We use FRAP to investigate the mobility and dynamic behavior of fluorescently labeled target molecules, such as GFP-tagged receptors expressed via heterologous expression systems, in cultured living cells. The technique involves the targeted photobleaching of a defined region of the neuronal membrane using a focused laser, followed by monitoring the recovery of fluorescence over time as unbleached molecules diffuse into the bleached area.

• FRAP can be employed to investigate neuronal plasticity by assessing the dynamic behavior of synaptic and membrane-associated proteins involved in synaptic remodeling in specific cell compartments, such as dendritic spines.

• FRAP provides insights into the molecular mechanisms underlying both activity-dependent and pharmacologically induced changes in synaptic structure and function.

• Alterations in fluorescence recovery kinetics may reflect changes in protein mobility, binding interactions, compartmental confinement

• These measurements serve as an indirect but informative readout of molecular remodeling processes associated with neuronal plasticity.