Postnatal change of GluR5 kainate receptor expression in the substantia gelatinosa neuron of the trigeminal subnucleus caudalis in mice.
The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) has been implicated in the processing of nociceptive information from the orofacial region. Kainate receptors (KARs) play an important role in sensory transmission. Five different KAR subunits have been cloned and the expression of the KAR subunits showed developmental changes. In this study, RT-PCR, western blotting, immunohistochemistry and a patch clamp technique were used examine the functional expression of the GluR5 subunit in the SG of the Vc in juvenile, peripubertal and/or adult mice. The levels of mRNA and protein expression of the GluR5 subunit in the SG of the Vc were higher in the juvenile mice than in the peripubertal or adult mice. In addition, the KA and ATPA, a GluR5 KAR agonist, induced membrane depolarization on the SG neurons in both juvenile and adult mice in a concentration-dependent manner. However, the juvenile SG neurons showed a stronger response to KA and ATPA than those of adults. The membrane depolarization by KA was suppressed slightly in the presence of the AMPA receptor antagonist, GYKI 52466. These results show that the GluR5 KAR subunits are expressed functionally on the SG neurons of the Vc in mice, and the expression levels of the GluR5 subunits decrease with postnatal development. These postnatal changes in the GluR5 KAR subunit may be a possible mechanism for age-dependent pain processing.
Department of Oral Physiology and BK21 program, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju, 561-756, Republic of Korea.
Seon Ah
SA
Park
Hua
H
Yin
Janardhan P
JP
Bhattarai
Soo Joung
SJ
Park
Jeong Chae
JC
Lee
Chul Jin
CJ
Kim
Seong Kyu
SK
Han
D000375:Aging / Q000378:metabolism; D000818:Animals; D001569:Benzodiazepines / Q000494:pharmacology; D015153:Blotting, Western; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D007150:Immunohistochemistry; D007608:Kainic Acid / Q000494:pharmacology; D008297:Male; D051379:Mice; D009474:Neurons / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D018092:Kainic Acid Receptors / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013376:Substantia Gelatinosa / Q000166:cytology / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology; D014278:Trigeminal Nuclei / Q000166:cytology / Q000378:metabolism*
D001569:Benzodiazepines; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D007608:Kainic Acid; D012333:RNA, Messenger; D018092:Kainic Acid Receptors; D013779:Tetrodotoxin; C061950:GYKI 52466