Ultrastructure of the retinal synapses in cubozoans
- UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
- Gregory Clark Gray (Creator)
- Institution
- The University of North Carolina Wilmington (UNCW )
- Web Site: http://library.uncw.edu/
- Advisor
- Richard Satterlie
Abstract: Cubomedusae (box jellyfish) are well known for their strong directional swimming and
responses to visual stimuli, and they have complex lensed eyes comparable to those of higher
multicellular animals. Cubomedusae possess a total of 24 eyes that are of four morphologically
different types, yet little is known about the neural organization of their eyes. The eyes are
located on ganglion-like structures called rhopalia – each of the four rhopalia contains an upper
and a lower lensed eye (with a cornea, lens and retina), two pit ocelli, and two slit ocelli. Using
transmission electron microcopy, the synaptic morphology of the eyes and pacemaker region of
four species of cubozoans (Carybdea alata, Carybdea marsupialis, Tripedalia cystophora, and
Chiropsalmus quadrumanus) were examined. Similarities in unique invaginated synaptic
structures were found in all four species, but only in their upper and lower lensed eyes. Density
measurements indicated that the invaginated synapses are located in close proximity to the basal
region of photoreceptor cells, and size differences of invaginated synapses were observed
between the upper and lower lensed eyes, as well as between species. Four additional types of
chemical synapses: clear unidirectional, dense core unidirectional, clear bidirectional, and clear
and dense core bidirectional were also observed in the rhopalia of these four species. Results
from this study raise the possibility that invaginated synapses may be useful in sorting out the
neural circuitry in the upper and lower lensed eyes of these four species.
Ultrastructure of the retinal synapses in cubozoans
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Additional Information
- Publication
- Thesis
- A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment of the Requirement for the Degree of Masters of Science
- Language: English
- Date: 2009
- Keywords
- Cubomedusae--Anatomy, Jellyfishes--Anatomy
- Subjects
- Jellyfishes -- Anatomy
- Cubomedusae -- Anatomy