Ifenprodil reduces excitatory synaptic transmission by blocking presynaptic P/Q type calcium channels.
Ifenprodil is a selective blocker of NMDA receptors that are heterodimers composed of GluN1/GluN2B subunits. This pharmacological profile has been extensively used to test the role of GluN2B-containing NMDA receptors in learning and memory formation. However, ifenprodil has also been reported to have actions at a number of other receptors, including high voltage-activated calcium channels. Here we show that, in the basolateral amygdala, ifenprodil dose dependently blocks excitatory transmission to principal neurons by a presynaptic mechanism. This action of ifenprodil has an IC(50) of ~10 μM and is fully occluded by the P/Q type calcium channel blocker ω-agatoxin. We conclude that ifenprodil reduces synaptic transmission in the basolateral amygdala by partially blocking P-type voltage-dependent calcium channels.
Queensland Brain Institute, The University of Queensland, Brisbane, Australia.
Andrew J
AJ
Delaney
John M
JM
Power
Pankaj
P
Sah
D000679:Amygdala / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D020865:Calcium Channels, P-Type / Q000378:metabolism*; D020907:Calcium Channels, Q-Type / Q000378:metabolism*; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects* / Q000502:physiology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010880:Piperidines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
D002121:Calcium Channel Blockers; D020865:Calcium Channels, P-Type; D020907:Calcium Channels, Q-Type; D010880:Piperidines; C010739:ifenprodil