The Experts below are selected from a list of 189 Experts worldwide ranked by ideXlab platform
Graeme Milligan - One of the best experts on this subject based on the ideXlab platform.
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The other side of opioid receptor signalling: regulation by protein-protein interaction.
Current drug targets, 2012Co-Authors: Zafiroula Georgoussi, Eirini-maria Georganta, Graeme MilliganAbstract:Opiate drugs mediate their analgesic, Euphoriant, and rewarding effects by activating opioid receptors. Pharmacological and molecular studies have demonstrated the existence of three opioid receptor subtypes, μ, δ, and κ- that couple predominantly to Gi/Go types of G proteins to regulate the activity of a diverse array of effector systems. Ample experimental evidence has demonstrated that these receptors can physically interact with a variety of accessory proteins, confirming that signal transduction of the opioid receptors is not restricted to heterotrimeric G protein activation. Such interactions can alter the effectiveness of agonist-driven cell signalling, determine the signals generated and alter the trafficking, targeting, fine tuning and cellular localization of these receptors by providing a scaffold that links the receptors to the cytoskeletal network. The current review will summarize opioid receptor interacting partners and their role as currently understood. Increasing knowledge of the mechanisms by which these interactions are regulated is expected to address problems related to phenomena such as pain perception, tolerance and dependence that occur upon chronic opiate administration and define whether disruption of such interactions may contribute to the development of novel therapeutic strategies.
Hanan Frenk - One of the best experts on this subject based on the ideXlab platform.
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Euphoriant effects of nicotine in smokers: fact or artifact?
Psychopharmacology, 2007Co-Authors: Reuven Dar, Rachel Kaplan, Lior Shaham, Hanan FrenkAbstract:Rationale The claim that nicotine in cigarettes is Euphoriant to smokers is largely based on two studies (Pomerleau and Pomerleau, Psychopharmacology, 108:460–465, 1992; Tobacco Control, 3:374, 1994) in which smokers were instructed to respond to sensations of rush, buzz, or high while smoking low-nicotine or regular cigarettes. However, the assumption that these sensations are pleasurable was not tested and may have biased the results. Objectives The aim of this study was to re-examine the claim that smoked nicotine is Euphoriant to smokers. Methods Study 1 surveyed the frequency and pleasantness of the smoking-related sensations of rush, buzz, and high in a sample of smokers. Study 2 replicated Pomerleau and Pomerleau (Psychopharmacology, 108:460–465, 1992) with two sets of instruction. One set, as in the original study, defined these sensations as pleasurable, whereas the other defined them as unpleasant. Results Study 1 found that whereas rush and high were perceived as pleasant, buzz was unpleasant to most smokers. Study 2 found that under both sets of instructions, smokers reported more sensations when smoking the regular, as compared to the low-nicotine cigarette. Additionally, the sensations of rush, buzz, and high were rated as more pleasant under the pleasant instructions as compared to the unpleasant instructions. Finally, in the pleasant instructions condition, many participants reported having pressed the button to indicate a pleasurable sensation despite having actually experienced that sensation as unpleasant. Conclusions Our results suggest that the findings of Pomerleau and Pomerleau (Psychopharmacology, 108:460–465, 1992; Tobacco Control, 3:374, 1994) may have been biased by the experimental instructions and cannot be taken as evidence that smoked nicotine is Euphoriant to smokers.
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Euphoriant effects of nicotine in smokers: fact or artifact?
Psychopharmacology, 2007Co-Authors: Reuven Dar, Rachel Kaplan, Lior Shaham, Hanan FrenkAbstract:Rationale The claim that nicotine in cigarettes is Euphoriant to smokers is largely based on two studies (Pomerleau and Pomerleau, Psychopharmacology, 108:460–465, 1992; Tobacco Control, 3:374, 1994) in which smokers were instructed to respond to sensations of rush, buzz, or high while smoking low-nicotine or regular cigarettes. However, the assumption that these sensations are pleasurable was not tested and may have biased the results.
Zafiroula Georgoussi - One of the best experts on this subject based on the ideXlab platform.
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The other side of opioid receptor signalling: regulation by protein-protein interaction.
Current drug targets, 2012Co-Authors: Zafiroula Georgoussi, Eirini-maria Georganta, Graeme MilliganAbstract:Opiate drugs mediate their analgesic, Euphoriant, and rewarding effects by activating opioid receptors. Pharmacological and molecular studies have demonstrated the existence of three opioid receptor subtypes, μ, δ, and κ- that couple predominantly to Gi/Go types of G proteins to regulate the activity of a diverse array of effector systems. Ample experimental evidence has demonstrated that these receptors can physically interact with a variety of accessory proteins, confirming that signal transduction of the opioid receptors is not restricted to heterotrimeric G protein activation. Such interactions can alter the effectiveness of agonist-driven cell signalling, determine the signals generated and alter the trafficking, targeting, fine tuning and cellular localization of these receptors by providing a scaffold that links the receptors to the cytoskeletal network. The current review will summarize opioid receptor interacting partners and their role as currently understood. Increasing knowledge of the mechanisms by which these interactions are regulated is expected to address problems related to phenomena such as pain perception, tolerance and dependence that occur upon chronic opiate administration and define whether disruption of such interactions may contribute to the development of novel therapeutic strategies.
Andrew J. Lees - One of the best experts on this subject based on the ideXlab platform.
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Changes in psychomotor effects of L-dopa and methylphenidate after sustained dopaminergic therapy in Parkinson’s disease
Journal of neurology neurosurgery and psychiatry, 2008Co-Authors: Andrew Evans, Andrew D. Lawrence, Andrew J. LeesAbstract:Background: Sustained drug therapy in Parkinson’s disease may alter the psychomotor responses to acute challenges with dopaminergic drugs, L-dopa and methylphenidate, and cause cross sensitisation. Methods: The mood, psychomotor and reward potentiating effects of an acute challenge with L-dopa and methylphenidate on separate occasions were assessed under double blind (medication naive) conditions after a placebo and then the testing sessions were repeated in the same (medication experienced) patients following a median period of 16.7 months of continuous dopaminergic drug therapy. Results: In the medication naive condition, affect was not changed by L-dopa or methylphenidate and only L-dopa improved motor function. In the medication experienced condition, active drugs improved positive affect compared with the medication naive condition and there was an enhanced effect of L-dopa on motor function. Reward responsivity was enhanced by both L-dopa and methylphenidate in medication naive and experienced conditions. Conclusion: Sustained dopaminergic drug therapy augments the motor effects of an acute challenge with L-dopa and induces Euphoriant effects to L-dopa and methylphenidate challenges.
Reuven Dar - One of the best experts on this subject based on the ideXlab platform.
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Euphoriant effects of nicotine in smokers: fact or artifact?
Psychopharmacology, 2007Co-Authors: Reuven Dar, Rachel Kaplan, Lior Shaham, Hanan FrenkAbstract:Rationale The claim that nicotine in cigarettes is Euphoriant to smokers is largely based on two studies (Pomerleau and Pomerleau, Psychopharmacology, 108:460–465, 1992; Tobacco Control, 3:374, 1994) in which smokers were instructed to respond to sensations of rush, buzz, or high while smoking low-nicotine or regular cigarettes. However, the assumption that these sensations are pleasurable was not tested and may have biased the results. Objectives The aim of this study was to re-examine the claim that smoked nicotine is Euphoriant to smokers. Methods Study 1 surveyed the frequency and pleasantness of the smoking-related sensations of rush, buzz, and high in a sample of smokers. Study 2 replicated Pomerleau and Pomerleau (Psychopharmacology, 108:460–465, 1992) with two sets of instruction. One set, as in the original study, defined these sensations as pleasurable, whereas the other defined them as unpleasant. Results Study 1 found that whereas rush and high were perceived as pleasant, buzz was unpleasant to most smokers. Study 2 found that under both sets of instructions, smokers reported more sensations when smoking the regular, as compared to the low-nicotine cigarette. Additionally, the sensations of rush, buzz, and high were rated as more pleasant under the pleasant instructions as compared to the unpleasant instructions. Finally, in the pleasant instructions condition, many participants reported having pressed the button to indicate a pleasurable sensation despite having actually experienced that sensation as unpleasant. Conclusions Our results suggest that the findings of Pomerleau and Pomerleau (Psychopharmacology, 108:460–465, 1992; Tobacco Control, 3:374, 1994) may have been biased by the experimental instructions and cannot be taken as evidence that smoked nicotine is Euphoriant to smokers.
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Euphoriant effects of nicotine in smokers: fact or artifact?
Psychopharmacology, 2007Co-Authors: Reuven Dar, Rachel Kaplan, Lior Shaham, Hanan FrenkAbstract:Rationale The claim that nicotine in cigarettes is Euphoriant to smokers is largely based on two studies (Pomerleau and Pomerleau, Psychopharmacology, 108:460–465, 1992; Tobacco Control, 3:374, 1994) in which smokers were instructed to respond to sensations of rush, buzz, or high while smoking low-nicotine or regular cigarettes. However, the assumption that these sensations are pleasurable was not tested and may have biased the results.
