Related Experiment Video
Updated: Jul 14, 2026
07:13
3D Modeling of Dendritic Spines with Synaptic Plasticity
Published on: May 18, 2020
Changes in synaptic morphology accompany actin signaling during LTP
Lulu Y Chen1, Christopher S Rex, Malcolm S Casale
1Department of Anatomy and Neurobiology, University of California, Irvine, California 92697-4292, USA.
Summary
Long-term potentiation (LTP) stabilization involves actin regulation and spine morphology changes. Theta-burst stimulation activates the PAK/cofilin pathway, leading to larger synapses crucial for LTP.
Area of Science:
- Neuroscience
- Cell Biology
- Synaptic Plasticity
Background:
- Long-term potentiation (LTP) stabilization is linked to synaptic structure changes.
- The role of actin cytoskeleton reorganization in LTP is under investigation.
Purpose of the Study:
- To investigate if theta-burst stimulation (TBS) activates actin regulatory pathways.
- To determine if TBS alters synapse morphology within dendritic spines.
Main Methods:
- Used theta-burst stimulation (TBS) to induce LTP in neurons.
- Quantified levels of phosphorylated p21-activated kinase (PAK) and cofilin via immunostaining.
- Analyzed synapse morphology and size using PSD95 co-localization.
Main Results:
- TBS significantly increased phosphorylated PAK and cofilin levels in spines.
- These changes peaked at 7 minutes post-TBS, indicating activation of actin regulatory pathways.
- Spines with high pPAK/pCofilin showed 60-70% larger synapses with a more normal size distribution.
Conclusions:
- Theta-burst stimulation activates the PAK/cofilin pathway, regulating actin dynamics.
- This activation promotes a shift towards larger, ovoid synapse morphology.
- This altered synapse morphology is critical for the expression and stabilization of LTP.
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