PT  - JOURNAL ARTICLE
AU  - Wayne A. Cass
AU  - Michael W. Manning
TI  - GDNF Protection against 6-OHDA–Induced Reductions in Potassium-Evoked Overflow of Striatal Dopamine
AID  - 10.1523/JNEUROSCI.19-04-01416.1999
DP  - 1999 Feb 15
TA  - The Journal of Neuroscience
PG  - 1416--1423
VI  - 19
IP  - 4
4099  - http://www.jneurosci.org/content/19/4/1416.short
4100  - http://www.jneurosci.org/content/19/4/1416.full
SO  - J. Neurosci.1999 Feb 15; 19
AB  - Glial cell line–derived neurotrophic factor (GDNF), when administered before 6-hydroxydopamine (6-OHDA), has been shown to prevent the reduction in nigral dopamine (DA) levels and tyrosine hydroxylase–positive neurons normally observed after 6-OHDA lesions. The present study examined the ability of GDNF to prevent 6-OHDA–induced reductions in striatal DA release and reductions in striatal and nigral DA levels. GDNF (10 μg), or vehicle, was injected into the right nigra of anesthetized male Fischer-344 rats and was followed 6 hr later by intranigral 6-OHDA or saline. Three to four weeks later the animals were anesthetized with urethane and prepared for in vivo electrochemistry. Potassium-evoked overflow of DA was dramatically decreased in the right striatum of the vehicle + 6-OHDA–treated animals. GDNF appeared to prevent the reduction in evoked overflow of DA in the right striatum of the 6-OHDA–treated animals. However, in comparison with that in animals that received GDNF + saline, the overflow of DA was significantly reduced in the GDNF + 6-OHDA animals. Similarly, although nigral levels of DA were above normal in the GDNF + 6-OHDA–treated animals, they were below DA levels found in GDNF + saline–treated rats. Striatal DA levels were partially protected by GDNF. In animals examined 10–12 weeks after the GDNF and 6-OHDA treatments, the apparent protective ability of GDNF on the evoked overflow of DA in the striatum was diminished. Thus, although intranigral GDNF can prevent 6-OHDA–induced reductions in nigral DA levels, long-term protection of the evoked overflow of DA in the striatum is minimal.