title: Ultrastructural peculiarities of the supraoptic nucleus of Mauremys caspica (turtle): its evolutionary interest in reptiles.
abstract: The hypothalamic Supraoptic Nucleus (SON) supposes an evolutionary achievement in the reptiles, zoological group in which this nucleus is first differentiated. Its scarce development in the chelonian, subject of the present study, is related to their primitive brain pattern. The peculiar location and the topographical configuration of the SON in the hypothalamus of the turtle Mauremys caspica allows to evidence morphologically the successive steps in the evolutionary process from lower to higher vertebrates. The marked neurosecretory character of the chelonian SON is the unequivocal proof of its philogenetic origin derived from the magnocellular preoptic nucleus of lower vertebrates.
authors.affiliation: Departamento Morfologia Microscópia, Faculta de Ciencias Biológicas, Universidad Complutense, Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Paz Doel
authors.forename: R G
authors.initials: RG
authors.lastname: Cordovilla
authors.forename: E
authors.initials: E
authors.lastname: Fernandez
authors.forename: I
authors.initials: I
authors.lastname: Azcoitia
authors.forename: J F
authors.initials: JF
authors.lastname: Soriano
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D008854:Microscopy, Electron; D013495:Supraoptic Nucleus / Q000648:ultrastructure*; D014426:Turtles / Q000033:anatomy & histology*