A new form of cerebellar long-term potentiation is postsynaptic and depends on nitric oxide but not cAMP.
Long-term depression (LTD) at cerebellar parallel fiber (PF)-Purkinje cell synapses must be balanced by long-term potentiation (LTP) to prevent saturation and allow reversal of motor learning. The only previously analyzed form of cerebellar LTP is induced by 4-8 Hz PF stimulation and requires cAMP but not nitric oxide. It is a poor candidate to reverse LTD because it is presynaptically expressed whereas LTD is postsynaptic. We now characterize a new form of LTP induced by 1 Hz PF stimulation for at least 300 s. This LTP is postsynaptically expressed, enhanced by chelating postsynaptic Ca(2+), and depends on nitric oxide but not cAMP or cGMP, making it a plausible anti-Hebbian counterpart to Hebbian LTD.
Lev-Ram
Varda
V
Department of Pharmacology, The Howard Hughes Medical Institute, University of California at San Diego, La Jolla, CA 92093-0647, USA.
Wong
Scott T
ST
Storm
Daniel R
DR
Tsien
Roger Y
RY
D000818:Animals; D002531:Cerebellum / Q000187:drug effects / Q000502:physiology*; D000242:Cyclic AMP / Q000502:physiology*; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D009569:Nitric Oxide / Q000502:physiology*; D019335:Nitroarginine / Q000494:pharmacology*; D051381:Rats; D013569:Synapses / Q000502:physiology
D019335:Nitroarginine; D009569:Nitric Oxide; D004533:Egtazic Acid; D000242:Cyclic AMP; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid