The relationship between saccharin and alcohol intake in rats

Male rats were given daily sessions during which a palatable saccharin solution was available. Based on intakes averaged over 3 days, groups with low, intermediate, or high intake of saccharin were formed. These rats were then given daily sessions in which alcohol (2-8%) or water were available. Initially, sessions were conducted with rats on a food restriction schedule; in later sessions, food was available ad lib. When rats were food restricted, there were no differences among the groups in terms of alcohol or water intake. When the food restriction schedule was discontinued, alcohol intake in the intermediate and high saccharin intake groups was generally higher than that of the low saccharin group. On the final series of alcohol sessions, the high saccharin group consumed significantly more 2% and 6% alcohol than the low saccharin group. These results are consistent with reports which have found that rats selected for high or low alcohol intake have corresponding high and low intakes of saccharin.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30072/1/0000442.pd

Fat-preferring rats consume more alcohol than carbohydrate-preferring rats

Rats with a genetic preference for alcohol (ETOH) have been found to consume more dietary fat then ETOH nonpreferring rats. We therefore hypothesized that rats selected on the basis of fat and carbohydrate (CHO) preferences would differ in ETOH intake. Patterns of macronutrient self-selection were determined by allowing rats to select diets from separate source of CHO, fat and protein. Subsequently, CHO- and fat-preferring groups were formed. All rats were then returned to a lab chow diet and trained to drink ETOH (4-14%) during one hour of access per day. Food restriction was used only in the first three weeks of the procedure. On the final drinking session, water and ETOH were alternated on a daily basis. Fat-preferring rats consumed significantly more ETOH than water, CHO-preferring rats consumed approximately equal amounts of ETOH and water. Futhermore, fat-preferring rats consumed more ETOH than CHO-preferring rats. This study suggests that there may be a common mechanism underlying diet preference and oral intake of ETOH.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29255/1/0000312.pd

The effects of continuous naltrexone infusions on diet preferences are modulated by adaptation to the diets

Two groups of male rats were placed on a feeding regimen in which a fat/protein diet and a carbohydrate/protein diet were available ad lib. Naltrexone was infused via osmotic minipumps either at the time the diets were introduced or after one week of adaptation to the diets. In rats adapted to the diets, naltrexone caused a decrease in the intakes of fat/protein and carbohydrate/protein diets. Relative preferences for the two diets were generally unchanged. In contrast, when naltrexone was infused at the time of introduction of the diets, a polarization phenomenon was observed: rats tended to consume nearly all of their daily calories from either one diet or the other. Six rats (out of 10) showed a stronger preference for the carbohydrate/protein diet than did any of the saline-treated rats, while 3 showed a stronger preference for the fat/protein diet than did any of the saline-treated rats. Thus, the effect was not diet- or macronutrient-specific. These preferences became significantly less extreme after termination of naltrexone infusions. Conditioned aversions and naltrexone-induced reductions in exploratory behavior are discussed as potential explanations for this polarization effect. These results indicate that naltrexone has differential effects on the development versus the maintenance of diet preferences. Further, they emphasize the importance of examining individual differences as well as baseline preferences in studies on the control of intake and diet selection.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30229/1/0000622.pd

Governments matter for capitalist economies: Regeneration and transition to green and decent jobs

Many traditional regions are undergoing change and transformation as industries restructure. The development of ‘green economies’ and the transition to a low-carbon economy offers areas experiencing industrial decline an opportunity to innovate around policies for regeneration. In this process, there is a necessary emphasis on skills development and the creation of decent jobs, but institutional context mediates such processes in different places in different ways. This article argues that an effective transition policy is more likely to emerge where a mutually reciprocal relationship is developed between the state qua government and the social groups that comprise the region, including employers and workers and their representatives. Utilising a ‘varieties of capitalism’ typology in relation to areas of industrial decline in Germany and the UK, the article illustrates the ways in which transition policies are elaborated and implemented, with an explicit focus on decent job creation

Forensic profiling of smokeless powders (SLPs) by gas chromatography–mass spectrometry (GC-MS): a systematic investigation into injector conditions and their effect on the characterisation of samples

Smokeless powders (SLPs) are composed of a combination of thermolabile and non-thermolabile compounds. When analysed by GC-MS, injection conditions may therefore play a fundamental role on the characterisation of forensic samples. However, no systematic investigations have ever been carried out. This casts doubt on the optimal conditions that should be adopted in advanced profiling applications (e.g. class attribution and source association), especially when a traditional split/splitless (S/SL) injector is used. Herein, a study is reported that specifically focused on the evaluation of the liner type (L type) and inlet temperature (T inj). Results showed that both could affect the exhaustiveness and repeatability of the observed chemical profiles, with L type being particularly sensitive despite typically not being clarified in published works. Perhaps as expected, degradation effects were observed for the most thermolabile compounds (e.g. nitroglycerin) at conditions maximising the heat transfer rates (L type = packed and T inj ≥ 200 °C). However, these did not seem to be as influential as, perhaps, suggested in previous studies. Indeed, the harshest injection conditions in terms of heat transfer rate (L type = packed and T inj = 260 °C) were found to lead to better performances (including better overall %RSDs and LODs) compared to the mildest ones. This suggested that implementing conditions minimising heat-induced breakdowns during injection was not necessarily a good strategy for comparison purposes. The reported findings represent a concrete step forward in the field, providing a robust body of data for the development of the next generation of SLP profiling methods. Graphical abstract: (Figure presented.).</p

The anorectic effects of CRH and restraint stress decrease with repeated exposures

Intracerebroventricular (icv) administration of corticotropin-releasing hormone (CRH) or exposure to a restraint stressor causes acute anorexia in rats. However, the effects on food intake of repeated injections of CRH or repeated exposures to restraint stress have not been previously reported. As the effects of these more chronic CRH and stress treatments may be of greater relevance to emerging hypotheses of the pathogenesis of human eating and affective disorders, we measured the changes in food intake and body weight of rats after repeated central injections of CRH. In two experiments using two different daily dosages of CRH and two different schedules of administration, we found that the anorectic effect of CRH decreased over repeated injections. Weight gain was slowed significantly only in the high-dose experiment. Rats may become tolerant to the anorectic effects of CRH delivered by repeated icv injections. These findings have important implications for hypothesized mechanisms of anorexia nervosa and/or depression.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28570/1/0000373.pd

Effects of preferential delta and kappa opioid receptor agonists on the intake of hypotonic saline

A previous study has implicated central mu opioid receptors in the preference for salt solutions. Because mu, kappa and delta receptors are all thought to play a role in food intake and/or the mediation of palatability, we performed a series of experiments to determine whether preferential agonists at kappa and delta receptors might also stimulate the intake of salt solutions. When injected centrally into nondeprived rats, two selective agonists at delta receptors caused increases in the intake of 0.6% saline; the intake of concurrently available water was either unchanged or slightly increased. The selective kappa agonist U-50, 488H had no effect on water or saline intake, whereas the preferential kappa agonist DAFPHEDYN caused a delayed increase in saline intake. These results indicate a role for central delta receptors in the preference for salt solutions, and are consistent with the suggestion that opioids play a role in the mediation of palatability.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28718/1/0000539.pd