Featured Research

from universities, journals, and other organizations

Brain imaging study evaluates effects of ingredients in marijuana on brain functioning during reactions to visual stimuli

Date:
January 2, 2012
Source:
JAMA and Archives Journals
Summary:
Different ingredients in marijuana appear to affect regions of the brain differently during brain processing functions involving responses to certain visual stimuli and tasks, according to a new report.

Different ingredients in marijuana appear to affect regions of the brain differently during brain processing functions involving responses to certain visual stimuli and tasks, according to a report in the January issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Related Articles


Sagnik Bhattacharyya, M.B.B.S., M.D., Ph.D, at the Institute of Psychiatry, King's College in London, and colleagues studied 15 healthy men, who were occasional marijuana users, to examine the effects of Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) on regional brain function during salience processing, which is how people perceive things around them.

The authors used functional MRI images to study each participant on three occasions after administration of Δ9-THC, CBD or placebo. Study participants performed a visual oddball task of pressing buttons according to the direction arrows on a screen were pointing, as a measure of attentional salience processing.

"Pairwise comparisons revealed that Δ9-THC significantly increased the severity of psychotic symptoms compared with placebo and CBD whereas there was no significant difference between the CBD and placebo conditions," the authors conclude.

Δ9-THC had a greater effect than placebo on reaction time to nonsalient relative to salient stimuli. This was associated with modulation of both prefrontal and striatal function by Δ9-THC, augmenting (increasing) activation in the former region and attenuating (weakening) it in the latter.

"Moreover, in the present study, the magnitude of Δ9-THC's effect on response times to nonsalient stimuli was correlated with its effect on activation in the right caudate, the region where the physiological effect of Δ9-THC was linked to its induction of psychotic symptoms," the authors write.

They conclude that "collectively, these observations suggest that Δ9-THC may increase the aberrant attribution of salience and induce psychotic symptoms through its effects on the striatum and lateral prefrontal cortex."

When the effects of CBD were contrasted with Δ9-THC and placebo with respect to the visual task there was a "significant effect" in the left caudate with CBD augmenting (increasing) the response and Δ9-THC attenuating (weakening) it.

"These effects suggest that CBD may also influence the effect of cannabis use on salience processing -- and hence psychotic symptoms -- by having an opposite effect, enhancing the appropriate response to salient stimuli," the authors wrote.


Story Source:

The above story is based on materials provided by JAMA and Archives Journals. Note: Materials may be edited for content and length.


Journal Reference:

  1. S. Bhattacharyya, J. A. Crippa, P. Allen, R. Martin-Santos, S. Borgwardt, P. Fusar-Poli, K. Rubia, J. Kambeitz, C. O'Carroll, M. L. Seal, V. Giampietro, M. Brammer, A. W. Zuardi, Z. Atakan, P. K. McGuire. Induction of Psychosis by  9-Tetrahydrocannabinol Reflects Modulation of Prefrontal and Striatal Function During Attentional Salience Processing. Archives of General Psychiatry, 2012; 69 (1): 27 DOI: 10.1001/archgenpsychiatry.2011.161

Cite This Page:

JAMA and Archives Journals. "Brain imaging study evaluates effects of ingredients in marijuana on brain functioning during reactions to visual stimuli." ScienceDaily. ScienceDaily, 2 January 2012. <www.sciencedaily.com/releases/2012/01/120102180854.htm>.
JAMA and Archives Journals. (2012, January 2). Brain imaging study evaluates effects of ingredients in marijuana on brain functioning during reactions to visual stimuli. ScienceDaily. Retrieved November 25, 2014 from www.sciencedaily.com/releases/2012/01/120102180854.htm
JAMA and Archives Journals. "Brain imaging study evaluates effects of ingredients in marijuana on brain functioning during reactions to visual stimuli." ScienceDaily. www.sciencedaily.com/releases/2012/01/120102180854.htm (accessed November 25, 2014).

Share This


More From ScienceDaily



More Mind & Brain News

Tuesday, November 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) — A new study links greater authority with increased depressive symptoms among women in the workplace. Video provided by Newsy
Powered by NewsLook.com
Winter Can Cause Depression — Here's How To Combat It

Winter Can Cause Depression — Here's How To Combat It

Newsy (Nov. 23, 2014) — Millions of American suffer from seasonal depression every year. It can lead to adverse health effects, but there are ways to ease symptoms. Video provided by Newsy
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) — Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com
Milestone Birthdays Can Bring Existential Crisis, Study Says

Milestone Birthdays Can Bring Existential Crisis, Study Says

Newsy (Nov. 21, 2014) — Researchers find that as people approach new decades in their lives they make bigger life decisions. 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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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