GABA-like immunoreactivity occurs in competent larvae of the marine gastropod Nassarius obsoletus

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Poorna Dharmasri (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Advisor
Esther Leise

Abstract: The marine gastropod Nassarius obsoletus undergoes an irreversible and permanent metamorphosis as it transforms from a veliger larva to a benthic adult. The neurological control for this metamorphic process includes actions mediated by the neurotransmitter ?-aminobutyric acid (GABA), which inhibits metamorphosis and thus preserves the larval state. I used immunocytochemistry (ICC) with antibodies to GABA and the CLARITY procedure to identify GABAergic neurons within N. obsoletus, some of which are part of the neuroanatomical framework that controls the initiation of metamorphosis. Results from the ICC experiments documented the presence of GABAergic axons throughout the velar lobes and in the larval foot. Particularly noteworthy is the presence of bilateral posterior pedal nerves that originate in the pedal ganglia and travel to the metapodium (posterior foot). These nerves branch extensively within the foot. The presence of a cluster of putative epithelial glandular cells in the foot was also demonstrated by ICC. An analysis of the adult central ganglia with the CLARITY method was inconclusive. Furthermore, ICC experiments failed to localize cell bodies, hypothesized to be in the apical ganglion, from which velar axons originate. My results support the hypothesis that GABAergic neurons function in the motor system of larval N. obsoletus, that GABA or GABA-like compounds are present in mucus-secreting cells of the foot, and that this neurotransmitter is involved in the regulation of the initiation of metamorphosis.

Additional Information

Publication
Thesis
Language: English
Date: 2015
Keywords
GABA, GABA-like Immunoreactivity, ICC, Immunocytochemistry, Metamorphosis, Nassarius obsoletus
Subjects
Nassarius obsoletus $x Metamorphosis
GABA $x Physiological effect
Immunocytochemistry

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