A pathway-specific function for different AMPA receptor subunits in amygdala long-term potentiation and fear conditioning.
The AMPA receptor subunit glutamate receptor 1 (GluR1 or GluR-A) contributes to amygdala-dependent emotional learning. It remains unclear, however, to what extent different amygdala pathways depend on GluR1, or other AMPA receptor subunits, for proper synaptic transmission and plasticity, and whether GluR1-dependent long-term potentiation (LTP) is necessary for auditory and contextual fear conditioning. Here, we dissected the role of GluR1 and GluR3 (GluR-C) subunits in AMPA receptor-dependent amygdala LTP and fear conditioning using knock-out mice (GluR1-/- and GluR3-/-). We found that, whereas LTP at thalamic inputs to lateral amygdala (LA) projection neurons and at glutamatergic synapses in the basal amygdala was completely absent in GluR1-/- mice, both GluR1 and GluR3 contributed to LTP in the cortico-LA pathway. Because both auditory and contextual fear conditioning were selectively impaired in GluR1-/- but not GluR3-/- mice, we conclude that GluR1-dependent synaptic plasticity is the dominant form of LTP underlying the acquisition of auditory and contextual fear conditioning, and that plasticity in distinct amygdala pathways differentially contributes to aversive conditioning.
Humeau
Yann
Y
Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland.
Reisel
Daniel
D
Johnson
Alexander W
AW
Borchardt
Thilo
T
Jensen
Vidar
V
Gebhardt
Christine
C
Bosch
Verena
V
Gass
Peter
P
Bannerman
David M
DM
Good
Mark A
MA
Hvalby
Øivind
Ø
Sprengel
Rolf
R
Lüthi
Andreas
A
D000679:Amygdala / Q000502:physiology*; D000818:Animals; D003213:Conditioning, Psychological / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D017774:Long-Term Potentiation / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009434:Neural Pathways / Q000502:physiology; D021122:Protein Subunits / Q000502:physiology; D018091:Receptors, AMPA / Q000502:physiology*
D021122:Protein Subunits; D018091:Receptors, AMPA