Why Marijuana Impairs Memory
Health SciTech
By Charles Q. Choi
Special to LiveScience
posted: 19 November 2006
01:00 pm ET
Scientists may have just found out why marijuana impairs memory and why the brain's natural versions of the drug might help against epilepsy.
The active ingredient of marijuana, THC, is known to impair memory and to bind to areas of the brain linked to memory, such as the hippocampus. Still, the exact mechanisms by which marijuana impairs memory remain unclear.
Neuroscientists David Robbe and Gyorgy Buzsaki at Rutgers University and their colleagues recorded hippocampus activity in rats. Normally brain cells in this region often synchronize their electrical activity.
When the researchers injected rats with THC or a related synthetic drug, they found the normally synchronized workings of the hippocampus became disrupted. While the cells did not change how often they fired nerve impulses, their timing became erratic.
Imagine an orchestra where the musicians are deafened and perhaps blindfolded, Buzsaki said.
"They could still play their own pieces, but without any feedback from the other instruments played by other musicians or the conductor, depending on the nature and the length of the music played, it could be just a bit worse or outright disastrous, even though every note has been played. What is missing is the temporal coordination," Buzsaki explained. This is similar to what the researchers think goes on "in the hippocampal circuits under the influence of marijuana."
>
Health SciTech
By Charles Q. Choi
Special to LiveScience
posted: 19 November 2006
01:00 pm ET
Scientists may have just found out why marijuana impairs memory and why the brain's natural versions of the drug might help against epilepsy.
The active ingredient of marijuana, THC, is known to impair memory and to bind to areas of the brain linked to memory, such as the hippocampus. Still, the exact mechanisms by which marijuana impairs memory remain unclear.
Neuroscientists David Robbe and Gyorgy Buzsaki at Rutgers University and their colleagues recorded hippocampus activity in rats. Normally brain cells in this region often synchronize their electrical activity.
When the researchers injected rats with THC or a related synthetic drug, they found the normally synchronized workings of the hippocampus became disrupted. While the cells did not change how often they fired nerve impulses, their timing became erratic.
Imagine an orchestra where the musicians are deafened and perhaps blindfolded, Buzsaki said.
"They could still play their own pieces, but without any feedback from the other instruments played by other musicians or the conductor, depending on the nature and the length of the music played, it could be just a bit worse or outright disastrous, even though every note has been played. What is missing is the temporal coordination," Buzsaki explained. This is similar to what the researchers think goes on "in the hippocampal circuits under the influence of marijuana."
>
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