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PubMed1986

Retinal projections in the lizard Podarcis hispanica.

The retinofugal of the lizard Podarcis hispanica has been examined by means of enzymatic method with horseradish peroxidase (HRP). The retinal ganglion cells project contralaterally to thalamus (nucleus geniculatus lateralis pars dorsalis, nucleus geniculatus lateralis pars ventralis and nucleus ventrolateralis pars ventralis and nucleus ventrolateralis pars ventralis), pretectum (nucleus lentiformis mesencephali, nucleus geniculatus pretectalis and nucleus posterodorsalis) and optic tectum (layers 14 and 12, mainly, and layers 13 and 11). A small ipsilateral tract has been observed. Some of these fibers project to the lateral geniculate complex and the nucleus ventrolateralis pars ventralis. Most of the ipsilateral fibers have been observed in the neuropil of nucleus geniculatus pretectalis and the layer 14 of the optic tectum. The ipsilateral component, an inconstant structure in reptiles, presents an important development in Podarcis hispanica, although the number of its fibers is relatively small.

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PubMed1986

Ultrastructure of the dorsal cortex of the lizard Psammodromus algirus.

The dorsal cortex of Psammodromus algirus shows three layers, superficial plexiform layer (SPL), cellular layer (CL), and deep plexiform layer (DPL), from the pia mater to the ependyma. The marginal glial sheet constitutes the outer limit of the SPL. This glial sheet consists of flattened tanycytic processes running parallel to the cortical surface. A few globous neurons are scattered within the neuropil of the SPL which is formed by axons, axon terminals, dendrites and dendritic spines. Three types of axon terminals, type S, type F, and axon terminals with large dense core vesicles, can be observed in the SPL. The CL presents numerous neuronal somata tightly packed. Large neurons with spherical to oval nucleus and dispersed chromatin, and smaller neurons with chromatin clumps are found in this layer. The DPL consists of neuropil with many solitary or clustered neurons. Three neuronal types are found: neurons with indented nucleus, small neurons with spherical nucleus and large juxtaependymal neurons. Glial cells are present throughout the dorsal cortex. Astrocytes are most abundant and do not show a defined pattern of distribution. Oligodendrocytes are frequently related to the alveus fibers. The ependyma forms the ventral limit of the dorsal cortex. It is formed by clear and electron-dense cells.

Animals↗