Figure 2.

Repetitive stimulation causes destaining of boutons. A, Images taken before stimulation, 15 sec after beginning stimulation, and 1 min after the end of stimulation. Arrowheads point to Synaptogreen-labeled boutons in a rat culture. B, Destaining profiles for 50 boutons from a single slice caused by 5 Hz field stimulation. Each trace is from a single bouton imaged at successive 15 sec intervals throughout the trial (nondestaining boutons are indicated in red). C, Mean data from the individual traces in B.