TY  - JOUR
A1  - ,  
T1  - Ontogenic development of the human subcommissural organ
JO  - Eur. J. Anat.
SN  - 1136-4890
Y1  - 2004
VL  - 8
SP  - 107
EP  - 120
UR  - http://www.eurjanat.com/web/paper.php?id=04030107
KW  - adult
KW  - aged
KW  - article
KW  - atrophy
KW  - brain aqueduct
KW  - brain development
KW  - brain maturation
KW  - embryo
KW  - embryo development
KW  - fetus
KW  - human
KW  - human tissue
KW  - neuroanatomy
KW  - ontogeny
KW  - organ size
KW  - pineal body
KW  - qualitative analysis
KW  - quantitative analysis
KW  - subcommissural organ
N2  - The structure of the human subcommissural organ during its ontogenic development in 24 human embryos and foetuses ranging from 6 to 40 weeks of gestation (WG), and three adult human brains from 27-, 65- and 70-year old subjects was investigated using both qualitative and quantitative methods. Concurrently, the appearance of the subcommissural organ, pineal gland and mesocoelic recess was determined by studying their structure, length and volume. The human SCO appears at the beginning of 8<sup>th</sup> WG, which confirms previous results; the complete maturation of the SCO occurs at the 15 <sup>th</sup> WG and the following three parts can be distinguished: the precommissural part, located in the rostral zone of the posterior commissure (PC) and extending to the pineal recess; the subcommissural part, located under the PC, and the retrocommissural part, located in the caudal zone of the PC, in the mesocoelic recess and at the beginning of the Sylvian aqueduct. The reduction in size of the SCO begins after the 17<sup>th</sup> WG and this decrease in size begins in the precommissural, continues in the subcommissural, and finishes in the retrocommissural part. The regression and atrophies of the SCO begin after birth, and the SCO disappears completely after the age of 30. The mesocoelic recess starts to form at the beginning of the 10<sup>th</sup> WG, and is completely formed by the 14<sup>th</sup> WG and this is where the retrocommissural part of the SCO is located. In the 40<sup>th</sup> WG the regression of the mesocoelic recess begins and this takes place at the same time as the regression of the SCO. A parallel development between the SCO and the pineal was found. Thus, we observed the first appearance of the pineal recess in the 7-8<sup>th</sup> WG; during the 10<sup>th</sup> WG a compact mass of cells appeared in the rostral part of pineal recess and by the 15<sup>th</sup> WG the pineal gland (PG) had acquired an almost definitive aspect.
ER  -