Jarvis Homology-Mammalian Neutral Proposal

Dear Avieaters, July 1st, 2002

I expect my second proposal to be met with some disgust, because it does not follow the consensus discussions that many of passionately pleaded for. I a also expect it to be met with some glee, because it represents to date, the first attempt at doing what some of you have asked, particularly Harvey and Constance, starting from a clean slate.

It is a semi homology-free and historical-free nomenclature, as much as I could possibly make it free of these issues. One Panel, the forth section down, is more homology-free than the others.

I make this second proposal to see what a more neutral nomenclature would look like. I want us to consider how it makes us think about the avian brain when compared to itself. On the other handm, I also do not want to break Tony's basal ganglia consensus, so I left these regions mostly alone, except partially for fourth section.

The scheme I used is as follows:

I used Striedter-Perkel's idea of Regions, as lamina separated. From rostral to caudal direction, I then labeled each division above the currently named lmd as Regions A to E.

Archistriatum conveiniently becomes Region A

Neostriatum - Region B

L2, E, and B - Regions C1, C2, C3 respectively as all part of Region C

Hyperstriatum Ventrale - Region D

HD, HI, HA - Regions E1, E2, E3 respectively as all part of Region E.

The only non-lamina separated Region is C, on its Region B (neostriatum side).

This is five global regions above lmd global to remember. Not so bad.

I then labeled the forth section with different names below lmd, Regions S and P:

PA, LPO, INP, Medial Septum - Region S (numbered Regions S1, S2, S3, S4 respectively)

PP, ventral cerebrum, Medial Septum - Region P (numbered Regions P1, P2, ? , P4, respectively)

S and P of course stand for striatum and pallidum. There is a non-lamina separated region here too, as far as I can tell, Region P on both its Region S (Striatum) side, and with the thalamus. This is two global regions below lmd to remember. Not so bad.

After doing of all this, I noticed some advantages. VP of birds does not get confused with VP of mammals. Lateral Striatum of birds does not get confused with Lateral Striatum of mammals. Region A is not committed to being all pallial, nor are other potentially contentious areas. These seven regions can be easily remembered by us and the many generations to come. It is a more global view of the telencephalon or cerebrum should that be the name you wish to call it, and is much in the spirit of Medina and Luis' proposal. A global view, I beleive, will help us and future generations to decipher more accurately the functions of the brain, whether it be bird, mammal, reptile or otherwise. One day the mammalian brain will be labeled as such in a more global fashion, and this type of naming if applied to birds sooner, will be ahead of its time.

The disadvantages of course are that it is a more dramatic break from the past. This does not bothersome me, but I think I am the minority here. I do not mind breaking with the past. It is the future that I am worried about. However, with such a dramatic break from the past, few people would be willing to use it. Therefore even if it is based more on reality, it may not be used. My global view may be different, or more or less uncertain than someone elses' global view. In this manner, some of the naming may be wrong and need revision in the near future as more data is collected. Anyway, I am rarely so pessimistic as I am now, but I thought I had to give such a nomenclature change a chance to see what it looks like.



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