2. Dopamine functions as an essential neurotransmitter, at some level, throughout all basal ganglia structures, and is sharply decreased in Parknsons

3. AAV2-hAADC expresses human aromatic l-amino acid decarboxylase (AADC) , the last enzymatic step in the biosynthesis of dopamine

4. Intraparenchymal injections avoids possible immunogenic complications

5. Provides insight into vector trafficking in brain and peripheral tissues after intraputamenal delivery and relationship with dosage

6. Ten animals in five dose groups received bilateral intraputamenal infusions

7. (2/hemisphere; 4/brain) of AAV2-hAADC at doses of 6, 18, 55, 170, and 500 U/hemisphere. Two control animals were similarly infused with AAV2-GFP at doses of 1,000 U/brain (1 U = 1 . 10 9 vector genomes)

8. Clinical response evaluated in terms of PD clinical rating scale, 6 months before and after

9. PCR, immunohistochemistry,HPLC and PET was used for analysis of data

11. No vector DNA detected in fluids and tissues except spleen

12. Observed lack of antibody response is interpreted as further evidence of a delivery problem

14. CED is a highly effective method of spreading the vector throughout the entire targeted striatal area

15. Possible that neuronal transport and perivascular mechnism can significantly influence biodistribution