Postsynaptic cAMP pathway gates early LTP in hippocampal CA1 region.
The role of the cAMP pathway in LTP was studied in the CA1 region of hippocampus. Widely spaced trains of high frequency stimulation generated cAMP postsynaptically via NMDA receptors and calmodulin, consistent with the Ca2+/calmodulin-mediated stimulation of postsynaptic adenylyl cyclase. The early phase of LTP produced by the same pattern of high frequency stimulation was dependent on postsynaptic cAMP. However, synaptic transmission was not increased by postsynaptic application of cAMP. Early LTP became cAMP-independent when protein phosphatase inhibitors were injected postsynaptically. These observations indicate that in early LTP the cAMP signaling pathway, instead of transmitting signals for the generation of LTP, gates LTP through postsynaptic protein phosphatases.
Blitzer
R D
RD
Department of Psychiatry, Mount Sinai School of Medicine, New York, New York 10029, USA.
Wong
T
T
Nouranifar
R
R
Iyengar
R
R
Landau
E M
EM
D000818:Animals; D002147:Calmodulin / Q000502:physiology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006624:Hippocampus / Q000502:physiology*; D015640:Ion Channel Gating; D017774:Long-Term Potentiation; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D013569:Synapses / Q000378:metabolism*; D013873:Thionucleotides / Q000494:pharmacology; D013997:Time Factors
D002147:Calmodulin; D004791:Enzyme Inhibitors; D016194:Receptors, N-Methyl-D-Aspartate; D013873:Thionucleotides; C016957:adenosine-3',5'-cyclic phosphorothioate; D000242:Cyclic AMP; D010749:Phosphoprotein Phosphatases