A new interpretation on the homology of the teleostean telencephalon based on hodology and a new eversion model.
Various hypotheses regarding the homology of the teleostean telencephalon with that of other vertebrates have been proposed to date. However, a firm conclusion on this issue has yet to be drawn. We propose here a new hypothesis with a new eversion model. Our hodological data and the analysis of dorsal telencephalic organization in adult cyprinids suggest that: (1) the area dorsalis pars posterior corresponds to the lateral pallium; (2) ventral region of area dorsalis pars lateralis to the medial pallium; (3) pars medialis, dorsal region of pars lateralis, pars dorsalis, and pars centralis of the area dorsalis to the dorsal pallium, and (4) nucleus taenia to the ventral pallium. We propose in a three dimensional model that the eversion process occurs not only dorsolaterally but also caudolaterally. We consider that the caudally directed component dominates for ventral zones of the pallium, or the lateral and ventral pallia; and the periventricular surface of these zones shift caudally, laterally, and then rostrally in teleosts with pronounced telencephalic eversion. This new model fits well with the putative homology based on hodology and the organization of telencephalic divisions in the adult brain.
Yamamoto
Naoyuki
N
Department of Anatomy and Neurobiology, Nippon Medical School, Tokyo, Japan. nyama@nms.ac.jp
Ishikawa
Yuji
Y
Yoshimoto
Masami
M
Xue
Hao-Gang
HG
Bahaxar
Nurmamat
N
Sawai
Nobuhiko
N
Yang
Chun-Ying
CY
Ozawa
Hitoshi
H
Ito
Hironobu
H
D000818:Animals; D005075:Biological Evolution; D005399:Fishes / Q000033:anatomy & histology* / Q000196:embryology / Q000235:genetics; D008959:Models, Neurological; D013687:Telencephalon / Q000033:anatomy & histology* / Q000166:cytology / Q000196:embryology