Study: Marijuana may affect neuron firing

November 29, 2006

U.S. scientists have discovered the active ingredient in marijuana interferes with synchronized activity between neurons in the hippocampus of rats.

The authors suggest action of tetrahydrocannabinol, or THC, might explain why marijuana impairs memory.

Gyorgy Buzsaki and colleagues at Rutgers University recorded the activity of multiple neurons in the hippocampus of rats. Normally neurons in that region form groups that fire action potentials, or nerve impulses, together at about 4-10 times per second. But when the authors injected THC, or a related synthetic drug, into the hippocampus, that synchrony was disrupted.

The researchers said the drugs did not change the total number of action potentials produced, just their tendency to occur at the same time. Animals with less synchronized neural activity under the drug performed less well in a standard test of memory, suggesting synchronized neural firing is important for normal hippocampal function.

The study appears in the December issue of the journal Nature Neuroscience.

Copyright 2006 by United Press International

Explore further: Marijuana increases alcohol toxicity in young rats

Related Stories

Marijuana increases alcohol toxicity in young rats

April 8, 2008

Marijuana is among the most frequently used illicit drugs by women during their childbearing years and there is growing concern that marijuana abuse during pregnancy, either alone or in combination with other drugs, may have ...

How do cannabinoids make us feel that way?

October 9, 2007

Marijuana and its main psychoactive component, THC, exert a plethora of behavioral and autonomic effects on humans and animals. Some of these effects are the cause of the widespread illicit use of marijuana, while others ...

Study overturns decade-old findings in neurobiology

May 12, 2010

In findings that should finally put to rest a decade of controversy in the field of neurobiology, a team at The Scripps Research Institute has found decisive evidence that a specific neurotransmitter system -- the endocannabinoid ...

Study: cannabis a double-edged sword

October 23, 2007

A new neurobiological study has found that a synthetic form of THC, the active ingredient in cannabis, is an effective anti-depressant at low doses. However, at higher doses, the effect reverses itself and can actually worsen ...

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

( -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.