Just a heads-up for those of you with access to Nature online - there is
a preprint by Pouille and Scanzani about work in hippocampal slices in
which they show that various inhibitory mechanisms kick in at different
times during the processing of afferent activity, and make some parts of
the dendritic tree active at stimulus onset, but other parts functional
during subsequent activity.
So when a burst of activity is received, the soma and perisomatic
dendrites are inhibited but the apical dendrites are active, but shortly
afterwards the apical dendrites are inhibited and taken out of play. As
the authors put it, "the onset of a series of action potentials and the
rate of action potentials in the series are selectively captured and
transformed into different spatial patterns of recurrent inhibition."