Morphological, cytochemical, and cytofluorimetric features of supramedullary neurons of the fish Solea ocellata

Autor: Barbara Cuoghi, Lucrezia Mola
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Popis: Various teleost species belonging to different orders possess a particular neuronal system formed by giant supramedullary neurons (SNs). In some species, SNs are scattered along the spinal cord; in others they are organized in a compacted and well-defined cluster located at the boundary between the medulla oblongata and spinal cord. In addition to the many morphological, physiological, and histochemical studies performed both in vivo and in vitro by several authors since the end of the 19th century, quantitative microfluorometric evaluation of the DNA content of SNs has showed that clustered SNs but not aligned SNs have a DNA content much greater than the normal value of 2C. Such a high DNA content is exceptional for vertebrate neurons. In the present study, we extend this analysis of SNs to the fish Solea ocellata. Our results show that the organization of the SNs of S. ocellata is neither strictly aligned nor clustered, but somewhere in between, and that this is also true of both their morphological characteristics and DNA content values. Interspecific differences in the distribution and morphology of SNs may reflect functional differences, possibly related to environmental or behavioral differences among species. In addition, the possible functional significance of endoreplication in SNs is discussed. The central nervous system of many teleost fish contains large cells, named supramedullary neurons (SNs), located on the dorsal surface of the spinal cord under the external limiting membrane. The SNs of some taxa (Lophiiformes, Tetraodontiformes, Batracoidiformes) are grouped in a cluster on the rostral spinal cord, whereas those in other taxa (Perciformes, Syngnatiformes, Clupeiformes, Scorpaeniformes, Pleuronectiformes) are scattered singly along the spinal cord. The morphology, number, and size of the SNs are characteristic for each species (1), while the ultrastruc
Databáze: OpenAIRE