How marijuana makes you forget

How marijuana makes you forget | Digg Lifestyle:



Researchers have discovered how marijuana disrupts short-term memory.

The drug impairs users’ working memory — the ability to retain and use information over short periods of time. Neuroscientists Giovanni Marsicano of the University of Bordeaux, France, and Xia Zhang of the University of Ottawa Institute of Mental Health Research now show that this common side effect occurs because of a previously unknown signalling mechanism between neurons and non-neuronal cells called astrocytes. Their work is published today in Cell.

The star-shaped astrocytes have long been considered nothing more than support cells that protect neurons. “Our study provides compelling evidence that astrocytes control neurons and memory,” says Zhang. “The supporting actor has become the leading actor.”

The psychoactive ingredient of marijuana is tetrahydrocannabinol (THC). Using microelectrodes implanted into the brains of anaesthetized rats, the researchers found that the compound weakens the connections, or synapses, between neurons in the hippocampus, a structure that is crucial for memory formation.