[The character of glial line-cell derived neurotrophic factor mRNA expression in a facial nerve-striking model].
OBJECTIVE
It has been known that glial line-cell derived neurotrophic factor (GDNF) has the nutritional and protective effect in motor neurons. In this experiment, we investigated the character of GDNF mRNA expression in a facial nerve-striking model; combined with other scholars' experimental results; and analyzed what role GDNF plays in the regeneration process of injured motor nerves.


METHODS
We established a striking model in rabbit facial nerves with a striking gun with the striking velocity of 10 m/s and the total striking energy of 7.5 J. Then we detected the GDNF mRNA expression in facial neurons and axons with in situ hybridization on days 3, 7, 14 and 21 after striking. We counted the expression numbers of facial neurons and, compared with normal facial neurons and peripheral facial nerves.


RESULTS
We detected GDNF mRNA expression in the facial neurons from day 3 to day 21 after the facial nerve injured by striking. The peak of GDNF mRNA expression appeared on the 7th day, and then the expression number of facial neurons decreased gradually. A high level expression was also detected on day 21. GDNF mRNA expression was not detected neither in Schwann cells nor in normal facial neurons from the 3rd day to the 21st day.


CONCLUSIONS
GDNF is a kind of neurotrophic growing factor (NGF) that could be activated by injury. The character of GDNF mRNA expression was accordant to the process of nerve regeneration. These results showed that GDNF plays a very important role in the regeneration of injured motor nerves.
Chen
Wang
W
Stomatological Department of the Second Rocket Army General Hospital.
Zhou
Shuxia
S
Zheng
Chunmei
C
Qiu
Jianyong
J
Song
Junfeng
J
D000818:Animals; D005154:Facial Nerve / Q000378:metabolism*; D020220:Facial Nerve Injuries / Q000378:metabolism*; D051100:Glial Cell Line-Derived Neurotrophic Factor; D017403:In Situ Hybridization; D008297:Male; D009044:Motor Cortex / Q000378:metabolism / Q000502:physiology; D009414:Nerve Growth Factors / Q000096:biosynthesis* / Q000235:genetics; D009416:Nerve Regeneration; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000378:metabolism; D011149:Pons / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011817:Rabbits
D051100:Glial Cell Line-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D012333:RNA, Messenger