Word: volkow
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Dates: during 1997-1997
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...team of researchers led by psychiatrist Dr. Nora Volkow of the Brookhaven National Laboratory in New York has published the strongest evidence to date that the surge of dopamine in addicts' brains is what triggers a cocaine high. In last week's edition of the journal Nature they described how powerful brain-imaging technology can be used to track the rise of dopamine and link it to feelings of euphoria...
...work on it), the evidence suggests that we may be fighting the wrong battle. Americans tend to think of drug addiction as a failure of character. But this stereotype is beginning to give way to the recognition that drug dependence has a clear biological basis. "Addiction," declares Brookhaven's Volkow, "is a disorder of the brain no different from other forms of mental illness...
...evidence that Volkow and her colleagues present in the current issue of Nature suggests that dopamine is directly responsible for the exhilarating rush that reinforces the desire to take drugs, at least in cocaine addicts. In all, 17 users participated in the study, says Volkow, and they experienced a high whose intensity was directly related to how extensively cocaine tied up available binding sites on the molecules that transport dopamine around the brain. To produce any high at all, she and her colleagues found, cocaine had to occupy at least 47% of these sites; the "best" results occurred when...
Indeed, the brain has many devious tricks for ensuring that the irrational act of taking drugs, deemed "good" because it enhances dopamine, will be repeated. pet-scan images taken by Volkow and her colleagues reveal that the absorption of a cocaine-like chemical by neurons is profoundly reduced in cocaine addicts in contrast to normal subjects. One explanation: the addicts' neurons, assaulted by abnormally high levels of dopamine, have responded defensively and reduced the number of sites (or receptors) to which dopamine can bind. In the absence of drugs, these nerve cells probably experience a dopamine deficit, Volkow speculates...