Time-dependent and regional expression of GABA transporter mRNAs following amygdala-kindled seizures in rats.
To investigate the role played by GABA transporters in epileptic seizures, we examined time-dependent and regional changes in expression of GAT-1 and GAT-3 GABA transporter mRNA in amygdala-kindled rat brain using an in situ hybridization method. GAT-1 mRNA was significantly increased bilaterally in the hippocampal dentate gyrus (111-116%) at 1 h after kindled generalized seizures. GAT-1 mRNA was also significantly increased bilaterally in the hippocampal subfields (CA1-4 and dentate gyrus [110-117%]) at 4 h after kindled seizures. There were no significant changes in GAT-1 mRNA level in the amygdalar nuclei, pyriform cortex or cerebral cortex either ipsilaterally or contralaterally at any time after kindled seizures. In contrast, GAT-3 mRNA was significantly increased bilaterally in the amygdalar nuclei and in the contralateral pyriform cortex and cerebral cortex 1 h after seizures. Since all these changes returned to control levels by 8 or 24 h after kindled seizures, the increases in GABA transporter mRNA appeared to be transient responses to seizure activity. These findings indicate that GAT-1 subtype transporter is specifically involved in seizure activity in the hippocampus, while GAT-3 subtype transporter is mainly involved in seizure activity in the amygdalar nuclei and pyriform cortex following amygdala-kindled generalized seizures.
Hirao
T
T
Department of Neuropsychiatry, Faculty of Medicine, Kagawa Medical University, Japan.
Morimoto
K
K
Yamamoto
Y
Y
Watanabe
T
T
Sato
H
H
Sato
K
K
Sato
S
S
Yamada
N
N
Tanaka
K
K
Suwaki
H
H
D000679:Amygdala / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics*; D050485:GABA Plasma Membrane Transport Proteins; D007696:Kindling, Neurologic / Q000235:genetics*; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics; D027361:Organic Anion Transporters; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D002352:Carrier Proteins; D050485:GABA Plasma Membrane Transport Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D027361:Organic Anion Transporters; D012333:RNA, Messenger; C493415:Slc6a1 protein, rat; D005680:gamma-Aminobutyric Acid