Spine expansion and stabilization associated with long-term potentiation.
Stable expression of long-term synaptic plasticity is critical for the developmental refinement of neural circuits and for some forms of learning and memory. Although structural remodeling of dendritic spines is associated with the stable expression of long-term potentiation (LTP), the relationship between structural and physiological plasticity remains unclear. To define whether these two processes are related or distinct, we simultaneously monitored EPSPs and dendritic spines, using combined patch-clamp recording and two-photon time-lapse imaging in the same CA1 pyramidal neurons in acute hippocampal slices. We found that theta burst stimulation paired with postsynaptic spiking, which reliably induced LTP, also induced a rapid and persistent expansion of dendritic spines. Like LTP, this expansion was NMDA receptor dependent. Spine expansion occurred even when LTP was inhibited by postsynaptic inhibition of exocytosis or PKA (protein kinase A); however, under these conditions, the spine expansion was unstable and collapsed spontaneously. Furthermore, similar changes in LTP and spine expansion were observed when hippocampal neurons were treated with protein synthesis inhibitors. Like LTP, spine expansion was reversed by low-frequency stimulation (LFS) via a phosphatase-dependent mechanism, but only if the LFS was applied in a critical time window after induction. These results indicate that the initial expression of LTP and spine expansion is dissociable, but there is a high degree of mechanistic overlap between the stabilization of structural plasticity and LTP.
Yang
Yunlei
Y
Department of Neurology, Mount Sinai School of Medicine, New York, New York 10029, USA.
Wang
Xiao-bin
XB
Frerking
Matthew
M
Zhou
Qiang
Q
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D017868:Cyclic AMP-Dependent Protein Kinases / Q000494:pharmacology; D049229:Dendritic Spines / Q000502:physiology*; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D006624:Hippocampus / Q000166:cytology; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D018408:Patch-Clamp Techniques / Q000379:methods; D017966:Pyramidal Cells / Q000502:physiology / Q000648:ultrastructure*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000528:radiation effects; D018709:Statistics, Nonparametric
D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D015124:8-Bromo Cyclic Adenosine Monophosphate; D017868:Cyclic AMP-Dependent Protein Kinases