Identification of upregulated SCG10 mRNA expression associated with late-phase long-term potentiation in the rat hippocampal Schaffer-CA1 pathway in vivo.
The maintenance of long-term potentiation (LTP) depends on alteration of gene transcription. By screening a subtracted cDNA library that is enriched in upregulated transcripts in rat hippocampus 3 hr after Schaffer-CA1 LTP induction in vivo, we identified a neural growth-associated protein SCG10 (superior cervical ganglia clone 10) gene. The semiquantitative reverse transcription-PCR and Northern blot experiments confirmed that SCG10 mRNA levels were elevated in tetanized rat hippocampi compared with those of sham controls that received only low-frequency stimulation. Both 1 and 2 kb forms of SCG10 mRNAs contributed to the increased expression. Using a riboprobe with a sequence specific to the 3'-untranslated region of rat SCG10 mRNA, in situ hybridization further revealed a significant increase of the SCG10 mRNA 2 kb form in the ipsilateral CA3 and CA1 regions of LTP animals. In addition, we systemically injected the competitive NMDA receptor antagonist d,l-3[(+/-)-2-carboxypiperazine-4-yl]-propyl-1-phosphonic acid (CPP) to determine whether the alteration of SCG10 expression depends on NMDA receptor activation or tetanus alone. Administration of CPP 1 hr before tetanus completely blocked LTP induction and the increase of SCG10 mRNA levels. Thus, these results suggest that the transcription of SCG10 in vivo is regulated by long-lasting synaptic activity and may contribute to the maintenance of long-term synaptic plasticity via a presynaptic remodeling mechanism.
Peng
Haixiang
H
Cajal Neuroscience Institute, Department of Biology, University of Texas, San Antonio, Texas 78249-0662, USA. hpeng@lonestar.utsa.edu
Derrick
Brian E
BE
Martinez
Joe L
JL
D000818:Animals; D015152:Blotting, Northern; D002352:Carrier Proteins; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D020869:Gene Expression Profiling; D006624:Hippocampus / Q000502:physiology*; D017403:In Situ Hybridization; D017774:Long-Term Potentiation / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D008297:Male; D008565:Membrane Proteins; D008868:Microtubule Proteins; D009414:Nerve Growth Factors / Q000235:genetics* / Q000378:metabolism; D009434:Neural Pathways / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology; D010879:Piperazines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics*
D002352:Carrier Proteins; D018691:Excitatory Amino Acid Antagonists; D008565:Membrane Proteins; D008868:Microtubule Proteins; D009414:Nerve Growth Factors; D010879:Piperazines; D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate; C512848:Stmn2 protein, rat; C050592:3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid