It's quite unrelated, but I've been wondering something about neuroscience grammar: Why is it "in primary visual cortex" and not "in _the_ primary visual cortex"?
Your innocuous question has kicked off a pretty feisty debate on my floor about whether it is 'primary' as in first (either in the circuit or evolutionarily) or primary as in most important.
If it's the former, adding a "the" seems to add some unwarranted emphasis. I think there's probably some parallelism too. Primary visual cortex is also called "V1" (as in the first cortical area involved in vision) or "Area 17" (according to a map that defines areas based on their cellular organization). While "in the primary visual cortex" sounds fine, "in the V1" and "in the Area 17" sound barbarous.