On Serotonin
Hey Boss, I ran across this study today from Science Daily, it will kick-start your dopamine research:
wip
Hey Boss, I ran across this study today from Science Daily, it will kick-start your dopamine research:
New research from Northwestern University's Feinberg School of Medicine has revealed that dopamine strengthens and weakens the two primary circuits in the brain that control our behavior. This provides new insight into why a flood of dopamine can lead to compulsive, addictive behavior and too little dopamaine can leave Parkinson's patients frozen and unable to move.
"The study shows how dopamine shapes the two main circuits of the brain that control how we choose to act and what happens in these disease states, " said D. James Surmeier, lead author and the Nathan Smith Davis Professor and chair of physiology at the Feinberg School. The paper is published in the August 8 issue of the journal Science.
These two main brain circuits help us decide whether to act out a desire or not. For example, do you get off the couch and drive to the store for an icy six-pack of beer on a hot summer night, or just lay on the couch?
One circuit is a "stop" circuit that prevents you from acting on a desire; the other is a "go" circuit that provokes you to action. These circuits are located in the striatum, the region of the brain that translates thoughts into actions.
In the study, researchers examined the strength of synapses connecting the cerebral cortex, the region of the brain involved in perceptions, feelings and thought, to the striatum, home of the stop and go circuits that select or prevent action.
Scientists electrically activated the cortical fibers to simulate movement commands and boosted the natural level of dopamine. What happened next surprised them. The cortical synapses connecting to the "go" circuit became stronger and more powerful. At the same time, dopamine weakened the cortical connections in the "stop" circuit.
"This could be what underlies addiction," Surmeier said. "Dopamine released by drugs leads to abnormal strengthening of the cortical synapses driving the striatal 'go' circuits, while weakening synapses at opposing 'stop' circuits. As a result, when events associated with drug taking – where you took the drug, what you were feeling – occur, there is an uncontrollable drive to go and seek drugs."
"All of our actions in a healthy brain are balanced by the urge to do something and the urge to stop," Surmeier said. "Our work suggests that it is not just the strengthening of the brain circuits helping select actions that is critical to dopamine's effects, it is the weakening of the connections that enable us to stop as well. "
"The study shows how dopamine shapes the two main circuits of the brain that control how we choose to act and what happens in these disease states, " said D. James Surmeier, lead author and the Nathan Smith Davis Professor and chair of physiology at the Feinberg School. The paper is published in the August 8 issue of the journal Science.
These two main brain circuits help us decide whether to act out a desire or not. For example, do you get off the couch and drive to the store for an icy six-pack of beer on a hot summer night, or just lay on the couch?
One circuit is a "stop" circuit that prevents you from acting on a desire; the other is a "go" circuit that provokes you to action. These circuits are located in the striatum, the region of the brain that translates thoughts into actions.
In the study, researchers examined the strength of synapses connecting the cerebral cortex, the region of the brain involved in perceptions, feelings and thought, to the striatum, home of the stop and go circuits that select or prevent action.
Scientists electrically activated the cortical fibers to simulate movement commands and boosted the natural level of dopamine. What happened next surprised them. The cortical synapses connecting to the "go" circuit became stronger and more powerful. At the same time, dopamine weakened the cortical connections in the "stop" circuit.
"This could be what underlies addiction," Surmeier said. "Dopamine released by drugs leads to abnormal strengthening of the cortical synapses driving the striatal 'go' circuits, while weakening synapses at opposing 'stop' circuits. As a result, when events associated with drug taking – where you took the drug, what you were feeling – occur, there is an uncontrollable drive to go and seek drugs."
"All of our actions in a healthy brain are balanced by the urge to do something and the urge to stop," Surmeier said. "Our work suggests that it is not just the strengthening of the brain circuits helping select actions that is critical to dopamine's effects, it is the weakening of the connections that enable us to stop as well. "
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