Virtually all notions about memory hold dear the central notion that learning relies on the modification of synaptic function. In recent years considerable attention has focused on one particular form of use-dependent synaptic plasticity known as long-term potentiation (LTP). LTP was first discovered by Terje Lomo, who observed that repetitive high-frequency electrical stimulations of the pathway from the cortex to the hippocampus resulted in a steeper rise time of the excitatory synaptic potential as well as recruitment of spike activity from a greater number of cells. Moreover, these changes in synaptic and cellular responses to subsequent single shocks lasted several hours, suggesting the possibility of a lasting memory mechanism. Keywords: long-term depression; NMDA receptor; CREB