Genetic evidence for a protein-kinase-A-mediated presynaptic component in NMDA-receptor-dependent forms of long-term synaptic potentiation

Proc Natl Acad Sci U S A. 2005 Jun 28;102(26):9365-70. doi: 10.1073/pnas.0503777102. Epub 2005 Jun 20.

Abstract

The synaptic vesicle protein Rab3A is a small GTP-binding protein that interacts with rabphilin and RIM1alpha, two presynaptic substrates of protein kinase A (PKA). Mice lacking RIM1alpha and Rab3A have a defect in PKA-dependent and NMDA receptor (NMDAR)-independent presynaptic long-term potentiation (LTP) at hippocampal mossy-fiber and cerebellar parallel-fiber synapses. In contrast, the NMDAR-dependent and PKA-independent early phase of LTP at hippocampal CA3-CA1 synapses does not require these presynaptic proteins. Here, we ask whether Rab3A and RIM1alpha participate in forms of LTP that require both PKA and NMDAR activation. We find that Rab3A is necessary for corticoamygdala LTP and late-phase LTP at CA3-CA1 synapses, two forms of LTP that require NMDAR and PKA activation. The latter form of LTP also requires RIM1alpha. These results provide genetic evidence that presynaptic proteins are required in LTP induced through the postsynaptic activation of NMDARs. Thus Rab3A and its effectors are general modules for four distinct types of PKA-dependent LTP in the brain.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Brain / metabolism
  • Calcium / metabolism
  • Cyclic AMP / metabolism
  • Cyclic AMP-Dependent Protein Kinases / genetics*
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • Electrodes
  • Enzyme Activation
  • GTP-Binding Proteins / metabolism
  • Guanosine Triphosphate / metabolism
  • Hippocampus / metabolism
  • Long-Term Potentiation
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Models, Neurological
  • Presynaptic Terminals*
  • Protein Binding
  • Receptors, N-Methyl-D-Aspartate / genetics
  • Receptors, N-Methyl-D-Aspartate / metabolism*
  • Synapses / metabolism
  • Synaptic Vesicles / metabolism
  • Time Factors
  • rab3A GTP-Binding Protein / metabolism

Substances

  • Receptors, N-Methyl-D-Aspartate
  • Rims1 protein, mouse
  • Guanosine Triphosphate
  • Cyclic AMP
  • Cyclic AMP-Dependent Protein Kinases
  • GTP-Binding Proteins
  • rab3A GTP-Binding Protein
  • Calcium