Fig. 1.

Schematic illustration of clustered synaptic alterations under various experimental conditions. A. Repetitive learning of the same task leads to clustered dendritic spine formation. B. Monocular deprivation leads to clustered formation of dendritic spines and inhibitory synapses. C. LTP induced at a single spine decreases the threshold for LTP at its neighboring spine. D. Simultaneous potentiation of multiple dendritic spines in a cluster leads to the shrinkage of the inactive spine in the cluster.