Long-term potentiation in vivo increases rat hippocampal tenascin-C expression.
We investigated the expression of the extracellular matrix glycoprotein tenascin-C after induction of long-term potentiation (LTP) by high-frequency tetanization (HFT) in the rat dentate gyrus in vivo. Expression of tenascin-C was evaluated at the mRNA and protein levels by in situ hybridization and immunocytochemistry, respectively. Whereas no tenascin-C mRNA was detectable in control animals, an increase in tenascin-C mRNA levels was observed in the granule cell layer of the dentate gyrus 4 h after HFT. At 24 h after HFT, tenascin-C mRNA had returned to control levels. Expression of tenascin-C protein 4 h after HFT followed that of controls in that tenascin was detectable in the strata oriens and radiatum of CA1, in the molecular layer, and within a narrow area at the inner surface of the granule cell layer in the dentate gyrus. However, 24 h after HFT, additional patches of tenascin-C immunoreactivity were observed in the molecular layer of the dentate gyrus. No increase in tenascin mRNA or protein levels was detected in control animals that received no stimulation, low-frequency stimulation, or HFT in the presence of the N-methyl-D-aspartate receptor antagonist D(-)-2-amino-5-phosphonopentanoic acid or the metabotropic glutamate receptor antagonist (R,S)-alpha-methyl-4-carboxyphenylglycine. These observations implicate a role for tenascin-C in N-methyl-D-aspartate and metabotropic glutamate receptor-dependent changes accompanying induction and/or maintenance of LTP.
Nakic
M
M
Department of Neurobiology, Swiss Federal Institute of Technology, Hönggerberg, Zürich.
Manahan-Vaughan
D
D
Reymann
K G
KG
Schachner
M
M
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D001565:Benzoates / Q000494:pharmacology; D018891:Dentate Gyrus / Q000378:metabolism*; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000502:physiology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D017774:Long-Term Potentiation; D008297:Male; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D009435:Synaptic Transmission / Q000502:physiology; D019063:Tenascin / Q000096:biosynthesis*
D001565:Benzoates; D018691:Excitatory Amino Acid Antagonists; D009419:Nerve Tissue Proteins; D019063:Tenascin; C079694:alpha-methyl-4-carboxyphenylglycine; D015763:2-Amino-5-phosphonovalerate; D005998:Glycine