Localization of dopamine receptor subtypes in the rat spiral ganglion.
Although dopaminergic neurons are thought to exist in the lateral olivocochlear efferent system and modulate the afferent nerve activity, the distribution of dopamine (DA) receptor subtypes is still obscure. In the present study, we investigated the localization of five subtypes of DA receptor (D1-5) by immunocytochemical analysis and the gene expression of D1-5 using RT-PCR procedure in the rat cochlea. Most, but not all, spiral ganglion neurons were immunolabeled with all the anti-DA receptor subunit antibodies and faint punctuate immunoreactivities were observed in inner hair cell regions. Gene expression for all receptors was detected. These results suggest that all DA receptor subtypes are present in spiral ganglion cells, and potentially regulate afferent neurotransmission.
Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki 036-8562, Japan.
Taku
T
Inoue
Atsushi
A
Matsubara
Shin-ichiro
S
Maruya
Yohei
Y
Yamamoto
Atsushi
A
Namba
Akira
A
Sasaki
Hideichi
H
Shinkawa
D000818:Animals; D015152:Blotting, Northern / Q000379:methods; D015870:Gene Expression / Q000502:physiology*; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D009474:Neurons / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011954:Receptors, Dopamine / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013136:Spiral Ganglion / Q000166:cytology / Q000378:metabolism*
D012333:RNA, Messenger; D011954:Receptors, Dopamine