Using Food to Demonstrate Earth Science Concepts: a Review

Researchers categorized over one hundred print and web resources that use food to demonstrate earth science concepts. This article describes their findings: food-based activities are found in print and web-based resources with nearly equal frequency; most feature geologic themes; most are designed for primary and middle school audiences, but can be adapted for older students; and most of these activities meet the National Science Standard "Structure of the Earth" for middle school students. The authors suggest that food-based activities are a way to make subject matter more exciting and understandable, particularly for those with little or no background in science, and that food, which students consume daily, can serve as a reality based analogy to better understand many of the unfamiliar, abstract concepts taught in earth science classes. Educational levels: Graduate or professional

A novel translational assay of response inhibition and impulsivity: effects of prefrontal cortex lesions, drugs used in ADHD, and serotonin 2C receptor antagonism

Animal models are making an increasing contribution to our understanding of the psychology and brain mechanisms underlying behavioral inhibition and impulsivity. The aim here was to develop, for the first time, a mouse analogue of the stop-signal reaction time task with high translational validity in order to be able to exploit this species in genetic and molecular investigations of impulsive behaviours. Cohorts of mice were trained to nose-poke to presentations of visual stimuli. Control of responding was manipulated by altering the onset of an auditory ‘stop-signal’ during the go response. The anticipated systematic changes in action cancellation were observed as stopping was made more difficult by placing the stop-signal closer to the execution of the action. Excitotoxic lesions of medial prefrontal cortex resulted in impaired stopping, whilst the clinically effective drugs methylphenidate and atomoxetine enhanced stopping abilities. The specific 5-HT2C receptor antagonist SB242084 also led to enhanced response control in this task. We conclude that stop-signal reaction time task performance can be successfully modelled in mice and is sensitive to prefrontal cortex dysfunction and drug treatments in a qualitatively similar manner to humans and previous rat models. Additionally, using the model we show novel and highly discrete effects of 5-HT2C receptor antagonism that suggest manipulation of 5-HT2C receptor function may be of use in correcting maladaptive impulsive behaviors and provide further evidence for dissociable contributions of serotonergic transmission to response control

Topiramate for cocaine dependence during methadone maintenance treatment: A randomized controlled trial

BackgroundDual dependence on opiate and cocaine occurs in about 60% of patients admitted to methadone maintenance and negatively impacts prognosis (Kosten et al. 2003. Drug Alcohol Depend. 70, 315). Topiramate (TOP) is an antiepileptic drug that may have utility in the treatment of cocaine dependence because it enhances the GABAergic system, antagonizes the glutamatergic system, and has been identified by NIDA as one of only a few medications providing a "positive signal" warranting further clinical investigation. (Vocci and Ling, 2005. Pharmacol. Ther. 108, 94).MethodIn this double-blind controlled clinical trial, cocaine dependent methadone maintenance patients (N=171) were randomly assigned to one of four groups. Under a factorial design, participants received either TOP or placebo, and monetary voucher incentives that were either contingent (CM) or non-contingent (Non-CM) on drug abstinence. TOP participants were inducted onto TOP over 7 weeks, stabilized for 8 weeks at 300 mg daily then tapered over 3 weeks. Voucher incentives were supplied for 12 weeks, starting during the fourth week of TOP induction. Primary outcome measures were cocaine abstinence (Y/N) as measured by thrice weekly urinalysis and analyzed using Generalized Estimating Equations (GEE) and treatment retention. All analyses were intent to treat and included the 12-week evaluation phase of combined TOP/P treatment and voucher intervention period.ResultsThere was no significant difference in cocaine abstinence between the TOP vs. P conditions nor between the CM vs. Non-CM conditions. There was no significant TOP/CM interaction. Retention was not significantly different between the groups.ConclusionTopiramate is not efficacious for increasing cocaine abstinence in methadone patients

The Impact of Selective Dopamine D2, D3 and D4 Ligands on the Rat Gambling Task

<div><p>Gambling is an addictive disorder with serious societal and personal costs. To-date, there are no approved pharmacological treatments for gambling disorder. Evidence suggests a role for dopamine in gambling disorder and thus may provide a therapeutic target. The present study therefore aimed to investigate the effects of selective antagonists and agonists of D2, D3 and D4 receptors in a rodent analogue of the Iowa gambling task used clinically. In this rat gambling task (rGT), animals are trained to associate different response holes with different magnitudes and probabilities of food pellet rewards and punishing time-out periods. As in the Iowa gambling task, the optimal strategy is to avoid the tempting high-risk high-reward options, and instead favor those linked to smaller per-trial rewards but also lower punishments, thereby maximizing the amount of reward earned over time. Administration of those selective ligands did not affect decision making under the rGT. Only the D4 drug had modest effects on latency measures suggesting that D4 may contribute in some ways to decision making under this task.</p></div

Effect of administration of a D3 antagonist on the rGT.

<p><b>A</b>: Mean ± SEM percent choice on the advantageous choice (dark bars), omissions (grey bars) and premature responses (open bars). <b>B</b>: Mean ± SEM number of trials initiated. <b>C</b>: Mean ± SEM latency to make a choice (grey bars) and latency to collect the food pellets (open bars). <b>D</b>: Ratio ± SEM perseverative responses for punished trials (grey bars) and rewarded trials (open bars). No significant differences were found for any analyses (n = 17).</p

Reward and punishment outcomes for the various response options in the rGT.

<p>Reward and punishment outcomes for the various response options in the rGT.</p