Stress, hippocampal plasticity, and spatial learning

During the last two decades numerous studies have been conducted in an atte mpt to correlate the mechanisms of long-term potentiation (LTP) of hippocam pal synaptic transmission with those required for spatial memory formation in the hippocampus. Because stressful events block the induction of hippoca mpal LTP, it has been suggested that deficits in spatial learning following stress may be related to suppression of LTP-like phenomena in the hippocam pus. Here I review these studies and discuss them in light of the emerging view that stress may induce changes in thresholds for synaptic plasticity n ecessary for both LTP induction and spatial memory formation. This phenomen on, known as metaplasticity, may involve a glucocorticoid modulation of cal cium homeostasis. Synapse 40:180-183, 2001. (C) 2001 Wiley-Liss, Inc.