Word: braine
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...course, not everyone becomes an addict. That's because we have other, more analytical regions that can evaluate consequences and override mere pleasure seeking. Brain imaging is showing exactly how that happens. Paulus, for example, looked at methamphetamine addicts enrolled in a VA hospital's intensive four-week rehabilitation program. Those who were more likely to relapse in the first year after completing the program were also less able to complete tasks involving cognitive skills and less able to adjust to new rules quickly. This suggested that those patients might also be less adept at using analytical areas...
Another area of focus for researchers involves the brain's reward system, powered largely by the neurotransmitter dopamine. Investigators are looking specifically at the family of dopamine receptors that populate nerve cells and bind to the compound. The hope is that if you can dampen the effect of the brain chemical that carries the pleasurable signal, you can loosen the drug's hold...
...just as there are two ways to stop a speeding car--by easing off the gas or hitting the brake pedal--there are two different possibilities for muting addiction. If dopamine receptors are the gas, the brain's own inhibitory systems act as the brakes. In addicts, this natural damping circuit, called GABA (gamma-aminobutyric acid), appears to be faulty. Without a proper chemical check on excitatory messages set off by drugs, the brain never appreciates that it's been satiated...
Among higher creatures like us, stress can also alter the way the brain thinks, particularly the way it contemplates the consequences of actions. Recall the last time you found yourself in a stressful situation--when you were scared, nervous or threatened. Your brain tuned out everything besides whatever it was that was frightening you--the familiar fight-or-flight mode. "The part of the prefrontal cortex that is involved in deliberative cognition is shut down by stress," says Vocci. "It's supposed to be, but it's even more inhibited in substance abusers." A less responsive prefrontal cortex sets...
...people become addicted as well. Studies have shown, for instance, that women may be more vulnerable to cravings for nicotine during the latter part of the menstrual cycle, when the egg emerges from the follicle and the hormones progesterone and estrogen are released. "The reward systems of the brain have different sensitivities at different points in the cycle," notes Volkow. "There is way greater craving during the later phase...