One Gray matter of diencephalon or many?

[Alan Ruttenberg]

Here's what is asserted:

'Gray matter of diencephalon'

  :SLOTS (('constitutional part of' 'Diencephalon')

          ('constitutional part' 'Neuronal component of gray matter of diencephalon')

          ('regional part of' 'Gray matter of forebrain')

          ('constitutional part of' 'Neural tissue of diencephalon')

          (FMA::FMAID "83912") ('dimension' "3-dimension")

          ('Preferred name' 'live_incus_fm_12252'))

  :SUBCLASSES ('Gray matter of subthalamus'

               'Gray matter of epithalamus'

               'Gray matter of thalamus'

               'Gray matter of hypothalamus')

  :IS-A ('Gray matter of neuraxis')

We have the same question as with Thalamus. There are several

subclasses, each of which would be an instance of Gray matter of

diencephalon, if that's the intended meaning.

Each would have a constitutional part 'Neuronal component of gray matter of diencephalon', which I expect is unintended.

What I think might be meant is that the Gray matter of xxx classes are

*part* of the Gray matter of the diencephalon.

Is that the case?

I think I see this pattern in a number of places. 

Separately, note that there are many cases where Gray matter of xxx and White matter of xxx are not asserted part of xxx. I believe that they should be asserted constitutional part of xxx, yes?

-Alan

[mej...@comcast.net]

Alan, you raised a very good point and I'm glad you brought this up because it is due for review.

There had been confusion among authors early on in the project on whether the parent class is a semantic class (as we called it) or a class that represents a single entity. This became clear later on when we dealt with blood (portion of blood) where we have decided that it is a semantic class which subsumes any portion of blood including all portion of blood. The same principle can also be applied to gray matter and white matter.

So with regards to gray matter of diencephalon, if we treat is as a semantic class, then the relation 'constitutional part of' 'Diencephalon' is not correct. There should be a class called 'set of all gray matters of diencephalon' which is the correct constitutional part of the diencephalon. This set will then have as members, the thalamic complex, epithalamus, hypothalamus; Therefore the current representation that gray matters of the thalamic complex, epithalamus, hypothalamus are subclasses of 'gray matter of diencephalon' (portion of gray matter of diencephalon? don't know yet about this, Barry) holds true.

The approach applies to white matter structures as well.

I will review these parts and again thanks for bringing this up. Man, you're making me work :-) Good stuff though!

Onard