Differential cAMP signaling at hippocampal output synapses

Christian Wozny, Nikolaus Maier, Pawel Fidzinski, Jörg Breustedt, Joachim Behr, Dietmar Schmitz

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15 Citations (Scopus)


cAMP is a critical second messenger involved in synaptic transmission and synaptic plasticity. Here, we show that activation of the adenylyl cyclase by forskolin and application of the cAMP-analog Sp-5,6-DCl-cBIMPS both mimicked and occluded tetanus-induced long-term potentiation (LTP) in subicular bursting neurons, but not in subicular regular firing cells. Furthermore, LTP in bursting cells was inhibited by protein kinase A (PKA) inhibitors Rp-8-CPT-cAMP and H-89. Variations in the degree of EPSC blockade by the low-affinity competitive AMPA receptor-antagonist gamma-d-glutamyl-glycine (gamma-DGG), analysis of the coefficient of variance as well as changes in short-term potentiation suggest an increase of glutamate concentration in the synaptic cleft after expression of LTP. We conclude that presynaptic LTP in bursting cells requires activation of PKA by a calcium-dependent adenylyl cyclase while LTP in regular firing cells is independent of elevated cAMP levels. Our results provide evidence for a differential role of cAMP in LTP at hippocampal output synapses.

Original languageEnglish
Pages (from-to)14358-14362
Number of pages5
JournalJournal of Neuroscience
Issue number53
Publication statusPublished - 31 Dec 2008


  • action potentials
  • analysis of variance
  • animals
  • Calcium
  • colforsin
  • cyclic AMP
  • electric stimulation
  • excitatory amino acid antagonists
  • excitatory postsynaptic potentials
  • GABA antagonists
  • hippocampus
  • in vitro techniques
  • isoquinolines
  • neurons
  • oligopeptides
  • patch-clamp techniques
  • protein kinase Inhibitors
  • pyridazines
  • quinoxalines
  • rats
  • signal transduction
  • sulfonamides
  • synapses
  • time factors

Cite this

Wozny, C., Maier, N., Fidzinski, P., Breustedt, J., Behr, J., & Schmitz, D. (2008). Differential cAMP signaling at hippocampal output synapses. Journal of Neuroscience, 28(53), 14358-14362. https://doi.org/10.1523/JNEUROSCI.4973-08.2008