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.

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.

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.

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.

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.

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.

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.

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.

Brain neuropeptide Y (NPY) in stress and alcohol dependence

Neuropeptide Y (NPY), the prototypical member of the NPY-like peptide family, antagonizes behavioral consequences of stress through actions within the brain. This was initially indicated by microinjection studies with NPY receptor ligands, suggesting that NPY Y1 receptors mediate the anti-stress effects of NPY. Behavioral anti-stress actions of NPY are note-worthy 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. These findings suggest that NPY acts with a high potency on a common core mechanism of emotionality and behavioral stress responses. This hypothesis is supported by behavioral studies in genetically modified animals. Increased emotionality, as well as increased alcohol intake, has been reported in mice with a homologous recombination knockout of the preproNPY gene. More detailed studies have been made possible by a transgenic rat system, in which NPY is selectively overexpressed within the hippocampus. These subjects display no overt phenotype under baseline conditions and have a normal endocrine stress response, but lack behavioral responses to stress. These findings point to the potential of the NPY system for developing novel pharmacological treatments of stress-related disorders, including anxiety and depression. Recent data additionally point to a role of NPY in the regulation of alcohol intake, and alcohol dependence emerges as a novel potential indication for compounds targeting the NPY system.

Blockade of central neuropeptide Y (NPY) Y2 receptors reduces ethanol self-administration in rats

Activation of central neuropeptide Y (NPY) receptors is known to produce several behavioral effects, including feeding, modulation of memory and antagonism of behavioral effects of stress. In addition, experiments in knock-out and transgenic mice have suggested a possible role of NPY regulation of voluntary ethanol intake. NPY receptors involved in this action are not known. Here, we examined the effects of a selective NPY-Y2 receptor antagonist, BIIE0246, on operant responding for ethanol in a sweetened solution, or the sweetened solution without ethanol, during 30 min sessions of free choice between the two. BIIE0246 produced a robust suppression of responding for ethanol (40% reduction, P=0.013) at an intracerebroventricular dose of 1.0 nmol, but not 0.3 nmol. Responding for the saccharin solution was not significantly affected. The dose range examined was selected since preliminary experiments with doses of 3 nmol and higher indicated sedative effects, but such effects were absent up to 1.0 nmol, as shown by unaffected exploratory locomotor activity. In summary, antagonism at central NPY-Y2 receptors seems to selectively suppress operant self-administration of ethanol. This suggests that Y2 receptors might be candidate targets for developing novel pharmacological treatments of alcoholism.

The dual-diagnosis concept used by Swedish social workers: limited validity upon examination using a structured diagnostic approach

A co-existence of chemical dependence and other psychiatric syndromes is commonly referred to as "dual-diagnosis." This categorization is commonly made by social workers in several European countries assigned the primary responsibility for the care of drug and alcohol dependence. Here, we examined the validity of this categorization through systematic, structured patient evaluation following a minimum of 3 weeks of abstinence from drugs and alcohol. Less than one-third of patients originally labelled as suffering from "dual-diagnosis" by the social services did in fact obtain any Axis I DSM IIIR diagnosis, and less than half of the patients had any psychiatric diagnosis other than dependence. Syndromes commonly discussed in the context of self-medication, i.e., unipolar depression and anxiety syndromes, were not over-represented compared to a population sample, while chronic psychoses and bipolar syndromes were highly significantly more common. We conclude that the dual-diagnosis concept, unless substantiated through stringent diagnostic procedures by psychiatrically trained personnel, may be of questionable utility in caring for patients presenting with psychiatric symptoms and substance dependence. A systematic individual evaluation in an alcohol- and drug-free state of sufficient duration is necessary to obtain a basis for an adequate individual treatment plan.

Diverse functions of neuropeptide Y revealed using genetically modified animals

Neuropeptide Y (NPY), a peptide abundantly expressed in the mammalian nervous system, has been extensively studied using traditional pharmacological and behavioral models. Central administration of NPY or synthetic ligands for its receptors has indicated a role of NPY in anxiety-related behaviors, feeding, regulation of blood pressure, circadian rhythm and other functions. Some limitations inherent in pharmacological approaches, such as lack of selectivity of receptor antagonists, can be elegantly circumvented using genetically modified animals. For NPY, mice lacking NPY, the Y1, the Y2 or the Y5 receptors have been generated. In addition, both mice and rats overexpressing NPY in the central nervous system are available. Here, we review the research carried out so far in the NPY-field using genetically modified animals. Together, these models indicate that stress-related behaviors and regulation of voluntary alcohol intake perhaps are among the most important functions of central NPY, and may provide attractive targets for developing novel therapies in depression, anxiety disorders and alcohol dependence.

Leptin suppression of hypothalamic NPY expression and feeding, but not amygdala NPY expression and experimental anxiety

Leptin decreases food intake through actions in the hypothalamus, partly through interactions with neuropeptide Y (NPY). However, NPY also produces behavioral antistress effects mediated inter alia through the amygdala. If leptin generally suppresses NPY function, the utility of leptin-mimics for treatment of obesity might be limited. Here, we therefore compared the effects of intracerebroventricular leptin on hypothalamic and amygdala NPY expression, as well as the respective related behaviors, i.e., feeding and experimental anxiety. Rats were injected intracerebroventricularly with leptin once daily for 6 days. Leptin-treated subjects consumed significantly less chow and had reduced body weight at the end of the treatment period compared to saline-treated controls. This was accompanied by a significant suppression of hypothalamic NPY expression. In contrast, the expression of NPY within the amygdala was unaffected by leptin. In parallel, in an established animal model of anxiety, the elevated plus-maze, no effect of leptin on anxiety-related behaviors was observed. In conclusion, leptin selectively affects the hypothalamic NPY system and its functional outflow, i.e., feeding and endocrine stress responses. Despite modifying endocrine responses, leptin treatment does not affect behavioral measures of experimental anxiety.

Effects of tiagabine and diazepam on operant ethanol self-administration in the rat

OBJECTIVE

Benzodiazepines (BDZ) are widely used in the treatment of anxiety and ethanol withdrawal. It has been suggested that this class of compounds may increase the reinforcing value of ethanol; however, the literature is scarce. Tiagabine has recently been introduced into clinical use as an anti-epileptic drug. It acts through inhibiting gamma-aminobutyric acid (GABA) reuptake, and thus represents a pharmacodynamically novel principle for potentiating GABAergic transmission. The objective of the present study was to examine whether these two manners of modulating GABAergic transmission would affect ethanol self-administration in rats.

METHOD

Rats were trained on an operant oral ethanol self-administration task in a two-lever free-choice paradigm. When trained, subjects were treated with tiagabine (2, 6 and 18 mg/kg, intraperitoneally [i.p.]) or diazepam (0.5, 1.5 and 4.5 mg/kg, i.p.). Postsession blood alcohol concentrations and locomotor activity measures also were obtained.

RESULTS

At nonsedating doses, neither tiagabine nor diazepam affected operant ethanol self-administration. At the highest doses (18 and 4.5 mg/kg, respectively), both drugs suppressed ethanol self-administration but also induced significant suppression of locomotion, indicative of sedation.

CONCLUSIONS

Systemic administration of either the GABA-uptake blocker, tiagabine, or the GABA/BDZ agonist, diazepam, at nonsedating doses does not seem to affect oral ethanol self-administration.

Long-lasting increase in voluntary ethanol consumption and transcriptional regulation in the rat brain after intermittent exposure to alcohol

Prolonged exposure of the brain to ethanol is a prerequisite for developing ethanol dependence, but the underlying neural adaptations are unknown. Here we demonstrate that rats subjected to repeated cycles of intoxication and withdrawal develop a marked and long-lasting increase in voluntary ethanol intake. Exposure-induced but not spontaneous alcohol intake is antagonized by acamprosate, a compound clinically effective in human alcoholism. Expression analysis of cingulate cortex and amygdala reveals a set of long-term up-regulated transcripts in this model. These include members of pathways previously implicated in alcohol dependence (glutamatergic, endocannabinoid, and monoaminergic neurotransmission), as well as pathways not previously thought to be involved in this disorder (e.g., members of the mitogen-activated protein kinase pathway). Thus, alternating periods of ethanol intoxication and withdrawal are sufficient to induce an altered functional brain state, which is likely to be encoded by long-term changes in gene expression. These observations may have important implications for how alcoholism is managed clinically. Novel clinically effective treatments may be possible to develop by targeting the products of genes found to be regulated in our model.

Anxiogenic-like action of centrally administered glucagon-like peptide-1 in a punished drinking test

A role for glucagon-like peptide-1 (GLP-1) has been postulated in the regulation of blood glucose and satiety. In addition, intracerebroventricular administration of GLP-1 has been shown to suppress locomotor activity, and produce a neuronal activation in the amygdala, a structure involved in mechanisms of fear and anxiety. Adult male Sprague-Dawley rats were prepared with chronic intracerebroventricular cannulae. Measures of experimental anxiety were assessed by the Vogel conflict test and the elevated plus maze. Central GLP-1 (fragment 7-36) administration produces a proconflict effect in the punished drinking test, while leaving measures of activity and nociception unaffected. GLP-1 may participate in the control of fear-induced suppression of behavior, probably via action in the amygdala.

Factors Affecting the Short-Term Prognosis of Alcohol Dependent Patients Undergoing Inpatient Detoxification

Stable measures of psychological functioning require a considerable period of abstinence. However, the duration of inpatient detoxification programs has decreased dramatically in most health care systems, posing a novel challenge for clinical evaluation of patients. The present study was carried out to examine whether factors predicting short-term prognosis can be identified in alcohol dependent subjects during early stages of inpatient detoxification. Self-reports of mood states were obtained, and executive cognitive functioning was examined. Outcome was studied at 2-3 months. No correlation was found between self-reported symptoms of depression, hopelessness, and anxiety, and percentage of nondrinking days. A significant positive correlation was found between Wisconsin Card Sorting Test (WCST) performance and short-term prognosis measured by this parameter. Thus, in addition to transient withdrawal-related effects, impairments of WCST performance in early stages of alcohol detoxification may reflect more long standing deficits in problem-solving strategies, of possible relevance for matching patients to treatment services.

Differential expression of NPY and its receptors in alcohol-preferring AA and alcohol-avoiding ANA rats

BACKGROUND

Central neuropeptide Y (NPY) is known to control feeding and stress responses. Recently, it has been suggested that NPY also has a role in regulation of alcohol consumption.

METHODS

NPY and NPY receptor expression in genetically selected alcohol-preferring (AA), alcohol-nonpreferring (ANA), and Wistar rats were investigated. Expression was assessed using in situ hybridization histochemistry with riboprobes specific for preproNPY, Y1, and Y2 receptors. Effects of central NPY administration on ethanol self-administration were also examined in AA, ANA, and Wistar rats by using oral operant self-administration.

RESULTS

NPY mRNA expression was higher in ANA than in both AA and Wistar rats in the hippocampal CA region and dentate gyrus, whereas AA and Wistar did not differ from each other. No differences in NPY expression were found in the other regions analyzed: cingulate cortex, medial nucleus of the amygdala, arcuate, and paraventricular nuclei of the hypothalamus. Y1 receptor mRNA expression did not differ between the three lines. Y2 expression was higher in the dentate gyrus of both AA and ANA rats than in Wistar subjects. In the medial amygdala, Y2 mRNA was reduced in the AA line, compared to both ANA and Wistar rats. NPY injected intracerebroventricularly (1.5-3.0 nmol) did not affect operant ethanol self-administration in any of the three lines examined.

CONCLUSION

The NPY system seems to differ in several respects between rat lines with different levels of alcohol preference. Differences observed within the hippocampus could be related to behavioral traits other than alcohol intake but it is also possible that elevated hippocampal expression of NPY in the ANA rats contributes to the low alcohol intake of this line. Aberrant NPY expression and/function within the amygdala complex could contribute to alcohol preference and constitute an anatomic substrate of the effects of NPY expression on alcohol intake observed previously in genetically modified animals.

Neuropeptide Y (NPY) mRNA in rat brain tissue: effects of decapitation and high-energy microwave irradiation on post mortem stability

mRNA recovery from brain tissue is affected by time-interval from death to inactivation of tissue, and may depend on sacrificial method. Sacrifice by high-energy microwave irradiation increases recovery of intact neuropeptides and proteins, and it has been suggested that this may be valid also for neuropeptide mRNAs. We therefore compared post-mortem NPY mRNA recovery following decapitation or microwave irradiation. Total RNA yield was significantly higher in tissue from decapitated rats. A decline in NPY mRNA (amol/mg tissue) over time, presumably reflecting degradation, was found in frontal cortex, hippocampus and striatum. Following high-energy microwaves, NPY message levels were higher in occipital cortex, lower in the hypothalamus, and unaltered in the other brain regions examined. These results show that post-mortem processes contribute to estimates of NPY mRNA levels obtained using standard methods for obtaining brain tissue from experimental animals and raise the question whether different pools of NPY mRNA might be differentially affected by post-mortem degradation. A general protective effect of high-energy radiation against degradation is not supported.

Pharmacological studies on the monoaminergic influence on the synthesis and expression of neuropeptide Y and corticotropin releasing factor in rat brain amygdala

Our earlier findings concerning the 6-OHDA lesion suggested dopaminergic regulation of neuropeptide Y (NPY) and corticotropin releasing factor (CRF) synthesis and expression in amygdala neurons. On the other hand, some other studies indicated that not only dopamine, but also other monoamines may modulate peptidergic neurons. Therefore the present study examined the effect of pharmacological deprivation of monoaminergic influences on NPY and CRF neurons in rat brain amygdala by means of in situ hybridization and immunohistochemical methods. It was found that NPY mRNA expression in the amygdala decreased after 24h blockade of dopaminergic D1 and D2 receptors, by haloperidol or SCH23390. At the same time the NPY-peptide expression measured immunohistochemically was not significantly changed. A prolonged, 14-day, blockade of dopaminergic receptors by haloperidol induced an opposite effect, an increase in NPY mRNA expression. Impairment of the serotonergic transmission by blockade of 5-HT synthesis using p-chlorophenylalanine, as well as attenuation of the noradrenergic transmission by NA depletion from terminals by DSP4, did not significantly change NPY mRNA expression or the mean number of NPY-immunoreactive neurons in the amygdala. Only a decrease in the staining intensity observed as a decreased number of darkly stained neurons was found after both compounds. Neither the dopamine receptor blockade nor the impairment of serotonergic or noradrenergic transmission changed CRF mRNA or the peptide expression in the amygdala. The obtained results indicate that in rat brain amygdala, of all the monoamines, dopamine seems to be the most important modulator of NPY biosynthesis and expression. The effect of blockade of dopaminergic receptors is biphasic: first it induces a decrease and then - after prolonged treatment an increase in NPY mRNA. Serotonergic and noradrenergic systems in the amygdala seem to be connected with regulation of NPY release rather than the biosynthesis.

Local 5,7-dihydroxytryptamine lesions of rat amygdala: release of punished drinking, unaffected plus-maze behavior and ethanol consumption

Several serotonergic drugs are effective for anxiety disorders, but underlying mechanisms are unclear, and findings in experimental animals are difficult to reconcile with human data. It has been proposed that differential effects of serotonin within specific anatomical systems may account for these difficulties, and the amygdala has been suggested as one of the structures involved. To examine this hypothesis, the neurotoxin 5,7-dihydroxytryptamine was administered locally in rat amygdala. Within the amygdala, serotonin was depleted by approximately 80%, with other transmitters unaffected, and serotonin transporter labelling was decreased by approximately 85%. Cortical areas near the lesion site were also affected, although to a lesser degree. Other forebrain areas were unaffected. Lesions resulted in a specific anti-conflict effect in a punished drinking test, but did not influence elevated plus-maze behavior (under baseline conditions and after restraint stress), locomotor activity or ethanol intake. These data suggest that the punished drinking test and the elevated plus-maze may activate different components of fear circuitry, and that the serotonergic input to the amygdala specifically participates in fear-related behavioral suppression mediated by this structure.

Reduction of the synaptic protein rab3a in the thalamus and connecting brain regions in post-mortem schizophrenic brains

Although the psychotic symptoms in schizophrenia can be alleviated by treatment with dopaminergic receptor antagonists, the etiology and underlying neurochemical pathology remains obscure. Both neuropathological and magnetic resonance imaging studies have found evidence for neuronal loss and atrophy in the thalamus in schizophrenia, implicating this key structure for gating information to cortical areas in the pathophysiology. Recent studies have also found evidence of synaptic loss in the thalamus in schizophrenia. To further examine possible synaptic disturbances, we studied the synaptic related protein rab3a as a marker for synaptic density, using both quantitative Western blotting and immunohistochemistry. The material consisted of brains from 22 schizophrenic patients (mean age 79.3 years), and 24 control subjects (74.8 years). Reduced rab3a protein levels were found in the left thalamus in schizophrenia (0.47 +/- 0.17 vs. 1.00 +/- 0.18; p < 0.0001), while a less marked decrease was found also in the right thalamus (0.75 +/- 0.13 vs. 1.00 +/- 0.09; p < 0.0001). Immunohistochemistry, performed on two schizophrenic and two control brains, revealed that rab3a immunoreactivity was most reduced in the left anterior and mediodorsal thalamic nuclei. Therefore, we extended the study to brain regions connected these thalamic nuclei. Reduced rab3a protein levels were found schizophrenia also in the frontal cortex, hippocampus, gyrus cinguli, and parietal cortex, while no significant differences were found in the temporal cortex, or in cerebellum. The reduction in rab3a was not found to be secondary to confounding factors such as age-differences, post-mortem delay time, generalized brain atrophy, or antipsychotic medication. Therefore, the reduction of rab3a probably reflects synaptic disturbances, possibly synaptic loss, in the limbic system and neocortical areas, in schizophrenia. This part of the brain is known to be involved in behavioral and emotional control, and thus to be crucial for higher mental functions, suggesting that synaptic disturbances in the limbic system may be of importance in the development of psychotic symptoms in schizophrenia.

Differential expression of diacylglycerol kinase iota and L18A mRNAs in the brains of alcohol-preferring AA and alcohol-avoiding ANA rats

Ethanol preference and behavioral disinhibition in AA (alcohol accepting) animals is a behavioral constellation similar to that seen in human type II alcoholism, for which considerable genetic loading has been shown. In search of novel neural substrates for this phenotype, we compared gene expression in the cerebral cortex of the AA rat with two groups of control animals, the ANA (alcohol non-accepting) line and heterogeneous Wistar animals, by differential display RT-PCR. We identified two transcripts, ribosomal protein L18a mRNA and diacyglycerol kinase iota mRNA, which are differentially expressed between AA and ANA rats. Ribosomal protein L18A mRNA is evenly expressed throughout the brain, but strongly reduced in cortex of AA rats vs controls. Diacylglycerol kinase iota is exclusively found in the brain, and expressed in a distinct regional pattern. Its cortical expression is about 25% higher in AA than ANA rats. Differential display RT-PCR seems to provide a feasible strategy to identify previously unknown genes whose differential expression correlates with behavioral phenotypes related to dependence.

Behavioral insensitivity to restraint stress, absent fear suppression of behavior and impaired spatial learning in transgenic rats with hippocampal neuropeptide Y overexpression

Exogenous neuropeptide Y (NPY) reduces experimental anxiety in a wide range of animal models. The generation of an NPY-transgenic rat has provided a unique model to examine the role of endogenous NPY in control of stress and anxiety-related behaviors using paradigms previously used by pharmacological studies. Locomotor activity and baseline behavior on the elevated plus maze were normal in transgenic subjects. Two robust phenotypic traits were observed. (i) Transgenic subjects showed a markedly attenuated sensitivity to behavioral consequences of stress, in that they were insensitive to the normal anxiogenic-like effect of restraint stress on the elevated plus maze and displayed absent fear suppression of behavior in a punished drinking test. (ii) A selective impairment of spatial memory acquisition was found in the Morris water maze. Control experiments suggest these traits to be independent. These phenotypic traits were accompanied by an overexpression of prepro-NPY mRNA and NPY peptide and decreased NPY-Y1 binding within the hippocampus, a brain structure implicated both in memory processing and stress responses. Data obtained using this unique model support and extend a previously postulated anti-stress action of NPY and provide novel evidence for a role of NPY in learning and memory.

Genetic polymorphism of alcohol dehydrogenase in europeans: the ADH2*2 allele decreases the risk for alcoholism and is associated with ADH3*1

Polymorphism at the ADH2 and ADH3 loci of alcohol dehydrogenase (ADH) has been shown to have an effect on the predisposition to alcoholism in Asian individuals. However, the results are not conclusive for white individuals. We have analyzed the ADH genotype of 876 white individuals from Spain (n = 251), France (n = 160), Germany (n = 184), Sweden (n = 88), and Poland (n = 193). Peripheral blood samples from healthy controls and groups of patients with viral cirrhosis and alcohol-induced cirrhosis, as well as alcoholics with no liver disease, were collected on filter paper. Genotyping of the ADH2 and ADH3 loci was performed using polymerase chain reaction-restriction fragment length polymorphism methods on white cell DNA. In healthy controls, ADH2*2 frequencies ranged from 0% (France) to 5.4% (Spain), whereas ADH3*1 frequencies ranged from 47. 6% (Germany) to 62.5% (Sweden). Statistically significant differences were not found, however, between controls from different countries, nor between patients with alcoholism and/or liver disease. When all individuals were grouped in nonalcoholics (n = 451) and alcoholics (n = 425), ADH2*2 frequency was higher in nonalcoholics (3.8%) than in alcoholics (1.3%) (P =.0016), whereas the ADH3 alleles did not show differences. Linkage disequilibrium was found between ADH2 and ADH3, resulting in an association of the alleles ADH2*2 and ADH3*1, both coding for the most active enzymatic forms. In conclusion, the ADH2*2 allele decreases the risk for alcoholism, whereas the ADH2*2 and ADH3*1 alleles are found to be associated in the European population.

Anxiogenic-like action of galanin after intra-amygdala administration in the rat

The neuropeptide galanin is expressed in brain structures implicated in regulation of emotionality. The amygdala is known to play a central role in mechanisms of fear and anxiety. We therefore examined the effects of galanin (0.2 and 0.6 nmol/side) on experimental anxiety upon microinjection into the amygdala. Two established animal models of anxiety were used: a punished drinking test, and the elevated plus-maze. Punished responding was dose dependently suppressed by intra-amygdala galanin, whereas unpunished responding, drinking motivation, locomotor activity, and shock thresholds were unaffected. No effects on experimental anxiety were seen in the plus-maze following galanin injection. When injected into parietal cortex, no anxiety promoting properties of galanin were detected. These data suggest that activation of galanin receptors in amygdala modulates neurotransmission involved in fear and experimental anxiety.

Behavioral and endocrine adaptation, and up-regulation of NPY expression in rat amygdala following repeated restraint stress

A single 1 h restraint increases experimental anxiety in the elevated plus-maze through actions within the amygdala, while intra-amygdala administration of neuropeptide Y (NPY) has the opposite effect. Endogenous amygdala NPY expression is suppressed by single restraint, providing a possible mechanism for the anxiety-promoting action of this stressor. Here, we examined whether repeated stressor exposure might lead to an adaptation (habituation or sensitization) with regard to plus-maze behavior and glucocorticoid response, and whether this might be accompanied by altered effects of the stressor on NPY expression. Following repeated restraint (1 h/day, 9-10 days), neither an anxiogenic-like effect of the stressor nor a glucocorticoid response were present. This behavioral and endocrine adaptation was accompanied by an up-regulation of prepro-NPY mRNA and NPY peptide in amygdala but not in hypothalamic or cortical extracts, an effect opposite to that previously seen after a single restraint session. Thus, an up-regulation of NPY expression in the amygdala complex may be an adaptive mechanism recruited to cope with a repeated stressor.

Lipid mediated gene delivery in the adult rat brain: quantitative analysis of expression

Gene transfer into the adult brain is potentially an attractive alternative to commonly employed transgenic approaches. DNA-lipid complexes have been used to obtain brain gene transfer, but data are sparse to indicate to what extent this results in significant expression of functional protein. Here, an expression construct encoding the functional reporter, chloramphenicol-acetyl-transferase (CAT), was complexed to a novel biodegradable lipid, and delivered into the rat brain. CAT-activity was assayed in tissue extracts to allow a precise quantitation of functional enzyme protein. Following bilateral intraventricular (i.c.v.) injection, robust enzyme activity was found in all brain regions studied, peaking at 4 weeks. Other routes of administration, e.g. intra-parenchymal injection or chronic infusion of complexes, resulted in marginal or no activity. Presence of CAT mRNA and plasmid DNA in tissue extracts was confirmed at 4 weeks post i.c.v. administration. In agreement with previous studies, labelled lipid-DNA complexes were mainly found in the ventricular ependyma. Present data support the feasibility of lipid mediated brain gene transfer, and outline some of its anatomical and temporal limitations.

[Antisense oligonucleotides are clinically tested. They inhibit the expression of disease-related genes]

Recent advances in molecular biology have improved our understanding of basic pathophysiological mechanisms, and indicated possible strategies for their manipulation. The use of oligonucleotides occupies a prominent position among the emerging strategies, and has given rise to a new generation of pharmaceutical preparations now entering clinical usage. Antisense oligonucleotides are capable of blocking the expression of specific genes, thus permitting highly precise intervention in pathophysiology at the molecular level. Several clinical trials have recently produced highly promising results. The most likely applications of antisense agents are viral infections, malignancies, and chronic inflammatory disease. The article consists in a presentation of the antisense principle, discussion of its advantages and limitations, and a review of recent clinical developments and future prospects.

High doses of testosterone increase anticonflict behaviour in rat

Male rats exposed to high levels of testosterone for 8 weeks, or to one high dose of testosterone 24 h before testing, displayed an increase in punished responding in the Vogel conflict test. The findings may be taken as indirect support for the assumption that the conflict paradigm reflects not only anxiety but also impulsivity.

Suppressed neuropeptide Y (NPY) mRNA in rat amygdala following restraint stress

We have previously demonstrated that NPY produces anxiolytic-like effects through actions in the amygdala, and that anxiogenic-like effects of restraint stress are mediated through this structure. Here, we examined the effects of restraint stress on NPY mRNA levels in amygdala and several other brain regions. A sensitive solution hybridization-RNase protection assay (RPA) was developed, employing a combination of internal and external standards, which allowed absolute quantitation of NPY mRNA in tissue-samples of less than 10 mg. NPY mRNA levels were determined, following a 1-h restraint stress, in homogenates of tissue from the amygdala, neocortex, striatum and hypothalamus, and the time course of these effects was examined. A highly significant decrease in NPY-mRNA levels was seen in the amygdala at 1 h and 2 h following restraint, with levels returning to normal within 10 h. A similar effect was seen in the neocortex, but was less pronounced and slower in onset. Striatal and hypothalamic NPY expression was not significantly affected. Tissue levels of NPY-peptide were modestly decreased in the amygdala at 1 h following restraint and had returned to normal within 4 h. The present findings support the hypothesis that anxiety related behavioral effects of stress may in part be mediated through modulation of NPY function in the amygdala.

Central administration of dopamine D3 receptor antisense to rat: effects on locomotion, dopamine release and [3H]spiperone binding

A 15-mer, all-phosphorothioate-modified antisense oligodeoxynucleotide (ASO) targeted against rat dopamine D3 receptor mRNA (4 microM, 5 days) significantly reduced (28%) the amount of binding sites labelled with [3H]spiperone in monolayer cultured Chinese hamster ovary (CHO) cells transfected with the complementary desoxyribonucleic acid (cDNA) for the rat D3 receptor. In contrast, D3-ASO treatment did not reduce the amount of bound [3H]spiperone in CHO cells transfected with D2 receptor cDNA. Intracerebroventricular infusion of D3-ASO (osmotic minipump, 10 microg/microl/h, 7 days) influenced dopamine receptor density in the limbic forebrain such that the upper part of the dopamine/[3H]spiperone displacement curve--tentatively representing the D3 receptor--was altered significantly. Spontaneous locomotor activity of non-habituated rats was increased significantly in D3-ASO-treated animals; in addition, in vivo microdialysis revealed a moderate increase in dopamine release in the nucleus accumbens in these animals. In all experiments, an oligodeoxynucleotide comprising the same nucleotides as the antisense sequence, but in random order, was used as control. It is concluded that the antisense strategy is useful for investigating the functional role of dopamine D3 receptors and that the dopamine D3 receptor is involved in rat locomotor behaviour.

The spread and uptake pattern of intracerebrally administered oligonucleotides in nerve and glial cell populations of the rat brain

The fate of 15-mer phosphorothioate-modified antisense oligonucleotides to c-fos was followed after their microinjection into rat brain. Using radiolabeled oligonucleotides, it was demonstrated that the bulk of the material stays in the injected region but that a minor part is transported with the projection pathways to regions far away from the site of injection. Using tetramethylrhodamine-isothiocyanate (TRITC) labeling as well as fluorescein isothiocyanate (FITC) labeling, it was found that the oligonucleotides were taken up by a great number of cells within 30 minutes after the injection. A diffuse cytoplasmic staining and also nuclear staining were observed in these cells, which could be identified exclusively as neurons by double labeling for the neuron-specific protein NeuN. At later times (6, 24, and 48 hours), the appearance of the oligonucleotides changed gradually to a punctate cytoplasmic staining, which by electron microscopic analysis was shown to be caused by the presence of the oligonucleotides in intracellular vesicles. The pattern of intracellular fluorescence was changed when the oligonucleotides were injected together with the cationic lipid 1,2-bis(oleoyloxy)-3-(trimethylammonio)propane (DOTAP). A small number of astrocytes and microglial cells were found to be labeled by the oligonucleotides, but only at later times after the injection and exclusively in a punctate cytoplasmic manner. Thus, the uptake of oligonucleotides in the nerve and glial cell populations of the brain might involve different mechanisms, the one in the neurons appearing to be very rapid and potent.

Involvement of a c-fos-dependent mechanism in caffeine-induced expression of the preprotachykinin A and neurotensin/neuromedin N genes in rat striatum

Striatal c-fos induction was blocked by local administration of phosphorothioated c-fos antisense oligonucleotides (AS-ODN) to examine the possible role of caffeine-induced c-fos expression in transcriptional regulation of striatal preproenkephalin, prodynorphin, preprotachykinin A and neurotensin/neuromedin N. Caffeine (100 mg/kg i.p.) induced both c-fos mRNA and Fos-protein, and this induction was significantly attenuated by intrastriatal injection of 4 (but not 1) nmol c-fos AS-ODN. This suggests that, in addition to translational arrest, other mechanisms may be involved in the mediation of antisense action. The action of the AS-ODN was sequence specific. The antisense blockade of c-fos reduced the effect of caffeine on the expression of mRNAs for preprotachykinin A and neurotensin/neuromedin N in the ventrolateral caudate-putamen. Levels of preproenkephalin and prodynorphin transcripts were unaffected. Thus caffeine induction of striatal preprotachykinin A mRNA and neurotensin/neuromedin N mRNA, but not of preproenkephalin mRNA or prodynorphin mRNA, may at least in part be mediated by a pathway involving Fos protein. The findings illustrate the utility of blockade of gene expression with antisense oligonucleotides for in vivo studies of drug actions.

Decreased experimental anxiety and voluntary ethanol consumption in rats following central but not basolateral amygdala lesions

A long-debated 'tension reduction' hypothesis postulates anti-anxiety effects to be important for ethanol reward, and states that elevated anxiety levels might predispose for ethanol consumption and addiction. Human data are contradictory, possibly due to heterogeneity of patient samples. In rats, baseline levels of experimental anxiety have been reported to correlate with voluntary ethanol consumption. Here, we addressed the possibility that mechanisms underlying experimental anxiety might be causally related to regulation of voluntary ethanol intake. Rats were bilaterally lesioned in central amygdala using microinjections of ibotenic acid. This resulted in a robust release of punished drinking in a modified Vogel conflict test, an effect typically seen with anxiety reducing drugs. This effect was specific, as unpunished drinking was unaffected by the lesion. On the elevated plus-maze, central amygdala lesions did not affect behaviour under baseline conditions, but attenuated the anxiogenic effect of restraint stress. Measures of locomotor activity were not affected. Voluntary ethanol consumption was examined in a two-bottle, free choice paradigm. Ethanol intake was markedly decreased in the lesion group. Total fluid intake was not affected. Basolateral amygdala lesions, which did not affect conflict behaviour, also left ethanol intake unaffected. These results are consistent with previous reports of an important role for central amygdala in anxiety related behaviours, and suggest that cell bodies located in central amygdala might be important in this context. Further, our results support a relation between experimental anxiety and voluntary ethanol consumption.