Featured Research

from universities, journals, and other organizations

Adolescent Brains Are Insensitive To Alcohol For A Short Time, But At Great Cost

Date:
October 25, 2006
Source:
Alcoholism: Clinical & Experimental Research
Summary:
Adolescent brains can compensate for some of alcohol's effects, including intoxication and hangover. New findings indicate they are also less impaired by alcohol's effects on social inhibition. However, this ability to have more drinks per occasion will also likely lead to alcohol abuse.

Whereas brain development during adolescence may initially serve to "safeguard" youth from certain effects of alcohol such as intoxication and hangover, it will also likely make them more vulnerable to the longer-term effects of alcohol. A first-of-its-kind study uses rodents to examine development of acute tolerance to alcohol-induced social impairment among adolescents and adults. Findings show that younger rodents have nervous systems that quickly adapt to alcohol's effects -- called tolerance -- which permits heavy drinking at an early age.

Results are published in the November issue of Alcoholism: Clinical & Experimental Research.

"Adolescence is a time of rapid changes of the brain," said Elena I. Varlinskaya, a research professor at Binghamton University and the study's corresponding author, "particularly in the prefrontal cortex and limbic and mesolimbic brain systems of human adolescents. Adolescent rodents show similarities with human adolescents in terms of dramatic age-related remodeling of the brain. Using animal models, researchers have shown that unpleasant physical symptoms associated with alcohol intoxication and hangover, which make adults stop drinking, are not experienced to the same degree by adolescents."

"There are several potential implications of having a brain that is less sensitive to alcohol," said Marisa M. Silveri, assistant professor of psychiatry at Harvard Medical School, "such as a disconnect between the behavioral and the physiological effects of alcohol use. Adults may not be aware of the level of intoxication in teens, given that they demonstrate significantly less motor impairment and sedation than adults do given the same amount of alcohol. Thus, a lack of overt signs of intoxication may mask the more potentially damaging effects of alcohol on neural systems involved in learning and memory."

Varlinskaya added that adolescent insensitivity to alcohol may also be related to an ability to rapidly counteract different effects of alcohol with compensatory responses such as acute tolerance. "Acute tolerance is characterized by a more rapid decline in alcohol-induced impairment than in blood or brain alcohol levels following a single alcohol dose," she said. "We know that social behavior is sensitive to low-to-moderate doses of alcohol. Therefore, this study examined development of acute tolerance to alcohol-induced impairment of social behavior among adolescent and adult rats."

Researchers used Sprague-Dawley rats. Social activity was examined after the animals were administered alcohol, after a five- or 30-minute interval: on postnatal day (P) 28, the equivalent of early adolescence; P35, mid adolescence; P42, late adolescence; or P70, the equivalent of young adulthood. Brain alcohol concentrations were also measured in the animals.

"We found greater acute tolerance in adolescent than adult animals at alcohol levels comparable to human binge drinking," said Varlinskaya. "In other words, both adolescents and adults showed the same degree of social impairment when tested immediately after or five minutes following alcohol exposure. However, the social behavior of adult animals was still severely suppressed 30 minutes after alcohol administration, whereas the social behavior of adolescents was almost similar to that of animals not exposed to alcohol."

"This study extends previous findings that adolescents are generally less impaired by alcohol's effects to now include alcohol's effects on social inhibition," said Silveri. "These findings support the notion that the adolescent brain functions quite differently than the adult brain, particularly in its response to alcohol. Even though the adolescent brain has the capacity to adapt to an alcohol challenge, this will likely come at great cost as valuable cerebral resources are redirected from the important role of brain development to instead adapting to an alcohol challenge, and then restoring the system back to status quo once alcohol is eliminated or the challenge is removed."

Varlinskaya concurs. "This ability of adolescents to rapidly counteract some unpleasant alcohol effects by developing acute tolerance may allow them to have more drinks per occasion," she said. "This binge pattern of drinking, being unsafe in general, might be extremely dangerous for adolescents, given that their brain is especially vulnerable to alcohol-related damage."

"Social behavior is an understudied area, particularly with regard to adolescence and alcohol's effects," added Silveri. "The choice of this dependent variable is timely in that human neuroimaging studies are beginning to examine developmental changes in brain function that are commensurate with the development of emotional intelligence and social behavior. In addition, this is one of the first studies to document tolerance to alcohol's effect on social behavior, which occurs in an age-dependent manner."

"Human adolescents are confronted with a variety of potentially stressful challenges, and they often use alcohol to control stress and cope with problems," said Varlinskaya. Her future work will therefore focus on the impact of stress on the effects of alcohol on social behavior of adolescent and adult rodents.

Alcoholism: Clinical & Experimental Research (ACER) is the official journal of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism. The co-author of the ACER paper, "Ontogeny of Acute Tolerance to Ethanol-Induced Social Inhibition in Sprague-Dawley Rats," was Linda P. Spear of the Department of Psychology at Binghamton University. The study was funded by the National Institute on Alcohol Abuse and Alcoholism


Story Source:

The above story is based on materials provided by Alcoholism: Clinical & Experimental Research. Note: Materials may be edited for content and length.


Cite This Page:

Alcoholism: Clinical & Experimental Research. "Adolescent Brains Are Insensitive To Alcohol For A Short Time, But At Great Cost." ScienceDaily. ScienceDaily, 25 October 2006. <www.sciencedaily.com/releases/2006/10/061025085455.htm>.
Alcoholism: Clinical & Experimental Research. (2006, October 25). Adolescent Brains Are Insensitive To Alcohol For A Short Time, But At Great Cost. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2006/10/061025085455.htm
Alcoholism: Clinical & Experimental Research. "Adolescent Brains Are Insensitive To Alcohol For A Short Time, But At Great Cost." ScienceDaily. www.sciencedaily.com/releases/2006/10/061025085455.htm (accessed July 31, 2014).

Share This




More Mind & Brain News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Dieting At A Young Age Might Lead To Harmful Health Habits

Dieting At A Young Age Might Lead To Harmful Health Habits

Newsy (July 30, 2014) Researchers say women who diet at a young age are at greater risk of developing harmful health habits, including eating disorders and alcohol abuse. Video provided by Newsy
Powered by NewsLook.com
It's Not Just Facebook: OKCupid Experiments With Users Too

It's Not Just Facebook: OKCupid Experiments With Users Too

Newsy (July 29, 2014) If you've been looking for love online, there's a chance somebody has been looking at how you're looking. Video provided by Newsy
Powered by NewsLook.com
How Your Face Can Leave A Good Or Bad First Impression

How Your Face Can Leave A Good Or Bad First Impression

Newsy (July 29, 2014) Researchers have found certain facial features can make us seem more attractive or trustworthy. Video provided by Newsy
Powered by NewsLook.com
Losing Sleep Leaves You Vulnerable To 'False Memories'

Losing Sleep Leaves You Vulnerable To 'False Memories'

Newsy (July 27, 2014) A new study shows sleep deprivation can make it harder for people to remember specific details of an event. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



    Save/Print:
    Share:

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile: iPhone Android Web
    Follow: Facebook Twitter Google+
    Subscribe: RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins