It is commonly known that, much like Pavlov's dogs salivating in response to hearing the bell they associate with dinner time, smokers feel cravings and have physiological reactions to pictures they associate with smoking. New research published in BioMed Central's open access journal BMC Neuroscience has shown that a smoker's cravings can also be trained to non-smoking related stimuli. Classical conditioning experiments link a neutral stimulus, such as a sound or a picture, to an event, like eating or smoking. Higher order, sometimes called second order conditioning, links this neutral stimulus to a second event. In the case of Pavlov's dogs, if they could have been trained to associate a light being switched on with the sound of the bell and consequently began to salivate to the light only this would be second order conditioning.
Research published by Cell Press in the journal Neuron provides fascinating insight into a newly discovered brain mechanism that limits the rewarding impact of cocaine. The study describes protective delayed mechanism that turns off the genes that support the development of addiction-related behaviors. The findings may lead to a better understanding of vulnerability to addiction and as well as new strategies for treatment. Drug addiction is associated with persistent and abnormal changes in the reward circuitry of the brain, and drug-induced changes in gene expression are thought to contribute to addiction behaviors. Recent research with rodent models of addiction has implicated histone deacetylases (HDACs), which are modulators of gene expression, in the regulation of cocaine-induced behaviors.
Jason Nickerson and Amir Attaran of the University of Ottawa, Canada examine in this week's PLoS Medicine the vast inequities in medical pain relief around the world, arguing that the imbalance has arisen from restrictive drug laws designed to prevent access to illegal substances, and proposing that the global control of licit narcotics be shifted from the International Narcotic Control Board to WHO. The authors say: "Transferring the public health responsibility for controlled medicines from INCB to WHO would end the impossibly contradictory situation in which INCB is mandated both to restrict and to promote access to controlled medicines... Attention must now shift to creating better legal frameworks that extricate pain treatment from drug prohibition."
Researchers have found clear associations between marijuana use in young males and cyclic vomiting syndrome (CVS), where patients experience episodes of vomiting separated by symptom free intervals. The study, published in the January issue of Neurogastroenterology and Motility, looked at 226 patients seen at the Mayo Clinic in Rochester, New York, USA, over a 13-year period. These were broken into three groups. Eighty-two patients with CVS were randomly matched with 82 patients with Irritable Bowel Syndrome (IBS) based on age, gender and geographic referral region. Researchers also examined the records of 62 patients with functional vomiting (FV), recurrent vomiting that cannot be attributed to a specific physical or psychiatric cause. "Our study showed that CVS and FV had very similar clinical features, apart from marijuana use" says Dr G Richard Locke III from the Division of Gastroenterology and Hepatology at the Clinic.
A hangover is a collection of signs and symptoms linked to a recent bout of heavy drinking. The sufferer typically has a headache, feels sick, dizzy, sleepy, confused and thirsty. Hangovers can occur at any time of day, but are usually more common the morning after a night of heavy drinking. As well as physical symptoms, the person may also experience elevated levels of anxiety, regret, shame, embarrassment, as well as depression. The severity of a hangover is closely linked to how much alcohol was consumed, and whether the sufferer had enough sleep. The less sleep the worse the hangover. It is impossible really to say how much alcohol can be safely consumed to avoid a hangover - it depends on the individual, his/her circumstances that day, how tired they were before their drinking started, whether they were already dehydrated before the drinking began, whether they drank plenty of water during their drinking session, how much sleep they got afterwards, etc.