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How many more times are they going to 'discover' this? Nic 58/16 On 11 November 2010 21:44, mschild <[log in to unmask]> wrote: > > > Dopamine agonist stimulation reduces activity in brain networks linked to > impulse control and response inhibition, according to a new study. In PD non- > gamblers, activity in these areas increased in response to the same > stimulation. > > PET imaging was performed before and after apomorphine administration in 14 PD > patients, 7 with DA-induced pathological gambling, and 7 without. During each > imaging session, the patient engaged in a simple card choice test, which > rewarded a correct choice with a visual display indicating the correct choice > had been made. > > The effect of DA administration was opposite in the two groups. In non- > gamblers, administration of apomorphine "significantly increased activity" in > the left lateral orbitofrontal cortex (OFC), right rostral cingulate zone > (RCZ), right amygdala, and left ventral anterior external pallidum (GPe), > "while gamblers showed a significant DA-induced reduction of neuronal activity > in these regions." In gamblers, the decrease in activity correlated with an > increase in gambling symptoms following DA administration, as determined by a > symptom questionnaire. > > "Hypoactivity of the lateral OFC has previously been reported in drug > addiction and pathological gambling in non-PD subjects," the authors note, > "and is thought to play a crucial role in assigning subjective value to > actions by encoding and updating expectations of future rewards or > punishments....The RCZ is thought to be engaged in monitoring functions that > are involved in preventing negative consequences." > > They conclude, "We propose that in vulnerable patients with PD, DAs produce an > abnormal neuronal pattern that resembles those found in nonparkinsonian > pathological gambling and drug addiction." > > Drug-induced deactivation of inhibitory networks predicts pathological > gambling in PD > T van Eimeren, G Pellechia, R Cilia, B Ballanger, TDL Steeves, S Houle, JM > Miyasaki, M Zurowski, AE Lang, AP Strafella > Neurology 2010;75:1711-1716 > > ---------------------------------------------------------------------- > To sign-off Parkinsn send a message to: mailto:[log in to unmask] > In the body of the message put: signoff parkinsn > ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn