[Neuroscience] Backpropagation in biological neurons

[Fredo]

I've been reading a bit about neurophysiology and neurobiology. A number of 
texts refer to backpropagation in real neurons, where the signal 
backpropagates, though significantly attenuated, up the dendrites.

I can't seem to find out much detail on the matter, beyond the fact that it 
exists. In particular, what is the significance? The backpropagation might 
affect gap junction-connected neurons, but it can't back-propagate through 
synapses, can it? If it can, what's the mechanism? Surely not 
neurotransmitter release in the dendrites...

Thanks