probes of calcium binding sites in receptor proteins from wild type Drosophila melanogaster and Torpedo californica. The receptor isolated from a nicotine resistant strain of Drosophila melanogaster displayed an altered dependency of cholinergic ligand induced cation displacement with respect to the other two receptor proteins. Both Drosophila strains' solubilized receptor proteins migrated as three bands of molecular weights 68,000, 66,000, and 60,000 on denaturing polyacrylamide gels. Carbon-13 NMR techniques were employed to examine the effects of solvent environment on rotational energy barriers in a series of molecules related to the analeptic, nikethamide: N,N-dimethylnicotinamide, 1-nicotinoyl piperidine, and N,N-dipropylnicotinamide.

  8. Dopaminergic and Cholinergic Modulation of Striatal Tyrosine Hydroxylase Interneurons

    PubMed Central

    Ibáñez-Sandoval, Osvaldo; Xenias, Harry S.; Tepper, James M.; Koós, Tibor

    2015-01-01

    The recent electrophysiological characterization of TH-expressing GABAergic interneurons (THINs) in the neostriatum revealed an unexpected degree of diversity of interneurons in this brain area (Ibáñez-Sandoval et al., 2010, Unal et al., 2011, 2013). Despite being relatively few in number, THINs may play a significant role in transmitting and distributing extra- and intrastriatal neuromodulatory signals in the striatal circuitry. Here we investigated the dopaminergic and cholinergic regulation of THINs in vitro. We found that the dominant effect of dopamine was a dramatic enhancement of the ability of THINs to generate long-lasting depolarizing plateau potentials (PPs). Interestingly, the same effect could also be elicited by amphetamine-induced release of endogenous dopamine suggesting that THINs may exhibit similar responses to changes in extracellular dopamine concentration in vivo. The enhancement of PPs in THINs is perhaps the most pronounced effect of dopamine on the intrinsic excitability of neostriatal neurons described to date. Further, we demonstrate that all subtypes of THINSs tested also express nicotinic cholinergic receptors. All THIS responded, albeit differentially, with depolarization, PPs and spiking to brief application of nicotinic agonists. Powerful modulation of the nonlinear integrative properties of THINs by dopamine and the direct depolarization of these neurons by acetylcholine may play important roles in mediating the effects of these neuromodulators in the neostriatum with potentially important implications for understanding the mechanisms of neuropsychiatric disorders affecting the basal ganglia. PMID:25908399

  9. Dopaminergic and cholinergic modulation of striatal tyrosine hydroxylase interneurons.

    PubMed

    Ibáñez-Sandoval, Osvaldo; Xenias, Harry S; Tepper, James M; Koós, Tibor

    2015-08-01

    The recent electrophysiological characterization of TH-expressing GABAergic interneurons (THINs) in the neostriatum revealed an unexpected degree of diversity of interneurons in this brain area (Ibáñez-Sandoval et al., 2010, Unal et al., 2011, 2015). Despite being relatively few in number, THINs may play a significant role in transmitting and distributing extra- and intrastriatal neuromodulatory signals in the striatal circuitry. Here we investigated the dopaminergic and cholinergic regulation of THINs in vitro. We found that the dominant effect of dopamine was a dramatic enhancement of the ability of THINs to generate long-lasting depolarizing plateau potentials (PPs). Interestingly, the same effect could also be elicited by amphetamine-induced release of endogenous dopamine suggesting that THINs may exhibit similar responses to changes in extracellular dopamine concentration in vivo. The enhancement of PPs in THINs is perhaps the most pronounced effect of dopamine on the intrinsic excitability of neostriatal neurons described to date. Further, we demonstrate that all subtypes of THINSs tested also express nicotinic cholinergic receptors. All THIS responded, albeit differentially, with depolarization, PPs and spiking to brief application of nicotinic agonists. Powerful modulation of the nonlinear integrative properties of THINs by dopamine and the direct depolarization of these neurons by acetylcholine may play important roles in mediating the effects of these neuromodulators in the neostriatum with potentially important implications for understanding the mechanisms of neuropsychiatric disorders affecting the basal ganglia. PMID:25908399

  10. Cholinergic Circuit Control of Postnatal Neurogenesis

    PubMed Central

    Asrican, Brent; Paez-Gonzalez, Patricia; Erb, Joshua; Kuo, Chay T.

    2016-01-01

    New neuron addition via continued neurogenesis in the postnatal/adult mammalian brain presents a distinct form of nervous system plasticity. During embryonic development, precise temporal and spatial patterns of neurogenesis are necessary to create the nervous system architecture. Similar between embryonic and postnatal stages, neurogenic proliferation is regulated by neural stem cell (NSC)-intrinsic mechanisms layered upon cues from their local microenvironmental niche. Following developmental assembly, it remains relatively unclear what may be the key driving forces that sustain continued production of neurons in the postnatal/adult brain. Recent experimental evidence suggests that patterned activity from specific neural circuits can also directly govern postnatal/adult neurogenesis. Here, we review experimental findings that revealed cholinergic modulation, and how patterns of neuronal activity and acetylcholine release may differentially or synergistically activate downstream signaling in NSCs. Higher-order excitatory and inhibitory inputs regulating cholinergic neuron firing, and their implications in neurogenesis control are also considered. PMID:27468423

  11. α6* nicotinic acetylcholine receptor expression and function in a visual salience circuit

    PubMed Central

    Mackey, Elisha D.W.; Engle, Staci E.; Kim, Mi Ran; O’Neill, Heidi C.; Wageman, Charles R.; Patzlaff, Natalie E.; Wang, Ying; Grady, Sharon R.; McIntosh, J. Michael; Marks, Michael J.; Lester, Henry A.; Drenan, Ryan M.

    2012-01-01

    Nicotinic ACh receptors (nAChRs) containing α6 subunits are expressed in only a few brain areas, including midbrain dopamine (DA) neurons, noradrenergic neurons of the locus coeruleus, and retinal ganglion cells. To better understand the regional and subcellular expression pattern of α6-containing nAChRs, we created and studied transgenic mice expressing a variant α6 subunit with GFP fused in-frame in the M3–M4 intracellular loop. Inα6-GFP transgenic mice, α6-dependent synaptosomal DA release and radioligand binding experiments confirmed correct expression and function in vivo. In addition to strong α6* nAChR expression in glutamatergic retinal axons which terminate in superficial superior colliculus (sSC), we also found α6 subunit expression in a subset of GABAergic cell bodies in this brain area. In patch clamp recordings from sSC neurons in brain slices from mice expressing hypersensitive α6* nAChRs, we confirmed functional, postsynaptic α6* nAChR expression. Further, sSC GABAergic neurons expressing α6* nAChRs exhibit a tonic conductance mediated by standing activation of hypersensitiveα6* nAChRs by ACh. α6* nAChRs also appear in a subpopulation of SC neurons in output layers. Finally, selective activation of α6* nAChRs in vivo induced sSC neuronal activation as measured with c-Fos expression. Together, these results demonstrate that α6* nAChRs are uniquely situated to mediate cholinergic modulation of glutamate and GABA release in SC. The SC has emerged as a potential key brain area responsible for transmitting short-latency salience signals to thalamus and midbrain DA neurons, and these results suggest that α6* nAChRs may be important for nicotinic cholinergic sensitization of this pathway. PMID:22836257

  12. Optogenetic activation of striatal cholinergic interneurons regulates L-dopa-induced dyskinesias.

    PubMed

    Bordia, Tanuja; Perez, Xiomara A; Heiss, Jaime E; Zhang, Danhui; Quik, Maryka

    2016-07-01

    L-dopa-induced dyskinesias (LIDs) are a serious complication of L-dopa therapy for Parkinson's disease. Emerging evidence indicates that the nicotinic cholinergic system plays a role in LIDs, although the pathways and mechanisms are poorly understood. Here we used optogenetics to investigate the role of striatal cholinergic interneurons in LIDs. Mice expressing cre-recombinase under the control of the choline acetyltransferase promoter (ChAT-Cre) were lesioned by unilateral injection of 6-hydroxydopamine. AAV5-ChR2-eYFP or AAV5-control-eYFP was injected into the dorsolateral striatum, and optical fibers implanted. After stable virus expression, mice were treated with L-dopa. They were then subjected to various stimulation protocols for 2h and LIDs rated. Continuous stimulation with a short duration optical pulse (1-5ms) enhanced LIDs. This effect was blocked by the general muscarinic acetylcholine receptor (mAChR) antagonist atropine indicating it was mAChR-mediated. By contrast, continuous stimulation with a longer duration optical pulse (20ms to 1s) reduced LIDs to a similar extent as nicotine treatment (~50%). The general nicotinic acetylcholine receptor (nAChR) antagonist mecamylamine blocked the decline in LIDs with longer optical pulses showing it was nAChR-mediated. None of the stimulation regimens altered LIDs in control-eYFP mice. Lesion-induced motor impairment was not affected by optical stimulation indicating that cholinergic transmission selectively regulates LIDs. Longer pulse stimulation increased the number of c-Fos expressing ChAT neurons, suggesting that changes in this immediate early gene may be involved. These results demonstrate that striatal cholinergic interneurons play a critical role in LIDs and support the idea that nicotine treatment reduces LIDs via nAChR desensitization. PMID:26921469

  13. Electrogenic NBCe1 (SLC4A4), but not electroneutral NBCn1 (SLC4A7), cotransporter undergoes cholinergic-stimulated endocytosis in salivary ParC5 cells

    PubMed Central

    Perry, Clint; Quissell, David O.; Reyland, Mary E.; Grichtchenko, Irina I.

    2008-01-01

    Cholinergic agonists are major stimuli for fluid secretion in parotid acinar cells. Saliva bicarbonate is essential for maintaining oral health. Electrogenic and electroneutral Na+-HCO3− cotransporters (NBCe1 and NBCn1) are abundant in parotid glands. We previously reported that angiotensin regulates NBCe1 by endocytosis in Xenopus oocytes. Here, we studied cholinergic regulation of NBCe1 and NBCn1 membrane trafficking by confocal fluorescent microscopy and surface biotinylation in parotid epithelial cells. NBCe1 and NBCn1 colocalized with E-cadherin monoclonal antibody at the basolateral membrane (BLM) in polarized ParC5 cells. Inhibition of constitutive recycling with the carboxylic ionophore monensin or the calmodulin antagonist W-13 caused NBCe1 to accumulate in early endosomes with a parallel loss from the BLM, suggesting that NBCe1 is constitutively endocytosed. Carbachol and PMA likewise caused redistribution of NBCe1 from BLM to early endosomes. The PKC inhibitor, GF-109203X, blocked this redistribution, indicating a role for PKC. In contrast, BLM NBCn1 was not downregulated in parotid acinar cells treated with constitutive recycling inhibitors, cholinergic stimulators, or PMA. We likewise demonstrate striking differences in regulation of membrane trafficking of NBCe1 vs. NBCn1 in resting and stimulated cells. We speculate that endocytosis of NBCe1, which coincides with the transition to a steady-state phase of stimulated fluid secretion, could be a part of acinar cell adjustment to a continuous secretory response. Stable association of NBCn1 at the membrane may facilitate constitutive uptake of HCO3− across the BLM, thus supporting HCO3− luminal secretion and/or maintaining acid-base homeostasis in stimulated cells. PMID:18815229

  14. Impact of a deletion of the full-length and short isoform of p75NTR on cholinergic innervation and the population of postmitotic doublecortin positive cells in the dentate gyrus

    PubMed Central

    Poser, Robert; Dokter, Martin; von Bohlen und Halbach, Viola; Berger, Stefan M.; Busch, Ruben; Baldus, Marian; Unsicker, Klaus; von Bohlen und Halbach, Oliver

    2015-01-01

    Analyses of mice carrying a deletion of the pan-neurotrophin receptor p75NTR have allowed identifying p75NTR as an important structural regulator of the hippocampus. Most of the previous analyses were done using p75NTRExIII knockout mice which still express the short isoform of p75NTR. To scrutinize the role of p75NTR in the hippocampus, we analyzed adult and aged p75NTRExIV knockout mice, in which both, the short and the full-length isoform are deleted. Deletion of these isoforms induced morphological alterations in the adult dentate gyrus (DG), leading to an increase in the thickness of the molecular and granular layer. Based on these observations, we next determined the morphological substrates that might contribute to this phenotype. The cholinergic innervation of the molecular and granular layer of the DG was found to be significantly increased in the knockout mice. Furthermore, adult neurogenesis in the DG was found to be significantly altered with increased numbers of doublecortin (DCX) positive cells and reduced numbers of apoptotic cells in p75NTRExIV knockout mice. However, cell proliferation as measured by phosphohiston H3 (PH3) positive cell numbers was not affected. These morphological alterations (number of DCX-positive cells and increased cholinergic fiber densities) as well as reduced cell death in the DG are likely to contribute to the observed thickening of the granular layer in p75NTRExIV knockout mice. In addition, Sholl-analysis of DCX-positive neurons revealed a higher dendritic complexity and could thus be a possible morphological correlate for the increased thickness of the molecular layer in p75NTR deficient animals. Our data clearly demonstrate that deletion of both, the short and the full-length isoform of p75NTR affects DG morphology, due to alterations of the cholinergic system and an imbalance between neurogenesis and programmed cell death within the subgranular zone. PMID:26074780

  15. Characterization of nicotine binding in mouse brain and comparison with the binding of alpha-bungarotoxin and quinuclidinyl benzilate

    SciTech Connect

    Marks, M.J.; Collins, A.C.

    1982-11-01

    The binding of (/sup 3/H)nicotine to mouse brain has been measured and subsequently compared with the binding of (/sup 125/I)alpha-bungarotoxin (alpha-BTX) and L-(/sup 3/H)quinuclidinyl benzilate (QNB). The binding of nicotine was saturable, reversible, and stereospecific. Although the rates of association and dissociation of nicotine were temperature-dependent, the incubation temperature had no effect on either KD or Bmax. Nicotine binding was unaffected by the addition of NaCl, KCl, CaCl/sub 2/, or MgSO/sub 4/ to the incubation medium. Nicotinic cholinergic agonists were potent inhibitors of nicotine binding; however, nicotinic antagonists were poor inhibitors. The regional distribution of binding was not uniform: midbrain and striatum contained the highest number of receptors, whereas cerebellum had the fewest. Differences in site densities, regional distribution, inhibitor potencies, and thermal denaturation indicated that nicotine binding was not the same as either QNB or alpha-BTX binding, and therefore that receptors for nicotine may represent a unique population of cholinergic receptors.

  16. Intrinsic Cholinergic Neurons in the Hippocampus: Fact or Artifact?

    PubMed Central

    Blusztajn, Jan Krzysztof; Rinnofner, Jasmine

    2016-01-01

    It is generally agreed that hippocampal acetylcholine (ACh) is synthesized and released exclusively from the terminals of the long-axon afferents whose cell bodies reside in the medial septum and diagonal band. The search for intrinsic cholinergic neurons in the hippocampus has a long history; however evidence for the existence of these neurons has been inconsistent, with most investigators failing to detect them using in situ hybridization or immunohistochemical staining of the cholinergic markers, choline acetyltransferase (ChAT) or vesicular acetylcholine transporter (VAChT). Advances in the use of bacterial artificial chromosome (BAC) transgenic mice expressing a reporter protein under the control of the genomic elements of the Chat gene (Chat-BAC mice) have facilitated studies of cholinergic neurons. Such mice show robust and faithful expression of the reporter proteins in all known cholinergic cell populations. The availability of the Chat-BAC mice re-ignited interest in hippocampal cholinergic interneurons, because a small number of such reporter-expressing cells is frequently observed in the hippocampus of these mice. However, to date, attempts to confirm that these neurons co-express the endogenous cholinergic marker ChAT, or release ACh, have been unsuccessful. Without such confirmatory evidence it is best to conclude that there are no cholinergic neurons in the hippocampus. Similar considerations apply to other BAC transgenic lines, whose utility as a discovery tool for cell populations heretofore not known to express the genes of interest encoded by the BACs, must be validated by methods that detect expression of the endogenous genes. PMID:27014052

  17. Acetylcholine receptors and cholinergic ligands: biochemical and genetic aspects in Torpedo californica and Drosophila melanogaster

    SciTech Connect

    Rosenthal, L.S.

    1987-01-01

    This study evaluates the biochemical and genetic aspects of the acetylcholine receptor proteins and cholinergic ligands in Drosophila melanogaster and Torpedo californica. Included are (1) a comparative study of nicotinic ligand-induced cation release from acetylcholine receptors isolated from Torpedo californica and from Drosophila melanogaster, (2) solution studies of the cholinergic ligands, nikethamide and ethamivan, aimed at measuring internal molecular rotational barriers in solvents of different polarity; and (3) the isolation and characterization of the gene(s) for the acetylcholine receptor in Drosophila melasogaster. Acetylcholine receptor proteins isolated from Drosphila melanogaster heads were found to behave kinetically similar (with regards to cholinergic ligand-induced /sup 155/Eu:/sup 3 +/ displacement from prelabeled proteins) to receptor proteins isolated from Torpedo californica electric tissue, providing additional biochemical evidence for the existence of a Drosophila acetylcholine receptor.

  18. Modified expression of peripheral blood lymphocyte muscarinic cholinergic receptors in asthmatic children.

    PubMed

    Cherubini, Emanuela; Tabbì, Luca; Scozzi, Davide; Mariotta, Salvatore; Galli, Elena; Carello, Rossella; Avitabile, Simona; Tayebati, Seyed Koshrow; Amenta, Francesco; De Vitis, Claudia; Mancini, Rita; Ricci, Alberto

    2015-07-15

    Lymphocytes possess an independent cholinergic system. We assessed the expression of muscarinic cholinergic receptors in lymphocytes from 49 asthmatic children and 10 age matched controls using Western blot. We demonstrated that CD4+ and CD8+ T cells expressed M2 and M4 muscarinic receptors which density were significantly increased in asthmatic children in comparison with controls. M2 and M4 receptor increase was strictly related with IgE and fraction of exhaled nitric oxide (FeNO) measurements and with impairment in objective measurements of airway obstruction. Increased lymphocyte muscarinic cholinergic receptor expression may concur with lung cholinergic dysfunction and with inflammatory molecular framework in asthma. PMID:26025056

  19. Local cholinergic and non-cholinergic neural pathways to the rat supraoptic nucleus

    SciTech Connect

    Meeker, M.L.

    1986-01-01

    An estimated two thirds of the input to the supraoptic nucleus of the rat hypothalamus (SON) including a functionally significant cholinergic innervation, arise from local sources of unknown origin. The sources of these inputs were identified utilizing Golgi-Cox, retrograde tracing, choline acetyltransferase immunocytochemistry and anterograde tracing methodologies. Multipolar Golgi impregnated neurons located dorsal and lateral to the SON extend spiney processes into the nucleus. Injections of the retrograde tracers, wheat germ agglutinin or wheat germ agglutinin-horseradish peroxidase, into the SON labeled cells bilaterally in the arcuate nucleus, and ipsilaterally in the lateral hypothalamus, anterior hypothalamus, nucleus of the diagonal band, subfornical organ, medial preoptic area, lateral preoptic area and in the region dorsolateral to the nucleus. Immunocytochemistry for choline acetyltransferase revealed cells within the ventro-caudal portion of cholinergic cell group, Ch4, which cluster dorsolateral to the SON, and extend axon- and dendrite-like processes into the SON. Cells double-labeled by choline acetyltransferase immunocytochemistry and retrograde tracer injections into the SON are localized within the same cholinergic cell group dorsolateral to the SON. Injections of the anterograde tracer, Phaseolus vulgaris-leucoagglutinin, deposited dorsolateral to the SON results in labeled pre-and post-synaptic processes within the SON. The identification and characterization of endogenous immunoglobulin within the SON and other neurons innervating areas lacking a blood-brain barrier established a novel and potentially important system for direct communication of the supraoptic cells with blood-borne constitutents.

  20. Modulation of dopamine release in the striatum by physiologically relevant levels of nicotine.

    PubMed

    Wang, Li; Shang, Shujiang; Kang, Xinjiang; Teng, Sasa; Zhu, Feipeng; Liu, Bin; Wu, Qihui; Li, Mingli; Liu, Wei; Xu, Huadong; Zhou, Li; Jiao, Ruiying; Dou, Haiqiang; Zuo, Panli; Zhang, Xiaoyu; Zheng, Lianghong; Wang, Shirong; Wang, Changhe; Zhou, Zhuan

    2014-01-01

    Striatal dopamine (DA) release can be independently triggered not only by action potentials (APs) in dopaminergic axons but also APs in cholinergic interneurons (ChIs). Nicotine causes addiction by modulating DA release, but with paradoxical findings. Here, we investigate how physiologically relevant levels of nicotine modulate striatal DA release. The optogenetic stimulation of ChIs elicits DA release, which is potently inhibited by nicotine with an IC50 of 28 nM in the dorsal striatum slice. This ChI-driven DA release is predominantly mediated by α6β2* nAChRs. Local electrical stimulus (Estim) activates both dopaminergic axons and ChIs. Nicotine does not affect the AP(DA)-dependent DA release (AP(DA), AP of dopaminergic axon). During burst Estim, nicotine permits the facilitation of DA release by prevention of DA depletion. Our work indicates that cholinergic stimulation-induced DA release is profoundly modulated by physiologically relevant levels of nicotine and resolves the paradoxical observation of nicotine's effects on striatal DA release. PMID:24968237

  1. Apamin-sensitive, small-conductance, calcium-activated potassium channels mediate cholinergic inhibition of chick auditory hair cells.

    PubMed

    Yuhas, W A; Fuchs, P A

    1999-11-01

    Acetylcholine released from efferent neurons in the cochlea causes inhibition of mechanosensory hair cells due to the activation of calcium-dependent potassium channels. Hair cells are known to have large-conductance, "BK"-type potassium channels associated with the afferent synapse, but these channels have different properties than those activated by acetylcholine. Whole-cell (tight-seal) and cell-attached patch-clamp recordings were made from short (outer) hair cells isolated from the chicken basilar papilla (cochlea equivalent). The peptides apamin and charybdotoxin were used to distinguish the calcium-activated potassium channels involved in the acetylcholine response from the BK-type channels associated with the afferent synapse. Differential toxin blockade of these potassium currents provides definitive evidence that ACh activates apamin-sensitive, "SK"-type potassium channels, but does not activate carybdotoxin-sensitive BK channels. This conclusion is supported by tentative identification of small-conductance, calcium-sensitive but voltage-insensitive potassium channels in cell-attached patches. The distinction between these channel types is important for understanding the segregation of opposing afferent and efferent synaptic activity in the hair cell, both of which depend on calcium influx. These different calcium-activated potassium channels serve as sensitive indicators for functionally significant calcium influx in the hair cell. PMID:10573868

  2. A muscarinic cholinergic mechanism underlies activation of the central pattern generator for locust flight.

    PubMed

    Buhl, Edgar; Schildberger, Klaus; Stevenson, Paul A

    2008-07-01

    A central question in behavioural control is how central pattern generators (CPGs) for locomotion are activated. This paper disputes the key role generally accredited to octopamine in activating the CPG for insect flight. In deafferented locusts, fictive flight was initiated by bath application of the muscarinic agonist pilocarpine, the acetylcholine analogue carbachol, and the acetylcholinesterase blocker eserine, but not by nicotine. Furthermore, in addition to octopamine, various other amines including dopamine, tyramine and histamine all induced fictive flight, but not serotonin or the amine-precursor amino acid tyrosine. However, flight initiation was not reversibly blocked by aminergic antagonists, and was still readily elicited by both natural stimulation (wind) and pilocarpine in reserpinized, amine-depleted locusts. By contrast, the muscarinic antagonists atropine and scopolamine reversibly blocked flight initiated by wind, cholinergic agonists, octopamine, and by selective stimulation of a flight-initiating interneurone (TCG). The short delay from TCG stimulation to flight onset suggests that TCG acts directly on the flight CPG, and accordingly that TCG, or its follower cell within the flight generating circuit, is cholinergic. We conclude that acetylcholine acting via muscarinic receptors is the key neurotransmitter in the mechanism underlying the natural activation of the locust flight CPG. Amines are not essential for this, but must be considered as potential neuromodulators for facilitating flight release and tuning the motor pattern. We speculate that muscarinic activation coupled to aminergic facilitation may be a general feature of behavioural control in insects for ensuring conditional recruitment of individual motor programs in accordance with momentary adaptive requirements. PMID:18587129

  3. Muscarinic acetylcholine receptor subtype 4 is essential for cholinergic stimulation of duodenal bicarbonate secretion in mice - relationship to D cell/somatostatin.

    PubMed

    Takeuchi, K; Kita, K; Takahashi, K; Aihara, E; Hayashi, S

    2015-06-01

    We investigated the roles of muscarinic (M) acetylcholine receptor subtype in the cholinergic stimulation of duodenal HCO3(-) secretion using knockout (KO) mice. Wild-type and M1-M5 KO C57BL/6J mice were used. The duodenal mucosa was mounted on an Ussing chamber, and HCO3(-) secretion was measured at pH 7.0 using a pH-stat method in vitro. Carbachol (CCh) or other agents were added to the serosal side. CCh dose-dependently stimulated HCO3(-) secretion in wild-type mice, and this effect was completely inhibited in the presence of atropine. The HCO3(-) response to CCh in wild-type mice was also inhibited by pirenzepine (M1 antagonist), 4DAMP (M3 antagonist), and tropicamide (M4 antagonist), but not by methoctramine (M2 antagonist). CCh stimulated HCO3(-) secretion in M2 and M5 KO animals as effectively as in WT mice; however, this stimulatory effect was significantly attenuated in M1, M3, and M4 KO mice. The decrease observed in the CCh-stimulated HCO3(-) response in M4 KO mice was reversed by the co-application of CYN154806, a somatostatin receptor type 2 (SST2) antagonist. Octreotide (a somatostatin analogue) decreased the basal and CCh-stimulated secretion of HCO3(-) in wild-type mice. The co-localized expression of somatostatin and M4 receptors was confirmed immunohistologically in the duodenum. We concluded that the duodenal HCO3(-) response to CCh was directly mediated by M1/M3 receptors and indirectly modified by M4 receptors. The activation of M4 receptors was assumed to inhibit the release of somatostatin from D cells and potentiate the HCO3(-) response by removing the negative influence of somatostatin via the activation of SST2 receptors. PMID:26084221

  4. Nitrosamines as nicotinic receptor ligands.

    PubMed

    Schuller, Hildegard M

    2007-05-30

    Nitrosamines are carcinogens formed in the mammalian organism from amine precursors contained in food, beverages, cosmetics and drugs. The potent carcinogen, NNK, and the weaker carcinogen, NNN, are nitrosamines formed from nicotine. Metabolites of the nitrosamines react with DNA to form adducts responsible for genotoxic effects. We have identified NNK as a high affinity agonist for the alpha7 nicotinic acetylcholine receptor (alpha7nAChR) whereas NNN bound with high affinity to epibatidine-sensitive nAChRs. Diethylnitrosamine (DEN) bound to both receptors but with lower affinity. High levels of the alpha7nAChR were expressed in human small cell lung cancer (SCLC) cell lines and in hamster pulmonary neuroendocrine cells (PNECs), which serve as a model for the cell of origin of human SCLC. Exposure of SCLC or PNECs to NNK or nicotine increased expression of the alpha7nAChR and caused influx of Ca(2+), activation of PKC, Raf-1, ERK1/2, and c-myc, resulting in the stimulation of cell proliferation. Signaling via the alpha7nAChR was enhanced when cells were maintained in an environment of 10-15% CO(2) similar to that in the diseased lung. Hamsters with hyperoxia-induced pulmonary fibrosis developed neuroendocrine lung carcinomas similar to human SCLC when treated with NNK, DEN, or nicotine. The development of the NNK-induced tumors was prevented by green tea or theophylline. The beta-adrenergic receptor agonist, isoproterenol or theophylline blocked NNK-induced cell proliferation in vitro. NNK and nicotine-induced hyperactivity of the alpha7nAChR/RAF/ERK1/2 pathway thus appears to play a crucial role in the development of SCLC in smokers and could be targeted for cancer prevention. PMID:17459420

  5. Nicotine replacement therapy

    MedlinePlus

    ... If wearing the patch at night causes odd dreams, try sleeping without the patch. People who smoke ... cessation - nicotine replacement; Tobacco - nicotine replacement therapy References American Cancer Society. Guide to quitting smoking. Last revised ...

  6. Isotopic rubidium ion efflux assay for the functional characterization of nicotinic acetylcholine receptors on clonal cell lines

    SciTech Connect

    Lukas, R.J.; Cullen, M.J.

    1988-11-15

    An isotopic rubidium ion efflux assay has been developed for the functional characterization of nicotinic acetylcholine receptors on cultured neurons. This assay first involves the intracellular sequestration of isotopic potassium ion analog by the ouabain-sensitive action of a sodium-potassium ATPase. Subsequently, the release of isotopic rubidium ion through nicotinic acetylcholine receptor-coupled monovalent cation channels is activated by application of nicotinic agonists. Specificity of receptor-mediated efflux is demonstrated by its sensitivity to blockade by nicotinic, but not muscarinic, antagonists. The time course of agonist-mediated efflux, within the temporal limitations of the assay, indicates a slow inactivation of receptor function on prolonged exposure to agonist. Dose-response profiles (i) have characteristic shapes for different nicotinic agonists, (ii) are described by three operationally defined parameters, and (iii) reflect different affinities of agonists for binding sites that control receptor activation and functional inhibition. The rubidium ion efflux assay provides fewer hazards but greater sensitivity and resolution than isotopic sodium or rubidium ion influx assays for functional nicotinic receptors.

  7. Cholinergic regulation of epithelial ion transport in the mammalian intestine

    PubMed Central

    Hirota, C L; McKay, D M

    2006-01-01

    Acetylcholine (ACh) is critical in controlling epithelial ion transport and hence water movements for gut hydration. Here we review the mechanism of cholinergic control of epithelial ion transport across the mammalian intestine. The cholinergic nervous system affects basal ion flux and can evoke increased active ion transport events. Most studies rely on measuring increases in short-circuit current (ISC = active ion transport) evoked by adding ACh or cholinomimetics to intestinal tissue mounted in Ussing chambers. Despite subtle species and gut regional differences, most data indicate that, under normal circumstances, the effect of ACh on intestinal ion transport is mainly an increase in Cl- secretion due to interaction with epithelial M3 muscarinic ACh receptors (mAChRs) and, to a lesser extent, neuronal M1 mAChRs; however, AChR pharmacology has been plagued by a lack of good receptor subtype-selective compounds. Mice lacking M3 mAChRs display intact cholinergically-mediated intestinal ion transport, suggesting a possible compensatory mechanism. Inflamed tissues often display perturbations in the enteric cholinergic system and reduced intestinal ion transport responses to cholinomimetics. The mechanism(s) underlying this hyporesponsiveness are not fully defined. Inflammation-evoked loss of mAChR-mediated control of epithelial ion transport in the mouse reveals a role for neuronal nicotinic AChRs, representing a hitherto unappreciated braking system to limit ACh-evoked Cl- secretion. We suggest that: i) pharmacological analyses should be supported by the use of more selective compounds and supplemented with molecular biology techniques targeting specific ACh receptors and signalling molecules, and ii) assessment of ion transport in normal tissue must be complemented with investigations of tissues from patients or animals with intestinal disease to reveal control mechanisms that may go undetected by focusing on healthy tissue only. PMID:16981004

  8. Reduction of Aggressive Episodes After Repeated Transdermal Nicotine Administration in a Hospitalized Adolescent with Autism Spectrum Disorder

    PubMed Central

    Lewis, Alan S.; Qayyum, Zheala; Koslosky, Kourtney; Picciotto, Marina R.; Volkmar, Fred R.

    2016-01-01

    Aggression remains a major cause of morbidity in patients with autism spectrum disorder (ASD). Current pharmacotherapy for aggression is not always effective and is often associated with morbidity. Nicotinic acetylcholinergic neurotransmission may play a prominent role in ASD pathophysiology based on human and animal studies, and preclinical studies show nicotine administration can reduce aggression-related behaviors. Transdermal nicotine has been used to treat agitation in neuropsychiatric conditions with cholinergic dysfunction. Here we report the use of transdermal nicotine as an adjunctive medication to treat aggression in a hospitalized adolescent with ASD. Nicotine patch was recurrently well tolerated, and reduced the need for emergency medication and restraint. These findings suggest further study of transdermal nicotine for aggression comorbid with ASD is warranted. PMID:25982311

  9. Cholinergic modulation of food and drug satiety and withdrawal

    PubMed Central

    Avena, Nicole M.; Rada, Pedro V.

    2015-01-01

    Although they comprise only a small portion of the neurons in the region, cholinergic interneurons in the dorsal striatum appear to play an important role in the regulation of various appetitive behaviors, in part, through their interactions with mesolimbic dopamine (DA) systems. In this review, we describe studies that suggest that the activity of cholinergic interneurons in the nucleus accumbens (NAc) and cholinergic projections to the ventral tegmental area (VTA) affect feeding behavior. In vivo microdialysis studies in rats have revealed that the cessation of a meal is associated with a rise in acetylcholine (ACh) levels in the NAc. ACh activation will suppress feeding, and this is also associated with an increase in synaptic accumulation of ACh. Further, we discuss how, in addition to their role in the ending of a meal, cholinergic interneurons in the NAc play an integral role in the cessation of drug use. Another cholinergic system involved in different aspects of appetitive behavior is the projection from the pedunculpontine nuclei directly to the VTA. Activation of this system enhances behaviors through activation of the mesolimbic DA system, and antagonism of ACh receptors in the VTA can reduce drug self-administration. Finally, we discuss the role of accumbens ACh in both drug and palatable food withdrawal. Studies reveal that accumbens ACh is increased during withdrawal from several different drugs of abuse (including cocaine, nicotine and morphine). This rise in extracellular levels of ACh, coupled with a decrease in extracellular levels of DA, is believed to contribute to an aversive state, which can manifest as behaviors associated with drug withdrawal. This theory has also been applied to studies of overeating and/or “food addiction,” and the findings suggest a similar imbalance in DA/ACh levels, which is associated with behavioral indications of drug-like withdrawal. In summary, cholinergic neurons play an important role in the modulation of

  10. PRENATAL NICOTINE EXPOSURE SELECTIVELY AFFECTS NICOTINIC RECEPTOR EXPRESSION IN PRIMARY AND ASSOCIATIVE VISUAL CORTICES OF THE FETAL BABOON

    PubMed Central

    Duncan, Jhodie R.; Garland, Marianne; Stark, Raymond I.; Myers, Michael M.; Fifer, William P.; Mokler, David J.; Kinney, Hannah C.

    2014-01-01

    Exposure to nicotine during pregnancy via maternal cigarette smoking is associated with visual deficits in children. This is possibly due to activation of nicotinic acetylcholine receptors (nAChRs) in the occipital cortex which are important in the development of visual mapping. Using a baboon model we explored the effects of prenatal nicotine on parameters in the primary and associated visual cortices. Pregnant baboons were infused with nicotine (0.5 mg/hr, i.v.) or saline from 86 days gestation. At 161 days gestation fetal brains were collected (n=5/group) and the occipital lobe assessed for nAChRs and markers of the serotonergic and catecholaminergic systems using tissue autoradiography and/or high performance liquid chromatography. Neuronal nAChRs and serotonergic markers were expressed in a region and subunit dependent manner. Prenatal nicotine exposure was associated with increased binding for 3H-epibatidine sensitive nAChRs in the primary visual cortex (BA 17) and BA 18, but not BA 19, of the associative visual cortex (p<0.05). Markers of the serotonergic or catecholaminergic systems were not significantly altered. Thus, prenatal nicotine exposure is associated with alterations in the cholinergic system in the occipital lobe which may aid in the explanation of the appearance of visual deficits in children from mothers who smoke during pregnancy. PMID:24903536

  11. Activation of Muscarinic Acetylcholine Receptor Subtype 4 Is Essential for Cholinergic Stimulation of Gastric Acid Secretion: Relation to D Cell/Somatostatin

    PubMed Central

    Takeuchi, Koji; Endoh, Takuya; Hayashi, Shusaku; Aihara, Takeshi

    2016-01-01

    Background/Aim: Muscarinic acetylcholine receptors exist in five subtypes (M1∼M5), and they are widely expressed in various tissues to mediate diverse autonomic functions, including gastric secretion. In the present study, we demonstrated, using M1∼M5 KO mice, the importance of M4 receptors in carbachol (CCh) stimulation of acid secretion and investigated how the secretion is modulated by the activation of M4 receptors. Methods: C57BL/6J mice of wild-type (WT) and M1–M5 KO were used. Under urethane anesthesia, acid secretion was measured in the stomach equipped with an acute fistula. CCh (30 μg/kg) was given subcutaneously (s.c.) to stimulate acid secretion. Atropine or octreotide (a somatostatin analog) was given s.c. 20 min before the administration of CCh. CYN154806 (a somatostatin SST2 receptor antagonist) was given i.p. 20 min before the administration of octreotide or CCh. Results: CCh caused an increase of acid secretion in WT mice, and the effect was totally inhibited by prior administration of atropine. The effect of CCh was similarly observed in the animals lacking M1, M2 or M5 receptors but significantly decreased in M3 or M4 KO mice. CYN154806, the SST2 receptor antagonist, dose-dependently and significantly reversed the decreased acid response to CCh in M4 but not M3 KO mice. Octreotide, the somatostatin analog, inhibited the secretion of acid under CCh-stimulated conditions in WT mice. The immunohistochemical study showed the localization of M4 receptors on D cells in the stomach. Serum somatostatin levels in M4 KO mice were higher than WT mice under basal conditions, while those in WT mice were significantly decreased in response to CCh. Conclusions: These results suggest that under cholinergic stimulation the acid secretion is directly mediated by M3 receptors and indirectly modified by M4 receptors. It is assumed that the activation of M4 receptors inhibits the release of somatostatin from D cells and minimizes the acid inhibitory effect of

  12. Halothane inhibits the cholinergic-receptor-mediated influx of calcium in primary culture of bovine adrenal medulla cells

    SciTech Connect

    Yashima, N.; Wada, A.; Izumi, F.

    1986-04-01

    Adrenal medulla cells are cholinoceptive cells. Stimulation of the acetylcholine receptor causes the influx of Ca to the cells, and Ca acts as the coupler of the stimulus-secretion coupling. In this study, the authors investigated the effects of halothane on the receptor-mediated influx of /sup 45/Ca using cultured bovine adrenal medulla cells. Halothane at clinical concentrations (0.5-2%) inhibited the influx of /sup 45/Ca caused by carbachol, with simultaneous inhibition of catecholamine secretion. The influx of /sup 45/Ca and the secretion of catecholamines caused by K depolarization were inhibited by a large concentration of Mg, which competes with Ca at Ca channels, but not inhibited by halothane. Inhibition of the /sup 45/Ca influx by halothane was not overcome by increase in the carbachol concentration. Inhibition of the /sup 45/Ca influx by halothane was examined in comparison with that caused by a large concentration of Mg by the application of Scatchard analysis as the function of the external Ca concentration. Halothane decreased the maximal influx of /sup 45/Ca without altering the apparent kinetic constant of Ca to Ca channels. On the contrary, a large concentration of Mg increased the apparent kinetic constant without altering the maximal influx of /sup 45/Ca. Based on these findings, the authors suggest that inhibition of the /sup 45/Ca influx by halothane was not due to the direct competitive inhibition of Ca channels, nor to the competitive antagonism of agonist-receptor interaction. As a possibility, halothane seems to inhibit the receptor-mediated activation of Ca channels through the interference of coupling between the receptor and Ca channels.

  13. Crystallization scale purification of α7 nicotinic acetylcholine receptor from mammalian cells using a BacMam expression system

    PubMed Central

    Cheng, Hao; Fan, Chen; Zhang, Si-wei; Wu, Zhong-shan; Cui, Zhi-cheng; Melcher, Karsten; Zhang, Cheng-hai; Jiang, Yi; Cong, Yao; Xu, H Eric

    2015-01-01

    Aim: To report our methods for expression and purification of α7 nicotinic acetylcholine receptor (α7-nAChR), a ligand-gated pentameric ion channel and an important drug target. Methods: α7-nAChRs of 10 different species were cloned into an inducible BacMam vector with an N-terminal tag of a tandem maltose-binding protein (MBP) and a TEV cleavage site. This α7-nAChR fusion receptor was expressed in mammalian HEK293F cells and detected by Western blot. The expression was scaled up to liters. The receptor was purified using amylose resin and size-exclusion chromatography. The quality of the purified receptor was assessed using SDS-PAGE gels, thermal stability analysis, and negative stain electron microscopy (EM). The expression construct was optimized through terminal truncations and site-directed mutagenesis. Results: Expression screening revealed that α7-nAChR from Taeniopygia guttata had the highest expression levels. The fusion receptor was expressed mostly on the cell surface, and it could be efficiently purified using one-step amylose affinity chromatography. One to two milligrams of the optimized α7-nAChR expression construct were purified from one liter of cell culture. The purified α7-nAChR samples displayed high thermal stability with a Tm of 60 °C, which was further enhanced by antagonist binding but decreased in the presence of agonist. EM analysis revealed ring-like structures with a central hydrophilic hole, which was consistent with the pentameric assembly of the α7-nAChR channel. Conclusion: We have established methods for crystallization scale expression and purification of α7-nAChR, which lays a foundation for high-resolution structural studies using X-ray crystallography or single particle cryo-EM analysis. PMID:26073323

  14. Pyramidal cells and cytochrome P450 epoxygenase products in the neurovascular coupling response to basal forebrain cholinergic input.

    PubMed

    Lecrux, Clotilde; Kocharyan, Ara; Sandoe, Claire H; Tong, Xin-Kang; Hamel, Edith

    2012-05-01

    Activation of the basal forebrain (BF), the primary source of acetylcholine (ACh) in the cortex, broadly increases cortical cerebral blood flow (CBF), a response downstream to ACh release. Although endothelial nitric oxide and cholinoceptive GABA (γ-aminobutyric acid) interneurons have been implicated, little is known about the role of pyramidal cells in this response and their possible interaction with astrocytes. Using c-Fos immunohistochemistry as a marker of neuronal activation and laser-Doppler flowmetry, we measured changes in CBF evoked by BF stimulation following pharmacological blockade of c-Fos-identified excitatory pathways, astroglial metabolism, or vasoactive mediators. Pyramidal cells including those that express cyclooxygenase-2 (COX-2) displayed c-Fos upregulation. Glutamate acting via NMDA, AMPA, and mGlu receptors was involved in the evoked CBF response, NMDA receptors having the highest contribution (~33%). In contrast, nonselective and selective COX-2 inhibition did not affect the evoked CBF response (+0.4% to 6.9%, ns). The metabolic gliotoxins fluorocitrate and fluoroacetate, the cytochrome P450 epoxygenase inhibitor MS-PPOH and the selective epoxyeicosatrienoic acids (EETs) antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE) all blocked the evoked CBF response by ~50%. Together, the data demonstrate that the hyperemic response to BF stimulation is largely mediated by glutamate released from activated pyramidal cells and by vasoactive EETs, likely originating from activated astrocytes. PMID:22293985

  15. Interaction of functionally bound vitamins in the distribution and metabolism of (/sup 14/C)nicotinic acid in tissues and blood cells

    SciTech Connect

    Rozanov, A.Ya.; Yakubik, E.Yu.

    1986-03-10

    Leukocytes absorb two orders of magnitude more of labeled nicotinic acid ((/sup 14/C)NA) than erythrocytes (recalculated per cell). The dynamics of the binding of the labeled vitamin by leukocytes is biphasic, with the formation chiefly of (/sup 14/C)-nicotinic coenzymes in the shortest periods after its injection into rats. At the same time, injected thiamine, riboflavin, lipoate, and pantothenate increase the accumulation of labeled metabolites of nicotinate in the blood and leukocytes of rats by a factor of 2.1 and 4.1, respectively. The metabolism of subcutaneously injected (/sup 14/C)NA occurs chiefly in the digestive system, with a pronounced biphasic dynamics of the changes in the content of labeled metabolites in the liver and small intestine, with secretion of substantial amounts of them with the digestive juices. At the same time, functionally bound vitamins introduced increase the incorporation of the total label into liver tissue (to 45% of the introduced dose, versus 33% in the control) and the rise in the content of (/sup 14/C)-pyridine nucleotides. Analogous effects were also observed in the accumulation of labeled metabolites of (/sup 14/C)NA in the membranes of the small intestine.

  16. Layer-specific cholinergic control of human and mouse cortical synaptic plasticity.

    PubMed

    Verhoog, Matthijs B; Obermayer, Joshua; Kortleven, Christian A; Wilbers, René; Wester, Jordi; Baayen, Johannes C; De Kock, Christiaan P J; Meredith, Rhiannon M; Mansvelder, Huibert D

    2016-01-01

    Individual cortical layers have distinct roles in information processing. All layers receive cholinergic inputs from the basal forebrain (BF), which is crucial for cognition. Acetylcholinergic receptors are differentially distributed across cortical layers, and recent evidence suggests that different populations of BF cholinergic neurons may target specific prefrontal cortical (PFC) layers, raising the question of whether cholinergic control of the PFC is layer dependent. Here we address this issue and reveal dendritic mechanisms by which endogenous cholinergic modulation of synaptic plasticity is opposite in superficial and deep layers of both mouse and human neocortex. Our results show that in different cortical layers, spike timing-dependent plasticity is oppositely regulated by the activation of nicotinic acetylcholine receptors (nAChRs) either located on dendrites of principal neurons or on GABAergic interneurons. Thus, layer-specific nAChR expression allows functional layer-specific control of cortical processing and plasticity by the BF cholinergic system, which is evolutionarily conserved from mice to humans. PMID:27604129

  17. Cholinergic hypofunction impairs memory acquisition possibly through hippocampal Arc and BDNF downregulation.

    PubMed

    Gil-Bea, Francisco J; Solas, Maite; Mateos, Laura; Winblad, Bengt; Ramírez, María J; Cedazo-Mínguez, Angel

    2011-09-01

    Recent evidence suggests that activity-regulated cytoskeleton associated protein (Arc) and brain-derived neurotrophic factor (BDNF) are key players in the cellular mechanisms that trigger synaptic changes and memory consolidation. Cholinergic deafferentiation of hippocampus has been largely shown to induce memory impairments in different behavioral tasks. However, the mechanisms underlying cholinergic-induced memory formation remain unclear. The role of hippocampal cholinergic denervation on synaptic consolidation and further acquisition of spatial memory was hereby examined by analyzing Arc and BDNF in standard environment and after behavioral training in Morris water maze (MWM). In standard environment, a cholinergic hypofunction induced by the toxin (192) IgG-saporin led to significant decreases in Arc protein and mRNA as well as in BDNF. Lesioned rats subjected to MWM showed a worse acquisition performance that was reversed after galantamine treatment. Recovery of memory acquisition was accompanied by normalization of Arc and BDNF levels in hippocampus. Stimulation of muscarinic, but not nicotinic receptors, in hippocampal primary neurons caused a rapid induction of Arc production. These data suggest that cholinergic denervation of hippocampus leads to deficits in muscarinic-dependent induction of Arc and a subsequent impairment of spatial memory acquisition. PMID:20865740

  18. CHRFAM7A: a human-specific α7-nicotinic acetylcholine receptor gene shows differential responsiveness of human intestinal epithelial cells to LPS

    PubMed Central

    Dang, Xitong; Eliceiri, Brian P.; Baird, Andrew; Costantini, Todd W.

    2015-01-01

    The human genome contains a unique, distinct, and human-specific α7-nicotinic acetylcholine receptor (α7nAChR) gene [CHRNA7 (gene-encoding α7-nicotinic acetylcholine receptor)] called CHRFAM7A (gene-encoding dup-α7-nicotinic acetylcholine receptor) on a locus of chromosome 15 associated with mental illness, including schizophrenia. Located 5′ upstream from the “wild-type” CHRNA7 gene that is found in other vertebrates, we demonstrate CHRFAM7A expression in a broad range of epithelial cells and sequenced the CHRFAM7A transcript found in normal human fetal small intestine epithelial (FHs) cells to prove its identity. We then compared its expression to CHRNA7 in 11 gut epithelial cell lines, showed that there is a differential response to LPS when compared to CHRNA7, and characterized the CHRFAM7A promoter. We report that both CHRFAM7A and CHRNA7 gene expression are widely distributed in human epithelial cell lines but that the levels of CHRFAM7A gene expression vary up to 5000-fold between different gut epithelial cells. A 3-hour treatment of epithelial cells with 100 ng/ml LPS increased CHRFAM7A gene expression by almost 1000-fold but had little effect on CHRNA7 gene expression. Mapping the regulatory elements responsible for CHRFAM7A gene expression identifies a 1 kb sequence in the UTR of the CHRFAM7A gene that is modulated by LPS. Taken together, these data establish the presence, identity, and differential regulation of the human-specific CHRFAM7A gene in human gut epithelial cells. In light of the fact that CHRFAM7A expression is reported to modulate ligand binding to, and alter the activity of, the wild-type α7nAChR ligand-gated pentameric ion channel, the findings point to the existence of a species-specific α7nAChR response that might regulate gut epithelial function in a human-specific fashion.—Dang, X., Eliceiri, B. P., Baird, A., Costantini, T. W. CHRFAM7A: a human-specific α7-nicotinic acetylcholine receptor gene shows differential

  19. Neonatal Nicotine Exposure Impairs Development of Auditory Temporal Processing

    PubMed Central

    Sun, Wei; Hansen, Anna; Zhang, Liyan; Lu, Jianzhong; Stolzberg, Daniel; Kraus, Kari Suzanne

    2008-01-01

    Accurate temporal processing of sound is essential for detecting word structures in speech. Maternal smoking affects speech processing in newborns and may influence child language development; however, it is unclear how neonatal exposure to nicotine, present in cigarettes, affects the normal development of temporal processing. The present study used the gap-induced prepulse inhibition (gap-PPI) of the acoustic startle response to investigate the effects of neonatal nicotine exposure on the normal development of gap detection, a behavioral testing procedure of auditory temporal resolution. Neonatal rats were injected twice per day with saline (control), 1 mg/kg nicotine (N-1mg) or 5 mg/kg nicotine (N-5mg) from postnatal day 8 to 12 (P8–P12). During the first month after birth, rats showed poor gap-PPI in all three groups. At P45 and P60, gap-PPI in control rats improved significantly, whereas rats exposed to nicotine exhibited less improvement. At P60, the gap-detection threshold in the N-5mg group was significantly higher than in the control group, suggesting that neonatal nicotine exposure affects the normal development of gap detection acuity. Additionally, 1 hour after receiving an acute nicotine injection (1 mg/kg), gap-PPI recorded in adult rats from the N-5mg group showed a temporary significant improvement. These results suggest that neonatal nicotine exposure reduces gap-PPI implying an impairment of the normal development of auditory temporal processing by inducing changes in cholinergic systems. PMID:18801421

  20. Ligand-binding assays for cyanobacterial neurotoxins targeting cholinergic receptors.

    PubMed

    Aráoz, Rómulo; Vilariño, Natalia; Botana, Luis M; Molgó, Jordi

    2010-07-01

    Toxic cyanobacterial blooms are a threat to public health because of the capacity of some cyanobacterial species to produce potent hepatotoxins and neurotoxins. Cyanobacterial neurotoxins are involved in the rapid death of wild and domestic animals by targeting voltage gated sodium channels and cholinergic synapses, including the neuromuscular junction. Anatoxin-a and its methylene homologue homoanatoxin-a are potent agonists of nicotinic acetylcholine receptors. Since the structural determination of anatoxin-a, several mass spectrometry-based methods have been developed for detection of anatoxin-a and, later, homoanatoxin-a. Mass spectrometry-based techniques provide accuracy, precision, selectivity, sensitivity, reproducibility, adequate limit of detection, and structural and quantitative information for analyses of cyanobacterial anatoxins from cultured and environmental cyanobacterial samples. However, these physicochemical techniques will only detect known toxins for which toxin standards are commercially available, and they require highly specialized laboratory personnel and expensive equipment. Receptor-based assays are functional methods that are based on the mechanism of action of a class of toxins and are thus, suitable tools for survey of freshwater reservoirs for cyanobacterial anatoxins. The competition between cyanobacterial anatoxins and a labelled ligand for binding to nicotinic acetylcholine receptors is measured radioactively or non-radioactively providing high-throughput screening formats for routine detection of this class of neurotoxins. The mouse bioassay is the method of choice for marine toxin monitoring, but has to be replaced by fully validated functional methods. In this paper we review the ligand-binding assays developed for detection of cyanobacterial and algal neurotoxins targeting the nicotinic acetylcholine receptors and for high-throughput screening of novel nicotinic agents. PMID:20238109

  1. Activation of α2A-Containing Nicotinic Acetylcholine Receptors Mediates Nicotine-Induced Motor Output in Embryonic Zebrafish

    PubMed Central

    Menelaou, Evdokia; Udvadia, Ava J.; Tanguay, Robert L.; Svoboda, Kurt R.

    2014-01-01

    It is well established that cholinergic signaling has critical roles during central nervous system development. In physiological and behavioral studies, activation of nicotinic acetylcholine receptors has been implicated in mediating cholinergic signaling. In developing spinal cord, cholinergic transmission is associated with neural circuits responsible for producing locomotor behaviors. In this study, we investigated the expression pattern of the α2A nAChR subunit as evidence from others suggested it could be expressed by spinal neurons. In situ hybridization and immunohistochemistry revealed that the α2A nAChR subunits are expressed in spinal Rohon-Beard (RB) neurons and olfactory sensory neurons in young embryos. In order to examine the functional role of the α2A nAChR subunit during embryogenesis, we blocked its expression using antisense modified oligonucleotides. Blocking the expression of α2A nAChR subunits had no effect on spontaneous motor activity. However, it did alter the embryonic nicotine-induced motor output. This reduction in motor activity was not accompanied by defects in neuronal and muscle elements associated with the motor output. Moreover, the anatomy and functionality of RB neurons was normal even in the absence of the α2A nAChR subunit. Thus, we propose that α2A-containing nAChR are dispensable for normal RB development. However, in the context of nicotine-induced motor output, α2A-containing nAChRs on RB neurons provide the substrate that nicotine acts upon to induce the motor output. These findings also indicate that functional neuronal nAChRs are present within spinal cord at the time when locomotor output in zebrafish first begins to manifest itself. PMID:24738729

  2. Characterization of Channelrhodopsin and Archaerhodopsin in Cholinergic Neurons of Cre-Lox Transgenic Mice

    PubMed Central

    Hedrick, Tristan; Danskin, Bethanny; Larsen, Rylan S.; Ollerenshaw, Doug; Groblewski, Peter; Valley, Matthew; Olsen, Shawn; Waters, Jack

    2016-01-01

    The study of cholinergic signaling in the mammalian CNS has been greatly facilitated by the advent of mouse lines that permit the expression of reporter proteins, such as opsins, in cholinergic neurons. However, the expression of opsins could potentially perturb the physiology of opsin-expressing cholinergic neurons or mouse behavior. Indeed, the published literature includes examples of cellular and behavioral perturbations in preparations designed to drive expression of opsins in cholinergic neurons. Here we investigate expression of opsins, cellular physiology of cholinergic neurons and behavior in two mouse lines, in which channelrhodopsin-2 (ChR2) and archaerhodopsin (Arch) are expressed in cholinergic neurons using the Cre-lox system. The two mouse lines were generated by crossing ChAT-Cre mice with Cre-dependent reporter lines Ai32(ChR2-YFP) and Ai35(Arch-GFP). In most mice from these crosses, we observed expression of ChR2 and Arch in only cholinergic neurons in the basal forebrain and in other putative cholinergic neurons in the forebrain. In small numbers of mice, off-target expression occurred, in which fluorescence did not appear limited to cholinergic neurons. Whole-cell recordings from fluorescently-labeled basal forebrain neurons revealed that both proteins were functional, driving depolarization (ChR2) or hyperpolarization (Arch) upon illumination, with little effect on passive membrane properties, spiking pattern or spike waveform. Finally, performance on a behavioral discrimination task was comparable to that of wild-type mice. Our results indicate that ChAT-Cre x reporter line crosses provide a simple, effective resource for driving indicator and opsin expression in cholinergic neurons with few adverse consequences and are therefore an valuable resource for studying the cholinergic system. PMID:27243816

  3. Physical urticarias and cholinergic urticaria.

    PubMed

    Abajian, Marina; Schoepke, Nicole; Altrichter, Sabine; Zuberbier, Torsten; Zuberbier, H C Torsten; Maurer, Marcus

    2014-02-01

    Physical urticarias are a unique subgroup of chronic urticaria in which urticarial responses can be reproducibly induced by different specific physical stimuli acting on the skin. These conditions include urticaria factitia/symptomatic dermographism, delayed pressure urticaria, cold contact urticaria, heat contact urticaria, solar urticaria, and vibratory urticaria/angioedema. Physical urticarias and cholinergic urticarias are diagnosed based on the patients' history and provocation tests including trigger threshold testing where possible. Treatment is mainly symptomatic. Many patients benefit from avoiding eliciting triggers, and desensitization to these triggers can be helpful in some physical urticarias and in cholinergic urticaria. PMID:24262690

  4. Localized low-level re-expression of high-affinity mesolimbic nicotinic acetylcholine receptors restores nicotine-induced locomotion but not place conditioning.

    PubMed

    Mineur, Y S; Brunzell, D H; Grady, S R; Lindstrom, J M; McIntosh, J M; Marks, M J; King, S L; Picciotto, M R

    2009-04-01

    High-affinity, beta2-subunit-containing (beta2*) nicotinic acetylcholine receptors (nAChRs) are essential for nicotine reinforcement; however, these nAChRs are found on both gamma-aminobutyric acid (GABA) and dopaminergic (DA) neurons in the ventral tegmental area (VTA) and also on terminals of glutamatergic and cholinergic neurons projecting from the pedunculopontine tegmental area and the laterodorsal tegmental nucleus. Thus, systemic nicotine administration stimulates many different neuronal subtypes in various brain nuclei. To identify neurons in which nAChRs must be expressed to mediate effects of systemic nicotine, we investigated responses in mice with low-level, localized expression of beta2* nAChRs in the midbrain/VTA. Nicotine-induced GABA and DA release were partially rescued in striatal synaptosomes from transgenic mice compared with tissue from beta2 knockout mice. Nicotine-induced locomotor activation, but not place preference, was rescued in mice with low-level VTA expression, suggesting that low-level expression of beta2* nAChRs in DA neurons is not sufficient to support nicotine reward. In contrast to control mice, transgenic mice with low-level beta2* nAChR expression in the VTA showed no increase in overall levels of cyclic AMP response element-binding protein (CREB) but did show an increase in CREB phosphorylation in response to exposure to a nicotine-paired chamber. Thus, CREB activation in the absence of regulation of total CREB levels during place preference testing was not sufficient to support nicotine place preference in beta2 trangenic mice. This suggests that partial activation of high-affinity nAChRs in VTA might block the rewarding effects of nicotine, providing a potential mechanism for the ability of nicotinic partial agonists to aid in smoking cessation. PMID:19077117

  5. Nicotinic Acid Adenine Dinucleotide Phosphate Plays a Critical Role in Naive and Effector Murine T Cells but Not Natural Regulatory T Cells.

    PubMed

    Ali, Ramadan A; Camick, Christina; Wiles, Katherine; Walseth, Timothy F; Slama, James T; Bhattacharya, Sumit; Giovannucci, David R; Wall, Katherine A

    2016-02-26

    Nicotinic acid adenine dinucleotide phosphate (NAADP), the most potent Ca(2+) mobilizing second messenger discovered to date, has been implicated in Ca(2+) signaling in some lymphomas and T cell clones. In contrast, the role of NAADP in Ca(2+) signaling or the identity of the Ca(2+) stores targeted by NAADP in conventional naive T cells is less clear. In the current study, we demonstrate the importance of NAADP in the generation of Ca(2+) signals in murine naive T cells. Combining live-cell imaging methods and a pharmacological approach using the NAADP antagonist Ned-19, we addressed the involvement of NAADP in the generation of Ca(2+) signals evoked by TCR stimulation and the role of this signal in downstream physiological end points such as proliferation, cytokine production, and other responses to stimulation. We demonstrated that acidic compartments in addition to the endoplasmic reticulum were the Ca(2+) stores that were sensitive to NAADP in naive T cells. NAADP was shown to evoke functionally relevant Ca(2+) signals in both naive CD4 and naive CD8 T cells. Furthermore, we examined the role of this signal in the activation, proliferation, and secretion of effector cytokines by Th1, Th2, Th17, and CD8 effector T cells. Overall, NAADP exhibited a similar profile in mediating Ca(2+) release in effector T cells as in their counterpart naive T cells and seemed to be equally important for the function of these different subsets of effector T cells. This profile was not observed for natural T regulatory cells. PMID:26728458

  6. Astrocyte Intermediaries of Septal Cholinergic Modulation in the Hippocampus.

    PubMed

    Pabst, Milan; Braganza, Oliver; Dannenberg, Holger; Hu, Wen; Pothmann, Leonie; Rosen, Jurij; Mody, Istvan; van Loo, Karen; Deisseroth, Karl; Becker, Albert J; Schoch, Susanne; Beck, Heinz

    2016-05-18

    The neurotransmitter acetylcholine, derived from the medial septum/diagonal band of Broca complex, has been accorded an important role in hippocampal learning and memory processes. However, the precise mechanisms whereby acetylcholine released from septohippocampal cholinergic neurons acts to modulate hippocampal microcircuits remain unknown. Here, we show that acetylcholine release from cholinergic septohippocampal projections causes a long-lasting GABAergic inhibition of hippocampal dentate granule cells in vivo and in vitro. This inhibition is caused by cholinergic activation of hilar astrocytes, which provide glutamatergic excitation of hilar inhibitory interneurons. These results demonstrate that acetylcholine release can cause slow inhibition of principal neuronal activity via astrocyte intermediaries. PMID:27161528

  7. Effects of Nicotine Exposure on In Vitro Metabolism of Chlorpyrifos in Male Sprague-Dawley Rats

    SciTech Connect

    Lee, Sookwang; Busby, Andrea L.; Timchalk, Charles; Poet, Torka S.

    2009-01-30

    Chlorpyrifos (CPF) is a common organophosphate (OP) insecticide which is metabolized by CYP450s to the neurotoxic metabolite, chlorpyrifos-oxon (CPF-oxon) and a non-toxic metabolite, 3,5,6-trichloro-2-pyridinol (TCP). The objective of this study was to quantify the effect of repeated in vivo nicotine exposures on CPF in vitro metabolism and marker substrate activities in rats. Male Sprague-Dawley rats were dosed subcutaneously with 1 mg nicotine/kg/, for up to 10 days. Animals showed signs of cholinergic crisis after the initial nicotine doses, but exhibited adaptation after a couple days of treatment. Rats were sacrificed on selected days 4 or 24 hr after the last nicotine-treatment. While CYP450 reduced CO spectra were not different across the treatments, the single nicotine dose group showed a 2-fold increase in CYP2E1 marker substrate (p-nitrophenol) activity 24 hr after a single nicotine treatment compared to saline controls. Conversely, repeated nicotine treatments resulted in decreased EROD marker substrate activity 4 hr after the 7th day of treatment. CPF-oxon Vmax and Km did not show significant changes across the different nicotine treatment groups. The Vmax describing the metabolism of CPF to TCP was increased on all groups (days 1, 7, and 10) 24 hr after nicotine treatment but were unchanged 4 hr after nicotine treatment. Results of this in vitro study suggest that repeated nicotine exposure (i.e., from smoking) may result in altered metabolism of CPF. Future in vivo experiments based on these results will be conducted to ascertain the impact of in vivo nicotine exposures on CPF metabolism in rats.

  8. Tracking the molecular evolution of calcium permeability in a nicotinic acetylcholine receptor.

    PubMed

    Lipovsek, Marcela; Fierro, Angélica; Pérez, Edwin G; Boffi, Juan C; Millar, Neil S; Fuchs, Paul A; Katz, Eleonora; Elgoyhen, Ana Belén

    2014-12-01

    Nicotinic acetylcholine receptors are a family of ligand-gated nonselective cationic channels that participate in fundamental physiological processes at both the central and the peripheral nervous system. The extent of calcium entry through ligand-gated ion channels defines their distinct functions. The α9α10 nicotinic cholinergic receptor, expressed in cochlear hair cells, is a peculiar member of the family as it shows differences in the extent of calcium permeability across species. In particular, mammalian α9α10 receptors are among the ligand-gated ion channels which exhibit the highest calcium selectivity. This acquired differential property provides the unique opportunity of studying how protein function was shaped along evolutionary history, by tracking its evolutionary record and experimentally defining the amino acid changes involved. We have applied a molecular evolution approach of ancestral sequence reconstruction, together with molecular dynamics simulations and an evolutionary-based mutagenesis strategy, in order to trace the molecular events that yielded a high calcium permeable nicotinic α9α10 mammalian receptor. Only three specific amino acid substitutions in the α9 subunit were directly involved. These are located at the extracellular vestibule and at the exit of the channel pore and not at the transmembrane region 2 of the protein as previously thought. Moreover, we show that these three critical substitutions only increase calcium permeability in the context of the mammalian but not the avian receptor, stressing the relevance of overall protein structure on defining functional properties. These results highlight the importance of tracking evolutionarily acquired changes in protein sequence underlying fundamental functional properties of ligand-gated ion channels. PMID:25193338

  9. Tracking the Molecular Evolution of Calcium Permeability in a Nicotinic Acetylcholine Receptor

    PubMed Central

    Lipovsek, Marcela; Fierro, Angélica; Pérez, Edwin G.; Boffi, Juan C.; Millar, Neil S.; Fuchs, Paul A.; Katz, Eleonora; Elgoyhen, Ana Belén

    2014-01-01

    Nicotinic acetylcholine receptors are a family of ligand-gated nonselective cationic channels that participate in fundamental physiological processes at both the central and the peripheral nervous system. The extent of calcium entry through ligand-gated ion channels defines their distinct functions. The α9α10 nicotinic cholinergic receptor, expressed in cochlear hair cells, is a peculiar member of the family as it shows differences in the extent of calcium permeability across species. In particular, mammalian α9α10 receptors are among the ligand-gated ion channels which exhibit the highest calcium selectivity. This acquired differential property provides the unique opportunity of studying how protein function was shaped along evolutionary history, by tracking its evolutionary record and experimentally defining the amino acid changes involved. We have applied a molecular evolution approach of ancestral sequence reconstruction, together with molecular dynamics simulations and an evolutionary-based mutagenesis strategy, in order to trace the molecular events that yielded a high calcium permeable nicotinic α9α10 mammalian receptor. Only three specific amino acid substitutions in the α9 subunit were directly involved. These are located at the extracellular vestibule and at the exit of the channel pore and not at the transmembrane region 2 of the protein as previously thought. Moreover, we show that these three critical substitutions only increase calcium permeability in the context of the mammalian but not the avian receptor, stressing the relevance of overall protein structure on defining functional properties. These results highlight the importance of tracking evolutionarily acquired changes in protein sequence underlying fundamental functional properties of ligand-gated ion channels. PMID:25193338

  10. Linking Cholinergic Interneurons, Synaptic Plasticity, and Behavior during the Extinction of a Cocaine-Context Association.

    PubMed

    Lee, Junuk; Finkelstein, Joel; Choi, Jung Yoon; Witten, Ilana B

    2016-06-01

    Despite the fact that cholinergic interneurons are a key cell type within the nucleus accumbens, a relationship between synaptic plasticity and the in vivo activity of cholinergic interneurons remains to be established. Here, we identify a three-way link between the activity of cholinergic interneurons, synaptic plasticity, and learning in mice undergoing the extinction of a cocaine-context association. We found that activity of cholinergic interneurons regulates extinction learning for a cocaine-context association and generates a sustained reduction in glutamatergic presynaptic strength onto medium spiny neurons. Interestingly, activation of cholinergic interneurons does not support reinforcement learning or plasticity by itself, suggesting that these neurons have a modulatory rather than a reinforcing function. PMID:27210555

  11. Down regulation of the muscarinic cholinergic receptor of the rat prostate following castration

    SciTech Connect

    Shapiro, E.; Miller, A.R.; Lepor, H.

    1985-07-01

    Prostatic secretion is dependent upon the integrity of the endocrine and autonomic nervous systems and is dramatically influenced by muscarinic cholinergic analogs. In this study, the authors have used radioligand receptor binding methods on whole tissue homogenates and slide mounted tissue sections of rat prostate to determine whether androgens regulate the density of muscarinic cholinergic receptors in the prostate. The muscarinic cholinergic receptor binding affinities (Kd) of (/sup 3/H) N-methylscopolamine in prostatic homogenates obtained from intact, castrate, and castrate rats receiving testosterone replacement (castrate + T) were similar (0.07 to 0.10 nM). The muscarinic cholinergic receptor binding capacity decreased 73 per cent following castration. Testosterone administration restored the density of muscarinic cholinergic receptors in castrate rats to intact levels. In order to ensure that the loss of receptor density was not due to a decrease in the epithelial: stromal cell ratio, the number of muscarinic cholinergic receptors per unit area of epithelium was determined in the 3 treatment groups using autoradiography on slide mounted tissue sections. The density of muscarinic cholinergic receptors in a unit area of epithelium was decreased 91 per cent following castration. Testosterone administration restored the density of muscarinic cholinergic receptors in the castrate rats to intact levels. The modulation of neurotransmitter receptors by steroid hormones may be a mechanism by which sex steroids regulate biological responsiveness of target tissues.

  12. Mechanisms of Nicotine Addiction

    SciTech Connect

    McGehee, Daniel

    2002-06-26

    Nicotine reinforces the use of tobacco products primarily through its interaction with specific receptor proteins within the brain's reward centers. A critical step in the process of addiction for many drugs, including nicotine, is the release of the neurotransmitter dopamine. A single nicotine exposure will enhance dopamine levels for hours, however, nicotinic receptors undergo both activation and then desensitization in minutes, which presents an important problem. How does the time course of receptor activity lead to the prolonged release of dopamine? We have found that persistent modulation of both inhibitory and excitatory synaptic connections by nicotine underlies the sustained increase in dopamine release. Because these inputs express different types of nicotinic receptors there is a coordinated shift in the balance of synaptic inputs toward excitation of the dopamine neurons. Excitatory inputs are turned on while inhibitory inputs are depressed, thereby boosting the brain's reward system.

  13. Mechanisms of Nicotine Addiction

    SciTech Connect

    McGehee, Daniel

    2009-06-26

    Nicotine reinforces the use of tobacco products primarily through its interaction with specific receptor proteins within the brain’s reward centers. A critical step in the process of addiction for many drugs, including nicotine, is the release of the neurotransmitter dopamine. A single nicotine exposure will enhance dopamine levels for hours, however, nicotinic receptors undergo both activation and then desensitization in minutes, which presents an important problem. How does the time course of receptor activity lead to the prolonged release of dopamine? We have found that persistent modulation of both inhibitory and excitatory synaptic connections by nicotine underlies the sustained increase in dopamine release. Because these inputs express different types of nicotinic receptors there is a coordinated shift in the balance of synaptic inputs toward excitation of the dopamine neurons. Excitatory inputs are turned on while inhibitory inputs are depressed, thereby boosting the brain’s reward system.

  14. Pharmacological Intervention of Nicotine Dependence

    PubMed Central

    Jain, Raka; Gupta, Tina

    2013-01-01

    Nicotine dependence is a major cause of mortality and morbidity all over the world. Various medications have been tried to treat nicotine dependence including nicotine replacement therapy, bupropion, and varenicline. A newer venture to nicotine dependence treatment is a nicotine vaccine which is yet to get footsteps in common practice. The present review assimilates various pharmacotherapeutic measures to address nicotine dependence. However, it is to be noted that psychological interventions, when combined with pharmacotherapy, offer the greatest benefits to the patients. PMID:24490153

  15. EFFECTS OF ACUTE AND WEEKLY EPISODIC EXPOSURES TO ANATOXIN-A ON THE MOTOR ACTIVITY OF RATS: COMPARISON WITH NICOTINE.

    EPA Science Inventory

    Anatoxin-a is a potent nicotinic cholinergic agonist, that is produced by many genera of cyanobacteria, and has caused several poisoning episodes of wildlife, livestock, and domestic animals. Cyanobacterial blooms and toxin exposures are likely to occur episodically as environmen...

  16. Expression patterns of nicotinic subunits α2, α7, α8, and β1 affect the kinetics and pharmacology of ACh-induced currents in adult bee olfactory neuropiles.

    PubMed

    Dupuis, Julien Pierre; Gauthier, Monique; Raymond-Delpech, Valérie

    2011-10-01

    Acetylcholine (ACh) is the main excitatory neurotransmitter of the insect brain, where nicotinic acetylcholine receptors (nAChRs) mediate fast cholinergic synaptic transmission. In the honeybee Apis mellifera, nAChRs are expressed in diverse structures including the primary olfactory centers of the brain, the antennal lobes (ALs) and the mushroom bodies (MBs), where they participate in olfactory information processing. To understand the nature and properties of the nAChRs involved in these processes, we performed a pharmacological and molecular characterization of nAChRs on cultured Kenyon cells of the MBs, using whole cell patch-clamp recordings combined with single-cell RT-PCR. In all cells, applications of ACh as well as nicotinic agonists such as nicotine and imidacloprid induced inward currents with fast desensitization. These currents were fully blocked by saturating doses of the antagonists α-bungarotoxin (α-BGT), dihydroxy-β-erythroidine (DHE), and methyllycaconitine (MLA) (MLA ≥ α-BGT ≥ DHE). Molecular analysis of ACh-responding cells revealed that of the 11 nicotinic receptor subunits encoded within the honeybee genome, α2, α8, and β1 subunits were expressed in adult Kenyon cells. Comparison with the expression pattern of adult AL cells revealed the supplementary presence of subunit α7, which could be responsible for the kinetic and pharmacological differences observed when comparing ACh-induced currents from AL and Kenyon cells. Together, our data demonstrate the existence of functional nAChRs on adult MB Kenyon cells that differ from nAChRs on AL cells in both their molecular composition and pharmacological properties, suggesting that changing receptor subsets could mediate different processing functions depending on the brain structure within the olfactory pathway. PMID:21734106

  17. Diminished trkA receptor signaling reveals cholinergic-attentional vulnerability of aging

    PubMed Central

    Parikh, Vinay; Howe, William M.; Welchko, Ryan M.; Naughton, Sean X.; D'Amore, Drew E.; Han, Daniel H.; Deo, Monika; Turner, David L.; Sarter, Martin

    2012-01-01

    The cellular mechanisms underlying the exceptional vulnerability of the basal forebrain (BF) cholinergic neurons during pathological aging have remained elusive. Here we employed an adeno-associated viral vector-based RNA interference (AAV-RNAi) strategy to suppress the expression of trkA receptors by cholinergic neurons in the nucleus basalis of Meynert/ substantia innominata (nMB/SI) of adult and aged rats. Suppression of trkA receptor expression impaired attentional performance selectively in aged rats. Performance correlated with trkA levels in the nMB/SI. TrkA knockdown neither affected nMB/SI cholinergic cell counts nor the decrease in cholinergic cell size observed in aged rats. However, trkA suppression augmented an age-related decrease in the density of cortical cholinergic processes and attenuated the capacity of cholinergic neurons to release ACh. The capacity of cortical synapses to release acetylcholine (ACh) in vivo was also lower in aged/trkA-AAV-infused rats than in aged or young controls, and it correlated with their attentional performance. Furthermore, age-related increases in cortical proNGF and p75 receptor levels interacted with the vector-induced loss of trkA receptors to shift NGF signaling toward p75-mediated suppression of the cholinergic phenotype, thereby attenuating cholinergic function and impairing attentional performance. These effects model the abnormal trophic regulation of cholinergic neurons and cognitive impairments in patients with early Alzheimer's disease. This rat model is useful for identifying the mechanisms rendering aging cholinergic neurons vulnerable as well as for studying the neuropathological mechanisms that are triggered by disrupted trophic signaling. PMID:23228124

  18. Mental Stress in Atopic Dermatitis – Neuronal Plasticity and the Cholinergic System Are Affected in Atopic Dermatitis and in Response to Acute Experimental Mental Stress in a Randomized Controlled Pilot Study

    PubMed Central

    Peters, Eva Milena Johanne; Michenko, Anna; Kupfer, Jörg; Kummer, Wolfgang; Wiegand, Silke; Niemeier, Volker; Potekaev, Nikolay; Lvov, Andrey; Gieler, Uwe

    2014-01-01

    Rationale In mouse models for atopic dermatitis (AD) hypothalamus pituitary adrenal axis (HPA) dysfunction and neuropeptide-dependent neurogenic inflammation explain stress-aggravated flares to some extent. Lately, cholinergic signaling has emerged as a link between innate and adaptive immunity as well as stress responses in chronic inflammatory diseases. Here we aim to determine in humans the impact of acute stress on neuro-immune interaction as well as on the non-neuronal cholinergic system (NNCS). Methods Skin biopsies were obtained from 22 individuals (AD patients and matched healthy control subjects) before and after the Trier social stress test (TSST). To assess neuro-immune interaction, nerve fiber (NF)-density, NF-mast cell contacts and mast cell activation were determined by immunohistomorphometry. To evaluate NNCS effects, expression of secreted mammal Ly-6/urokinase-type plasminogen activator receptor-related protein (SLURP) 1 and 2 (endogenous nicotinic acetylcholine receptor ligands) and their main corresponding receptors were assessed by quantitative RT-PCR. Results With respect to neuro-immune interaction we found higher numbers of NGF+ dermal NF in lesional compared to non-lesional AD but lower numbers of Gap43+ growing NF at baseline. Mast cell-NF contacts correlated with SCORAD and itch in lesional skin. With respect to the NNCS, nicotinic acetylcholine receptor α7 (α7nAChR) mRNA was significantly lower in lesional AD skin at baseline. After TSST, PGP 9.5+ NF numbers dropped in lesional AD as did their contacts with mast cells. NGF+ NF now correlated with SCORAD and mast cell-NF contacts with itch in non-lesional skin. At the same time, SLURP-2 levels increased in lesional AD skin. Conclusions In humans chronic inflammatory and highly acute psycho-emotional stress interact to modulate cutaneous neuro-immune communication and NNCS marker expression. These findings may have consequences for understanding and treatment of chronic inflammatory

  19. Activation of nicotinic acetylcholine receptors increases the rate of fusion of cultured human myoblasts.

    PubMed Central

    Krause, R M; Hamann, M; Bader, C R; Liu, J H; Baroffio, A; Bernheim, L

    1995-01-01

    1. Fusion of myogenic cells is important for muscle growth and repair. The aim of this study was to examine the possible involvement of nicotinic acetylcholine receptors (nAChR) in the fusion process of myoblasts derived from postnatal human satellite cells. 2. Acetylcholine-activated currents (ACh currents) were characterized in pure preparations of freshly isolated satellite cells, proliferating myoblasts, myoblasts triggered to fuse and myotubes, using whole-cell and single-channel voltage clamp recordings. Also, the effect of cholinergic agonists on myoblast fusion was tested. 3. No nAChR were observed in freshly isolated satellite cells. nAChR were first observed in proliferating myoblasts, but ACh current densities increased markedly only just before fusion. At that time most mononucleated myoblasts had ACh current densities similar to those of myotubes. ACh channels had similar properties at all stages of myoblast maturation. 4. The fraction of myoblasts that did not fuse under fusion-promoting conditions had no ACh current and thus resembled freshly isolated satellite cells. 5. The rate of myoblast fusion was increased by carbachol, an effect antagonized by alpha-bungarotoxin, curare and decamethonium, but not by atropine, indicating that nAChR were involved. Even though a prolonged exposure to carbachol led to desensitization, a residual ACh current persisted after several days of exposure to the nicotinic agonist. 6. Our observations suggest that nAChR play a role in myoblast fusion and that part of this role is mediated by the flow of ions through open ACh channels. Images Figure 1 Figure 2 Figure 3 PMID:8788942

  20. Evaluation of the Nicotinic Acetylcholine Receptor-Associated Proteome at Baseline and Following Nicotine Exposure in Human and Mouse Cortex.

    PubMed

    McClure-Begley, Tristan D; Esterlis, Irina; Stone, Kathryn L; Lam, TuKiet T; Grady, Sharon R; Colangelo, Christopher M; Lindstrom, Jon M; Marks, Michael J; Picciotto, Marina R

    2016-01-01

    Nicotinic acetylcholine receptors (nAChRs) support the initiation and maintenance of smoking, but the long-term changes occurring in the protein complex as a result of smoking and the nicotine in tobacco are not known. Human studies and animal models have also demonstrated that increasing cholinergic tone increases behaviors related to depression, suggesting that the nAChR-associated proteome could be altered in individuals with mood disorders. We therefore immunopurified nAChRs and associated proteins for quantitative proteomic assessment of changes in protein-protein interactions of high-affinity nAChRs containing the β2 subunit (β2*-nAChRs) from either cortex of mice treated with saline or nicotine, or postmortem human temporal cortex tissue from tobacco-exposed and nonexposed individuals, with a further comparison of diagnosed mood disorder to control subjects. We observed significant effects of nicotine exposure on the β2*-nAChR-associated proteome in human and mouse cortex, particularly in the abundance of the nAChR subunits themselves, as well as putative interacting proteins that make up core components of neuronal excitability (Na/K ATPase subunits), presynaptic neurotransmitter release (syntaxins, SNAP25, synaptotagmin), and a member of a known nAChR protein chaperone family (14-3-3ζ). These findings identify candidate-signaling proteins that could mediate changes in cholinergic signaling via nicotine or tobacco use. Further analysis of identified proteins will determine whether these interactions are essential for primary function of nAChRs at presynaptic terminals. The identification of differences in the nAChR-associated proteome and downstream signaling in subjects with various mood disorders may also identify novel etiological mechanisms and reveal new treatment targets. PMID:27559543

  1. Evaluation of the Nicotinic Acetylcholine Receptor-Associated Proteome at Baseline and Following Nicotine Exposure in Human and Mouse Cortex

    PubMed Central

    Esterlis, Irina; Stone, Kathryn L.; Grady, Sharon R.; Lindstrom, Jon M.; Marks, Michael J.

    2016-01-01

    Abstract Nicotinic acetylcholine receptors (nAChRs) support the initiation and maintenance of smoking, but the long-term changes occurring in the protein complex as a result of smoking and the nicotine in tobacco are not known. Human studies and animal models have also demonstrated that increasing cholinergic tone increases behaviors related to depression, suggesting that the nAChR-associated proteome could be altered in individuals with mood disorders. We therefore immunopurified nAChRs and associated proteins for quantitative proteomic assessment of changes in protein–protein interactions of high-affinity nAChRs containing the β2 subunit (β2*-nAChRs) from either cortex of mice treated with saline or nicotine, or postmortem human temporal cortex tissue from tobacco-exposed and nonexposed individuals, with a further comparison of diagnosed mood disorder to control subjects. We observed significant effects of nicotine exposure on the β2*-nAChR-associated proteome in human and mouse cortex, particularly in the abundance of the nAChR subunits themselves, as well as putative interacting proteins that make up core components of neuronal excitability (Na/K ATPase subunits), presynaptic neurotransmitter release (syntaxins, SNAP25, synaptotagmin), and a member of a known nAChR protein chaperone family (14-3-3ζ). These findings identify candidate-signaling proteins that could mediate changes in cholinergic signaling via nicotine or tobacco use. Further analysis of identified proteins will determine whether these interactions are essential for primary function of nAChRs at presynaptic terminals. The identification of differences in the nAChR-associated proteome and downstream signaling in subjects with various mood disorders may also identify novel etiological mechanisms and reveal new treatment targets. PMID:27559543

  2. In vitro test of nicotine's permeability through human skin. Risk evaluation and safety aspects.

    PubMed

    Zorin, S; Kuylenstierna, F; Thulin, H

    1999-08-01

    Permeability tests with Franz' diffusion cells and an in vitro test model were made to evaluate the importance of dermal absorption of nicotine as a pathway for intoxication. Studies were carried out to ensure that safety procedures, when spilling nicotine on skin, are sufficient to prevent poisoning. Pure nicotine and nicotine in various concentrations in water or ethanol were applied on human skin or gloves in Franz' cells. Washing was simulated by removing nicotine from skin after 3 or 5 min. Permeation rate (flux) and lag time were calculated and estimated for human skin. Different glove materials were tested for their nicotine breakthrough time. Flux depended on concentration in a non-linear way when nicotine-water solutions were tested. Highest flux was found in 50% w/w nicotine dissolved in water. Solutions with low concentration of nicotine (1% w/w) dissolved in water had a similar permeation rate to 100% nicotine. Flux was found to be low when using ethanol as a vehicle; flux was also pH-dependent. The nicotine-water solution containing acetic acid had the lowest flux. The tests where nicotine was washed away revealed that skin served as a possible nicotine depot, because nicotine concentration in the receptor compartment continued to increase after removing the nicotine from the surface. The length of contact time affected the amount of substance passing the skin, resulting in great difference between 3 and 5 min contact time, 5 min giving higher nicotine concentration and 3 min lower. This emphasizes the importance of washing away nicotine spilled on skin rapidly. Two glove types were tested and they were found to be appropriate in their use with nicotine if changed regularly. PMID:10518466

  3. Potential animal model of multiple chemical sensitivity with cholinergic supersensitivity.

    PubMed

    Overstreet, D H; Miller, C S; Janowsky, D S; Russell, R W

    1996-07-17

    Multiple Chemical Sensitivity (MCS) is a clinical phenomenon in which individuals, after acute or intermittent exposure to one or more chemicals, commonly organophosphate pesticides (OPs), become overly sensitive to a wide variety of chemically-unrelated compounds, which can include ethanol, caffeine and other psychotropic drugs. The Flinders Sensitive Line (FSL) rats were selectively bred to be more sensitive to the OP diisopropylfluorophosphate (DFP) compared to their control counterparts, the Flinders Resistant Line (FRL) rats. The present paper will summarize evidence which indicates that the FSL rats exhibit certain similarities to individuals with MCS. In addition to their greater sensitivity to DFP, the FSL rats are more sensitive to nicotine and the muscarinic agonists arecoline and oxotremorine, suggesting that the number of cholinergic receptors may be increased, a conclusion now supported by biochemical evidence. The FSL rats have also been found to exhibit enhanced responses to a variety of other drugs, including the serotonin agonists m-chlorophenylpiperazine and 8-OH-DPAT, the dopamine antagonist raclopride, the benzodiazepine diazepam, and ethanol. MCS patients report enhanced responses to many of these drugs, indicating some parallels between FSL rats and MCS patients. The FSL rats also exhibit reduced activity and appetite and increased REM sleep relative to their FRL controls. Because these behavioral features and the enhanced cholinergic responses are also observed in human depressives, the FSL rats have been proposed as a genetic animal model of depression. It has also been reported that MCS patients have a greater incidence of depression, both before and after onset of their chemical sensitivities, so cholinergic supersensitivity may be a state predisposing individuals to depressive disorders and/or MCS. Further exploration of the commonalities and differences between MCS patients, human depressives, and FSL rats will help to elucidate the

  4. Synaptic connectivity of the cholinergic axons in the olfactory bulb of the cynomolgus monkey

    PubMed Central

    Liberia, Teresa; Blasco-Ibáñez, José Miguel; Nácher, Juan; Varea, Emilio; Lanciego, José Luis; Crespo, Carlos

    2015-01-01

    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 periglomerular cells, which receive axo-somatic and axo-dendritic synapses. In the inframitral region, their main targets are the granule cells, which receive synaptic contacts on their dendritic shafts and spines. Although the cholinergic boutons were frequently found in close vicinity of the dendrites of principal cells, we have not found synaptic contacts on them. From a comparative perspective, our data indicate that the synaptic connectivity of the cholinergic circuits is highly preserved in the OB of macrosmatic and microsmatic mammals. PMID:25852490

  5. Nicotine and sympathetic neurotransmission.

    PubMed

    Haass, M; Kübler, W

    1997-01-01

    Nicotine increases heart rate, myocardial contractility, and blood pressure. These nicotine-induced cardiovascular effects are mainly due to stimulation of sympathetic neurotransmission, as nicotine stimulates catecholamine release by an activation of nicotine acetylcholine receptors localized on peripheral postganglionic sympathetic nerve endings and the adrenal medulla. The nicotinic acetylcholine receptor is a ligand-gated cation channel with a pentameric structure and a central pore with a cation gate, which is essential for ion selectivity and permeability. Binding of nicotine to its extracellular binding site leads to a conformational change of the central pore, which results in the influx of sodium and calcium ions. The resulting depolarization of the sympathetic nerve ending stimulates calcium influx through voltage-dependent N-type calcium channels, which triggers the nicotine-evoked exocytotic catecholamine release. In the isolated perfused guinea-pig heart, cardiac energy depletion sensitizes cardiac sympathetic nerves to the norepinephrine-releasing effect of nicotine, as indicated by a leftward shift of the concentration-response curve, a potentiation of maximum transmitter release, and a delay of the tachyphylaxis of nicotine-evoked catecholamine release. This sensitization was also shown to occur in the human heart under in vitro conditions. Through the intracardiac release of norepinephrine, nicotine induces a beta-adrenoceptor-mediated increase in heart rate and contractility, and an alpha-adrenoceptor-mediated increase in coronary vasomotor tone. The resulting simultaneous increase in oxygen demand and coronary resistance has a detrimental effect on the oxygen balance of the heart, especially in patients with coronary artery disease. Sensitization of the ischemic heart to the norepinephrine-releasing effect of nicotine may be a trigger for acute cardiovascular events in humans, such as acute myocardial infarction and/or life

  6. The role of nicotinic acid metabolites in flushing and hepatotoxicity.

    PubMed

    Stern, Ralph H

    2007-07-01

    Flushing and hepatotoxicity are important adverse effects of nicotinic acid. This article reviews the role of metabolism of nicotinic acid in the production of these side effects. The suggestion that nicotinic acid (NUA) formation produces flushing is traced to a correlation of flushing with NUA C(max) (maximal concentration) and the observation that aspirin inhibits NUA formation and flushing. The former does not establish causation and the latter can be explained by inhibition of prostaglandin formation. Recent characterization of the GPR109A receptor that mediates prostaglandin release by Langerhans cells to produce flushing has shown nicotinic acid, not NUA, is responsible. The suggestion that nicotinamide metabolites produce hepatotoxicity is not supported by any data. The mechanism of hepatotoxicity is unknown and a toxic metabolite of nicotinic acid has not been identified. Different nicotinic acid formulations produce different metabolite patterns due to nonlinear pharmacokinetics, but there is no evidence that these differences have any clinical importance. PMID:21291680

  7. Ventral tegmental area cholinergic mechanisms mediate behavioral responses in the forced swim test

    PubMed Central

    Addy, N.A.; Nunes, E.J.; Wickham, R.J.

    2015-01-01

    Recent studies revealed a causal link between ventral tegmental area (VTA) phasic dopamine (DA) activity and pro-depressive and antidepressant-like behavioral responses in rodent models of depression. Cholinergic activity in the VTA has been demonstrated to regulate phasic DA activity, but the role of VTA cholinergic mechanisms in depression-related behavior is unclear. The goal of this study was to determine whether pharmacological manipulation of VTA cholinergic activity altered behavioral responding in the forced swim test (FST) in rats. Here, male Sprague-Dawley rats received systemic or VTA-specific administration of the acetylcholinesterase inhibitor, physostigmine (systemic; 0.06 or 0.125 mg/kg, intra-cranial; 1 or 2 μg/side), the muscarinic acetylcholine receptor (AChR) antagonist scopolamine (2.4 or 24 μg/side), or the nicotinic AChR antagonist mecamylamine (3 or 30 μg/side), prior to the FST test session. In control experiments, locomotor activity was also examined following systemic and intra-cranial administration of cholinergic drugs. Physostigmine administration, either systemically or directly into the VTA, significantly increased immobility time in FST, whereas physostigmine infusion into a dorsal control site did not alter immobility time. In contrast, VTA infusion of either scopolamine or mecamylamine decreased immobility time, consistent with an antidepressant-like effect. Finally, the VTA physostigmine-induced increase in immobility was blocked by co-administration with scopolamine, but unaltered by co-administration with mecamylamine. These data show that enhancing VTA cholinergic tone and blocking VTA AChRs has opposing effects in FST. Together, the findings provide evidence for a role of VTA cholinergic mechanisms in behavioral responses in FST. PMID:25865152

  8. Ventral tegmental area cholinergic mechanisms mediate behavioral responses in the forced swim test.

    PubMed

    Addy, N A; Nunes, E J; Wickham, R J

    2015-07-15

    Recent studies revealed a causal link between ventral tegmental area (VTA) phasic dopamine (DA) activity and pro-depressive and antidepressant-like behavioral responses in rodent models of depression. Cholinergic activity in the VTA has been demonstrated to regulate phasic DA activity, but the role of VTA cholinergic mechanisms in depression-related behavior is unclear. The goal of this study was to determine whether pharmacological manipulation of VTA cholinergic activity altered behavioral responding in the forced swim test (FST) in rats. Here, male Sprague-Dawley rats received systemic or VTA-specific administration of the acetylcholinesterase inhibitor, physostigmine (systemic; 0.06 or 0.125mg/kg, intra-cranial; 1 or 2μg/side), the muscarinic acetylcholine receptor (AChR) antagonist scopolamine (2.4 or 24μg/side), or the nicotinic AChR antagonist mecamylamine (3 or 30μg/side), prior to the FST test session. In control experiments, locomotor activity was also examined following systemic and intra-cranial administration of cholinergic drugs. Physostigmine administration, either systemically or directly into the VTA, significantly increased immobility time in FST, whereas physostigmine infusion into a dorsal control site did not alter immobility time. In contrast, VTA infusion of either scopolamine or mecamylamine decreased immobility time, consistent with an antidepressant-like effect. Finally, the VTA physostigmine-induced increase in immobility was blocked by co-administration with scopolamine, but unaltered by co-administration with mecamylamine. These data show that enhancing VTA cholinergic tone and blocking VTA AChRs has opposing effects in FST. Together, the findings provide evidence for a role of VTA cholinergic mechanisms in behavioral responses in FST. PMID:25865152

  9. Retinal ganglion cell neuroprotection induced by activation of alpha7 nicotinic acetylcholine receptors.

    PubMed

    Mata, David; Linn, David M; Linn, Cindy L

    2015-12-01

    The α7nAChR agonist, PNU-282987, has previously been shown to have a neuroprotective effect against loss of retinal ganglion cells (RGCs) in an in vivo glaucoma model when the agent was injected into the vitreous chamber of adult Long Evans rat eyes. Here, we characterized the neuroprotective effect of PNU-282987 at the nerve fiber and retinal ganglion cell layer, determined that neuroprotection occurred when the agonist was applied as eye drops and verified detection of the agonist in the retina, using LC/MS/MS. To induce glaucoma-like conditions in adult Long Evans rats, hypertonic saline was injected into the episcleral veins to induce scar tissue and increase intraocular pressure. Within one month, this procedure produced significant loss of RGCs compared to untreated conditions. RGCs were quantified after immunostaining with an antibody against Thy 1.1 and imaged using a confocal microscope. In dose-response studies, concentrations of PNU-282987 were applied to the animal's right eye two times each day, while the left eye acted as an internal control. Eye drops of PNU-282987 resulted in neuroprotection against RGC loss in a dose-dependent manner using concentrations between 100 μM and 2 mM PNU-282987. LC/MS/MS results demonstrated that PNU-282987 was detected in the retina when applied as eye drops, relatively small amounts of PNU-282987 were measured in blood plasma and no PNU-282987 was detected in cardiac tissue. These results support the hypothesis that eye drop application of PNU-282987 can prevent loss of RGCs associated with glaucoma, which can lead to neuroprotective treatments for diseases that involve α7nAChRs. PMID:26239818

  10. A Nicotinic Acetylcholine Receptor Agonist Prevents Loss of Retinal Ganglion Cells in a Glaucoma Model

    PubMed Central

    Iwamoto, Kazuhiro; Birkholz, Patrick; Schipper, Austin; Mata, David; Linn, David M.; Linn, Cindy L.

    2014-01-01

    Purpose. The purpose of this study was to analyze the neuroprotective effect of an α7 nAChR agonist, PNU-282987, using an in vivo model of glaucoma in Long Evans rats. Methods. One eye in each animal was surgically manipulated to induce glaucoma in control untreated animals and in animals that were treated with intravitreal injections of PNU-282987. To induce glaucoma-like conditions, 0.05 mL of 2 M NaCl was injected into the episcleral veins of right eyes in each rat to create scar tissue and increase intraocular pressure. The left eye in each rat acted as an internal control. One month following NaCl injection, rats were euthanized, retinas were removed, flatmounted, fixed, and nuclei were stained with cresyl violet or RGCs were immunostained with an antibody against Thy 1.1 or against Brn3a. Stained nuclei in the RGC layer and labeled RGCs in NaCl-injected retinas were counted and compared with cell counts from untreated retinas in the same animal. Results. NaCl injections into the episcleral veins caused a significant loss of cells by an average of 27.35% (±2.12 SEM) in the RGC layer within 1 month after NaCl injection, which corresponded to a significant loss of RGCs. This loss of RGCs was eliminated if 5 μL of 100 μM PNU-282987 was injected into the right eye an hour before NaCl injection. Conclusions. The results from this study support the hypothesis that the α7 agonist, PNU-282987, has a neuroprotective effect in the rat retina. PNU-282987 may be a viable candidate for future therapeutic treatments of glaucoma. PMID:24458148

  11. Megakaryocytopoiesis in culture: modulation by cholinergic mechanisms.

    PubMed

    Burstein, S A; Adamson, J W; Harker, L A

    1980-05-01

    Treatment of murine bone marrow cultures with the cholinergic agonist carbamylcholine enhanced megakaryocytic colony growth by as much as 65%. In contrast, adrenergic agonists had no such effect. Addition to cultures of dibutyryl cyclic GMP (db-cGMP) also enhanced megakaryocytic colonies up to 50%, whereas dibutyryl cyclic AMP (db-cAMP) had no effect. Sodium nitroprusside and sodium nitrite, putative guanyl cyclase activators, also enhanced colony numbers, as did imidazole, a postulated cGMP phosphodiesterase inhibitor. Preincubation of marrow for two hours with carbamylcholine resulted both an increase in colony numbers (58%) and percent of progenitors in DNA synthesis (48%, compared to 14% for controls) as determined by tritiated thymidine suicide studies. Treatment of mice with the acetylcholinesterase inhibitor neostigmine resulted in an increase in CFU-M/humerus (62%) and percent in DNA synthesis (45%). These data indicate that 1) cholinergic, but not adrenergic, agonists modulate megakaryocytopoiesis in culture; 2) this effect may be mediated by cyclic GMP; and 3) only a brief period of exposure of marrow cells to agonist results in enhancement of megakaryocytic colonies. PMID:6108328

  12. Mitochondrial Transplantation Attenuates Airway Hyperresponsiveness by Inhibition of Cholinergic Hyperactivity

    PubMed Central

    Su, Yuan; Zhu, Liping; Yu, Xiangyuan; Cai, Lei; Lu, Yankai; Zhang, Jiwei; Li, Tongfei; Li, Jiansha; Xia, Jingyan; Xu, Feng; Hu, Qinghua

    2016-01-01

    Increased cholinergic activity has been highlighted in the pathogenesis of airway hyperresponsiveness, and alternations of mitochondrial structure and function appear to be involved in many lung diseases including airway hyperresponsiveness. It is crucial to clarify the cause-effect association between mitochondrial dysfunction and cholinergic hyperactivity in the pathogenesis of airway hyperresponsiveness. Male SD rats and cultured airway epithelial cells were exposed to cigarette smoke plus lipopolysaccharide administration; mitochondria isolated from airway epithelium were delivered into epithelial cells in vitro and in vivo. Both the cigarette smoke plus lipopolysaccharide-induced cholinergic hyperactivity in vitro and the airway hyperresponsiveness to acetylcholine in vivo were reversed by the transplantation of exogenous mitochondria. The rescue effects of exogenous mitochondria were imitated by the elimination of excessive reactive oxygen species or blockage of muscarinic M3 receptor, but inhibited by M receptor enhancer. Mitochondrial transplantation effectively attenuates cigarette smoke plus lipopolysaccharide-stimulated airway hyperresponsiveness through the inhibition of ROS-enhanced epithelial cholinergic hyperactivity. PMID:27279915

  13. Tritiated-nicotine- and /sup 125/I-alpha-bungarotoxin-labeled nicotinic receptors in the interpeduncular nucleus of rats. II. Effects of habenular destruction

    SciTech Connect

    Clarke, P.B.; Hamill, G.S.; Nadi, N.S.; Jacobowitz, D.M.; Pert, A.

    1986-09-15

    The cholinergic innervation of the interpeduncular nucleus (IPN) is wholly extrinsic and is greatly attenuated by bilateral habenular destruction. We describe changes in the labeling of putative nicotinic receptors within this nucleus at 3, 5, or 11 days after bilateral habenular lesions. Adjacent tissue sections of the rat IPN were utilized for /sup 3/H-nicotine and /sup 125/I-alpha-bungarotoxin (/sup 125/I-BTX) receptor autoradiography. Compared to sham-operated controls, habenular destruction significantly reduced autoradiographic /sup 3/H-nicotine labeling in rostral (-25%), intermediate (-13%), and lateral subnuclei (-36%). Labeling in the central subnucleus was unchanged. Loss of labeling was maximal at the shortest survival time (3 days) and did not change thereafter. In order to establish whether this loss was due to a reduction in the number or the affinity of /sup 3/H-nicotine-binding sites, a membrane assay was performed on microdissected IPN tissue from rats that had received surgery 3 days previously. Bilateral habenular lesions produced a 35% reduction of high-affinity /sup 3/H-nicotine-binding sites, with no change in binding affinity. Bilateral habenular lesions reduced /sup 125/I-BTX labeling in the intermediate subnuclei, and a slight increase occurred in the rostral subnucleus. In the lateral subnuclei, /sup 125/I-BTX labeling was significantly reduced (27%) at 3 days but not at later survival times. In view of the known synaptic morphology of the habenulointerpeduncular tract, it is concluded that a subpopulation of /sup 3/H-nicotine binding sites within the IPN is located on afferent axons and/or terminals. This subpopulation, located within rostral, intermediate, and lateral subnuclei, may correspond to presynaptic nicotinic cholinergic receptors. Sites that bind /sup 125/I-BTX may include a presynaptic subpopulation located in the lateral and possibly the intermediate subnuclei.

  14. Blocking mPTP on Neural Stem Cells and Activating the Nicotinic Acetylcholine Receptor α7 Subunit on Microglia Attenuate Aβ-Induced Neurotoxicity on Neural Stem Cells.

    PubMed

    Chen, Qingzhuang; Wang, Kewan; Jiang, Deqi; Wang, Yan; Xiao, Xiaodan; Zhu, Ning; Li, Mingxing; Jia, Siyuan; Wang, Yong

    2016-06-01

    β-Amyloid (Aβ) can stimulate microglia to release a variety of proinflammatory cytokines and induce neurotoxicity. Nicotine has been reported to inhibit TNF-α, IL-1, and ROS production in microglia. Mitochondrial permeability transition pore (mPTP) plays an important role in neurotoxicity as well. Here, we investigated whether activating the microglial α7-nAChR has a neuroprotective role on neural stem cells (NSCs) and the function of mPTP in NSCs in this process. The expression of α7-nAChR in rat NSCs was detected by immunocytochemistry and RT-PCR. The viability of microglia and NSCs was examined by MTT assay. The mitochondrial membrane potential (ΔΨm) and morphological characteristics of NSCs was measured by JC-1 staining and transmission electron microscopy respectively. The distribution of cytochrome c in the subcellular regions of NSCs was visualized by confocal laser scanning microscopy, and the expression levels of cyclophilin D and cleaved caspase-3 were assayed by western blot. The apoptotic rate of NSCs was measured by flow cytometry. The expression of α7-nAChR was detected in microglial cells, but no expression was found in NSCs. The viability of rat microglial cells and NSCs was not affected by reagents or coculture itself. Aβ1-42-mediated microglial activation impaired the morphology and the ΔΨm of mitochondria of NSCs as well as increased cell apoptosis. However, the damage was attenuated when the α7-nAChRs on microglial cells were activated or the mPTPs on NSCs were blocked. Blockade of mPTPs on NSCs and activation of α7-nAChRs on microglia exhibit neuroprotective roles in Aβ-induced neurotoxicity of NSCs. PMID:26875732

  15. The Conqueror Worm: recent advances with cholinergic anthelmintics and techniques excite research for better therapeutic drugs

    PubMed Central

    Martin, R.J.; Puttachary, S.; Buxton, S.K.; Verma, S.; Robertson, A.P.

    2014-01-01

    The following account is based on a review lecture given recently at the British Society of Parasitology. We point out that nematode parasites cause very widespread infections of humans, particularly in economically underdeveloped areas where sanitation and hygiene are not adequate. In the absence of adequate clean water and effective vaccines, control and prophylaxis relies on anthelmintic drugs. Widespread use of anthelmintics to control nematode parasites of animals has given rise to the development of resistance and so there is a concern that similar problems will occur in humans if mass drug administration is continued. Recent research on the cholinergic anthelmintic drugs has renewed enthusiasm for the further development of cholinergic anthelmintics. Here we illustrate the use of three parasite nematode models, Ascaris suum, Oesophagostomum dentatum and Brugia malayi, microfluidic techniques and the Xenopus oocyte expression system for testing and examining the effects of cholinergic anthelmintics. We also show how the combination of derquantel, the selective nematode cholinergic antagonist and abamectin produce increased inhibition of the nicotinic acetylcholine receptors on the nematode body muscle. We are optimistic that new compounds and combinations of compounds can limit the effects of drug resistance, allowing anthelmintics to be continued to be used for effective treatment of human and animal helminth parasites. PMID:24871674

  16. Cholinergic influences on feature binding.

    PubMed

    Botly, Leigh C P; De Rosa, Eve

    2007-04-01

    The binding problem refers to the fundamental challenge of the central nervous system to integrate sensory information registered by multiple brain regions to form a unified neural representation of a stimulus. Human behavioral, neuropsychological, and functional neuroimaging evidence suggests a fundamental role for attention in feature binding; however, its neurochemical basis is currently unknown. This study examined whether acetylcholine (ACh), a neuromodulator that has been implicated in attentional processes, plays a critical role in feature binding. Using a within-subjects pharmacological design and the cholinergic muscarinic antagonist scopolamine, the present experiments demonstrate, in a rat model, a critical role for the cortical muscarinic cholinergic system in feature binding. Specifically, ACh and the attentional resources that it supports are essential for the initial feature binding process but are not required to maintain neural representations of bound stimuli. PMID:17469916

  17. Biodegradation of nicotine by a newly isolated Pseudomonas stutzeri JZD

    NASA Astrophysics Data System (ADS)

    Petricevic, Jelena; Gujanicic, Vera; Radic, Danka; Jovicic Petrovic, Jelena; Jovic, Jelena; Raicevic, Vera

    2013-04-01

    The tobacco-manufacturing process and all activities that use tobacco, produce solid or liquid wastes with high concentrations of nicotine. Nicotine is a significant toxic waste product in tobacco industry. This waste is classified as 'toxic and hazardous' by European Union regulations when the nicotine content exceeds 500 milligrams per kilogram dry weight. Therefore, there is a major environmental requirement to remove nicotine from tobacco wastes. Bioremediation techniques which involve nicotine degradation by microorganisms have attracted attention during the last years, because microorganisms have the potential to reduce nicotine levels in tobacco and to detoxify tobacco wastes. The aim of this study is isolation and identification of nicotine degraded bacteria and optimization of nicotine degradation in laboratory conditions. An aerobic bacterial strain capable of effectively degrading nicotine was isolated from the tobacco industry waste, Serbia. After isolation, the liquid culture was spread onto the solid plates of the nicotine inorganic salt medium using the dilution plate method. Cell morphology of strain was observed by a light microscope and physiological characteristics were determined by Api technique and sequence analyzes of 16S rDNA. This isolate was identified as Pseudomonas stutzeri based on morphology, physiological characteristics, and Apiweb technique. Comparison with sequences available in data library showed the 99% similarity with 16S rDNA gene sequence of the species Pseudomonas stutzeri ( GenBank Acc. No. CP003725). We analyzed the effect of initial nicotine concentration (1g/L, 1.5 g/L, 2.5 g/L) on microbial activity in aim to optimize biodegradation. The effect of cultivation temperature (25°C; 30°C; 37°C) on nicotine degradation by P. stutzeri was evaluated after 24 h of cultivation, with 1.5 g/L nicotine added as the sole carbon source. Effect of biodegradation has depended on initial concentration. During incubation, number of

  18. Neuropharmacology of memory consolidation and reconsolidation: Insights on central cholinergic mechanisms.

    PubMed

    Blake, M G; Krawczyk, M C; Baratti, C M; Boccia, M M

    2014-01-01

    Central cholinergic system is critically involved in all known memory processes. Endogenous acetylcholine release by cholinergic neurons is necessary for modulation of acquisition, encoding, consolidation, reconsolidation, extinction, retrieval and expression. Experiments from our laboratory are mainly focused on elucidating the mechanisms by which acetylcholine modulates memory processes. Blockade of hippocampal alpha-7-nicotinic receptors (α7-nAChRs) with the antagonist methyllycaconitine impairs memory reconsolidation. However, the administration of a α7-nAChR agonist (choline) produce a paradoxical modulation, causing memory enhancement in mice trained with a weak footshock, but memory impairment in animals trained with a strong footshock. All these effects are long-lasting, and depend on the age of the memory trace. This review summarizes and discusses some of our recent findings, particularly regarding the involvement of α7-nAChRs on memory reconsolidation. PMID:24819880

  19. Cholinergic modulation of hippocampal network function

    PubMed Central

    Teles-Grilo Ruivo, Leonor M.; Mellor, Jack R.

    2013-01-01

    Cholinergic septohippocampal projections from the medial septal area to the hippocampus are proposed to have important roles in cognition by modulating properties of the hippocampal network. However, the precise spatial and temporal profile of acetylcholine release in the hippocampus remains unclear making it difficult to define specific roles for cholinergic transmission in hippocampal dependent behaviors. This is partly due to a lack of tools enabling specific intervention in, and recording of, cholinergic transmission. Here, we review the organization of septohippocampal cholinergic projections and hippocampal acetylcholine receptors as well as the role of cholinergic transmission in modulating cellular excitability, synaptic plasticity, and rhythmic network oscillations. We point to a number of open questions that remain unanswered and discuss the potential for recently developed techniques to provide a radical reappraisal of the function of cholinergic inputs to the hippocampus. PMID:23908628

  20. Activation of α7 nicotinic acetylcholine receptors protects potentiated synapses from depotentiation during theta pattern stimulation in the hippocampal CA1 region of rats.

    PubMed

    Galvez, Bryan; Gross, Noah; Sumikawa, Katumi

    2016-06-01

    Long-term potentiation (LTP) shows memory-like consolidation and thus becomes increasingly resistant to disruption by low-frequency stimulation (LFS). However, it is known that nicotine application during LFS uniquely depotentiates consolidated LTP. Here, we investigated how nicotine contributes to the disruption of stabilized LTP in the hippocampal CA1 region. We found that nicotine-induced depotentiation is not due to masking LTP by inducing long-term depression and requires the activation of GluN2A-containing NMDARs. We further examined whether nicotine-induced depotentiation involves the reversal of LTP mechanisms. LTP causes phosphorylation of Ser-831 on GluA1 subunits of AMPARs that increases the single-channel conductance of AMPARs. This phosphorylation remained unchanged after depotentiation. LTP involves the insertion of new AMPARs into the synapse and the internalization of AMPARs is associated with dephosphorylation of Ser-845 on GluA1 and caspase-3 activity. Nicotine-induced depotentiation occurred without dephosphorylation of the Ser-845 and in the presence of a caspase-3 inhibitor. LTP is also accompanied by increased filamentous actin (F-actin), which controls spine size. Nicotine-induced depotentiation was prevented by jasplakinolide, which stabilizes F-actin, suggesting that nicotine depotentiates consolidated LTP by destabilizing F-actin. α7 nicotinic acetylcholine receptor (nAChR) antagonists mimicked the effect of nicotine and selective removal of hippocampal cholinergic input caused depotentiation in the absence of nicotine, suggesting that nicotine depotentiates consolidated LTP by inducing α7 nAChR desensitization. Our results demonstrate a new role for nicotinic cholinergic systems in protecting potentiated synapses from depotentiation by preventing GluN2A-NMDAR-mediated signaling for actin destabilization. PMID:26867505

  1. Biocidal action of chlorhexidine is annulled by nicotinic acid.

    PubMed Central

    Baker, H; Frank, O; DeAngelis, B; Baker, E R

    1994-01-01

    An analytical system comprising a bacterium and a protozoan was used to pinpoint the metabolic lesion whereby chlorhexidine (CLX) produced cell death. Nicotinic acid but not nicotinamide annulled the biocidal action of CLX. The results suggest that CLX may not permit bioconversion of nicotinamide to nicotinic acid to annul the growth inhibition induced by CLX. PMID:7840588

  2. L-theanine inhibits nicotine-induced dependence via regulation of the nicotine acetylcholine receptor-dopamine reward pathway.

    PubMed

    Di, Xiaojing; Yan, Jingqi; Zhao, Yan; Chang, Yanzhong; Zhao, Baolu

    2012-12-01

    In this study, the inhibitory effect of L-theanine, an amino acid derivative of tea, on the rewarding effects of nicotine and its underlying mechanisms of action were studied. We found that L-theanine inhibited the rewarding effects of nicotine in a conditioned place preference (CPP) model of the mouse and reduced the excitatory status induced by nicotine in SH-SY5Y cells to the same extent as the nicotine receptor inhibitor dihydro-beta-erythroidine (DHβE). Further studies using high performance liquid chromatography, western blotting and immunofluorescence staining analyses showed that L-theanine significantly inhibited nicotine-induced tyrosine hydroxylase (TH) expression and dopamine production in the midbrain of mice. L-theanine treatment also reduced the upregulation of the α(4), β(2) and α(7) nicotine acetylcholine receptor (nAChR) subunits induced by nicotine in mouse brain regions that related to the dopamine reward pathway, thus decreasing the number of cells that could react to nicotine. In addition, L-theanine treatment inhibited nicotine-induced c-Fos expression in the reward circuit related areas of the mouse brain. Knockdown of c-Fos by siRNA inhibited the excitatory status of cells but not the upregulation of TH induced by nicotine in SH-SY5Y cells. Overall, the present study showed that L-theanine reduced the nicotine-induced reward effects via inhibition of the nAChR-dopamine reward pathway. These results may offer new therapeutic strategies for treatment of tobacco addiction. PMID:23233221

  3. A genetic rat model of cholinergic hypersensitivity: implications for chemical intolerance, chronic fatigue, and asthma.

    PubMed

    Overstreet, D H; Djuric, V

    2001-03-01

    The fact that only some individuals exposed to environmental chemicals develop chemical intolerance raises the possibility that genetic factors could be contributing factors. The present communication summarizes evidence from a genetic animal model of cholinergic supersensitivity that suggests that an abnormal cholinergic system could be one predisposing genetic factor. The Flinders Sensitive Line (FSL) rats were established by selective breeding for increased responses to an organophosphate. It was subsequently found that these FSL rats were also more sensitive to direct-acting muscarinic agonists and had elevated muscarinic receptors compared to the selectively bred parallel group, the Flinders Resistant Line (FRL) rats, or randomly bred control rats. Increased sensitivity to cholinergic agents has also been observed in several human populations, including individuals suffering from chemical intolerance. Indeed, the FSL rats exhibit certain behavioral characteristics such as abnormal sleep, activity, and appetite that are similar to those reported in these human populations. In addition, the FSL rats have been reported to exhibit increased sensitivity to a variety of other chemical agents. Peripheral tissues, such as intestinal and airway smooth muscle, appear to be more sensitive to both cholinergic agonists and an antigen, ovalbumin. Hypothermia, a centrally mediated response, is more pronounced in the FSL rats after nicotine and alcohol, as well as agents that are selective for the dopaminergic and serotonergic systems. In some cases, the increased sensitivity has been detected in the absence of any changes in the receptors with which the drugs interact (dopamine receptors), while receptor changes have been seen in other cases (nicotine receptors). Therefore, there may be multiple mechanisms underlying the multiple chemical sensitivity-chemical intolerance of the FSL rats. An elucidation of these mechanisms may provide useful clues to those involved in

  4. Activation of endplate nicotinic acetylcholine receptors by agonists.

    PubMed

    Auerbach, Anthony

    2015-10-15

    The interaction of a small molecule made in one cell with a large receptor made in another is the signature event of cell signaling. Understanding the structure and energy changes associated with agonist activation is important for engineering drugs, receptors and synapses. The nicotinic acetylcholine receptor (AChR) is a ∼300kD ion channel that binds the neurotransmitter acetylcholine (ACh) and other cholinergic agonists to elicit electrical responses in the central and peripheral nervous systems. This mini-review is in two sections. First, general concepts of skeletal muscle AChR operation are discussed in terms of energy landscapes for conformational change. Second, adult vs. fetal AChRs are compared with regard to interaction energies between ACh and agonist-site side chains, measured by single-channel electrophysiology and molecular dynamics simulations. The five aromatic residues that form the core of each agonist binding site can be divided into two working groups, a triad (led by αY190) that behaves similarly at all sites and a coupled pair (led by γW55) that has a large influence on affinity only in fetal AChRs. Each endplate AChR has 5 homologous subunits, two of α(1) and one each of β, δ, and either γ (fetal) or ϵ (adult). These nicotinic AChRs have only 2 functional agonist binding sites located in the extracellular domain, at αδ and either αγ or αϵ subunit interfaces. The receptor undergoes a reversible, global isomerization between structures called C and O. The C shape does not conduct ions and has a relatively low affinity for ACh, whereas O conducts cations and has a higher affinity. When both agonist sites are empty (filled only with water) the probability of taking on the O conformation (PO) is low, <10(-6). When ACh molecules occupy the agonist sites the C→O opening rate constant and C↔O gating equilibrium constant increase dramatically. Following a pulse of ACh at the nerve-muscle synapse, the endplate current rises rapidly

  5. Cholinergic Mesopontine Signals Govern Locomotion and Reward through Dissociable Midbrain Pathways.

    PubMed

    Xiao, Cheng; Cho, Jounhong Ryan; Zhou, Chunyi; Treweek, Jennifer B; Chan, Ken; McKinney, Sheri L; Yang, Bin; Gradinaru, Viviana

    2016-04-20

    The mesopontine tegmentum, including the pedunculopontine and laterodorsal tegmental nuclei (PPN and LDT), provides major cholinergic inputs to midbrain and regulates locomotion and reward. To delineate the underlying projection-specific circuit mechanisms, we employed optogenetics to control mesopontine cholinergic neurons at somata and at divergent projections within distinct midbrain areas. Bidirectional manipulation of PPN cholinergic cell bodies exerted opposing effects on locomotor behavior and reinforcement learning. These motor and reward effects were separable via limiting photostimulation to PPN cholinergic terminals in the ventral substantia nigra pars compacta (vSNc) or to the ventral tegmental area (VTA), respectively. LDT cholinergic neurons also form connections with vSNc and VTA neurons; however, although photo-excitation of LDT cholinergic terminals in the VTA caused positive reinforcement, LDT-to-vSNc modulation did not alter locomotion or reward. Therefore, the selective targeting of projection-specific mesopontine cholinergic pathways may offer increased benefit in treating movement and addiction disorders. PMID:27100197

  6. Nicotinic receptor blockade decreases fos immunoreactivity within orexin/hypocretin-expressing neurons of nicotine-exposed rats.

    PubMed

    Simmons, Steven J; Gentile, Taylor A; Mo, Lili; Tran, Fionya H; Ma, Sisi; Muschamp, John W

    2016-11-01

    Tobacco smoking is the leading cause of preventable death in the United States. Nicotine is the principal psychoactive ingredient in tobacco that causes addiction. The structures governing nicotine addiction, including those underlying withdrawal, are still being explored. Nicotine withdrawal is characterized by negative affective and cognitive symptoms that enhance relapse susceptibility, and suppressed dopaminergic transmission from ventral tegmental area (VTA) to target structures underlies behavioral symptoms of nicotine withdrawal. Agonist and partial agonist therapies help 1 in 4 treatment-seeking smokers at one-year post-cessation, and new targets are needed to more effectively aid smokers attempting to quit. Hypothalamic orexin/hypocretin neurons send excitatory projections to dopamine (DA)-producing neurons of VTA and modulate mesoaccumbal DA release. The effects of nicotinic receptor blockade, which is commonly used to precipitate withdrawal, on orexin neurons remain poorly investigated and present an attractive target for intervention. The present study sought to investigate the effects of nicotinic receptor blockade on hypothalamic orexin neurons using mecamylamine to precipitate withdrawal in rats. Separate groups of rats were treated with either chronic nicotine or saline for 7-days at which point effects of mecamylamine or saline on somatic signs and anxiety-like behavior were assessed. Finally, tissue from rats was harvested for immunofluorescent analysis of Fos within orexin neurons. Results demonstrate that nicotinic receptor blockade leads to reduced orexin cell activity, as indicated by lowered Fos-immunoreactivity, and suggest that this underlying cellular activity may be associated with symptoms of nicotine withdrawal as effects were most prominently observed in rats given chronic nicotine. We conclude from this study that orexin transmission becomes suppressed in rats upon nicotinic receptor blockade, and that behavioral symptoms associated

  7. Transcriptional regulation by nicotine in dopaminergic neurons

    PubMed Central

    Henley, Beverley M.; Williams, Brian A.; Srinivasan, Rahul; Cohen, Bruce N.; Xiao, Cheng; Mackey, Elisha D.W.; Wold, Barbara J.; Lester, Henry A.

    2013-01-01

    Dopaminergic neurons in the substantia nigra pars compacta (SNc) degenerate in Parkinson’s disease. These neurons robustly express several nicotinic acetylcholine receptor (nAChR) subtypes. Smoking appears to be neuroprotective for Parkinson’s disease but the mechanism is unknown. To determine whether chronic nicotine-induced changes in gene expression contribute to the neuroprotective effects of smoking, we develop methods to measure the effect of prolonged nicotine exposure on the SNc neuronal transcriptome in an unbiased manner. Twenty neurons were collected using laser-capture microscopy and transcriptional changes were assessed using RNA deep sequencing. These results are the first whole-transcriptome analyses of chronic nicotine treatment in SNc neurons. Overall, 129 genes were significantly regulated: 67 upregulated, 62 downregulated. Nicotine-induced relief of endoplasmic reticulum (ER) stress has been postulated as a potential mechanism for the neuroprotective effects of smoking. Chronic nicotine did not significantly affect the expression of ER stress-related genes, nor of dopamine-related or nAChR genes, but it did modulate expression of 129 genes that could be relevant to the neuroprotective effects of smoking, including genes involved in (1) the ubiquitin–proteasome pathway, (2) cell cycle regulation, (3) chromatin modification, and (4) DNA binding and RNA regulation. We also report preliminary transcriptome data for single-cell dopaminergic and GABAergic neurons isolated from midbrain cultures. These novel techniques will facilitate advances in understanding the mechanisms taking place at the cellular level and may have applications elsewhere in the fields of neuroscience and molecular biology. The results give an emerging picture of the role of nicotine on the SNc and on dopaminergic neurons. PMID:23939186

  8. Nicotinic binding in rat brain: autoradiographic comparison of (/sup 3/H)acetylcholine, (/sup 3/H)nicotine, and (/sup 125/I)-alpha-bungarotoxin

    SciTech Connect

    Clarke, P.B.; Schwartz, R.D.; Paul, S.M.; Pert, C.B.; Pert, A.

    1985-05-01

    Three radioligands have been commonly used to label putative nicotinic cholinoceptors in the mammalian central nervous system: the agonists (/sup 3/H)nicotine and (/sup 3/H)acetylcholine ((/sup 3/H)ACh--in the presence of atropine to block muscarinic receptors), and the snake venom extract, (/sup 125/I)-alpha-bungarotoxin((/sup 125/I)BTX), which acts as a nicotinic antagonist at the neuromuscular junction. Binding studies employing brain homogenates indicate that the regional distributions of both (/sup 3/H)nicotine and (/sup 3/H)ACh differ from that of (/sup 125/I)BTX. The possible relationship between brain sites bound by (/sup 3/H)nicotine and (/sup 3/H)ACh has not been examined directly. The authors have used the technique of autoradiography to produce detailed maps of (/sup 3/H)nicotine, (/sup 3/H)ACh, and (/sup 125/I)BTX labeling; near-adjacent tissue sections were compared at many levels of the rat brain. The maps of high affinity agonist labeling are strikingly concordant, with highest densities in the interpeduncular nucleus, most thalamic nuclei, superior colliculus, medial habenula, presubiculum, cerebral cortex (layers I and III/IV), and the substantia nigra pars compacta/ventral tegmental area. The pattern of (/sup 125/I)BTX binding is strikingly different, the only notable overlap with agonist binding being the cerebral cortex (layer I) and superior colliculus. (/sup 125/I)BTX binding is also dense in the inferior colliculus, cerebral cortex (layer VI), hypothalamus, and hippocampus, but is virtually absent in thalamus. Various lines of evidence suggest that the high affinity agonist-binding sites in brain correspond to nicotinic cholinergic receptors similar to those found at autonomic ganglia; BTX-binding sites may also serve as receptors for nicotine and are possibly related to neuromuscular nicotinic cholinoceptors.

  9. Differential effects of subtype-specific nicotinic acetylcholine receptor agonists on early and late hippocampal LTP.

    PubMed

    Kroker, Katja S; Rast, Georg; Rosenbrock, Holger

    2011-12-01

    Brain nicotinic acetylcholine receptors are involved in several neuropsychiatric disorders, e.g. Alzheimer's and Parkinson's diseases, Tourette's syndrome, schizophrenia, depression, autism, attention deficit hyperactivity disorder, and anxiety. Currently, approaches selectively targeting the activation of specific nicotinic acetylcholine receptors are in clinical development for treatment of memory impairment of Alzheimer's disease patients. These are α4β2 and α7 nicotinic acetylcholine receptor agonists which are believed to enhance cholinergic and glutamatergic neurotransmission, respectively. In order to gain a better insight into the mechanistic role of these two nicotinic acetylcholine receptors in learning and memory, we investigated the effects of the α4β2 nicotinic acetylcholine receptor agonist TC-1827 and the α7 nicotinic acetylcholine receptor partial agonist SSR180711 on hippocampal long-term potentiation (LTP), a widely accepted cellular experimental model of memory formation. Generally, LTP is distinguished in an early and a late form, the former being protein-synthesis independent and the latter being protein-synthesis dependent. TC-1827 was found to increase early LTP in a bell-shaped dose dependent manner, but did not affect late LTP. In contrast, the α7 nicotinic acetylcholine receptor partial agonist SSR180711 showed enhancing effects on both early and late LTP in a bell-shaped manner. Furthermore, SSR180711 not only increased early LTP, but also transformed it into late LTP, which was not observed with the α4β2 nicotinic acetylcholine receptor agonist. Therefore, based on these findings α7 nicotinic acetylcholine receptor (partial) agonists appear to exhibit stronger efficacy on memory improvement than α4β2 nicotinic acetylcholine receptor agonists. PMID:21968142

  10. Pesticide exposure during pregnancy, like nicotine, affects the brainstem α7 nicotinic acetylcholine receptor expression, increasing the risk of sudden unexplained perinatal death.

    PubMed

    Lavezzi, Anna Maria; Cappiello, Achille; Pusiol, Teresa; Corna, Melissa Felicita; Termopoli, Veronica; Matturri, Luigi

    2015-01-15

    This study indicates the impact of nicotine and pesticides (organochlorine and organophosphate insecticides used in agriculture) on neuronal α7-nicotinic acetylcholine receptor expression in brainstem regions receiving cholinergic projections in human perinatal life. An in-depth anatomopathological examination of the autonomic nervous system and immunohistochemistry to analyze the α7-nicotinic acetylcholine receptor expression in the brainstem from 44 fetuses and newborns were performed. In addition, the presence of selected agricultural pesticides in cerebral cortex samples of the victims was determined by specific analytical procedures. Hypodevelopment of brainstem structures checking the vital functions, frequently associated with α7-nicotinic acetylcholine receptor immunopositivity and smoke absorption in pregnancy, was observed in high percentages of victims of sudden unexpected perinatal death. In nearly 30% of cases however the mothers never smoked, but lived in rural areas. The search for pesticides highlighted in many of these cases traces of both organochlorine and organophosphate pesticides. We detain that exposition to pesticides in pregnancy produces homologous actions to those of nicotine on neuronal α7-nicotinic acetylcholine receptor, allowing to developmental alterations of brainstem vital centers in victims of sudden unexplained death. PMID:25433450

  11. Architecture of the mammalian pituitary cholinergic system with observations on a putative blood acetylcholine sensor.

    PubMed

    Caffe, A R

    1996-04-01

    Acetylcholine (ACh) plays an important role in pituitary gland function. Little is known, however, about the source and trajectory of pituitary ACh, the location of pituitary cholinergic receptors, and the pathways along which the release of pituitary ACh is controlled. Therefore choline acetyltransferase (CHAT) immunoreactive profiles have been investigated in the rat median eminence and pituitary. Furthermore, both muscarinic- (mAChRp-L) and nicotinic receptor proteinlike (nAChRp-L) immunoreactivity have been examined in the rat, rabbit, and cat pituitary. The results have demonstrated that the rat pituitary ChAT network is composed of neurons in the hypothalamic arcuate nucleus and a great number of terminals in the median eminence. In the pituitary, ChAT immunolabeled profiles were virtually absent. This suggests that much of the ACh acting on pituitary cells is released as a humoral factor from the median eminence. All the examined animals expressed mAChRp-L immunostained endocrine cells in the intermediate lobe. Apart from this, marked species differences in AChRp-L immunolabeled profiles have been found. In addition, strong mAChRp-L immunoreactive rod to cone-shaped bodies were detected associated with blood vessels of the anterior and intermediate lobes in the rat and rabbit, but not in the cat. The immunolabeling was present in particles on the body plasma membrane. These characteristics suggest that the function of these structures might be to sense pituitary blood ACh levels. Consequently the name blood acetylcholine reading bodies (BARBs) was adopted to indicate these structures. It is proposed that the BARBs may play a role in the feedback control of ACh release from the median eminence. PMID:8861775

  12. ICV STZ induced impairment in memory and neuronal mitochondrial function: A protective role of nicotinic receptor.

    PubMed

    Saxena, Gunjan; Patro, Ishan K; Nath, Chandishwar

    2011-10-10

    The present study was planned to evaluate the cholinergic influence on mitochondrial activity and neurodegeneration associated with impaired memory in intracerebroventricular (ICV) streptozotocin (STZ) treated rats. STZ (3mg/kg), administered ICV twice with an interval of 48h between the two doses, showed significant impairment in spatial memory tested by water maze test 14 days after first dose without altering blood glucose level and locomotor activity. Animals were sacrificed on 21st day of ICV administration. STZ significantly increased malondialdehyde (MDA), reactive oxygen species (ROS), Ca(2+) ion influx, caspase-3 activity and decreased glutathione (GSH) level. Acetylcholinesterase inhibitors tacrine and donepezil (5mg/kg, PO) pretreatment significantly prevented STZ induced memory deficit, oxidative stress, Ca(2+) influx and caspase-3 activity. Carbachol, a muscarinic cholinergic agonist (0.01mg/kg, SC) did not show any significant effect on ROS generation, Ca(2+) ion influx and caspase-3 activity. While nicotinic cholinergic agonist, nicotine, significantly attenuated ICV STZ induced mitochondrial dysfunction and caspase-3 activity. The results indicate that instead of muscarinic receptors nicotinic receptors may be involved in neuroprotection by maintaining mitochondrial functions. PMID:21620901

  13. Nicotine receptors mediating sensorimotor gating and its enhancement by systemic nicotine

    PubMed Central

    Pinnock, Farena; Bosch, Daniel; Brown, Tyler; Simons, Nadine; Yeomans, John R.; DeOliveira, Cleusa; Schmid, Susanne

    2015-01-01

    Prepulse inhibition (PPI) of startle occurs when intensity stimuli precede stronger startle-inducing stimuli by 10–1000 ms. PPI deficits are found in individuals with schizophrenia and other psychiatric disorders, and they correlate with other cognitive impairments. Animal research and clinical studies have demonstrated that both PPI and cognitive function can be enhanced by nicotine. PPI has been shown to be mediated, at least in part, by mesopontine cholinergic neurons that project to pontine startle neurons and activate muscarinic and potentially nicotine receptors (nAChRs). The subtypes and anatomical location of nAChRs involved in mediating and modulating PPI remain unresolved. We tested the hypothesis that nAChRs that are expressed by pontine startle neurons contribute to PPI. We also explored whether or not these pontine receptors are responsible for the nicotine enhancement of PPI. While systemic administration of nAChR antagonists had limited effects on PPI, PnC microinfusions of the non-α7nAChR preferring antagonist TMPH, but not of the α7nAChR antagonist MLA, into the PnC significantly reduced PPI. Electrophysiological recordings from startle-mediating PnC neurons confirmed that nicotine affects excitability of PnC neurons, which could be antagonized by TMPH, but not by MLA, indicating the expression of non-α7nAChR. In contrast, systemic nicotine enhancement of PPI was only reversed by systemic MLA and not by TMPH or local microinfusions of MLA into the PnC. In summary, our data indicate that non-α7nAChRs in the PnC contribute to PPI at stimulus intervals of 100 ms or less, whereas activation of α7nAChRs in other brain areas is responsible for the systemic nicotine enhancement of PPI. This is important knowledge for the correct interpretation of behavioral, preclinical, and clinical data as well as for developing drugs for the amelioration of PPI deficits and the enhancement of cognitive function. PMID:25717295

  14. Nicotine and health.

    PubMed

    2014-07-01

    Nicotine, an alkaloid derived from the leaves of tobacco plants (Nicotiana tabacum and Nicotiana rustica) is the primary addictive agent in tobacco products.(1,2) There are different ways of administering the various products including smoking cigarettes, chewing tobacco, holding moist snuff in the mouth, inhaling dry snuff through the nose, inhaling smoke from a waterpipe and inhaling vapour from an electronic cigarette.(3-6) It can be difficult differentiating the effects of nicotine from the many other toxic substances these products also contain. Here we review the pharmacological effects of nicotine but we will not review the well-known harmful effects of cigarettes, where it is primarily the toxins and carcinogens in tobacco smoke rather than the nicotine that cause illness and death.(7) A future article will consider the use of electronic cigarettes. PMID:25012148

  15. Republished: Nicotine and health.

    PubMed

    2014-01-01

    Nicotine, an alkaloid derived from the leaves of tobacco plants (Nicotiana tabacum and Nicotiana rustica) is the primary addictive agent in tobacco products.(1,2) There are different ways of administering the various products including smoking cigarettes, chewing tobacco, holding moist snuff in the mouth, inhaling dry snuff through the nose, inhaling smoke from a waterpipe and inhaling vapour from an electronic cigarette.(3-6) It can be difficult differentiating the effects of nicotine from the many other toxic substances these products also contain. Here we review the pharmacological effects of nicotine but we will not review the well-known harmful effects of cigarettes, where it is primarily the toxins and carcinogens in tobacco smoke rather than the nicotine that cause illness and death.(7) A future article will consider the use of electronic cigarettes. PMID:25428425

  16. Nicotine Oral Inhalation

    MedlinePlus

    ... class of medications called smoking cessation aids. It works by providing nicotine to your body to decrease ... want to try different schedules to see what works best for you.Ask your pharmacist or doctor ...

  17. Nicotine replacement therapy

    MedlinePlus

    ... come in many forms: Gum Inhalers Lozenges Nasal spray Skin patch All of these work well if ... inhaler and patch together when quitting. Nicotine Nasal Spray The nasal spray provides a quick dose of ...

  18. Tritiated-nicotine and /sup 125/I-alpha-bungarotoxin-labeled nicotinic receptors in the interpeduncular nucleus of rats. I. Subnuclear distribution

    SciTech Connect

    Hamill, G.S.; Clarke, P.B.; Pert, A.; Jacobowitz, D.M.

    1986-09-15

    The distribution of nicotinic receptors within the interpeduncular nucleus (IPN) was determined in male rats following in vitro labeling with the cholinergic ligands /sup 3/H-nicotine and /sup 125/I-alpha-bungarotoxin (BTX). Autoradiographic images of two rostrocaudal levels of IPN were analyzed by computer-assisted densitometry and the optical density contributed by displaceable labeling was determined in the rostral, central, intermediate, and lateral subnuclei. /sup 3/H-nicotine labeling density within the four subnuclei differs significantly at both levels of IPN. The greatest density of labeling is localized in the rostral subnucleus, followed in order of diminishing density by the central, intermediate, and lateral subnuclei. Labeling within the rostral subnucleus is prominently localized within its central zone. In the central subnucleus, a dense concentration of binding sites is apparent in the middle region, adjacent to less dense vertically oriented columns; /sup 3/H-nicotine binding sites in the lateral subnuclei appear to be most concentrated medially, adjacent to the intermediate subnuclei. /sup 125/I-BTX labeling density within the four subnuclei also differs significantly at both levels of IPN. The greatest density of labeling is found in the rostral subnucleus, followed in order of decreasing density by the lateral, central, and intermediate subnuclei. The ovoid regions of the rostral subnucleus contain dense /sup 125/I-BTX labeling. In the lateral subnuclei, /sup 125/I-BTX binding appears to be predominantly along the lateral margins of the subnucleus. The present data indicate that the IPN contains two distinct populations of putative cholinergic nicotinic receptors identified, respectively, by /sup 3/H-nicotine and /sup 125/I-BTX labeling. Each population of labeled receptors is uniquely localized in patterns that suggest differences in density within and across subnuclei.

  19. Role of α7 nicotinic receptor in the immune system and intracellular signaling pathways

    PubMed Central

    Zdanowski, Robert; Ujazdowska, Dominika; Lewicka, Aneta; Lewicki, Sławomir

    2015-01-01

    Acetylcholine has been well known as one of the most exemplary neurotransmitters. In humans, this versatile molecule and its synthesizing enzyme, choline acetyltransferase, have been found in various non-neural tissues such as the epithelium, endothelium, mesothelium muscle, blood cells and immune cells. The non-neuronal acetylcholine is accompanied by the expression of acetylcholinesterase and nicotinic/muscarinic acetylcholine receptors. Increasing evidence of the non-neuronal acetylcholine system found throughout the last few years has indicated this neurotransmitter as one of the major cellular signaling molecules (associated e.g. with kinases and transcription factors activity). This system is responsible for maintenance and optimization of the cellular function, such as proliferation, differentiation, adhesion, migration, intercellular contact and apoptosis. Additionally, it controls proper activity of immune cells and affects differentiation, antigen presentation or cytokine production (both pro- and anti-inflammatory). The present article reviews recent findings about the non-neuronal cholinergic system in the field of immune system and intracellular signaling pathways. PMID:26648784

  20. The Sensory Impact of Nicotine on Noradrenergic and Dopaminergic Neurons of the Nicotine Reward - Addiction Neurocircuitry

    PubMed Central

    Rose, Jed E; Dehkordi, Ozra; Manaye, Kebreten F; Millis, Richard M; Cianaki, Salman Ameri; Jayam-Trouth, Annapurni

    2016-01-01

    The sensory experience of smoking is a key component of nicotine addiction known to result, in part, from stimulation of nicotinic acetylcholine receptors (nAChRs) at peripheral sensory nerve endings. Such stimulation of nAChRs is followed by activation of neurons at multiple sites in the mesocorticolimbic reward pathways. However, the neurochemical profiles of CNS cells that mediate the peripheral sensory impact of nicotine remain unknown. In the present study in mice, we first used c-Fos immunohistochemistry to identify CNS cells stimulated by nicotine (NIC, 40 μg/kg, IP) and by a peripherally-acting analog of nicotine, nicotine pyrrolidine methiodide (NIC-PM, 30 μg/kg, IP). Sequential double-labelling was then performed to determine whether noradrenergic and dopaminergic neurons of the nicotine reward-addiction circuitry were primary targets of NIC and NIC-PM. Double-labelling of NIC and/or NIC-PM activated c-Fos immunoreactive cells with tyrosine hydroxylase (TH) showed no apparent c-Fos expression by the dopaminergic cells of the ventral tegmental area (VTA). With the exception of sparse numbers of TH immunoreactive D11 cells, dopamine-containing neurons in other areas of the reward-addiction circuitry, namely periaqueductal gray, and dorsal raphe, were also devoid of c-Fos immunoreactivity. Noradrenergic neurons of locus coeruleus (LC), known to innervate VTA, were activated by both NIC and NIC-PM. These results demonstrate that noradrenergic neurons of LC are among the first structures that are stimulated by single acute IP injection of NIC and NIC-PM. Dopaminergic neurons of VTA and other CNS sites, did not respond to acute IP administration of NIC or NIC-PM by induction of c-Fos. PMID:27347434

  1. Rapid and slow chemical synaptic interactions of cholinergic projection neurons and GABAergic local interneurons in the insect antennal lobe.

    PubMed

    Warren, Ben; Kloppenburg, Peter

    2014-09-24

    The antennal lobe (AL) of insects constitutes the first synaptic relay and processing center of olfactory information, received from olfactory sensory neurons located on the antennae. Complex synaptic connectivity between olfactory neurons of the AL ultimately determines the spatial and temporal tuning profile of (output) projection neurons to odors. Here we used paired whole-cell patch-clamp recordings in the cockroach Periplaneta americana to characterize synaptic interactions between cholinergic uniglomerular projection neurons (uPNs) and GABAergic local interneurons (LNs), both of which are key components of the insect olfactory system. We found rapid, strong excitatory synaptic connections between uPNs and LNs. This rapid excitatory transmission was blocked by the nicotinic acetylcholine receptor blocker mecamylamine. IPSPs, elicited by synaptic input from a presynaptic LN, were recorded in both uPNs and LNs. IPSPs were composed of both slow, sustained components and fast, transient components which were coincident with presynaptic action potentials. The fast IPSPs were blocked by the GABAA receptor chloride channel blocker picrotoxin, whereas the slow sustained IPSPs were blocked by the GABAB receptor blocker CGP-54626. This is the first study to directly show the predicted dual fast- and slow-inhibitory action of LNs, which was predicted to be key in shaping complex odor responses in the AL of insects. We also provide the first direct characterization of rapid postsynaptic potentials coincident with presynaptic spikes between olfactory processing neurons in the AL. PMID:25253851

  2. Cholinergic dysregulation produced by selective inactivation of the dystonia-associated protein TorsinA

    PubMed Central

    Sciamanna, Giuseppe; Hollis, Robert; Ball, Chelsea; Martella, Giuseppina; Tassone, Annalisa; Marshall, Andrea; Parsons, Dee; Li, Xinru; Yokoi, Fumiaki; Zhang, Lin; Li, Yuqing; Pisani, Antonio; Standaert, David G.

    2012-01-01

    DYT1 dystonia, a common and severe primary dystonia, is caused by a 3-bp deletion in TOR1A which encodes torsinA, a protein found in the endoplasmic reticulum. Several cellular functions are altered by the mutant protein, but at a systems level the link between these and the symptoms of the disease is unclear. The most effective known therapy for DYT1 dystonia is use of anticholinergic drugs. Previous studies have revealed that in mice, transgenic expression of human mutant torsinA under a non-selective promoter leads to abnormal function of striatal cholinergic neurons. To investigate what pathological role torsinA plays in cholinergic neurons, we created a mouse model in which the Dyt1 gene, the mouse homolog of TOR1A, is selectively deleted in cholinergic neurons (ChKO animals). These animals do not have overt dystonia, but do have subtle motor abnormalities. There is no change in the number or size of striatal cholinergic cells or striatal acetylcholine content, uptake, synthesis, or release in ChKO mice. There are, however, striking functional abnormalities of striatal cholinergic cells, with paradoxical excitation in response to D2 receptor activation and loss of muscarinic M2/M4 receptor inhibitory function. These effects are specific for cholinergic interneurons, as recordings from nigral dopaminergic neurons revealed normal responses. Amphetamine stimulated dopamine release was also unaltered. These results demonstrate a cell-autonomous effect of Dyt1 deletion on striatal cholinergic function. Therapies directed at modifying the function of cholinergic neurons may prove useful in the treatment of the human disorder. PMID:22579992

  3. N-Benzylpiperidine Derivatives as α7 Nicotinic Receptor Antagonists.

    PubMed

    Criado, Manuel; Mulet, José; Sala, Francisco; Sala, Salvador; Colmena, Inés; Gandía, Luis; Bautista-Aguilera, Oscar M; Samadi, Abdelouahid; Chioua, Mourad; Marco-Contelles, José

    2016-08-17

    A series of multitarget directed propargylamines, as well as other differently susbstituted piperidines have been screened as potential modulators of neuronal nicotinic acetylcholine receptors (nAChRs). Most of them showed antagonist actions on α7 nAChRs. Especially, compounds 13, 26, and 38 displayed submicromolar IC50 values on homomeric α7 nAChRs, whereas they were less effective on heteromeric α3β4 and α4β2 nAChRs (up to 20-fold higher IC50 values in the case of 13). Antagonism was concentration dependent and noncompetitive, suggesting that these compounds behave as negative allosteric modulators of nAChRs. Upon the study of a series of less complex derivatives, the N-benzylpiperidine motif, common to these compounds, was found to be the main pharmacophoric group. Thus, 2-(1-benzylpiperidin-4-yl)-ethylamine (48) showed an inhibitory potency comparable to the one of the previous compounds and also a clear preference for α7 nAChRs. In a neuroblastoma cell line, representative compounds 13 and 48 also inhibited, in a concentration-dependent manner, cytosolic Ca(2+) signals mediated by nAChRs. Finally, compounds 38 and 13 inhibited 5-HT3A serotonin receptors whereas they had no effect on α1 glycine receptors. Given the multifactorial nature of many pathologies in which nAChRs are involved, these piperidine antagonists could have a therapeutic potential in cases where cholinergic activity has to be negatively modulated. PMID:27254782

  4. The role of cholinergic anti-inflammatory pathway in acetic acid-induced colonic inflammation in the rat.

    PubMed

    Kolgazi, Meltem; Uslu, Unal; Yuksel, Meral; Velioglu-Ogunc, Ayliz; Ercan, Feriha; Alican, Inci

    2013-09-01

    The "cholinergic anti-inflammatory pathway" provides neurological modulation of cytokine synthesis to limit the magnitude of the immune response. This study aimed to evaluate the impact of the cholinergic anti-inflammatory pathway on the extent of tissue integrity, oxidant-antioxidant status and neutrophil infiltration to the inflamed organ in a rat model of acetic acid-induced colitis. Colitis was induced by intrarectal administration of 5% acetic acid (1ml) to Sprague-Dawley rats (200-250g; n=7-8 per group). Control group received an equal volume of saline intrarectally. The rats were treated with either nicotine (1mg/kg/day) or huperzine A (0.1mg/kg/day) intraperitoneally for 3 days. After decapitation, the distal colon was scored macroscopically and microscopically. Tissue samples were used for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels, and myeloperoxidase (MPO) activity. Formation of reactive oxygen species was monitored by using chemiluminescence (CL). Nuclear factor (NF)-κB expression was evaluated in colonic samples via immunohistochemical analysis. Trunk blood was collected for the assessment of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-10, resistin and visfatin levels. Both nicotine and huperzine A reduced the extent of colonic lesions, increased colonic MDA level, high MPO activity and NF-κB expression in the colitis group. Elevation of serum IL-1β level due to colitis was also attenuated by both treatments. Additionally, huperzine A was effective to reverse colitis-induced high lucigenin-enhanced CL values and serum TNF-α levels. Colitis group revealed decreased serum visfatin levels compared to control group which was completely reversed by nicotine. In conclusion, modulation of the cholinergic system either by nicotine or ACh esterase inhibition improved acetic acid-induced colonic inflammation as confirmed by macroscopic and microscopic examination and biochemical assays. PMID:23810507

  5. Choline metabolism as a basis for the selective vulnerability of cholinergic neurons

    NASA Technical Reports Server (NTRS)

    Wurtman, R. J.

    1992-01-01

    The unique propensity of cholinergic neurons to use choline for two purposes--ACh and membrane phosphatidylcholine synthesis--may contribute to their selective vulnerability in Alzheimer's disease and other cholinergic neurodegenerative disorders. When physiologically active, the neurons use free choline taken from the 'reservoir' in membrane phosphatidylcholine to synthesize ACh; this can lead to an actual decrease in the quantity of membrane per cell. Alzheimer's disease (but not Down's syndrome, or other neurodegenerative disorders) is associated with characteristic neurochemical lesions involving choline and ethanolamine: brain levels of these compounds are diminished, while those of glycerophosphocholine and glycerophosphoethanolamine (breakdown products of their respective membrane phosphatides) are increased, both in cholinergic and noncholinergic brain regions. Perhaps this metabolic disturbance and the tendency of cholinergic neurons to 'export' choline--in the form of ACh--underlie the selective vulnerability of the neurons. Resulting changes in membrane composition could abnormally expose intramembraneous proteins such as amyloid precursor protein to proteases.

  6. Effect of nicotine on melanogenesis and antioxidant status in HEMn-LP melanocytes

    SciTech Connect

    Delijewski, Marcin; Beberok, Artur; Otręba, Michał; Wrześniok, Dorota; Rok, Jakub; Buszman, Ewa

    2014-10-15

    Nicotine is a natural ingredient of tobacco plants and is responsible for the addictive properties of tobacco. Nowadays nicotine is also commonly used as a form of smoking cessation therapy. It is suggested that nicotine may be accumulated in human tissues containing melanin. This may in turn affect biochemical processes in human cells producing melanin. The aim of this study was to examine the effect of nicotine on melanogenesis and antioxidant status in cultured normal human melanocytes HEMn-LP. Nicotine induced concentration-dependent loss in melanocytes viability. The value of EC{sub 50} was determined to be 7.43 mM. Nicotine inhibited a melanization process in human light pigmented melanocytes and caused alterations of antioxidant defense system. Significant changes in cellular antioxidant enzymes: superoxide dismutase and catalase activities and in hydrogen peroxide content were stated. The obtained results may explain a potential influence of nicotine on biochemical processes in melanocytes in vivo during long term exposition to nicotine. - Graphical abstract: Nicotine inhibits melanogenesis and induces oxidative stress in HEMn-LP melanocytes. - Highlights: • Nicotine induces concentration-dependent loss in melanocytes viability. • Nicotine in non-cytotoxic concentrations inhibits melanogenesis. • Nicotine in higher concentrations induces oxidative stress.

  7. Hypocretins regulate the anxiogenic-like effects of nicotine and induce reinstatement of nicotine-seeking behavior

    PubMed Central

    Plaza-Zabala, Ainhoa; Martín-García, Elena; de Lecea, Luis; Maldonado, Rafael; Berrendero, Fernando

    2010-01-01

    Emerging evidence suggests that the hypocretinergic system is involved in addictive behavior. In this study, we investigated the role of these hypothalamic neuropeptides in anxiety-like responses of nicotine and stress-induced reinstatement of nicotine-seeking behavior. Acute nicotine (0.8 mg/kg, sc) induced anxiogenic-like effects in the elevated plus-maze and activated the paraventricular nucleus of the hypothalamus (PVN) as revealed by c-Fos expression. Pretreatment with the hypocretin receptor 1 (Hcrtr-1) antagonist SB334867 or prepro-hypocretin gene deletion blocked both nicotine effects. In the PVN, SB334867 also prevented the activation of corticotrophin releasing factor (CRF) and arginine-vasopressin (AVP) neurons, which expressed Hcrtr-1. In addition, an increase of the percentage of c-Fos positive hypocretin cells in the perifornical and dorsomedial hypothalamic (PFA/DMH) areas was found after nicotine (0.8 mg/kg, sc) administration. Intracerebroventricular (icv) infusion of hypocretin-1 (Hcrt-1) (0.75 nmol/1 μl) or footshock stress reinstated a previously extinguished nicotine-seeking behavior. The effects of Hcrt-1 were blocked by SB334867, but not by the CRF1 receptor antagonist antalarmin. Moreover, SB334867 did not block CRF-dependent footshock-induced reinstatement of nicotine-seeking while antalarmin was effective in preventing this nicotine motivational response. Therefore, the Hcrt system interacts with CRF and AVP neurons in the PVN and modulates the anxiogenic-like effects of nicotine whereas Hcrt and CRF play a different role in the reinstatement of nicotine-seeking. Indeed, Hcrt-1 reinstates nicotine-seeking through a mechanism independent of CRF activation whereas CRF mediates the reinstatement induced by stress. PMID:20147556

  8. Biosynthesis of trigonelline from nicotinate mononucleotide in mungbean seedlings.

    PubMed

    Zheng, Xin-Qiang; Matsui, Ayu; Ashihara, Hiroshi

    2008-01-01

    To determine the biosynthetic pathway to trigonelline, the metabolism of [carboxyl-(14)C]nicotinate mononucleotide (NaMN) and [carboxyl-(14)C]nicotinate riboside (NaR) in protein extracts and tissues of embryonic axes from germinating mungbeans (Phaseolus aureus) was investigated. In crude cell-free protein extracts, in the presence of S-adenosyl-L-methionine, radioactivity from [(14)C]NaMN was incorporated into NaR, nicotinate and trigonelline. Activities of NaMN nucleotidase, NaR nucleosidase and trigonelline synthase were also observed in the extracts. Exogenously supplied [(14)C]NaR, taken up by embryonic axes segments, was readily converted to nicotinate and trigonelline. It is concluded that the NaMN-->NaR-->nicotinate-->trigonelline pathway is operative in the embryonic axes of mungbean seedlings. This result suggests that trigonelline is synthesised not only from NAD but also via the de novo biosynthetic pathway of pyridine nucleotides. PMID:17888466

  9. [Participation of cholinergic mechanisms in the regulation of immunological processes].

    PubMed

    Gushchin, G V; Shkhinek, E K

    1979-01-01

    Chronic administration of cholinomimetic (arecolin, pilocarpin, nicotin) and cholinolytic (bezohexonium, pedifen) drugs produces changes of different directions in the number of rosette-forming cells in the spleen of CBA mice immunized with sheep red blood cells. The analysis performed does not allow the effect of the drugs on immunologic processes to be accounted for by an immediate action on lymphoid cells or by an action of the function of the pituitary-adrenal system. PMID:574093

  10. Nighttime Administration of Nicotine Improves Hepatic Glucose Metabolism via the Hypothalamic Orexin System in Mice.

    PubMed

    Tsuneki, Hiroshi; Nagata, Takashi; Fujita, Mikio; Kon, Kanta; Wu, Naizhen; Takatsuki, Mayumi; Yamaguchi, Kaoru; Wada, Tsutomu; Nishijo, Hisao; Yanagisawa, Masashi; Sakurai, Takeshi; Sasaoka, Toshiyasu

    2016-01-01

    Nicotine is known to affect the metabolism of glucose; however, the underlying mechanism remains unclear. Therefore, we here investigated whether nicotine promoted the central regulation of glucose metabolism, which is closely linked to the circadian system. The oral intake of nicotine in drinking water, which mainly occurred during the nighttime active period, enhanced daily hypothalamic prepro-orexin gene expression and reduced hyperglycemia in type 2 diabetic db/db mice without affecting body weight, body fat content, and serum levels of insulin. Nicotine administered at the active period appears to be responsible for the effect on blood glucose, because nighttime but not daytime injections of nicotine lowered blood glucose levels in db/db mice. The chronic oral treatment with nicotine suppressed the mRNA levels of glucose-6-phosphatase, the rate-limiting enzyme of gluconeogenesis, in the liver of db/db and wild-type control mice. In the pyruvate tolerance test to evaluate hepatic gluconeogenic activity, the oral nicotine treatment moderately suppressed glucose elevations in normal mice and mice lacking dopamine receptors, whereas this effect was abolished in orexin-deficient mice and hepatic parasympathectomized mice. Under high-fat diet conditions, the oral intake of nicotine lowered blood glucose levels at the daytime resting period in wild-type, but not orexin-deficient, mice. These results indicated that the chronic daily administration of nicotine suppressed hepatic gluconeogenesis via the hypothalamic orexin-parasympathetic nervous system. Thus, the results of the present study may provide an insight into novel chronotherapy for type 2 diabetes that targets the central cholinergic and orexinergic systems. PMID:26492471

  11. Nicotine effects on regional cerebral blood flow in awake, resting tobacco smokers.

    PubMed

    Domino, E F; Minoshima, S; Guthrie, S; Ohl, L; Ni, L; Koeppe, R A; Zubieta, J K

    2000-12-01

    The hypothesis for this research was that regional cerebral blood flow (rCBF) would increase following nasal nicotine administration to overnight abstinent tobacco smokers in relationship to the known brain distribution of nicotinic cholinergic receptors (nAChRs). Nine male and nine female healthy adult smokers were studied. They abstained overnight from tobacco products for 10 or more hours prior to study the next morning. Nicotine nasal spray was given in doses of 1-2.5 mg total with half in each nostril while the subject was awake and resting in a supine position. Oleoresin of pepper solution in a similar volume was used as an active placebo to control for the irritating effects of nicotine. Both substances were given single blind to the subjects. Positron emission tomography (PET) with H(2)(15)O was used to measure rCBF. The data from each subject volunteer were normalized to global activity to better assess regional brain changes. Both nasal nicotine and pepper spray produced similar increases in CBF in somesthetic area II, consistent with the irritant effects of both substances. The mean rCBF effects of nasal pepper were subtracted from those of nasal nicotine to determine the actions of nicotine alone. The latter produced increases in rCBF in the thalamus, pons, Brodman area 17 of the visual cortex, and cerebellum. Some brain areas that contain a large number of nAChRs, such as the thalamus, showed an increase in CBF. Other areas that have few nAChRs, such as the cerebellum, also showed an increase in relative CBF. The hippocampal/parahippocampal areas showed greater regional decreases (left) and lesser increases (right) in CBF that correlated with the increase in plasma arterial nicotine concentrations. The results obtained indicate complex primary and secondary effects of nicotine in which only some regional brain CBF changes correlate with the known distribution of nAChR. No gender differences were noted. PMID:11020234

  12. Blockade by 2,2',2''-tripyridine of the nicotinic acetylcholine receptor channels in embryonic Xenopus muscle cells.

    PubMed Central

    Hsu, K. S.; Fu, W. M.; Lin-Shiau, S. Y.

    1993-01-01

    1. The effects of 2,2',2''-tripyridine on the nicotinic acetylcholine (ACh) receptor channels were studied in the cultured myocytes of 1-day-old Xenopus embryos. 2. 2,2',2''-Tripyridine depressed the amplitude of iontophoretic ACh-induced current at a low frequency of 0.7 Hz stimulation and it not only decreased the initial responses but also enhanced the run-down of ACh-induced current at higher frequency stimulation of 7 Hz and 30 Hz. 3. Single ACh channel recordings showed that 2,2',2''-tripyridine decreased the channel conductance, the opening frequency and mean open time of both types of low- and high-conductance channels. 4. These results suggest that the blocking actions of 2,2',2''-tripyridine on ACh receptor channels in the skeletal muscle may contribute to the depression of the nerve-evoked contraction of the mouse diaphragm as reported previously. PMID:7693275

  13. The Corticofugal Effects of Auditory Cortex Microstimulation on Auditory Nerve and Superior Olivary Complex Responses Are Mediated via Alpha-9 Nicotinic Receptor Subunit

    PubMed Central

    Aedo, Cristian; Terreros, Gonzalo; León, Alex; Delano, Paul H.

    2016-01-01

    Background and Objective The auditory efferent system is a complex network of descending pathways, which mainly originate in the primary auditory cortex and are directed to several auditory subcortical nuclei. These descending pathways are connected to olivocochlear neurons, which in turn make synapses with auditory nerve neurons and outer hair cells (OHC) of the cochlea. The olivocochlear function can be studied using contralateral acoustic stimulation, which suppresses auditory nerve and cochlear responses. In the present work, we tested the proposal that the corticofugal effects that modulate the strength of the olivocochlear reflex on auditory nerve responses are produced through cholinergic synapses between medial olivocochlear (MOC) neurons and OHCs via alpha-9/10 nicotinic receptors. Methods We used wild type (WT) and alpha-9 nicotinic receptor knock-out (KO) mice, which lack cholinergic transmission between MOC neurons and OHC, to record auditory cortex evoked potentials and to evaluate the consequences of auditory cortex electrical microstimulation in the effects produced by contralateral acoustic stimulation on auditory brainstem responses (ABR). Results Auditory cortex evoked potentials at 15 kHz were similar in WT and KO mice. We found that auditory cortex microstimulation produces an enhancement of contralateral noise suppression of ABR waves I and III in WT mice but not in KO mice. On the other hand, corticofugal modulations of wave V amplitudes were significant in both genotypes. Conclusion These findings show that the corticofugal modulation of contralateral acoustic suppressions of auditory nerve (ABR wave I) and superior olivary complex (ABR wave III) responses are mediated through MOC synapses. PMID:27195498

  14. Laminar organization and age-related loss of cholinergic receptors in temporal neocortex of rhesus monkey.

    PubMed

    Wagster, M V; Whitehouse, P J; Walker, L C; Kellar, K J; Price, D L

    1990-09-01

    Using in vitro receptor autoradiography, the distributions of cholinergic muscarinic [3H-N-methyl scopolamine (NMS), 3H-pirenzepine (PZ), and 3H-oxotremorine-M (OXO-M)] and nicotinic [3H-acetylcholine (ACh)] receptors were mapped in the temporal cortices of rhesus monkeys (Macaca mulatta) ranging from 2-22 years of age. Although high-affinity 3H-PZ, low-affinity 3H-NMS binding (M1 sites) and high-affinity 3H-OXO-M, high-affinity 3H-NMS binding (M2 sites) occurred across all layers of the temporal neocortex, the laminar distribution of M1 and M2 receptor binding sites was different. M1 muscarinic receptor binding was concentrated in layers II and III, whereas M2 muscarinic receptor binding was greatest in layers IV and V. The concentration of both muscarinic (M1 and M2) and nicotinic receptor binding sites declined with increasing age, and decrements were uniform across all cortical layers. This investigation provides evidence for a decrease in cholinergic receptor binding with age in temporal cortices of rhesus monkeys. Moreover, these changes appear to precede previously reported age-associated memory deficits and neuropathological changes that occur in this species. PMID:2398366

  15. Long-term exposure to nicotine markedly reduces kynurenic acid in rat brain - In vitro and ex vivo evidence

    SciTech Connect

    Zielinska, Elzbieta; Kuc, Damian; Zgrajka, Wojciech; Turski, Waldemar A.; Dekundy, Andrzej

    2009-10-15

    Kynurenic acid (KYNA) is a recognized broad-spectrum antagonist of excitatory amino acid receptors with a particularly high affinity for the glycine co-agonist site of the N-methyl-D-aspartate (NMDA) receptor complex. KYNA is also a putative endogenous neuroprotectant. Recent studies show that KYNA strongly blocks {alpha}7 subtype of nicotinic acetylcholine receptors (nAChRs). The present studies were aimed at assessing effects of acute and chronic nicotine exposure on KYNA production in rat brain slices in vitro and ex vivo. In brain slices, nicotine significantly increased KYNA formation at 10 mM but not at 1 or 5 mM. Different nAChR antagonists (dihydro-{beta}-erythroidine, methyllycaconitine and mecamylamine) failed to block the influence exerted by nicotine on KYNA synthesis in cortical slices in vitro. Effects of acute (1 mg/kg, i.p.), subchronic (10-day) and chronic (30-day) administration of nicotine in drinking water (100 {mu}g/ml) on KYNA brain content were evaluated ex vivo. Acute treatment with nicotine (1 mg/kg i.p.) did not affect KYNA level in rat brain. The subchronic exposure to nicotine in drinking water significantly increased KYNA by 43%, while chronic exposure to nicotine resulted in a reduction in KYNA by 47%. Co-administration of mecamylamine with nicotine in drinking water for 30 days reversed the effect exerted by nicotine on KYNA concentration in the cerebral cortex. The present results provide evidence for the hypothesis of reciprocal interaction between the nicotinic cholinergic system and the kynurenine pathway in the brain.

  16. Evidence for thymopoietin and thymopoietin/. alpha. -bungarotoxin/nicotinic receptors within the brain

    SciTech Connect

    Quik, M. ); Babu, U.; Audhya, T.; Goldstein, G. )

    1991-03-15

    Thymopoietin, a polypeptide hormone of the thymus that has pleiotropic actions on the immune, endocrine, and nervous systems, potently interacts with the neuromuscular nicotinic acetylcholine receptor. Thymopoietin binds to the nicotinic {alpha}-bungarotoxin ({alpha}-BGT) receptor in muscle and, like {alpha}BGT, inhibits cholinergic transmission at this site. Evidence is given that radiolabeled thymopoietin similarly binds to a nicotinic {alpha}-BGT-binding site within the brain and does so with the characteristics of a specific receptor ligand. Thus specific binding to neuronal membranes was saturable, of high affinity linear with increased tissue concentration, and readily reversible; half-time was {approximately}5 min for association and 10 min for dissociation. Binding of {sup 125}I-labeled thymopoietin was displaced not only by unlabeled thymopoietin but also by {alpha}-BGT and the nicotinic receptor ligands d-tubocurarine and nicotine; various other receptor ligands (muscarinic, adrenergic, and dopaminergic) did not affect binding of {sup 125}I-labeled thymopoietin. Thymopoietin was shown by ELISA to be present in brain extracts, displacement curves of thymus and brain extracts being parallel to the standard thymopoietin curve, and Western (immuno) blot identified in brain and thymus extracts a thymopoietin-immunoreactive polypeptide of the same molecular mass as purified thymopoietin polypeptide. The authors conclude that thymopoietin and thymopoietin-binding sites are present within the brain and that the receptor for thymopoietin is the previously identified nicotinic {alpha}-BGT-binding site of neuronal tissue.

  17. Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP) and Endolysosomal Two-pore Channels Modulate Membrane Excitability and Stimulus-Secretion Coupling in Mouse Pancreatic β Cells*

    PubMed Central

    Arredouani, Abdelilah; Ruas, Margarida; Collins, Stephan C.; Parkesh, Raman; Clough, Frederick; Pillinger, Toby; Coltart, George; Rietdorf, Katja; Royle, Andrew; Johnson, Paul; Braun, Matthias; Zhang, Quan; Sones, William; Shimomura, Kenju; Morgan, Anthony J.; Lewis, Alexander M.; Chuang, Kai-Ting; Tunn, Ruth; Gadea, Joaquin; Teboul, Lydia; Heister, Paula M.; Tynan, Patricia W.; Bellomo, Elisa A.; Rutter, Guy A.; Rorsman, Patrik; Churchill, Grant C.; Parrington, John; Galione, Antony

    2015-01-01

    Pancreatic β cells are electrically excitable and respond to elevated glucose concentrations with bursts of Ca2+ action potentials due to the activation of voltage-dependent Ca2+ channels (VDCCs), which leads to the exocytosis of insulin granules. We have examined the possible role of nicotinic acid adenine dinucleotide phosphate (NAADP)-mediated Ca2+ release from intracellular stores during stimulus-secretion coupling in primary mouse pancreatic β cells. NAADP-regulated Ca2+ release channels, likely two-pore channels (TPCs), have recently been shown to be a major mechanism for mobilizing Ca2+ from the endolysosomal system, resulting in localized Ca2+ signals. We show here that NAADP-mediated Ca2+ release from endolysosomal Ca2+ stores activates inward membrane currents and depolarizes the β cell to the threshold for VDCC activation and thereby contributes to glucose-evoked depolarization of the membrane potential during stimulus-response coupling. Selective pharmacological inhibition of NAADP-evoked Ca2+ release or genetic ablation of endolysosomal TPC1 or TPC2 channels attenuates glucose- and sulfonylurea-induced membrane currents, depolarization, cytoplasmic Ca2+ signals, and insulin secretion. Our findings implicate NAADP-evoked Ca2+ release from acidic Ca2+ storage organelles in stimulus-secretion coupling in β cells. PMID:26152717

  18. Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP) and Endolysosomal Two-pore Channels Modulate Membrane Excitability and Stimulus-Secretion Coupling in Mouse Pancreatic β Cells.

    PubMed

    Arredouani, Abdelilah; Ruas, Margarida; Collins, Stephan C; Parkesh, Raman; Clough, Frederick; Pillinger, Toby; Coltart, George; Rietdorf, Katja; Royle, Andrew; Johnson, Paul; Braun, Matthias; Zhang, Quan; Sones, William; Shimomura, Kenju; Morgan, Anthony J; Lewis, Alexander M; Chuang, Kai-Ting; Tunn, Ruth; Gadea, Joaquin; Teboul, Lydia; Heister, Paula M; Tynan, Patricia W; Bellomo, Elisa A; Rutter, Guy A; Rorsman, Patrik; Churchill, Grant C; Parrington, John; Galione, Antony

    2015-08-28

    Pancreatic β cells are electrically excitable and respond to elevated glucose concentrations with bursts of Ca(2+) action potentials due to the activation of voltage-dependent Ca(2+) channels (VDCCs), which leads to the exocytosis of insulin granules. We have examined the possible role of nicotinic acid adenine dinucleotide phosphate (NAADP)-mediated Ca(2+) release from intracellular stores during stimulus-secretion coupling in primary mouse pancreatic β cells. NAADP-regulated Ca(2+) release channels, likely two-pore channels (TPCs), have recently been shown to be a major mechanism for mobilizing Ca(2+) from the endolysosomal system, resulting in localized Ca(2+) signals. We show here that NAADP-mediated Ca(2+) release from endolysosomal Ca(2+) stores activates inward membrane currents and depolarizes the β cell to the threshold for VDCC activation and thereby contributes to glucose-evoked depolarization of the membrane potential during stimulus-response coupling. Selective pharmacological inhibition of NAADP-evoked Ca(2+) release or genetic ablation of endolysosomal TPC1 or TPC2 channels attenuates glucose- and sulfonylurea-induced membrane currents, depolarization, cytoplasmic Ca(2+) signals, and insulin secretion. Our findings implicate NAADP-evoked Ca(2+) release from acidic Ca(2+) storage organelles in stimulus-secretion coupling in β cells. PMID:26152717

  19. Expression of nicotinic acetylcholine receptor subunits in HEp-2 cells for immunodetection of autoantibody specificities in sera from Myasthenia gravis patients.

    PubMed

    George, S; Noack, M; Vanek, M; Rentzsch, J; Röber, N; Conrad, K; Roggenbuck, D; Küpper, J-H

    2015-01-01

    Myasthenia gravis (MG) is an autoimmune disease characterized by the formation of pathogenic autoantibodies mostly targeting the nicotinic acetylcholine receptor (AChR). The AChR is composed of two alpha subunits and one subunit of each beta, delta and gamma (fetal AChR), or epsilon (adult AChR), respectively. Serological diagnostics is commonly done by radioimmunoassay (RIA). Here we used an indirect immunofluorescence assay with MG patient sera on transiently transfected HEp-2 cells expressing selected components of the AChR. Our data show that already 12 out of 13 MG patient sera showed autoantibody binding to HEp-2 cells transfected to express the alpha subunit solely. Interestingly, 11 out of 13 patient sera reacted positive with cells transfected to reconstitute the complete fetal AChR, but only 6 out of 13 sera showed positive signals with cells expressing the components of adult AChR. Moreover, there was no strict correlation of the serum concentration required to obtain clear-cut fluorescence signals to the antibody titer as measured by RIA. It will be an interesting topic to further investigate if the optimal serum dilution for indirect immunofluorescence as well as the autoantibody binding preferences to defined AChR subunits and to the adult versus the fetal receptor variant could provide additional predictive value in MG diagnostics. PMID:26410878

  20. Assessment of the expression and role of the α1-nAChR subunit in efferent cholinergic function during the development of the mammalian cochlea.

    PubMed

    Roux, Isabelle; Wu, Jingjing Sherry; McIntosh, J Michael; Glowatzki, Elisabeth

    2016-08-01

    Hair cell (HC) activity in the mammalian cochlea is modulated by cholinergic efferent inputs from the brainstem. These inhibitory inputs are mediated by calcium-permeable nicotinic acetylcholine receptors (nAChRs) containing α9- and α10-subunits and by subsequent activation of calcium-dependent potassium channels. Intriguingly, mRNAs of α1- and γ-nAChRs, subunits of the "muscle-type" nAChR have also been found in developing HCs (Cai T, Jen HI, Kang H, Klisch TJ, Zoghbi HY, Groves AK. J Neurosci 35: 5870-5883, 2015; Scheffer D, Sage C, Plazas PV, Huang M, Wedemeyer C, Zhang DS, Chen ZY, Elgoyhen AB, Corey DP, Pingault V. J Neurochem 103: 2651-2664, 2007; Sinkkonen ST, Chai R, Jan TA, Hartman BH, Laske RD, Gahlen F, Sinkkonen W, Cheng AG, Oshima K, Heller S. Sci Rep 1: 26, 2011) prompting proposals that another type of nAChR is present and may be critical during early synaptic development. Mouse genetics, histochemistry, pharmacology, and whole cell recording approaches were combined to test the role of α1-nAChR subunit in HC efferent synapse formation and cholinergic function. The onset of α1-mRNA expression in mouse HCs was found to coincide with the onset of the ACh response and efferent synaptic function. However, in mouse inner hair cells (IHCs) no response to the muscle-type nAChR agonists (±)-anatoxin A, (±)-epibatidine, (-)-nicotine, or 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP) was detected, arguing against the presence of an independent functional α1-containing muscle-type nAChR in IHCs. In α1-deficient mice, no obvious change of IHC efferent innervation was detected at embryonic day 18, contrary to the hyperinnervation observed at the neuromuscular junction. Additionally, ACh response and efferent synaptic activity were detectable in α1-deficient IHCs, suggesting that α1 is not necessary for assembly and membrane targeting of nAChRs or for efferent synapse formation in IHCs. PMID:27098031

  1. Endothelial disruptive proinflammatory effects of nicotine and e-cigarette vapor exposures.

    PubMed

    Schweitzer, Kelly S; Chen, Steven X; Law, Sarah; Van Demark, Mary; Poirier, Christophe; Justice, Matthew J; Hubbard, Walter C; Kim, Elena S; Lai, Xianyin; Wang, Mu; Kranz, William D; Carroll, Clinton J; Ray, Bruce D; Bittman, Robert; Goodpaster, John; Petrache, Irina

    2015-07-15

    The increased use of inhaled nicotine via e-cigarettes has unknown risks to lung health. Having previously shown that cigarette smoke (CS) extract disrupts the lung microvasculature barrier function by endothelial cell activation and cytoskeletal rearrangement, we investigated the contribution of nicotine in CS or e-cigarettes (e-Cig) to lung endothelial injury. Primary lung microvascular endothelial cells were exposed to nicotine, e-Cig solution, or condensed e-Cig vapor (1-20 mM nicotine) or to nicotine-free CS extract or e-Cig solutions. Compared with nicotine-containing extract, nicotine free-CS extract (10-20%) caused significantly less endothelial permeability as measured with electric cell-substrate impedance sensing. Nicotine exposures triggered dose-dependent loss of endothelial barrier in cultured cell monolayers and rapidly increased lung inflammation and oxidative stress in mice. The endothelial barrier disruptive effects were associated with increased intracellular ceramides, p38 MAPK activation, and myosin light chain (MLC) phosphorylation, and was critically mediated by Rho-activated kinase via inhibition of MLC-phosphatase unit MYPT1. Although nicotine at sufficient concentrations to cause endothelial barrier loss did not trigger cell necrosis, it markedly inhibited cell proliferation. Augmentation of sphingosine-1-phosphate (S1P) signaling via S1P1 improved both endothelial cell proliferation and barrier function during nicotine exposures. Nicotine-independent effects of e-Cig solutions were noted, which may be attributable to acrolein, detected along with propylene glycol, glycerol, and nicotine by NMR, mass spectrometry, and gas chromatography, in both e-Cig solutions and vapor. These results suggest that soluble components of e-Cig, including nicotine, cause dose-dependent loss of lung endothelial barrier function, which is associated with oxidative stress and brisk inflammation. PMID:25979079

  2. Endothelial disruptive proinflammatory effects of nicotine and e-cigarette vapor exposures

    PubMed Central

    Schweitzer, Kelly S.; Chen, Steven X.; Law, Sarah; Van Demark, Mary; Poirier, Christophe; Justice, Matthew J.; Hubbard, Walter C.; Kim, Elena S.; Lai, Xianyin; Wang, Mu; Kranz, William D.; Carroll, Clinton J.; Ray, Bruce D.; Bittman, Robert; Goodpaster, John

    2015-01-01

    The increased use of inhaled nicotine via e-cigarettes has unknown risks to lung health. Having previously shown that cigarette smoke (CS) extract disrupts the lung microvasculature barrier function by endothelial cell activation and cytoskeletal rearrangement, we investigated the contribution of nicotine in CS or e-cigarettes (e-Cig) to lung endothelial injury. Primary lung microvascular endothelial cells were exposed to nicotine, e-Cig solution, or condensed e-Cig vapor (1–20 mM nicotine) or to nicotine-free CS extract or e-Cig solutions. Compared with nicotine-containing extract, nicotine free-CS extract (10–20%) caused significantly less endothelial permeability as measured with electric cell-substrate impedance sensing. Nicotine exposures triggered dose-dependent loss of endothelial barrier in cultured cell monolayers and rapidly increased lung inflammation and oxidative stress in mice. The endothelial barrier disruptive effects were associated with increased intracellular ceramides, p38 MAPK activation, and myosin light chain (MLC) phosphorylation, and was critically mediated by Rho-activated kinase via inhibition of MLC-phosphatase unit MYPT1. Although nicotine at sufficient concentrations to cause endothelial barrier loss did not trigger cell necrosis, it markedly inhibited cell proliferation. Augmentation of sphingosine-1-phosphate (S1P) signaling via S1P1 improved both endothelial cell proliferation and barrier function during nicotine exposures. Nicotine-independent effects of e-Cig solutions were noted, which may be attributable to acrolein, detected along with propylene glycol, glycerol, and nicotine by NMR, mass spectrometry, and gas chromatography, in both e-Cig solutions and vapor. These results suggest that soluble components of e-Cig, including nicotine, cause dose-dependent loss of lung endothelial barrier function, which is associated with oxidative stress and brisk inflammation. PMID:25979079

  3. Inhibition of airway surface fluid absorption by cholinergic stimulation

    PubMed Central

    Joo, Nam Soo; Krouse, Mauri E.; Choi, Jae Young; Cho, Hyung-Ju; Wine, Jeffrey J.

    2016-01-01

    In upper airways airway surface liquid (ASL) depth and clearance rates are both increased by fluid secretion. Secretion is opposed by fluid absorption, mainly via the epithelial sodium channel, ENaC. In st