[Fine structure or retina in Chiroptera (author's transl)]

Abstract

The retina of Chiroptera, studied during the various seasons of the year, appears well developed, and provided with morphological and structural characters very near to the humans and other mammalians. The retina of Chiroptera it is composed of five layers: 1) it is composed exclusively by rods: his morphological behaviour has been yet described in other night life birds and mammalians (e.g. mice and guinea pigs (Hollenberg e Bernstein), 2) plexiform layer, composed by rod's prolongations and by bipolar cells that there form conventional synapsis and mainly ribbon synapsis, 3) horizontal and amacrine bipolar cells and the middle portion of Müller's cells, 4) inner plexiform layer with conventional type synapsis, 5) layer of the ganglionar cells and of the enlarged prolongations of the inner portion of Müller's cell. The prolongations are separated from the vitreous body by basement membrane. After a detailed description of the elements constituent the different retina's layer, the Author asserts that remarkable qualitative, quantitative and season variations were not found. The inner granular layer as well as the middle part of the Müller's cells, is composed by three different types of cells: horizontal, amacrine, bipolar, which have all the characters of a typical nervous cell. Granules found in pigmented cells how a structural range of variations linked more with the different stages of maturation than with the variety of species investigated. Citoplasmatic polarity of the granules and mytochondria concentration were not noticed as, on the contrary, in other mammalians. The Author emphasizes pynocitosis phenomena both a level of the inner and outer surface of pigmented cells, and at the level of the most outer prolongations of Müller's cell: those cytologic aspects seem to witness a possible transfer of liquids, salts and metabolites from capillaries of the choroid to photoreceptors. Moreover the total absense of blood capillaries in all five layers of the retina is emphasized.he