Need references on cortical mini-columns

Thanks for the links guys! I have another related question. Is there a reference that explains (at a high level) the model of the mammalian neocortex used for HTM? I understand HTM deviates from the operation of a real brains for technical reasons, but I’d like the reader to understand what the algorithms are inspired by, and how they got to where they are in the current nupic implementation.