A recent online news post states that experts analyzed the brain functions of over 40 people, one-third of them being women, and found that women are apt to suffer a 50 percent drop in the number of serotonin functions after only four years of heavy drinking. Kristina Berglund, the lead author of the study, says the research findings show that the damage is especially rapid for women.

Berglund explained that they were not surprised to find the impaired serotonin function in the excessive drinkers’ brains, but they were surprised by how much more in danger women were than men in regard to brain functioning. Berglund emphasized the danger of how the functioning of the brain was impaired and was especially concerned with the rapid nature of the damage.

Another report conducted by the Health Research Board exposed an increase of over 40 percent in the number of cases for treatment of alcohol abuse in the past six years. The report further noted alcohol as the root of problems for treatment of drug cases, with over 42,000 cases in the five years between 2005 and 2010.

The authors are concerned about how quickly the female brain can incur damage caused by excessive alcohol consumption.

Co-lead author Shelly B. Flagel, Ph.D., a research investigator at the U-M Medical School’s Molecular and Behavioral Neuroscience Institute, said they were able to answer the question of what role the neurotransmitter dopamine plays in the reward center of the brain.

To get some perspective, think about a rat learning to associate a lever with the appearance of food. Until now, scientists hadn’t figured out whether dopamine was released in the rats’ brains at the sight of the lever itself or when the rats accurately predicted the appearance of food. With this study, the researchers found that the answer depends on the rat’s genes. 

Flagel said to think about a sign for an ice cream store. Some people will see the sign and think of it as an indicator that ice cream is available. Other people, however, will have a stronger reaction to the sign, and they’ll hurry over to the store, unable to resist the opportunity. 

The researchers studied rats that were bred for certain personality traits, including increased risk for drug addiction. Rats that were more prone to substance abuse tended to focus their attention on the lever, whereas the other rats focused on the area where the food appeared.

The researchers used a method called fast-scan cyclic voltammetry to measure the dopamine responses in the rats’ brains, and found that the rats that were more susceptible to drug abuse experienced a reward just from seeing the lever, whereas the other rats did not. Even when the food was removed, the drug-prone rats’ desire for the lever continued.

The study also measured the rats’ ability to learn when the reward feelings (dopamine) were blocked, and repeated the experiments with rats that had not been selectively bred.

The researchers, including co-lead author Jeremy J. Clark, Ph.D., of the University of Washington, hope their study will help scientists discover my some people are much more influenced by environmental cues and are at a higher risk for compulsive behavior such as addiction.

Source: Science Daily, Unlocking the Secrets of Our Compulsions, December 8, 2010

“There is a scarcity of information about alcohol use and the elderly,” said Marcos Antonio Lopes, corresponding author for the study and currently a visiting lecturer at Newcastle University in the United Kingdom, “which needs to be resolved in order to construct a real diagnosis and promote proper health care for this population.”

Jerson Laks, associate professor at the State University of Rio de Janeiro and a researcher with the Brazilian National Committee for Research, agrees. “Alcohol use is frequently an exclusion criterion for any study of cognition and dementia in the elderly, as well as in studies aimed at depression,” he said. “Therefore, by simply excluding alcohol use and abuse, most studies cannot reveal the interaction between drinking behaviors and cognition in this age range.”

The current study is also important, Laks added, because it did not have any expectations that the elderly would drink less than younger subjects and, furthermore, it asked many difficult questions despite their negative stigmas in order to uncover the facts about drinking among the elderly in Brazil and its association with dementia.

Lopes and his colleagues recruited a sample of 1,145 individuals who were 60 years of age and older (419 men, 726 women), from different socioeconomic levels, and examined them in two phases. The first phase used several instruments, including the CAGE questionnaire, a four-question screening test for alcohol dependence, to identify potential alcohol-related problems, as well as a screening test for dementia to identify cognitive and functional impairment.

The second phase used the Cambridge Mental Disorders of the Elderly Examination, as well as the Diagnostic and Statistical Manual of Mental Disorders—Fourth Edition, to establish a clinical diagnosis of dementia.

“We found that heavy alcohol use among the elderly people we investigated was high at 8.2 percent and affected principally men from low socioeconomic levels,” said Lopes. “However, the effects of heavy alcohol use on memory and other cognitive functions were more evident in women.” Lopes added that their finding of 8.2 percent was greater than expected, when compared to previous studies, but that the fundamental lack of information in this area of study makes comparisons difficult.

“This study shows that older people keep drinking along the life span,” said Laks. “Taking into consideration that drinking may lead to falls and to cognitive impairment when heavy use is the case, this study creates important awareness about this issue.”

The study was funded by the Fundação de Amparo à Pesquisa de São Paulo (FAPESP). This release is supported by the Addiction Technology Transfer Center Network.

According to a recent Science Daily release, research is being done to study how the brain’s chemicals and synaptic mechanisms react to cocaine addiction and what it could mean for future therapies.

This research is being conducted by University of Missouri researchers Ashwin Mohan and Sandeep Pendyam, doctoral students in the Department of Electrical and Computer Engineering.

“With cocaine addiction, addicts don’t feel an urge to revolt because there is a strong connection in the brain from the decision-making center to the pleasure center, which overwhelms other normal rewards and is why they keep seeking it,” Pendyam said in Science Daily. “By using computational models, we’re targeting the connection in the brain that latches onto the pleasure center and the parameters that maintain that process.”

In using the computational model, MU researchers determined that in an addict’s brain, there is excessive glutamate produced in the pleasure center, which makes the brain’s mechanisms unable to regulate themselves. This creates permanent damage, increasing the known risk for cocaine.

“Our model showed that the glutamate transporters, a protein present around these connections that remove glutamate, are almost 40 percent less functional after chronic cocaine usage,” Mohan said. “This damage is long lasting, and there is no way for the brain to regulate itself. Thus, the brain structure in this context actually changes in cocaine addicts.”