Figure 2.

Early-long-term potentiation is facilitated into late-long-term potentiation by re-exposure to environmental enrichment. Six weeks after cessation of environmental enrichment (EE), animals were once more exposed to EE for 14 days. (A) In this case, E-LTP was prolonged into L-LTP that lasted for over 24 h. (B) Seven days after cessation of EE, fEPSP values returned to control (pre-EE) levels. Time-point of high frequency stimulation (HFS) is marked with a filled arrow. Insets: Analog examples of field potentials (averages of five consecutive sweeps) from typical experiments at the time indicated by the numbers. Horizontal bar: 10 ms, vertical bar: 2 mV.