A critical role of a facilitatory presynaptic kainate receptor in mossy fiber LTP.
The mechanisms involved in mossy fiber LTP in the hippocampus are not well established. In the present study, we show that the kainate receptor antagonist LY382884 (10 microM) is selective for presynaptic kainate receptors in the CA3 region of the hippocampus. At a concentration at which it blocks mossy fiber LTP, LY382884 selectively blocks the synaptic activation of a presynaptic kainate receptor that facilitates AMPA receptor-mediated synaptic transmission. Following the induction of mossy fiber LTP, there is a complete loss of the presynaptic kainate receptor-mediated facilitation of synaptic transmission. These results identify a central role for the presynaptic kainate receptor in the induction of mossy fiber LTP. In addition, these results suggest that the pathway by which kainate receptors facilitate glutamate release is utilized for the expression of mossy fiber LTP.
Lauri
S E
SE
MRC Centre for Synaptic Plasticity, Department of Anatomy, Medical School, University of Bristol, Bristol BS8 1TD, United Kingdom.
Bortolotto
Z A
ZA
Bleakman
D
D
Ornstein
P L
PL
Lodge
D
D
Isaac
J T
JT
Collingridge
G L
GL
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D001569:Benzodiazepines / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology; D017774:Long-Term Potentiation / Q000502:physiology*; D019599:Mossy Fibers, Hippocampal / Q000502:physiology*; D051381:Rats; D018092:Kainic Acid Receptors / Q000037:antagonists & inhibitors / Q000502:physiology*; D017661:Receptors, Presynaptic / Q000037:antagonists & inhibitors / Q000502:physiology; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
D015763:2-Amino-5-phosphonovalerate; D001569:Benzodiazepines; D018691:Excitatory Amino Acid Antagonists; D007546:Isoquinolines; D018092:Kainic Acid Receptors; D017661:Receptors, Presynaptic; C400802:LY382884; C079692:GYKI 53655