How does the border between two Brodmann areas look like in Nissl stains? How large is the transition zone where one cannot tell to which of the two areas a neuron belongs to? How many neurons are ambiguous compared to the number of unambiguous ones, roughly? 1%, 5%, 10%?
Is the inner connectivity of a Brodmann area greater than its connectivity with a neighbouring area across the border? Can this be seen in Nissl stains? Or is short-range inner-cortical connectivity somehow homogenuous over adjacent Brodmann areas?