PubMed Health⌕ Search

Biomedical subjects

Markus Heilig

Publications and source records attributed to Markus Heilig.

At least 37 records · Page 2Linked to original sources
PubMed2004

The NPY system in stress, anxiety and depression.

NPY antagonizes behavioral consequences of stress through actions within the brain. Behavioral anti-stress actions of NPY are noteworthy in that (1) their magnitude surpasses that of other endogenous compounds; (2) they are produced across a wide range of animal models, normally thought to reflect different aspects of emotionality. This suggests that NPY acts with a high potency on a common core mechanism of emotionality and behavioral stress responses. Behavioral studies in genetically modified animals support this hypothesis. Increased emotionality is seen upon inactivation of NPY transmission, while the opposite is found when NPY signalling is made overactive. Several brain structures are involved in mediating anti-stress actions of NPY, with the most extensive evidence available for amygdala and hippocampus, and some evidence for regions within the septum, and locus coeruleus. Antistress actions of NPY are mimicked by Y1-receptor agonists, and blocked by Y1 antagonists, although Y5 receptors may substitute for Y1 actions in some cases. Blockade of Y2 receptors produces anti-stress effects indistinguishable from those produced by Y1 agonism, presumably through potentiation of presynaptic release of endogenous NPY. Together, available data point to the potential of the NPY system as a target for novel pharmacological treatments of stress-related disorders, including anxiety and depression. Development of Y2 antagonists presently appears to offer the most promising strategy for developing these clinical treatments.

Animals↗
PubMed2004

Corticotropin-releasing hormone (CRH) mRNA expression in rat central amygdala in cannabinoid tolerance and withdrawal: evidence for an allostatic shift?

Chronic treatment with cannabinoid agonists leads to tolerance. One possible mechanism for this is receptor internalization, but tolerance has also been reported with compounds that only cause internalization to a low degree. Furthermore, cannabinoid antagonist administration precipitates a characteristic withdrawal syndrome in tolerant subjects, accompanied by neuronal activation and enhanced release of corticotropin-releasing hormone (CRH) in the central amygdala. The underlying molecular mechanisms are unknown. We examined the role of cannabinoid tolerance and withdrawal for the expression of the cannabinoid 1 (CB1) receptor and of CRH in rats. Tolerance was first established functionally. An acute dose (100 microg/kg) of the CB1 agonist HU-210 suppressed locomotor activity, and had an anxiogenic-like effect on the elevated plus-maze. Both effects were absent following daily treatment with the same agonist or a lower (40 microg/kg) dose for 14 days. Next, withdrawal was reliably precipitated by a single dose (3 mg/kg) of the CB1 antagonist SR141716A in rats treated subchronically with 14-day HU-210. Using in situ hybridization, a robust suppression of CB1 mRNA expression was found in the caudate-putamen, indicating a downregulation of CB1 expression levels as one mechanism for tolerance to the locomotor suppressant effects of HU-210. The CRH transcript was upregulated in the central amygdala in precipitated withdrawal compared to nonwithdrawn tolerant subjects, suggesting that increased gene expression contributes to the previously reported CRH release in withdrawal. Most importantly, this increase occurred from a suppressed level in tolerant subjects, and behavioral signs of withdrawal, presumably mediated by CRH, were seen at the CRH expression that had only returned to normal nontolerant levels. This suggests the possibility of an allostatic shift, as previously proposed on theoretical grounds. The expression of CRH-R1, CRH-R2alpha, NPY, and its Y1 receptor mRNA was analyzed in search of neural substrates for the allostatic shift observed, but did not seem to contribute to the dysregulated state.

Amygdala↗
PubMed2004

Beliefs and reality: detection and prevention of high alcohol consumption in Swedish antenatal clinics.

BACKGROUND: Public antenatal care (ANC) clinics in Sweden contribute to low prenatal mortality and morbidity, through early detection of somatic risk factors, and referral to appropriate specialized care. Available statistics indicate, however, that this system is ineffective in dealing with psychosocial health problems, such as hazardous drug and alcohol use. Factors underlying this failure have not been explored. METHODS: An anonymous survey was carried out among all 207 ANC midwives in Stockholm County to establish their level of training within this problem area, clinical experience, theoretical clinical strategies, and actual clinical actions. FINDINGS: Responses indicate that ANC midwives: 1. are well aware of the health hazards of drug and alcohol use during pregnancy; 2. confirm having met and cared for subjects with hazardous substance use; 3. are familiar with specialized care resources available for this patient category; 4. make adequate choices regarding clinical action, i.e. problem identification and referral to specialized care, in hypothetical situations of encountering this patient category; 5. report consistent failure to actually exercise these choices in real clinical situations. CONCLUSIONS: A structured, clinically acceptable methodology needs to be developed in order for ANC clinics to fulfill their mission in the area of hazardous substance use in pregnant women.

Adult↗
PubMed2003

Attenuation of ethanol self-administration and of conditioned reinstatement of alcohol-seeking behaviour by the antiopioid peptide nociceptin/orphanin FQ in alcohol-preferring rats.

RATIONALE: Nociceptin/orphanin FQ (N/OFQ), the endogenous ligand of the opioid-like orphan receptor NOP, was shown to reduce home-cage ethanol consumption, ethanol-induced conditioned place preference and stress-induced reinstatement of alcohol-seeking behaviour. OBJECTIVES: The present study, using genetically selected Marchigian Sardinian alcohol-preferring (msP) rats, was designed to evaluate the effect of this opioid peptide on 10% ethanol and 10% sucrose self-administration, under a fixed-ratio 1 (FR 1) or a progressive-ratio (PR) schedule of reinforcement. Furthermore, using an experimental model of relapse in which rats were trained to lever press for ethanol in the presence of the discriminative stimulus of an orange odour (S(+)) and a 1-s cue light (CS(+)) or for water in the presence of anise odour (S(-)) and 1-s white noise (CS(-)), the effect of N/oFQ on cue-induced reinstatement of extinguished ethanol responding was investigated. RESULTS: Sub-chronic (6 days) intracerebroventricular (i.c.v.) injection of 0.5 microg or 1.0 microg N/OFQ per rat significantly reduced alcohol self-administration under both the FR 1 and PR schedules of reinforcement. Conversely, i.c.v. administration of 0.5, 1.0 or 4.0 microg of the peptide per rat did not affect sucrose self-administration. In addition, i.c.v. N/OFQ (1.0-2.0 microg per rat) significantly inhibited the reinstatement of extinguished ethanol responding under an S(+)/CS(+) condition, whereas lever pressing under S(-)/CS(-) was not altered. CONCLUSIONS: The present study demonstrates that the reinforcing effects of ethanol are markedly blunted by activation of the opioidergic N/OFQ receptor system. Moreover, the data provide evidence of the efficacy of N/OFQ to prevent reinstatement of ethanol-seeking behaviour elicited by environmental conditioned stimuli.

Alcohol Drinking↗
PubMed2003

Behavioural analysis of melanin-concentrating hormone in rats: evidence for orexigenic and anxiolytic properties.

Melanin-concentrating hormone (MCH) is a cyclic neuropeptide, predominantly expressed in hypothalamus, and recognized as a key regulator in feeding behaviour and energy balance. In this study, we examined the behavioural effects of intracerebroventricularly administered MCH on food intake, anxiety, exploratory behaviour and body core temperature in rats. MCH (0.15-10.0 microg, i.c.v.) acutely increased food intake in a dose-dependent manner. In addition, MCH (0.6-10.0 microg, i.c.v.) produced effects similar to anxiolytics in an animal model of anxiety, Vogel's punished drinking test. Thus, punished drinking episodes were significantly increased. We found no effects of MCH (5.0-20.0 microg, i.c.v.) on locomotor activity either in habituated or non-habituated animals. Furthermore, MCH did not produce any changes in body core temperature. Together, these observations further support a role for MCH as an orexigenic neuropeptide and also suggest anti-anxiety properties for MCH.

Animals↗
PubMed2003

Persistent behavioral and autonomic supersensitivity to stress following prenatal stress exposure in rats.

Prenatal restraint stress (PS) has been suggested as an attractive chronic model of anxiety. Here, we characterized the behavioral and autonomic responsivity to acute stress exposure in adult PS subjects. In Wistar rats, locomotor activity, as well as spontaneous behavior in an established animal model of anxiety, the elevated plus-maze, was unaffected by PS. However, the anxiogenic-like response normally seen on the plus-maze following a restraint stress was markedly potentiated in adult PS subjects, despite indistinguishable corticosterone responses. In addition, we assessed the tail skin temperature response to a mild social stressor, transient social mixing. The diazepam-sensitive, late phase of the temperature response was markedly potentiated in adult PS subjects. In summary, PS induces a persistent phenotype of increased behavioral and autonomic sensitivity to stress. This paradigm might serve as an attractive screening model for anti-anxiety compounds.

Animals↗
PubMed2003

1-year retention and social function after buprenorphine-assisted relapse prevention treatment for heroin dependence in Sweden: a randomised, placebo-controlled trial.

BACKGROUND: The partial opiate-receptor agonist buprenorphine has been suggested for treatment of heroin dependence, but there are few long-term and placebo-controlled studies of its effectiveness. We aimed to assess the 1-year efficacy of buprenorphine in combination with intensive psychosocial therapy for treatment of heroin dependence. METHODS: 40 individuals aged older than 20 years, who met DSM-IV criteria for opiate dependence for at least 1 year, but did not fulfil Swedish legal criteria for methadone maintenance treatment were randomly allocated either to daily buprenorphine (fixed dose 16 mg sublingually for 12 months; supervised daily administration for a least 6 months, possible take-home doses thereafter) or a tapered 6 day regimen of buprenorphine, thereafter followed by placebo. All patients participated in cognitive-behavioural group therapy to prevent relapse, received weekly individual counselling sessions, and submitted thrice weekly supervised urine samples for analysis to detect illicit drug use. Our primary endpoint was 1-year retention in treatment and analysis was by intention to treat. FINDINGS: 1-year retention in treatment was 75% and 0% in the buprenorphine and placebo groups, respectively (p=0.0001; risk ratio 58.7 [95% CI 7.4-467.4]). Urine screens were about 75% negative for illicit opiates, central stimulants, cannabinoids, and benzodiazepines in the patients remaining in treatment. INTERPRETATION: The combination of buprenorphine and intensive psychosocial treatment is safe and highly efficacious, and should be added to the treatment options available for individuals who are dependent on heroin.

Adult↗
PubMed2003

Neuropeptide systems as novel therapeutic targets for depression and anxiety disorders.

The health burden of stress-related diseases, including depression and anxiety disorders, is rapidly increasing, whereas the range of available pharmacotherapies to treat these disorders is limited and suboptimal with regard to efficacy and tolerability. Recent findings support a major role for neuropeptides in mediating the response to stress and thereby identify neuropeptide systems as potential novel therapeutic targets for the treatment of depression and anxiety disorders. In preclinical models, pharmacological and/or genetic manipulation of substance P, corticotropin-releasing factor (CRF), vasopressin, neuropeptide Y and galanin function alters anxiety- and depression-related responses. Recently, specific and highly potent small-molecule neuropeptide receptor agonists and antagonists have been developed that can readily cross the blood-brain barrier. Clinical assessment of several compounds is currently underway, with antidepressant efficacy confirmed in double-blind, placebo-controlled trials of tachykinin NK(1) (substance P) receptor antagonists, and preliminary evidence of antidepressant activity in an open-label trial of a CRF(1) receptor antagonist.

Animals↗
PubMed2003

Fetus at risk: prevalence of alcohol consumption during pregnancy estimated with a simple screening method in Swedish antenatal clinics.

AIMS: Maternal alcohol consumption is a major health hazard for the fetus. Sweden has an extensive system of public antenatal care clinics, whose mission is to detect and prevent this type of health hazards. However, very few cases of alcohol consumption during pregnancy are detected. The aim of this study was to examine the prevalence of hazardous or harmful alcohol consumption during pregnancy in a consecutive series of Swedish pregnant females. DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS: The Alcohol Use Disorders Identification Test (AUDIT) was used to collect anonymous data from consecutive pregnant subjects admitted during 1 year to an antenatal clinic in Stockholm, and signing up for parental education offered routinely (n = 1327). Data were obtained from 1101 subjects, typically in pregnancy week 30. A complete AUDIT form was filled out referring to alcohol use during the year prior to pregnancy. A separate form with the consumption items from AUDIT was filled out to report behaviour during pregnancy. FINDINGS: For the year preceding pregnancy, 17% of subjects reported AUDIT scores of 6 or higher, indicating hazardous or harmful alcohol use in women. Few individuals reported scores of 13 or higher (indicating abuse or dependence), but almost half the subjects (46%) reported binge drinking (six standard drinks on a single occasion) once/month or more often, and 6% reported binge drinking on every occasion of alcohol consumption. One-third of the subjects (30%) continued regular alcohol use during pregnancy, and 6% reported consumption two to four times/month. In a logistic regression model, AUDIT scores for the year prior to pregnancy and subject age, but not education level were significant predictors of continued alcohol use during pregnancy. CONCLUSIONS: Alcohol use during pregnancy is more extensive than has been presumed in Sweden. Simple, clinically useful screening methodology detects hazardous consumption during pregnancy in a manner which regular antenatal care does not. If this methodology can be shown to have similar sensitivity when administered under non-anonymous conditions, it should be made part of routine antenatal care.

Adult↗
PubMed2003

NPY Leu7Pro and alcohol dependence in Finnish and Swedish populations.

BACKGROUND: Neuropeptide Y (NPY) is a modulator of alcohol intake in animal models of alcoholism, and is potentially involved in alcohol dependence. A coding Leu7Pro polymorphism in the signal peptide of preproNPY has been described, and the Pro7 allele has been reported to correlate with increased alcohol consumption in non-dependent Finnish males. Recently, this polymorphism was also reported to be associated with an actual diagnosis of alcohol dependence. METHODS: We compared Pro7 allele frequencies in one Finnish (n = 135) and one Swedish (n = 472) population of alcohol dependent individuals, and ethnically matched controls (Finns: n = 213; Swedes: n = 177) in whom alcohol dependence was established, or any diagnosis of substance disorder was excluded, respectively, through the use of structured face-to-face interviews. RESULTS: Pro7 frequencies in alcoholics were 5.2 and 4.1% in Finns and Swedes, respectively, similar to the 5.0-5.5% recently reported in European Americans in a Yale study. However, corresponding frequencies in the control populations were similar, at 6.1 and 5.9% in Finns and Swedes, respectively, yielding no association, in contrast with the Yale study, where an association was reported based on a 2.0% Pro7 frequency in European American controls. A meta-analysis of available data yields Pro7 frequencies of 4.7% both in Caucasian alcoholics and Caucasian controls. CONCLUSIONS: Pro7 does not seem to be associated with a diagnosis of alcoholism in Caucasian populations.

Alcoholism↗
PubMed2003

Neuropeptide y and alcoholism: genetic, molecular, and pharmacological evidence.

This article presents the proceedings of a symposium presented at the combined meeting of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism, held in San Francisco, CA, in June 2002. The organizers and chairpersons were Subhash C. Pandey and Todd E. Thiele. The presentations were (1) Altered ethanol-induced sedation and ethanol drinking in mutant mice lacking specific NPY receptor, by Todd E. Thiele; (2) NPY in P and NP rats: polymorphism and mRNA expression, by Lucinda G. Carr; (3) The cAMP-dependent PKA in the central amygdala regulates alcohol intake through NPY gene, by Subhash C. Pandey; (4) Involvement of NPY in alcohol dependence: from animal models to human genetics, by Markus Heilig; and (5) Association of neuropeptide Y polymorphism with the occurrence of type 1 and type 2 alcoholism, by Erkki Ilveskoski.

Alcoholism↗
PubMed2003

A temporal threshold for induction of persistent alcohol preference: behavioral evidence in a rat model of intermittent intoxication.

OBJECTIVE: Development of alcohol dependence is gradual, requires prolonged exposure to alcohol and reflects neuroadaptive processes in the brain. An understanding of these neuroadaptive processes can lead to novel treatment targets. We recently showed that 7 weeks of intermittent alcohol vapor exposure in rats induces a long-lasting increase of voluntary ethanol consumption, accompanied by changes in gene expression patterns in cingulate cortex and amygdala. These findings prompt the question of whether underlying adaptive processes develop gradually over time or whether a temporal threshold exists for this phenotype conversion to occur. We addressed this question by examining the functional consequences of different exposure durations. METHOD: Male Wistar rats (N = 43) were exposed to alcohol according to the previously published protocol for 2, 4 or 7 weeks. Following 3 weeks of abstinence to eliminate effects of acute withdrawal, subjects were introduced to voluntary alcohol self-administration in a two-bottle free-choice paradigm with continuous access. RESULTS: Rats exposed to alcohol vapor for 7 weeks displayed a marked increase in voluntary ethanol consumption and a dramatic increase in ethanol preference. In rats exposed for shorter periods (2 and 4 weeks), neither ethanol self-administration nor ethanol preference were increased at any time point. CONCLUSIONS: These observations support the existence of a temporal threshold for induction of long-lasting changes in voluntary alcohol consumption. The search for underlying molecular processes should be carried out in this context.

Alcohol Drinking↗