A juvenile form of postsynaptic hippocampal long-term potentiation in mice deficient for the AMPA receptor subunit GluR-A.
In adult mice, long-term potentiation (LTP) of synaptic transmission at CA3-to-CA1 synapses induced by tetanic stimulation requires L-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors containing GluR-A subunits. Here, we report a GluR-A-independent form of LTP, which is comparable in size to LTP in wild-type mice at postnatal day 14 (P14) but diminishes between P14 and P42 in brain slices of GluR-A-deficient mice. The GluR-A-independent form of LTP is sensitive to D(-)-2-amino-5-phosphonopentanoic acid (D-AP5), but lacks short-term potentiation (STP) and can also be observed in the pairing induction protocol. As judged by unaltered paired-pulse facilitation, this LTP form is postsynaptically expressed despite depleted extrasynaptic AMPA receptor pools with reduced levels of GluR-B, which accumulates in somata and synapses of CA1 pyramidal neurons in GluR-A-deficient mice. Our results show that in the developing hippocampus synaptic plasticity can be expressed by AMPA receptors lacking the GluR-A subunit.
Jensen
Vidar
V
Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, PO Box 1103 Blindern, N0317 Oslo, Norway.
Kaiser
Katharina M M
KM
Borchardt
Thilo
T
Adelmann
Giselind
G
Rozov
Andrei
A
Burnashev
Nail
N
Brix
Christian
C
Frotscher
Michael
M
Andersen
Per
P
Hvalby
Øivind
Ø
Sakmann
Bert
B
Seeburg
Peter H
PH
Sprengel
Rolf
R
D000818:Animals; D001483:Base Sequence; D003433:Crosses, Genetic; D017931:DNA Primers; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D016253:Microscopy, Immunoelectron; D021122:Protein Subunits / Q000235:genetics; D017966:Pyramidal Cells / Q000502:physiology; D018091:Receptors, AMPA / Q000172:deficiency* / Q000235:genetics / Q000502:physiology*; D012016:Reference Values; D009435:Synaptic Transmission
D017931:DNA Primers; D021122:Protein Subunits; D018091:Receptors, AMPA