Thread by @hipposubfields

Last week we received over 100 (!) responses on our quiz about which hippocampal subfield accumulates tau pathology earliest in the disease.

#SubfieldWednesday (1/n)

https://twitter.com/hipposubfields/status/1316412624247099395

This week we will explain that the correct answer for Alzheimer's disease (but not all types of dementia) is CA1!

#SubfieldWednesday (2/n)

Work from Braak & Braak (1991) showed that CA1 develops tau pathology before the other subfields.

#SubfieldWednesday (3/n)

However, if you said, "other" then you might have been thinking of more recent investigations from Heiko Braak and Kelly Del Tredici that have looked at the transition region between subiculum and CA1 (which some neuroanatomists call "prosubiclum")

#SubfieldWednesday (4/n)

This region is the "first stop" along the perforant pathway fibers that project from entorhinal cortex to hippocampus

#SubfieldWednesday (5/n)

Thanks @relajoie for pointing us to this newer reference!

https://twitter.com/relajoie/status/1316415241689812993?s=20

#SubfieldWednesday (6/n)

So, a better answer might have been "distal CA1"!

#SubfieldWednesday (7/n)

The second most common answer on the quiz was dentate gyrus. But according to Braak, this region does not develop abnormal tau until Stage 5 or 6.

#SubfieldWednesday (8/n)

For those of you who like quizzes, @lemwisse has prepared a new one for you this week on the transentorhinal cortex! Stay tuned!

#SubfieldWednesday (end)