New brain cells implicated in machinery of cannabinoid signaling

Mar 26, 2008

The brain cells called astrocytes, and not just neurons, are sensitive to the substances called cannabinoids—the active chemicals in marijuana.

The researchers said their findings could aid in development of treatments for cannabinoid drug abuse. Also, because so-called “endocannabinoids” produced by brain cells are involved in the neural machinery of pain perception and learning and memory, the findings could help in understanding those processes, said the researchers.

Marta Navarrete and Alfonso Araque published their findings in the March 27, 2008, issue of the journal Neuron, published by Cell Press.

Astrocytes do not transmit nerve impulses, as do neurons. Rather, they provide neurons with support and nutrition and modulate signaling among neurons.

In their experiments with mouse brain slices, Navarrete and Araque sought to establish the role that cannabinoid receptors on astrocytes—which previous studies had indicated to exist—played in astrocyte function. Receptors are proteins that rest in the membranes of cells and that are triggered by specific chemicals, like a key fitting a lock. That triggering activates a cellular response.

The researchers’ electrophysiological and imaging studies showed that astrocytes do express endocannabinoid receptors that, when activated, produce a cellular response. They also found that neurons associated with the astrocytes release endocannabinoids that trigger an astrocyte response. Finally, they also showed that this response in astrocytes can, in turn, activate neurons to release the neurotransmitter glutamate, which mediates signaling among neurons.

Navarrete and Araque concluded that “These results indicate that neurons and astrocytes communicate via endocannabinoid signaling and suggest the existence of intercellular communication pathways mediated by endocannabinoid-glutamate signaling where astrocytes serve as a bridge for interneuronal communication.”

The researchers also concluded that their findings identify astrocytes “as cellular elements possibly involved in the physiology of cannabinoid addiction as well as potential targets for the treatment of cannabinoid-related drug abuse. Furthermore, considering the importance of the endocannabinoid-mediated intercellular signaling in numerous processes of the nervous system, such as pain perception or learning and memory, present findings indicate that astrocytes may be actively involved in relevant phenomena of brain physiology.

Source: Cell Press

Explore further: Study reveals one reason brain tumors are more common in men

add to favorites email to friend print save as pdf

Related Stories

Molecular gate that could keep cancer cells locked up

1 hour ago

In a study published today in Genes & Development, Dr Christian Speck from the MRC Clinical Sciences Centre's DNA Replication group, in collaboration with Brookhaven National Laboratory (BNL), New York, ...

Taking great ideas from the lab to the fab

2 hours ago

A "valley of death" is well-known to entrepreneurs—the lull between government funding for research and industry support for prototypes and products. To confront this problem, in 2013 the National Science ...

SR Labs research to expose BadUSB next week in Vegas

3 hours ago

A Berlin-based security research and consulting company will reveal how USB devices can do damage that can conduct two-way malice, from computer to USB or from USB to computer, and can survive traditional ...

Recommended for you

Clues to curbing obesity found in neuronal 'sweet spot'

4 hours ago

Preventing weight gain, obesity, and ultimately diabetes could be as simple as keeping a nuclear receptor from being activated in a small part of the brain, according to a new study by Yale School of Medicine ...

Small RNAs in blood may reveal heart injury

13 hours ago

(Medical Xpress)—Like clues to a crime, specific molecules in the body can hint at exposure to toxins, infectious agents or even trauma, and so help doctors determine whether and how to treat a patient. ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

Argiod
1 / 5 (1) Mar 28, 2008
Give 'em time, and they'll find a way to treat any form of pleasure. That way, they can turn all of humanity into pleasureless drones. Once that's done, put the drones to work making the world a better place.... for the wealthy controllers of the drones, that is.
COCO
1 / 5 (1) Apr 07, 2008
ya - after reading this cure to the scourage of this century I had to spark a bowl.