Dear colleagues,

We would like to share our suggestions for the new nomenclature. Because of our research interests, we are particularly focused on the pallium. Basically, our main position is summarized in three points:

1. If we decide to change names, we should change as few as possible. Too many changes will cause more confusion in the literature and would be not only difficult for established avian scientists, but a nightmare for non-avian researchers, new students, and others who tend to forget new information.

2. We should change only the names of structures for which we can all agree. During the forum, we should not fight over whose data are better. If we need to fight over a new name, why not leave it as it is now until we have more information / consensus?

3. If we need to change a term, the change should be as simple as possible. But at the same time, it should have some logic to it, or characteristics that make the term easier to remember.

Of all the proposals, we are in agreement more with Reiner-Csillag (and portions of Striedter-Perkel), mostly for conserving abbreviations and fewer drastic changes. We believe the original impetus for nomenclature revision was the cringe we all felt when hearing the "-striatum" suffix for avian telencephalic structures, along with having to include in all our articles that we really didn't mean "striatum", that it was a holdover from earlier times. With this in mind, nomenclature change has as its primary goal the removal of this source of comparative errors. Outside this consideration, there should be few other changes needed at this time. Based on these points, our basic proposal is to replace the suffix -"sriatum" with "-pallium" for most telencephalic structures, leaving the term archistriatum as it is now.

Thus, our suggestions would follow along the lines of: Neostriatum --> Neopallium, Ectostriatum --> Ectopallium, Hyperstriatum --> Hyperpallium, Lamina Hyperstriatica --> Lamina Hyperpallium (?), and Archistriatum --> No change.

We have attached a table (adapted from Reiner-Csillag's) that summarizes our position. A few brief comments are given below to explain our rationale.

PALLIUM: NEOSTRIATUM, HYPERSTRIATUM, and ECTOSTRIATUM

We believe the prefixes "Hypso-" and "Nido-" in the Reiner-Csillag proposal (while maintaining abbreviations which we are in favor of) do not add considerably to cross-fostering comparisons with mammalian scientists. These terms, in our opinion, are not significantly better than simply retaining "Hyper-" and "Neo-" with the replacing of striatum with pallium for the root. Loretta also pointed out that "Hypso-" and "Nido-" are not well known Latin prefixes among scientists; probably few of us always consult our Latin dictionary when learning new brain names (although it is helpful sometimes). In the same vein, "Entopallium" or "Endopallium" are not significantly better than Ectopallium, despite being more "Latin correct"; although the term "Ecto-" will imply outside, there is not too much of a problem in retaining it, in the spirit of changing as little as possible

WULST

While some have pointed out the benefit of disentangling HA, HIS, HD from HV, in the interests of making as few changes as absolutely needed, we should keep hyperpallium (hyperpallium ventrale, hyperpallium accessorium etc.). In the Wulst, the border between the hyperstriatum and the hippocampal complex is not well defined: the lateral Wulst includes portions of HA, HIS, and HD whereas the medial Wulst includes part of APH and Hp. Using Hyperpallium is desirable, despite the "Hyper-" part meaning above or outside pallium, no one will likely be confused by this.

ARCHISTRIATUM

Don't change it for now; pallial/subpallial divisions remain unclear (and contentious!); amygdala-like aspects require more data to sort out.

We do not have a strong opinion about most other subpallial structures. We believe that the same principles should be maintained. We do, however, offer the following in this regard:

PALEOSTRIATAL STRUCTURES and LPO (and related areas)

Using the terms Lateral Striatum for PA, and Medial Striatum for LPO are sufficiently neutral and descriptive and will do fine. While it is true (as Erich asserted) that much of LPO is rostral to PA instead of medial in many anterior to posterior sections, we think the usefulness of the terms outweighs this consideration. Similarly, the use of dorsal pallidum for PP, and ventral pallidum for VP is acceptable to us. The renaming of the accumbens (Acc) area of the Karten and Hodos atlas to BnST is also justified in our opinion.

THALAMUS and MIDBRAIN

We concur with Reiner-Csillag on midbrain cell groups. Regarding thalamus, there are no compelling reasons for change. However, we concur with Reiner-Csillag that Ala is similar enough to mammalian subthalamic nucleus to earn the name change and abbreviation if this is agreed upon.

Finally, we would like to reiterate our sincere gratitude to Erich and people in his lab for working on this difficult task. Looking forward to seeing everyone at the conference!

Cheers,

Toru Shimizu & Scott Husband