Bursting seems to be complex and heterogeneous across the pyramidal cells in the cortical micro-column. Really, as physical phenomenon, is fascinating .
The intuition of HTM seems to fit quite nicely (i think). My understanding is that if a cell soma reach the threshold tension without enough depolarisation in the distal tree, the spike is reflected into the soma again. This reflection might generate a burst through the axon (with certain probability). The bursting probability seems to be network-depentent status forming and hysteresis loop ! (beware, are model derived numbers). [If you to something like that in the current HTM algorithm (by assigning a network state dependent probability to the dendritic segment creation), still works!].
What intrigues me is that there are at least two different bursting pyramidal cells in the column (with clear different behaviour): FRB in supra granular layers and IB in infra granular layers. The current sensory-motor models are not considering this (the algorithm if the TM is mainly the same in all layers). It looks like a control circuit to me.
Any thoughts about this? Perhaps is not important … perhaps it’s… just wanted to share some big doubts about this apparently small details.