Heterosynaptic long-term depression (hetLTD) at one input can be induc
ed by applying a conditioning stimulus to an adjacent set of synapses.
In hippocampal CA1 pyramidal cells, our results suggest that hetLTD i
s triggered by an extracellular diffusible factor that is released fol
lowing tetanic activation of NMDA receptors. This hetLTD occludes with
homosynaptic LTD suggesting common underlying mechanisms.