Phenotypic variation in biting behavior associated with differences in expression of olfactory genes in the vector mosquito, Aedes albopictus (Diptera: Culicidae)

We evaluated miRNA and mRNA expression differences in head tissues between avid-biting vs. reluctant-biting Aedes albopictus (Skuse) females from a single population over a 20-min timescale. We found no differences in miRNA expression between avid vs. reluctant biters, indicating that translational modulation of blood-feeding behavior occurs on a longer timescale than mRNA transcription. In contrast, we detected 19 differentially expressed mRNAs. Of the 19 differentially expressed genes at the mRNA level between avid-biting vs. reluctant-biting A. albopictus, 9 are implicated in olfaction, consistent with the well-documented role of olfaction in mosquito host-seeking. Additionally, several of the genes that we identified as differentially expressed in association with phenotypic variation in biting behavior share similar functions with or are inferred orthologues of, genes associated with evolutionary variation in biting behaviors of Wyeomyia smithii (Coq.) and Culex pipiens (Lin.). A future goal is to determine whether these genes are involved in the evolutionary transition from a biting to a non-biting life history.

Efficient RNAi knockdown at 20 °C in Aedes albopictus (Diptera: Culicidae)

RNA interference (RNAi) is a conserved cellular pathway found in nearly all eukaryotes that leads to the silencing of target mRNAs. Using RNAi as a mechanism to knockdown specific genes has enabled functional and reverse genetics studies in a wide range of eukaryotes. Previous work suggests that RNAi is inhibited at lower temperatures, potentially limiting the possibility to perform knockdown studies on ecologically relevant phenotypes that are only expressed at low temperatures. To determine whether RNAi is inhibited at low temperatures in Aedes albopictus (Skuse), we injected mosquitoes reared at 20 ± 1 °C, with dsRNA targeting yellow-g2 and compared knockdown efficacy to mosquitoes injected at 26.5 ± 1 °C. Our results demonstrate efficient knockdown at both temperatures, thereby establishing the feasibility of RNAi for functional genetic studies in A. albopictus at low temperatures.

Improved piggyBac Transformation with Capped Transposase mRNA in Pest Insects

Creating transgenic insects is a key technology in insect genetics and molecular biology. A widely used instrument in insect transgenesis is the piggyBac transposase, resulting in essentially random genomic integrations. In contrast, site-specific recombinases allow the targeted integration of the transgene construct into a specific genomic target site. Both strategies, however, often face limitations due to low transgenesis efficiencies. We aimed to enhance transgenesis efficiencies by utilizing capped mRNA as a source of transposase or recombinase instead of a helper plasmid. A systematic comparison of transgenesis efficiencies in Aedes mosquitoes, as models for hard-to-transform insects, showed that suppling piggyBac transposase as mRNA increased the average transformation efficiency in Aedes aegypti from less than 5% with the plasmid source to about 50% with mRNA. Similar high activity was observed in Ae. albopictus with pBac mRNA. No efficiency differences between plasmid and mRNA were observed in recombination experiments. Furthermore, a hyperactive version of piggyBac transposase delivered as a plasmid did not improve the transformation efficiency in Ae. aegypti or the agricultural pest Drosophila suzukii. We believe that the use of mRNA has strong potential for enhancing piggyBac transformation efficiencies in other mosquitoes and important agricultural pests, such as tephritids.

Does acute stress play a role in the lasting therapeutic effects of psychedelic drugs?

Psychedelic drugs, when used in the context of psychotherapy, can produce significant and long-lasting memories with enduring beneficial effects. Yet, the behavioral and neurobiological mechanisms that underlie these beneficial effects remain a mystery. Here, we suggest that both the quality and durability of memories of the drug-facilitated therapeutic experience may be mediated, in part, by the acute stress responses induced by the drugs. It is known that high doses of psychedelic drugs activate autonomic and hormonal stress responses. For evolutionarily adaptive reasons, acute stress is known to i) instill meaning to the immediate context in which it is experienced, and ii) lead to the formation of salient and lasting memories of the events surrounding the stress. Thus, the stress-inducing effect of psychedelic drugs may contribute to the reported sense of meaning, as well as the durability of the memory of the drug experience. When used in a therapeutic context these actions may i) enhance the salience of insights gained during the experience and ii) strengthen the memories formed by these experiences. Future empirical studies will help to determine whether acute stress contributes to the emotional significance and lasting effects of psychedelic-assisted psychotherapy.

Measurement of the α-Particle Monopole Transition Form Factor Challenges Theory: A Low-Energy Puzzle for Nuclear Forces?

We perform a systematic study of the α-particle excitation from its ground state 0_{1}^{+} to the 0_{2}^{+} resonance. The so-called monopole transition form factor is investigated via an electron scattering experiment in a broad Q^{2} range (from 0.5 to 5.0  fm^{-2}). The precision of the new data dramatically supersedes that of older sets of data, each covering only a portion of the Q^{2} range. The new data allow the determination of two coefficients in a low-momentum expansion, leading to a new puzzle. By confronting experiment to state-of-the-art theoretical calculations, we observe that modern nuclear forces, including those derived within chiral effective field theory that are well tested on a variety of observables, fail to reproduce the excitation of the α particle.

Germline biomarkers predict toxicity to anti-PD1/PDL1 checkpoint therapy

BACKGROUND

There is great interest in finding ways to identify patients who will develop toxicity to cancer therapies. This has become especially pressing in the era of immune therapy, where toxicity can be long-lasting and life-altering, and primarily comes in the form of immune-related adverse effects (irAEs). Treatment with the first drugs in this class, anti-programmed death 1 (anti-PD1)/programmed death-ligand 1 (PDL1) checkpoint therapies, results in grade 2 or higher irAEs in up to 25%-30% of patients, which occur most commonly within the first 6 months of treatment and can include arthralgias, rash, pruritus, pneumonitis, diarrhea and/or colitis, hepatitis, and endocrinopathies. We tested the hypothesis that germline microRNA pathway functional variants, known to predict altered systemic stress responses to cancer therapies, would predict irAEs in patients across cancer types.

METHODS

MicroRNA pathway variants were evaluated for an association with grade 2 or higher toxicity using four classifiers on 62 patients with melanoma, and then the panel's performance was validated on 99 patients with other cancer types. Trained classifiers included classification trees, LASSO-regularized logistic regression, boosted trees, and random forests. Final performance measures were reported on the training set using leave-one-out cross validation and validated on held-out samples. The predicted probability of toxicity was evaluated for its association, if any, with response categories to anti-PD1/PDL1 therapy in the melanoma cohort.

RESULTS

A biomarker panel was identified that predicts toxicity with 80% accuracy (F1=0.76, area under the curve (AUC)=0.82) in the melanoma training cohort and 77.6% accuracy (F1=0.621, AUC=0.778) in the pan-cancer validation cohort. In the melanoma cohort, the predictive probability of toxicity was not associated with response categories to anti-PD1/PDL1 therapy (p=0.70). In the same cohort, the most significant biomarker of toxicity in RAC1, predicting a greater than ninefold increased risk of toxicity (p<0.001), was also not associated with response to anti-PD1/PDL1 therapy (p=0.151).

CONCLUSIONS

A germline microRNA-based biomarker signature predicts grade 2 and higher irAEs to anti-PD1/PDL1 therapy, regardless of tumor type, in a pan-cancer manner. These findings represent an important step toward personalizing checkpoint therapy, the use of which is growing rapidly.

Live predator stress in adolescence results in distinct adult behavioral consequences and dorsal diencephalic brain activation patterns

Exposure to traumatic events during childhood increases the risk of adult psychopathology, including anxiety, depression, alcohol use disorders and their co-morbidity. Early life trauma also results in increased symptom complexity, treatment resistance and poor treatment outcomes. The purpose of this study was to establish a novel rodent model of adolescent stress, based on an ethologically relevant life-threatening event, live predator exposure. Rats were exposed to a live predator for 10 min. at three different time points (postnatal day (PND)31, 46 and 61). Adult depression-, anxiety-like behaviors and ethanol consumption were characterized well past the last acute stress event (two weeks). Behavioral profiles across assessments were developed to characterize individual response to adolescent stress. CNS activation patterns in separate groups of subjects were characterized after the early (PND31) and last predator exposure (PND61). Subjects exposed to live-predator adolescent stress generally exhibited less exploratory behavior, less propensity to venture into open spaces, a decreased preference for sweet solutions and decreased ethanol consumption in a two-bottle preference test. Additional studies demonstrated blunted cortisol response and CNS activation patterns suggestive of habenula, rostromedial tegmental (RMTg), dorsal raphe and central amygdala involvement in mediating the adult consequences of adolescent stress. Thus, adolescent stress in the form of live-predator exposure results in significant adult behavioral and neurobiological disturbances. Childhood trauma, its impact on neurodevelopment and the subsequent development of mood disorders is a pervasive theme in mental illness. Improving animal models and our neurobiological understanding of the symptom domains impacted by trauma could significantly improve treatment strategies.

Lessons learned from community-based tuberculosis case-finding in western Kenya

SETTING

Although Kenya has a high burden of tuberculosis (TB), only 46% of cases were diagnosed in 2016.

OBJECTIVE

To identify strategies for increasing attendance at community-based mobile screening units.

DESIGN

We analysed operational data from a cluster-randomised trial, which included community-based mobile screening implemented during February 2015-April 2016. Community health volunteers (CHVs) recruited individuals with symptoms from the community, who were offered testing for human immunodeficiency virus (HIV) and sputum collection for Xpert® MTB/RIF testing. We compared attendance across different mobile unit sites using Wilcoxon rank-sum test.

RESULTS

A total of 1424 adults with symptoms were screened at 25 mobile unit sites. The median total attendance among sites was 54 (range 6-134, interquartile range [IQR] 24-84). The median yields of TB diagnoses and new HIV diagnoses were respectively 2.4% (range 0.0-16.7, IQR 0.0-5.3) and 2.5% (range 0.0-33.3, IQR 1.2-4.2). Attendance at urban sites was variable; attendance at rural sites where CHVs were paid a daily minimum wage was significantly higher than at rural sites where CHVs were paid a nominal monthly stipend (P < 0.001).

CONCLUSION

Mobile units were most effective and efficient when implemented as a single event with community health workers who are paid a daily wage.

A germline microRNA-based biomarker signature of immune-associated toxicity to anti-PD1/PDL1 therapy

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Background: Treatment with anti-PD1/anti-PDL1 agents is associated with toxicity termed immune related adverse events (iRAEs). While the prevalence of Grade 2 and higher iRAEs is approximately 25-30%, biomarkers have not been previously identified. We tested the hypothesis that functional, germ-line mutations would predict iRAEs. Methods: Four classifiers were trained on a set of 61 melanoma patients evaluated for toxicity and response. Subjects were classified as experiencing high toxicity (≥ Grade 2) vs low toxicity (< Grade 2). Performance of the classifiers was tested on a validation set of 89 cancer patients with a variety of cancer types, with the most common being GU and NSCLC. Classifiers were built for each treatment of marker data including classification trees, LASSO-regularized logistic regression, boosted trees (BT), and random forests. The final performance measures, accuracy, specificity, sensitivity, negative predictive value, positive predictive value, area under the curve (AUC), and F1 score, were reported on the categorical treatment of the training data using leave-one-out cross validation on the validation data. We also evaluated the association between our most significant toxicity biomarker and response to anti-PD1/PDL1 therapy. Results: Within the melanoma training sample, we found a biomarker signature where toxicity is predicted with 79.0% accuracy (F1 = .714, AUC = .827) using BT. The same biomarker panel also accurately predicted toxicity in the validation cohort with 85.6% accuracy (F1 = .760, AUC = .883). Of the most predictive biomarkers, three were in microRNA binding sites in RAC1, CD274, and KRAS, two in immune related genes IL2RA and FCGR2A, and one in the DNA repair gene ATM. Our most significant biomarker in RAC1 did not predict response to anti-PD1/PDL1 treatment (p=0.91). Conclusions: We have identified a germ-line biomarker signature which predicts Grade 2 or higher iRAEs for patients treated with anti-PD1/anti-PDL1 therapy, regardless of cancer type, and does not predict an increased likelihood of response to these therapies. These findings are an important step in defining how to better safely personalize immune therapy, whose use is growing rapidly.

Preclinical evaluation of the kappa-opioid receptor antagonist CERC-501 as a candidate therapeutic for alcohol use disorders

Prior work suggests a role of kappa-opioid signaling in the control of alcohol drinking, in particular when drinking is escalated due to alcohol-induced long-term neuroadaptations. Here, we examined the small molecule selective kappa antagonist CERC-501 in rat models of alcohol-related behaviors, with the objective to evaluate its potential as a candidate therapeutic for alcohol use disorders. We first tested the effect of CERC-501 on acute alcohol withdrawal-induced anxiety-like behavior. CERC-501 was then tested on basal as well as escalated alcohol self-administration induced by 20% alcohol intermittent access. Finally, we determined the effects of CERC-501 on relapse to alcohol seeking triggered by both stress and alcohol-associated cues. Control experiments were performed to confirm the specificity of CERC-501 effects on alcohol-related behaviors. CERC-501 reversed anxiety-like behavior induced by alcohol withdrawal. It did not affect basal alcohol self-administration but did dose-dependently suppress self-administration that had escalated following long-term intermittent access to alcohol. CERC-501 blocked relapse to alcohol seeking induced by stress, but not when relapse-like behavior was triggered by alcohol-associated cues. The effects of CERC-501 were observed in the absence of sedative side effects and were not due to effects on alcohol metabolism. Thus, in a broad battery of preclinical alcohol models, CERC-501 has an activity profile characteristic of anti-stress compounds. Combined with its demonstrated preclinical and clinical safety profile, these data support clinical development of CERC-501 for alcohol use disorders, in particular for patients with negatively reinforced, stress-driven alcohol seeking and use.

Bedeutung der Spurenelemente Zink und Eisen bei der Gebärparese des Rindes

Ziel der Studie war, die Zink(Zn)- und Eisen(Fe)-Konzentrationen sowie Beziehungen zu Stoffwechselparametern bei festliegenden Kühen zu analysieren. Material und Methoden: Festliegende und klinisch gesunde Fleckviehkühe wurden in fünf Gruppen eingeteilt: a) Kontrollgruppe (KG, n = 21), b) Gebärparese(GP)-Kühe gesamt (n = 174), c) GP-Kühe ohne Zusatzkrankheiten (n = 145), d) GP-Kühe mit Mastitis (n = 10), e) GP-Kühe mit Retentio secundinarum oder postpartaler Endometritis (n = 19). Die Blutserumanalyse umfasste folgende Parameter: Selen (Se), Zn, Fe, Mangan (Mn), Kupfer (Cu), Kalzium (Ca), anorganisches Phosphat (Pi), Magnesium (Mg), Kalium (K), Tumornekrosefaktor α (TNFα), Haptoglobin (Hp), Antioxidanzien (Trolox Equivalent Antioxidative Capacity, TEAC), Protein, Albumin, freie Fettsäuren (FFS), Beta-Hydroxybutyrat (BHB), Bilirubin, Harnstoff, Kreatinin, Glukose, Cholesterol, Gamma-Glutamyltransferase (GGT) und alkalische Phosphatase (AP). Ergebnisse: Die Konzentrationen von Zn, Fe, Ca, Pi und TEAC waren bei allen festliegenden Kühen niedriger, die von Hp höher als in der KG (p 0,05). In Gruppe c) lagen Ca- und Pi-Konzentration niedriger als in den Gruppen d) und e) (p 0,05). In Gruppe e) wurde eine signifikant geringere Zn-Konzentration bestimmt als in Gruppe c) (p 0,05). Zn korrelierte negativ mit K (KG), positiv mit TEAC, Cu, Mn und Fe (Gruppe b und c) und Mn (Gruppe e) (p 0,05). Fe korrelierte gesichert positiv mit Ca (Gruppe c), mit Pi (Gruppe c), mit K (Gruppe b und c), mit Mg (Gruppen b–d) sowie mit Zn, Cu und Se (Gruppe b und c) (p 0,05). TNFα war in den Gruppen b) und c) erhöht und korrelierte negativ mit Fe (p 0,05). Die Aktivität der AP war in den Gruppen b) und e) niedriger als in der KG (p 0,05). Schlussfolgerung: Die Resultate und Literaturberichte befürworten die Hypothese, dass Zn und Fe unmittelbar den Knochenstoffwechsel beeinflussen und in die Pathogenese der GP involviert sein können. Die Hp- und TEAC-Konzentrationen unterstützen diese Interpretation. Die Kontrolle des Zn- und des Fe-Status der Kühe und die Supplementation von Zn sollten in die Prävention und erweiterte Therapie der GP eingeschlossen werden.

Intermittent Access to Ethanol Induces Escalated Alcohol Consumption in Primates

BACKGROUND

Escalation of voluntary alcohol drinking is characteristic of alcohol addiction and can be induced in rodents using intermittent access to alcohol. This model has been used to evaluate candidate therapeutics, but key systems involved in the transition into alcohol addiction, such as CRF, differ in their organization between rodents and primates. We examined the ability of an intermittent access schedule to induce escalation of voluntary alcohol drinking in non-human primates and used this model to assess the role of corticotropin releasing hormone (CRF) signaling in this process.

METHODS

Four young adult male rhesus macaques were given access to an 8.4% alcohol solution every other weekday (EOD; M, W, F), while four other young adult males were given the same solution every weekday (ED; M-F). Subjects were then administered a CRF1 antagonist, antalarmin.

RESULTS

EOD increased alcohol intake by up to 50% over baseline, with a more pronounced increase immediately following reintroduction of alcohol. For the morning/daytime sessions, EOD subjects increased their consumption by 83% over baseline. Differences between ED and EOD schedules emerged quickly, and EOD-induced escalation resulted in pharmacologically active BAC's. EOD-induced alcohol consumption was insensitive to CRFR1 blockade by antalarmin, but subjects with high CSF levels of CRF were more responsive.

CONCLUSIONS

Similar to what has been observed in rodents, intermittent access results in an escalation of voluntary alcohol drinking in non-human primates. In contrast to findings in rats, recruitment of the CRF system does not seem to be involved in the escalated alcohol drinking observed under these conditions, though individual differences in CRF system activity may play a role.

Reprogramming of mPFC transcriptome and function in alcohol dependence

Despite its limited immediate reinforcement value, alcohol has a potent ability to induce neuroadaptations that promote its incentive salience, escalation of voluntary alcohol intake and aversion-resistant alcohol seeking. A constellation of these traits, collectively called 'post-dependent', emerges following brain exposure to repeated cycles of intoxication and withdrawal. The medial prefrontal cortex (mPFC) and its subdivisions exert top-down regulation of approach and avoidance behaviors, including those that lead to alcohol intake. Here, we review an emerging literature which indicates that a reprogramming of mPFC function occurs with prolonged exposure of the brain to cycles of alcohol intoxication and withdrawal. This reprogramming results in molecular dysregulations that contribute to the post-dependent syndrome. Convergent evidence has identified neuroadaptations resulting in altered glutamatergic and BDNF-mediated signaling, and for these pathways, direct evidence for a mechanistic role has been obtained. Additional evidence points to a dysregulation of pathways involving calcium homeostasis and neurotransmitter release. Recent findings indicate that global DNA hypermethylation is a key factor in reprogramming the mPFC genome after a history of dependence. As one of the results of this epigenetic remodeling, several histone modifying epigenetic enzymes are repressed. Among these, PR-domain zinc-finger protein 2, a methyltransferase that selectively mono-methylates histone H3 at lysine 9 has been functionally validated to drive several of the molecular and behavioral long-term consequences of alcohol dependence. Information processing within the mPFC involves formation of dynamic neuronal networks, or functional ensembles that are shaped by transcriptional responses. The epigenetic dysregulations identified by our molecular studies are likely to alter this dynamic processing in multiple ways. In summary, epigenetic molecular switches in the mPFC appear to be turned on as alcoholism develops. Strategies to reverse these processes may offer targets for disease-modifying treatments.

A gene-by-sex interaction for nicotine reward: evidence from humanized mice and epidemiology

It has been proposed that vulnerability to nicotine addiction is moderated by variation at the μ-opioid receptor locus (OPRM1), but results from human studies vary and prospective studies based on genotype are lacking. We have developed a humanized mouse model of the most common functional OPRM1 polymorphism rs1799971_A>G (A118G). Here we use this model system together with a cohort of German youth to examine the role of the OPRM1 A118G variation on nicotine reward. Nicotine reinforcement was examined in the humanized mouse model using i.v. self-administration. Male (n=17) and female (n=26) mice homozygous either for the major human A allele (AA) or the minor G allele (GG) underwent eight daily 2 h sessions of nicotine self-administration. Furthermore, male (n=104) and female (n=118) subjects homozygous for the A allele or carrying the G allele from the Mannheim Study of Children at Risk were evaluated for pleasurable and unpleasant experiences during their initial smoking experience. A significant sex-by-genotype effect was observed for nicotine self-administration. Male 118GG mice demonstrated higher nicotine intake than male 118AA mice, suggesting increased nicotine reinforcement. In contrast, there was no genotype effect in female mice. Human male G allele carriers reported increased pleasurable effects from their first smoking experience, as compared to male homozygous A, female G and female homozygous A allele carriers. The 118G allele appears to confer greater sensitivity to nicotine reinforcement in males, but not females.

3D high throughput screening and profiling of embryoid bodies in thermoformed microwell plates

3D organoids using stem cells to study development and disease are now widespread. These models are powerful to mimic in vivo situations but are currently associated with high variability and low throughput. For biomedical research, platforms are thus necessary to increase reproducibility and allow high-throughput screens (HTS). Here, we introduce a microwell platform, integrated in standard culture plates, for functional HTS. Using micro-thermoforming, we form round-bottom microwell arrays from optically clear cyclic olefin polymer films, and assemble them with bottom-less 96-well plates. We show that embryonic stem cells aggregate faster and more reproducibly (centricity, circularity) as compared to a state-of-the-art microwell array. We then run a screen of a chemical library to direct differentiation into primitive endoderm (PrE) and, using on-chip high content imaging (HCI), we identify molecules, including regulators of the cAMP pathway, regulating tissue size, morphology and PrE gene activity. We propose that this platform will benefit to the systematic study of organogenesis in vitro.

Wistar rats acquire and maintain self-administration of 20 % ethanol without water deprivation, saccharin/sucrose fading, or extended access training

RATIONALE

Operant self-administration (SA) is an important model of motivation to consume ethanol (EtOH), but low rates of voluntary consumption in rats are thought to necessitate water deprivation and saccharin/sucrose fading for acquisition of responding.

OBJECTIVES

Here, we sought to devise an effective model of SA that does not use water deprivation or saccharin/sucrose fading.

METHODS

First, we tested if Wistar rats would acquire and maintain SA behavior of 20 % EtOH under two conditions, water deprivation (WD) and non-water deprivation (NWD). Second, we tested the efficacy of our SA procedure by confirming a prior study which found that the NK1 antagonist L822429 specifically blocked stress-induced reinstatement of EtOH seeking but not SA. Finally, we assessed the effect of naltrexone, an FDA-approved medication for alcohol dependence that has been shown to suppress EtOH SA in rodents.

RESULTS

Lever presses (LPs) and rewards were consistent with previous reports that utilized WD and saccharin/sucrose fading. Similar to previous findings, we found that L822429 blocked stress-induced reinstatement but not baseline SA of 20 % EtOH. Moreover, naltrexone dose-dependently decreased alcohol intake and motivation to consume alcohol for rats that are self-administering 20 % EtOH.

CONCLUSIONS

Our findings provide a method for voluntary oral EtOH SA in rats that is convenient for experimenters and eliminates the potential confound of sweeteners in EtOH-operant SA studies. Unlike models that use intermittent access to 20 % EtOH, this method does not induce escalation, and based on pharmacological experiments, it appears to be driven by the positive reinforcing effects of EtOH.

[Potential involvement of selenium in the occurrence of milk fever in cattle]

OBJECTIVE

Frequent occurrence of parturient paresis (milk fever [MF]) and a partly unsatisfactory treatment success raises the question as to whether in addition to the known causes, other factors influence the incidence and success of MF treatment. Trace elements, including selenium (Se), are involved in bone metabolism, however, there is little knowledge regarding the influence of Se on MF development. The aim of this study was to analyse the concentrations of Se and the statistical relationships to parameters associated with Se influence in downer cows.

MATERIAL AND METHODS

A total of 195 Simmental cows, downer cows and clinically healthy control animals were divided into five groups: a) control group (CG, n = 21), b) all cows with MF (n = 174), c) MF cows without additional diseases (n = 145), d) cows with MF and mastitis (n = 10) and e) cows with MF and retained placenta or endometritis (n = 19). Se, calcium (Ca), inorganic phosphate (Pi), tumour necrosis factor α (TNFα), haptoglobin (Hp), antioxidants (Trolox Equivalent Antioxidative Capacity: TEAC) and further metabolic parameters were analysed in the blood serum.

RESULTS

The serum concentrations of Se, Ca, Pi and TEAC were lower in groups b) to e), whereas Hp was higher than in the CG (p ≤ 0.05). Se was positively correlated with Pi in the CG, in groups b) and c) with Ca, Pi, K and Mg and in group c) with Hp (p ≤ 0.05). Both Ca and Pi were significantly lower in group c) compared to group d) (p ≤ 0.05). TNFα was increased in groups b) and c) compared to group a) and correlated with Se in group e) (p ≤ 0.05). Alkaline phosphatase activity in groups b) and e) was lower than in the CG and correlated with Se in the CG and group b) (p ≤ 0.05).

CONCLUSION

These results, in agreement with the literature data, support the hypothesis that Se could be directly involved in bone metabolism and therefore in the pathogenesis of MF. Se acts via cytokines on Ca mobilization from bone. The concentrations of Hp and TEAC support this interpretation. Therefore, control of the Se status and Se supplementation of cows should be included in the prevention and advanced therapy of MF.

[The relevance of the trace elements zinc and iron in the milk fever disease of cattle]

OBJECTIVE

The aim of this study was to analyse the concentrations of Zn and Fe as well as their relationships to metabolic parameters in milk fever cows.

MATERIAL AND METHODS

A total of 195 Simmental cows, downer cows and clinically healthy control animals were divided into five groups: a) control group (CG, n = 21), b) all cows with milk fever (MF) (n = 174), c) MF cows without additional diseases (n = 145), d) cows with MF and mastitis (n = 10) and e) cows with retained placenta or endometritis (n = 19). Selenium (Se), zinc (Zn), iron (Fe), calcium (Ca), inorganic phosphorus (Pi), tumour necrosis factor α (TNFα), haptoglobin (Hp), antioxidants (Trolox Equivalent Antioxidative Capacity: TEAC), non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), bilirubin, urea, creatinine, glucose, cholesterol, gamma-glutamyl transferase (GGT) and alkaline phosphatase (AP) were analysed in the blood serum.

RESULTS

The concentrations of Zn, Fe, Ca, Pi and TEAC were lower in groups b) to e) whereas Hp was higher than in the CG (p ≤ 0.05). In group c), lower Ca and Pi concentrations were found when compared to groups d) and e) (p ≤ 0.05). In group e), Zn concentrations were significantly lower than in group c) (p ≤ 0.05). Zn was negatively correlated with K (CG) and positively correlated with TEAC, Cu, Mn and Fe (groups b and c) and with Mn (group e) (p ≤ 0.05). Fe was positively correlated with Ca (group c), Pi (group c), K (groups b and c) and Mg (groups b-d) as well as with Zn, Cu and Se (groups b and c) (p ≤ 0.05). In groups b) and c), TNFα was increased and negatively correlated with Fe (p ≤ 0.05). AP activity in groups b) and e) was lower than in the CG (p ≤ 0.05).

CONCLUSION

These results and literature data support the hypothesis that Zn and Fe could be engaged in bone metabolism and be involved in the pathogenesis of MF. The concentrations of Hp and TEAC support this interpretation. Control of the Zn and Fe status of cows and Zn supplementation should be included in the prevention and advanced therapy of MF.

Potenzielle Bedeutung des Spurenelements Selen für die Entstehung der Gebärparese beim Rind

Gegenstand und Ziel: Häufiges Auftreten der Gebärparese (GP) sowie zum Teil unbefriedigende Behandlungserfolge zwingen zur Frage, inwieweit neben den bekannten Ursachen weitere Faktoren Inzidenz und Therapieerfolg bei GP beeinflussen. Spurenelemente, wie Selen (Se), sind in den Knochenstoffwechsel involviert, doch gibt es wenige Kenntnisse über fördernde Einflüsse von Se bei der Entstehung der GP. Ziel der Studie war deshalb, die Konzentration von Se und statistische Beziehungen zu unter Se-Einflüssen stehenden Parametern bei festliegenden Kühen zu analysieren. Material und Methoden: Festliegende und klinisch gesunde Fleckviehkühe wurden in fünf Gruppen eingeteilt: a) Kontrollgruppe (KG, n = 21) b) GP-Kühe gesamt (n = 174), c) GP-Kühe ohne Zusatzkrankheiten (n = 145), d) GP-Kühe mit Mastitis (n = 10) sowie e) GP-Kühe mit Retentio secundinarum oder puerperaler Metritis (n = 19). Die Blutserumanalysen umfassten Selen (Se), Kalzium (Ca), anorganisches Phosphat (Pi), Tumornekrosefaktor α (TNFα), Haptoglobin (Hp), Antioxidanzien (Trolox Equivalent Antioxidative Capacity) sowie weitere metabolische Parameter. Ergebnisse: Die Serumkonzentrationen von Se, Ca, Pi und TEAC waren in den Gruppen b) bis e) signifikant niedriger bzw. Hp höher als in der KG (p 0,05). Se korrelierte in der KG positiv mit Pi, in den Gruppen b) und c) mit Ca, Pi, K, Mg und in Gruppe c) mit Hp (p 0,05). Die Ca- und Pi-Konzentrationen lagen in Gruppe c) signifikant niedriger als in Gruppe d) (p 0,05). Die TNFα-Konzentration zeigte sich in den Gruppen b) und c) gegenüber a) erhöht und korrelierte in der Gruppe e) mit Se (p 0,05). Die Aktivität der alkalischen Phosphatase war in den Gruppen b) und e) niedriger als in der KG und korrelierte in der Gruppe a) mit Se (p 0,05). Schlussfolgerung: In Übereinstimmung mit Literaturangaben unterstützen die Resultate die Hypothese, dass Se unmittelbar in den Knochenstoffwechsel eingreift und damit in der Pathogenese der GP involviert sein könnte. Se wirkt über Zytokine auf die Ca-Mobilisierbarkeit aus dem Knochen. Die gemessenen Konzentrationen von Hp und TEAC unterstützen diese Interpretation. Die Kontrolle des Se-Status und die Se-Supplementation der Kühe sollten bei der Prävention und erweiterten Therapie der GP berücksichtigt werden.

Coordinated dysregulation of mRNAs and microRNAs in the rat medial prefrontal cortex following a history of alcohol dependence

Long-term changes in brain gene expression have been identified in alcohol dependence, but underlying mechanisms remain unknown. Here, we examined the potential role of microRNAs (miRNAs) for persistent gene expression changes in the rat medial prefrontal cortex (mPFC) after a history of alcohol dependence. Two-bottle free-choice alcohol consumption increased following 7-week exposure to intermittent alcohol intoxication. A bioinformatic approach using microarray analysis, quantitative PCR (qPCR), bioinformatic analysis and microRNA-messenger RNA (mRNA) integrative analysis identified expression patterns indicative of a disruption in synaptic processes and neuroplasticity. About 41 rat miRNAs and 165 mRNAs in the mPFC were significantly altered after chronic alcohol exposure. A subset of the miRNAs and mRNAs was confirmed by qPCR. Gene ontology categories of differential expression pointed to functional processes commonly associated with neurotransmission, neuroadaptation and synaptic plasticity. microRNA-mRNA expression pairing identified 33 miRNAs putatively targeting 89 mRNAs suggesting transcriptional networks involved in axonal guidance and neurotransmitter signaling. Our results demonstrate a significant shift in microRNA expression patterns in the mPFC following a history of dependence. Owing to their global regulation of multiple downstream target transcripts, miRNAs may have a pivotal role in the reorganization of synaptic connections and long-term neuroadaptations in alcohol dependence. MicroRNA-mediated alterations of transcriptional networks may be involved in disrupted prefrontal control over alcohol drinking observed in alcoholic patients.

Familial influence and childhood trauma in female alcoholism

BACKGROUND

To assess the role of genetic and environmental factors in female alcoholism using a large population-based twin sample, taking into account possible differences between early and late onset disease subtype.

METHOD

Twins aged 20-47 years from the Swedish Twin Registry (n=24 119) answered questions to establish lifetime alcohol use disorders. Subjects with alcoholism were classified for subtype. Structural equation modeling was used to quantify the proportion of phenotypic variance due to genetic and environmental factors and test whether heritability in women differed from that in men. The association between childhood trauma and alcoholism was then examined in females, controlling for background familial factors.

RESULTS

Lifetime prevalence of alcohol dependence was 4.9% in women and 8.6% in men. Overall, heritability for alcohol dependence was 55%, and did not differ significantly between men and women, although women had a significantly greater heritability for late onset (type I). Childhood physical trauma and sexual abuse had a stronger association with early onset compared to late onset alcoholism [odds ratio (OR) 2.54, 95% confidence interval (CI) 1.53-3.88 and OR 2.29, 95% CI 1.38-3.79 respectively]. Co-twin analysis indicated that familial factors largely accounted for the influence of physical trauma whereas the association with childhood sexual abuse reflected both familial and specific effects.

CONCLUSIONS

Heritability of alcoholism in women is similar to that in men. Early onset alcoholism is strongly association with childhood trauma, which seems to be both a marker of familial background factors and a specific individual risk factor per se.

Effect of pharmacological manipulations of neuropeptide Y and corticotropin-releasing factor neurotransmission on incubation of conditioned fear

We recently developed a procedure to study fear incubation in which rats given 100 tone-shock pairings over 10 days show low fear 2 days after conditioned fear training and high fear after 30 or 60 days. Here, we studied the role of the stress-related peptides, neuropeptide Y (NPY) and corticotropin-releasing factor (CRF), in fear incubation. We gave rats either 10 or 100 30-s tone-0.5-s footshock pairings over 1 day (short training) or 10 days (long training) and then assessed tone-cue-induced conditioned suppression of lever responding 2 days after short training or 2 days and 1 month after long training. Prior to testing, we injected NPY (5-10 microg, i.c.v.), the NPY Y1 receptor antagonist BIBO3304 (20-40 microg, i.c.v.), the NPY Y2 receptor antagonist BIIE0246 (2.5-5 mg/kg s.c.), the non-selective CRF receptor antagonist D-Phe CRF(12-41) (10 microg, i.c.v.), or the CRF1 receptor antagonist MTIP (10-20 mg/kg s.c.). Conditioned suppression after long training was higher after 1 month than after 2 days (fear incubation); conditioned suppression was robustly expressed 2 days after short training (non-incubated fear). Both incubated and non-incubated fear responses were attenuated by NPY. In contrast, D-Phe CRF(12-41), MTIP, BIBO3304, or BIIE0246 had no effect on conditioned fear at the different time points. Results confirm previous work on the potent effect of exogenous NPY administration on conditioned fear, but the negative results with BIBO3304 and BIIE0246 question whether endogenous NPY contributes to incubated (or non-incubated) fear. Results also suggest that CRF receptors are not involved in cue-induced fear in the conditioned suppression procedure.

Modulation of voluntary ethanol consumption by beta-arrestin 2

Beta-arrestin 2 is a multifunctional key component of the G protein-coupled receptor complex and is involved in mu-opiate and dopamine D2 receptor signaling, both of which are thought to mediate the rewarding effects of ethanol consumption. We identified elevated expression of the beta-arrestin 2 gene (Arrb2) in the striatum and the hippocampus of ethanol-preferring AA rats compared to their nonpreferring counterpart ANA line. Differential mRNA expression was accompanied by different levels of Arrb2 protein. The elevated expression was associated with a 7-marker haplotype in complete linkage disequilibrium, which segregated fully between the lines, and was unique to the preferring line. Furthermore, a single, distinct, and highly significant quantitative trait locus for Arrb2 expression in hippocampus and striatum was identified at the locus of this gene, providing evidence that genetic variation may affect a cis-regulatory mechanism for expression and regional control of Arrb2. These findings were functionally validated using mice lacking Arrb2, which displayed both reduced voluntary ethanol consumption and ethanol-induced psychomotor stimulation. Our results demonstrate that beta-arrestin 2 modulates acute responses to ethanol and is an important mediator of ethanol reward.

Plasticity and impact of the central renin–angiotensin system during development of ethanol dependence

Pharmacological and genetic interference with the renin-angiotensin system (RAS) seems to alter voluntary ethanol consumption. However, understanding the influence of the RAS on ethanol dependence and its treatment requires modeling the neuroadaptations that occur with prolonged exposure to ethanol. Increased ethanol consumption was induced in rats through repeated cycles of intoxication and withdrawal. Expression of angiotensinogen, angiotensin-converting enzyme, and the angiotensin II receptor, AT1a, was examined by quantitative reverse transcription polymerase chain reaction. Increased ethanol consumption after a history of dependence was associated with increased angiotensinogen expression in medial prefrontal cortex but not in nucleus accumbens or amygdala. Increased angiotensinogen expression also demonstrates that the astroglia is an integral part of the plasticity underlying the development of dependence. The effects of low central RAS activity on increased ethanol consumption were investigated using either spirapril, a blood-brain barrier-penetrating inhibitor of angiotensin-converting enzyme, or transgenic rats (TGR(ASrAOGEN)680) with reduced central angiotensinogen expression. Spirapril reduced ethanol intake in dependent rats compared to controls. After induction of dependence, TGR(ASrAOGEN)680 rats had increased ethanol consumption but to a lesser degree than Wistar rats with the same history of dependence. These data suggest that the central RAS is sensitized in its modulatory control of ethanol consumption in the dependent state, but pharmacological or genetic blockade of the system appears to be insufficient to halt the progression of dependence.

Variation at the rat Crhr1 locus and sensitivity to relapse into alcohol seeking induced by environmental stress

Alcoholism is a chronic relapsing disorder with substantial heritability. Uncovering gene-environment interactions underlying this disease process can aid identification of novel treatment targets. Here, we found a lowered threshold for stress-induced reinstatement of alcohol seeking in Marchigian-Sardinian Preferring (msP) rats genetically selected for high alcohol preference. In situ hybridization for a panel of 20 stress-related genes in 16 brain regions was used to screen for differential gene expression that may underlie this behavioral phenotype. An innate up-regulation of the Crhr1 transcript, encoding the corticotropin-releasing hormone receptor 1 (CRH-R1), was found in several limbic brain areas of msP rats genetically selected for high alcohol preference, was associated with genetic polymorphism of the Crhr1 promoter, and was accompanied by increased CRH-R1 density. A selective CRH-R1 antagonist (antalarmin, 10-20 mg/kg) was devoid of effects on operant alcohol self-administration in unselected Wistar rats but significantly suppressed this behavior in the msP line. Stress-induced reinstatement of alcohol seeking was not significantly affected by antalarmin in Wistar rats but was fully blocked in msP animals. These data demonstrate that Crhr1 genotype and expression interact with environmental stress to reinstate alcohol-seeking behavior.

Glutathione-S-transferase expression in the brain: possible role in ethanol preference and longevity

Identification of genes that are differentially expressed in rats bidirectionally selected for alcohol preference might reveal biological mechanisms underlying alcoholism or related phenotypes. Microarray analysis from medial prefrontal cortex (mPFC), a key brain region for drug reward, indicated increased expression of glutathione-S-transferases of the alpha (Gsta4) and mu (Gstm1-5) classes in ethanol-preferring AA rats compared with nonpreferring ANA rats. Real-time RT polymerase chain reaction (RT-PCR) analysis demonstrated approximately 2-fold higher Gsta4 transcript levels in several brain regions of ethanol-naive AA compared with ANA rats. Differences in mRNA levels were accompanied by differential levels of GSTA4 protein. We identified a novel haplotype variant in the rat Gsta4 gene, defined here as var3. Allele frequencies of var3 were markedly different between AA and ANA rats, 52% and 100%, respectively. Gsta4 expression was strongly correlated with the gene dose of var3, with approximately 60% of the variance in expression accounted for by genotype at this locus. The contribution of glutathione S-transferase expression to the ethanol-preferring phenotype is presently unclear. It could, however, underlie observed differences in life span between AA and ANA lines, prompting a utility of this animal model in aging research.

The search for candidate genes of alcoholism: evidence from expression profiling studies

Alcoholism is the outcome of complex interactions between the environment and multiple gene loci, which may encode pre-existing susceptibility, or contribute to the neuroadaptations underlying the process of developing dependence. Because of this, the prospect of simultaneous, genome wide, high-throughput analysis of gene expression allowed by microarray technology has met with great expectations. The hope has been that new insights into pathogenesis of substance disorders will rapidly be gained, leading to identification of novel treatment targets. The usefulness of this approach as a discovery tool in addiction research will be critically reviewed here. In this article, we describe the evolution of our experimental approaches, from first generation Affymetrix expression arrays to present high-density arrays, and from the use of original Affymetrix software to more advanced analysis of the probe signal, and different statistical approaches to creating candidate gene lists. Further, we address some methodological issues critical to the study of brain samples by microarray technology. We also summarize findings from several expression profiling experiments involving different animal models of alcoholism. The accumulation of expression data from different animal models allows mining the database for patterns of overlap. Such second level analysis depends on the generation of uniform and reliable datasets.

A cluster of differentially expressed signal transduction genes identified by microarray analysis in a rat genetic model of alcoholism

Analyzing gene expression patterns in genetic models of alcoholism may uncover previously unknown susceptibility genes, and point to novel targets for drug development. Here, we compared expression profiles in alcohol-preferring AA rats with the alcohol-avoiding counterpart ANA line, and unselected Wistar rats. Cingulate cortex, Nc. accumbens, amygdala and hippocampus of each line were analyzed using the Afymetrix RN U34 arrays and dChip 1.1 software. Analysis of line-specific expression revealed 48 differentially expressed genes between AA and ANA rats. Elevated hippocampal neuropeptide Y (NPY) was found in ANA rats in agreement with previous studies. A cluster of MAP-kinases indicating altered signal transduction was upregulated within the Nc. Accumbens of the AA line, and is of particular functional interest. Within the amygdala, a more loosely inter-related cluster of cytoskeleton-associated genes may point to structural abnormalities. The observed dysregulations may contribute to the alcohol-preferring phenotype.

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.

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.

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.