PT  - JOURNAL ARTICLE
AU  - Rajendra Badgaiyan
AU  - Alan Fischman
AU  - Nathaniel Alpert
TI  - Detection of task-induced release of extrastriatal dopamine using fallypride
DP  - 2007 May 01
TA  - Journal of Nuclear Medicine
PG  - 239P--239P
VI  - 48
IP  - supplement 2
4099  - http://jnm.snmjournals.org/content/48/supplement_2/239P.4.short
4100  - http://jnm.snmjournals.org/content/48/supplement_2/239P.4.full
SO  - J Nucl Med2007 May 01; 48
AB  - 1118 Objectives: Since a reliable technique to study the neurochemistry of human cognition is not available, an important aspect of cognitive processing remains unexplored. We have earlier demonstrated that task-induced release of striatal dopamine can be detected using a molecular imaging technique. This demonstration however, is of limited use because it can not be used to detect dopamine released in the extrastriatal areas, where a majority of human cognitive processing occurs. Methods: We used the ligand 18F-fallypride to examine whether this ligand can be used to detect endogenous dopamine released in extrastriatal areas during performance of a cognitive task. Since evidence suggests that the processing of emotional memory is associated with release of extrastriatal dopamine, in this experiment, after a single intravenous administration of 18F-fallypride, healthy volunteers were asked to perform an emotional memory task which consisted of a control (no emotional memory) and a test condition. The test condition was started 25 min after the ligand administration. The ligand concentration was measured using an ECAT HR+ camera. Results: Behavioral data indicated elicitation of emotional memory in the test condition. Immediately after initiation of this condition the rate of ligand displacement increased significantly in the areas that have previously been implicated in the processing of emotional memory. These areas included amygdala, medial temporal lobe and ventral prefrontal cortex. The displacement rate did not change in the reference region. Conclusions: Since the experiment found evidence of significant dopamine release in the extrastriatal areas that have previously been implicated in the processing of emotional memories, the results suggest that the ligand 18F-fallypride can be used to detect task induced release of extrastriatal dopamine. Research Support (if any): NIH (1R21MH073624), Dana Foundation, Shriners Hospital for Children