Jarvis on Striedter-Perkel

X-Sender: Jarvis@neuro.duke.edu (Unverified) Date: Wed, 22 May 2002 14:56:25 -0400 To: "List for Toru Shimizu" <avi-eaters@lists.cas.usf.edu> From: "Erich D. Jarvis" <jarvis@neuro.duke.edu> Subject: Comments in Striedter-Perkel Proposal List-Unsubscribe: <mailto:leave-avi-eaters-9101U@lists.cas.usf.edu> List-Subscribe: <mailto:subscribe-avi-eaters@lists.cas.usf.edu> List-Owner: <mailto:owner-avi-eaters@lists.cas.usf.edu> Reply-To: "List for Toru Shimizu" <avi-eaters@lists.cas.usf.edu> X-Message-Id: <a05100302b9113206b1a6@[]> Sender: bounce-avi-eaters-9101@lists.cas.usf.edu X-RCPT-TO: <jarvis@neuro.duke.edu> Status: R

For those who want to stay informed and involved, please read through the emails. Also consider that we are also trying to bring a entire group of scientists with one stroke into using a new nomenclature. Thus, even if you do not have comments, which is fine, at least read the messages so that you stay informed.

This proposal also has homology terms, and I indicate acceptance of them only to the point that it is possible. That is, with homology terms it is nearly impossible to be 100% accurate with out having observed the process through evolution. Thus, with homology terms I suggest that we consider being flexible such that in the future as more data comes in we would be willing to change some names again.

Below, I form my comments with two concepts in mind: a) accuracy of nomenclature interpretation as the primary concern, and/or b) whether I like the name or not as a secondary concern.

1) Changing PP to pallidum. The weight of the evidence that I am aware of does suggest PP is homologous to mammalian pallidum. Of course we would need to specify the evidence. Thus, this change is fine with me in terms of accuracy. Not to call it globus pallidus is also a good idea.

2) Changing PA to lateral striatum and LPO to medial striatum. The weight of the evidence is also favors that PA and LPO are somehow homologous to mammalian striatum. Thus, having the homologous name striatum does not pose a problem. I also like to the idea of having PA and LPO changed to names that designate different parts of the same structure, striatum. Thus, I would state that PA and LPO combined be called striatum. There are several concerns, though: technically PA is situated as caudal-lateral striatum and LPO as rostral-medial striatum. I would recommend naming them as such in your scheme (as I suggested for the Reiner-Csillag proposal). I know the terms are more cumbersome, but I prefer the accuracy. LPO (along with Area X) may have both striatal and pallidal cells (data from Perkel and Bottjer laboratories). With the clarifier though, calling it striatum homologue seems OK, but I am concerned about the implications. I do remember Weiss (who studies drug addication) once mentioning in a review that the rat accumbens has large neurons that project directly the the thalamus. Thus, it may not be entirely true that the parts of the mammalian striatum do not have such direct projecting thalamic neurons.

3) Renaming the dorsal telencephalon Region W for "Wulst" (minus Hippocampus, parahippocampus and old HV). I like the idea of separating HV from other regions currently named hyperstriatum. It is now separated from them by ventricle, and a number of results indicate that there are not different subdivisions of the same region. In terms of homology, although I have read Medina's, Reiner's, Puelle's and others work on the homology of bird W and mammalian dorsal pallium, I have not been convinced that this is the case or I am confused by what I read? It would be useful someone to make a table spelling out this homology. However, it is not necessary for renaming the dorsal regions to Region W, as this nomenclature does not imply homology. Saying that HIA, HIS, HA and HD as capital letter names in of themselves are regions within the wulst without implications of homology will also work. However, I think that you guys or someone needs to give evidence as to why these regions should be grouped together separate from other regions (maybe group them as regions on the dorsal side of the lateral ventricle?). At this piont, unless there is convincing evidence, I would not call functional regions of Region W with the same names as in mammals. Rather I recommend calling the functional regions as Visual W (VW), Motor W (MW), etc. Finally, I never liked the name Wulst. But that is besides the point. Like I mentioned above, I am mostly focusing my comments on accuracy.

4) Region HV. By maintaining the abbreviation HV, Region HV will automatically still be associated with HA, HD, etc. Moreover, except for the ventricle all these regions are mainly separated by axonal lamina. Thus, should region HV be thought of as a counterpart to Region W? In terms of location, it always confused me to consider HV as lateral pallium, when in the avian brain it is dorsal not lateral in the telencephalon? In addition, similar to the W homology proposed, the proposed HV homology to mammalian lateral pallium has been something difficult for me to follow. Again, as above, it is not necessary to know the homology to call this as "Region HV". So, I would recommend removing such statements in the proposal, unless they are useful for designating homology terms.

5) Renaming avian Neostriatum to Region N: This makes sense in terms of the other naming above, except for Region W which has a few lamina separated regions within it. lMAN would still work as lateral Magnocellular nucleus within Anterior region N. I am opposed to replacing the term field with nucleus, such as nucleus L2. It hardly appears like a nucleus in the usual sense. Rather there is so much evidence showing that L2, Basalis and Ectostriatum have different characteristics than the surrounding N, that I would recommend that in your terminology scheme to call them field L2, field B, and field E. Reserve "nucleus and area" for the other parts of Region N. In terms of confusion with Rose' terminology, except for L, no one uses it. So I do not see any potential confusion. In terms of homology, I believe that there is evidence to suggest that bird N is has characteristics of claustrum and amygdala (as Georg and David state), but also has many characteristics of mammalian cortex layers II, III, and IV (L2 for the later for example) as Harvey orginally suggested. So, I can not accept (at least yet without hearing more evidence) that the avian N is "certainly" homologous to mammalian claustrum-amygdala as stated in the Striedter-Perkel proposal (or others). Can both be right? In terms of the proposal, it does not matter, because the suggestions are not based upon either proposed homology.

6) Piriform Cortex and Dorsolateral Corticoid Area. Why do these need not to be renamed or reconsidered. Is the piriform cortex homology really straightforward? I do not know enough on this, but it seems that for those names that stay the same, particularly homology ones, we should have some justification. The same applies to the dorsolateral corticoid area (CDL). It is an area difficult to define the boundaries of and most publications that I see include the entire area as part of what would be renamed as Region N, anteriorly or HA posteriorly. That is the CDL area has different names to it, depending upon who's atlas or drawing one is looking at. At this time I do not have an alternative to suggest, accept to say could you reconsider your conclusion about it in your proposal.

7) Renaming Archistriatum to Region A. Nothing incorrect about this. It does need to be decided whether nucleus taeniae will be considered as part of Region A.

In summary, I like the idea of breaking things down into regions and nuclei. I don't mind keeping the term field. I am concerned that what is needed is a definition of a region versus nucleus, etc. I count 7-8 major lamina boundaries in the avian brain. Maybe their these should separate Regions in the proposal or that of others.



Erich D. Jarvis
Assistant Professor
Department of Neurobiology, Box 3209
Duke University Medical Center
Durham, North Carolina 27710
(919) 681-1680 Phone
(919) 681-0877 Fax