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The compound eye and first optic ganglion of the fly: A light and electron microscopic study
Author(s) -
PEDLER C.,
GOODLAND H.
Publication year - 1965
Publication title -
journal of the royal microscopical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0368-3974
DOI - 10.1111/j.1365-2818.1965.tb02118.x
Subject(s) - ommatidium , compound eye , retina , axon , biology , ganglion , optic nerve , ultrastructure , microtubule , anatomy , optics , physics , neuroscience , microbiology and biotechnology
SYNOPSIS The object of this work was to determine the main ultrastructural features of the ommatidium with particular reference to its base and the region of the cone; to establish some architectural features of the first optic ganglion and to clarify the nature of the connections between the ommatidium and the periopticon. Studies of sections cut in several planes have led to the construction of an incomplete schema depicting the main pattern of connections. It is suggested that this pattern is similar in principle to some of the connections found between first and second neurone in the vertebrate retina. It is pointed out that the dimensions of the ommatidium are well suited to the task of providing maximum spatial resolving power together with high sensitivity. The prevalent view that individual rhabdomes in a particular ommatidium can be differentially stimulated is also shown to be highly unlikely. In addition, the finding that the constituent microtubules of radially opposed rhabdomes are parallel is not confirmed. Regularly sized and spaced densities on the plasma membranes of the rhabdome microtubules are reported and the possibility is raised that these may bear some relation to photo‐pigments. A new variety of synapse is reported on localized lengths of axon in the 1st optic ganglion. Finally, the belief that the compound eye is an image‐forming device is criticized and it is suggested that it is more concerned with data processing of light‐evoked responses in order to generate signals concerning particular aspects of the environment.