Simultaneous analyses of clutch coupling and actin polymerization in dendritic spines of rodent hippocampal neurons during chemical LTP.

Dendritic spine enlargement by synaptic activation is thought to increase synaptic efficacy underlying learning and memory. This process requires forces generated by actin polymerization and actin-adhesion coupling (clutch coupling). Here, we describe a protocol to monitor actin filament retrograde flow and actin polymerization within spines using a standard epi-fluorescence microscope. In combination with chemical long-term potentiation, this protocol allows us to quantify clutch coupling efficiency and actin polymerization rate, which are essential variables for generating forces for activity-dependent spine enlargement. For complete details on the use and execution of this protocol, please refer to Kastian et al. (2021).