GABA is an inhibitory neurotransmitter in the neural circuit regulating metamorphosis in Ilyanassa obsoleta

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Dhani Biscocho (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:
Esther Leise

Abstract: The marine mud snail, Ilyanassa obsoleta, displays a biphasic life cycle. The initial phase consists of weakly swimming larval animals with ciliated feeding structures on the head, the velar lobes. The second phase consists of adult animals residing on intertidal mudflats as obligate omnivores. Metamorphosis, the event that links these life history stages, is initiated by external stimuli but coordinated by internal signaling molecules. Internally, molluscan metamorphosis includes neurotransmitters that modify the behavior of cells in neural circuits. For several species of molluscs, including abalone and scallops, larval metamorphosis can be induced by the external application of the neurotransmitter, gamma-aminobutyric acid (GABA). In this situation, GABA is presumed to mimic the actions of food-related ligands that bind to external sensory receptors. GABA is the only neurotransmitter known to act in such a fashion. In contrast, results of our preliminary experiments with I. obsoleta strongly support the hypothesis that GABA works internally in this species as a neurotransmitter in the larval central nervous system (CNS) to inhibit metamorphosis. External application of GABA to metamorphically competent larvae of I. obsoleta does not elicit metamorphosis, but does repress metamorphic induction. I utilized a battery of GABAergic reagents to modify internal GABAergic activity to address the hypothesis that GABA inhibits metamorphosis due to its actions within the larval CNS. My results strongly suggest that GABA inhibits metamorphosis in this molluscan model organism. My results indicate that GABA acts downstream from or directly on serotonergic neurons to decrease the metamorphosis-inducing effects of serotonin.

Additional Information

Language: English
Date: 2013
Marine mud snail, Ilyanassa obsoleta, Metamorphosis, Gamma-aminobutyric acid (GABA
Snails $x Metamorphosis
GABA $x Physiological effect

Email this document to