[Detection of GABAA alpha 2 mRNA in rat cochlear spiral neuron with in situ hybridization].
OBJECTIVE
To investigate the expression of gamma-aminobutyric acid (GABA)A receptor alpha 2 subunit mRNA on rat cochlear spiral neurons and its' significance.


METHODS
In the rat cochlear paraffin slides, the GABAA alpha 2 receptor in spiral ganglion neuron was detected with in situ hybridization. Digoxigenin-GABAA alpha 2 cDNA probe (549 base pair), anti-digoxigenin-AP(Fab fragments) and BM purple substrate(precipitating) were used.


RESULTS
Positive signals(GABAA alpha 2 mRNA) were seen in all cochlear spiral neurons and their nerves. GABAA alpha 2 mRNA was not found in other structure such as bony spiral lamina. As a positive control, GABAA alpha 2 mRNA was seen in Purkinje cells, granule cells and their axons in rat's cerebellum. GABAA alpha 2 mRNA was not found in OMP cDNA probe (olfactory membrane estrogen receptor probe) negative control, non-probe negative control and non-anti-digoxingenin control in cochlear spiral neuron and cerebellum.


CONCLUSIONS
GABAA alpha 2 receptor has been found in type I spiral neurons and their nerves. It strongly indicates that GABA as a nerve transmitter plays an important role in inhibiting the excessive stimulation transmission of the inner hair cells.
Zheng
Hong
H
Department of Otolaryngology, West China Hospital, Sichuan University, Chengdu 610041, China.
Tang
Yue-di
YD
Zheng
Yun
Y
Yang
Hui
H
D000818:Animals; D003056:Cochlear Nerve / Q000378:metabolism*; D006199:Hair Cells, Auditory, Inner / Q000502:physiology; D017403:In Situ Hybridization; D008297:Male; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D011963:Receptors, GABA-A / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D013136:Spiral Ganglion / Q000378:metabolism*
D012333:RNA, Messenger; D011963:Receptors, GABA-A