Somatic action potentials are sufficient for late-phase LTP-related cell signaling.
A question of critical importance confronting neuroscientists today is how biochemical signals initiated at a synapse are conveyed to the nucleus. This problem is particularly relevant to the generation of the late phases of long-term potentiation (LTP). Here we provide evidence that some signaling pathways previously associated with late-LTP can be activated in hippocampal CA1 neurons without synaptic activity; somatic action potentials, induced by backfiring the cells, were found to be sufficient for phosphorylation of extracellular signal-regulated kinase-1/2 and cAMP response element-binding protein, as well as for induction of zif268. Furthermore, such antidromic stimulation was adequate to rescue "tagged" synapses (early-LTP) from decay. These results show that a synapse-to-nucleus signal is not necessary for late-phase LTP-associated signaling cascades in the regulation of gene expression.
Dudek
Serena M
SM
Laboratory of Cellular and Synaptic Neurophysiology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
Fields
R Douglas
RD
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D051766:Early Growth Response Protein 1; D005786:Gene Expression Regulation / Q000187:drug effects; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D017874:Immediate-Early Proteins; D066298:In Vitro Techniques; D007736:Kynurenic Acid / Q000494:pharmacology; D017774:Long-Term Potentiation / Q000187:drug effects; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009543:Nifedipine / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D013569:Synapses / Q000187:drug effects / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D051766:Early Growth Response Protein 1; C486110:Egr1 protein, rat; D017874:Immediate-Early Proteins; D014157:Transcription Factors; D020928:Mitogen-Activated Protein Kinases; D007736:Kynurenic Acid; D009543:Nifedipine