Region-specific depression of striatal activity in Wistar rat by modest ethanol consumption over a ten-month period

The nucleus accumbens (nAc) is the primary target for the mesolimbic dopamine system and a key brain region for the reinforcing effects displayed by drugs of abuse, including ethanol. During the transition from recreational to compulsive consumption of reinforcing drugs, however, the dorsal striatum seems to be recruited. Understanding how synaptic activity is altered in a sub-region specific manner in the striatum during the course of long-term drug consumption thus could be essential for understanding the long-lasting changes produced by addictive substances, including ethanol. Here we evaluated synaptic activity in the dorsolateral striatum (DLS) and ventral striatum (nucleus accumbens, nAc) of single-housed Wistar rats consuming water, or water and ethanol, for up to 10 months. Even though ethanol intake was moderate, it was sufficient to decrease input/output function in response to stimulation intensity in the DLS, while recorded population spike (PS) amplitudes in the nAc were unaffected. Striatal disinhibition induced by the GABA_A receptor antagonist bicuculline had a slower onset in rats that had consumed ethanol for 2 months, and was significantly depressed in slices from rats that had consumed ethanol for 4 months. Bicuculline-induced disinhibition in the nAc, on the other hand, was not significantly altered by long-term ethanol intake. Changes in PS amplitude induced by taurine or the glycine receptor antagonist strychnine were not significantly altered by ethanol in any brain region. Even though input/output function was not significantly affected by age, there was a significant decline in antagonist-induced disinhibition in brain slices from aged rats. The data presented here suggest that even modest consumption of ethanol is sufficient to alter neurotransmission in the striatum, while synaptic activity appears to be relatively well-preserved in the nAc during the course of long-term ethanol consumption.     

Genetic variation in the hTAS2R38 taste receptor and brassica vegetable intake

Abstract

The human TAS2R38 receptor is believed to be partly responsible for the ability to taste phenylthiocarbamide (PTC), a bitter compound very similar to the bitter glucosinolates found in brassica vegetables. These vegetables and their active compounds have chemo-protective properties. This study investigated the relationship between genetic variation in the hTAS2R38 receptor and the actual consumption of brassica vegetables with the hypothesis that taster status was associated with intake of these vegetables. Furthermore, secondary intake information on alcohol, chocolate, coffee, smoking, BMI and waist-circumference was analysed for association with the hTAS2R38 receptor polymorphisms. The subjects were selected from the Diet, Cancer and Health (DCH) study, which is an ongoing prospective Danish cohort study. Two groups, each consisting of 250 healthy subjects were selected based on their brassica vegetables intake from the upper quartile (≥23 g/day) and the lower quartile (≤7 g/day) daily intake of brassicas from a randomly selected sub-cohort of DCH. DNA was analysed for three functional SNPs in the hTAS2R38 gene. The hTAS2R38 bitter taste receptor haplotypes were not associated with the daily intake of brassica vegetables in our study, and no association between the haplotypes and any of the other variables tested was found. We have demonstrated that the hTAS2R38 haplotypes are not associated with brassica vegetable intake and that results from experimental setups cannot be applied directly to the everyday situation. This indicates that non-genetic factors may have more influence on dietary choice than genetics.     

Using handheld computers for daily alcohol assessment: Results from a pilot study

Aims: The purpose of this pilot study was to determine the feasibility and usability of daily retrospective assessments of alcohol use using handheld computers and to explore their comparability to Timeline Followback (TLFB) assessments.

Methods: College student participants received a Handheld Assessment Tool (HAT) at enrolment, which surveyed alcohol consumption and contextual factors for the previous day. After 1 week of daily monitoring, participants completed a paper‐and‐pencil TLFB assessment and HAT usability scale.

Results: Of the 1,800 matched data points on the HAT and TLFB, the overall level of agreement was very good (kappa = 0.80, p<0.001). The mean difference between the number of drinks per drinking days recorded using both methods was 0.19 (SD = 0.56). Participants completed HAT surveys on 87 out of 91 total possible survey days (95.6%). The HAT recorded 34 drinking days and the TLFB recorded 37 out the 91 possible days; the HAT was reported to be highly usable by all participants.

Conclusion: Overall, the HAT was found to be usable and feasible and produced high adherence. Further research should validate this alcohol assessment approach and apply it to representative populations.     

Adolescent and young adult perceptions of Australian alcohol advertisements

There is substantial evidence that children and youth are exposed to and recall alcohol advertising, and increasing evidence of associations between liking alcohol advertisements and under-age drinking. Alcohol advertising in Australia, as in many industrialized countries, is subject to a self-regulatory code developed and administered by the alcohol industry. The purpose of the current study was to investigate young people’s perceptions of the messages in recent alcohol advertisements and whether these perceptions support the industry view that self-regulation is effective in protecting young people from inappropriate messages about alcohol. Six print and six television advertisements were selected for the study, and 287 respondents aged 15–24 years viewed two alcohol advertisements (one print and one television) and completed a questionnaire immediately after viewing each advertisement. The respondents perceived messages in the advertisements regarding several social benefits of consuming alcohol, including that the advertised product would make them more sociable and outgoing, help them have a great time, help them fit in, help them feel more confident, help them feel less nervous, and help them succeed with the opposite sex. All of these messages transgress the terms of the self-regulatory code for alcohol advertising. There was also a strong association between emotional responses to the advertisements and stated intentions to try the advertised products.     

Why people enter treatment for alcohol problems: Findings from UK Alcohol Treatment Trial pre‐treatment interviews

Aim: To develop a model of why people seek professional treatment for drinking problems, grounded in what clients say about the process at treatment entry.

Participants: Three sets of consecutive entrants to the UK Alcohol Treatment Trial, sets commencing at intervals during trial recruitment (total n = 98).

Location: Statutory and non‐statutory alcohol problem treatment agencies in three areas of England and Wales.

Data: Open‐ended interviews according to a brief interview guide, leading to 400–800‐word post‐interview reports used for analysis (tape recordings used for auditing the interview and analysis process).

Analysis: Reports analysed by a team according to grounded theory principles, involving an iterative process with successive refinement of interviewing and analysis with each successive set of data.

Findings: A model of professional treatment entry was developed, refined and “tested” with the last set of data. The process of seeking professional treatment was depicted in the model as involving a realization of worsening, accumulating and multiple problems related to drinking, especially in health and family domains; in conjunction with, in most cases (but not all), a trigger event and/or family or professional influence; combined with rejection of the possibility of unaided change or non‐professional help; leading to the seeking or accepting of professional help.

Conclusions: The findings support conclusions already in the literature about the process of seeking professional help for a drinking problem, but provide further refinement of existing ideas: for example regarding the accumulation of drinking‐related problems, the ways in which a realization of those problems combines with triggers or pressure, and the complex role of the family and primary care professionals in assisting motivation to seek treatment.     

People and Places: some factors in the alcohol-violence link

The possible association between heavy drinking and intoxication with aggression and violence has been debated for centuries. A select and concise review of some of the evidence on this topic will be presented. This seeks to draw some general conclusions from an extensive, flawed and often contradictory literature. The main focus of this review is on social and contextual factors. Experimental evidence suggests that alcohol consumption probably does increase the propensity for aggression in men, but less so for women. The effects of drinking depend upon the alcohol consumed, the drinker and the setting in which consumption occurs. Most drinking occasions do not result in aggression or violence, and drinking is neither necessary nor sufficient to cause violence. Heavy and inappropriate drinking is associated with both violent and nonviolent crimes; heavy and problem drinkers are at risk of being violent or of being the victims of violence. Experience of violence (including sexual abuse) in childhood or later in life are associated with the development of heavy or problem drinking. The risk of exposure to violence is influenced by a host of demographic, lifestyle and contextual factors. Responses to alcohol-related violence at the societal level involve a number of harm minimization strategies. At an individual level it has been shown that treatment for problem drinking can lead to reduced risk levels (for both perpetrators and victims of violence).