Dhani Biscocho – MS degree 2013 conducted bath application and injection experiments whose results support our hypothesis that GABA acts as an inhibitory neurotransmitter in the circuit that controls metamorphosis in larval Tritia. Below are examples of data we collected that demonstrate GABAergic inhibition of metamorphosis. (Below Left), larvae were exposed to 100µM serotonin (5-hydroxytryptamine or 5-HT) for 5 hours, then incubated in GABA at the indicated concentrations (5-HT to [GABA]). Multiple concentrations of GABA significantly reduced levels of metamorphosis (*) compared to the 5-HT to FIO control. (Below Right), the GABAA agonist, muscimol, inhibited metamorphosis after larvae were incubated in 100µM 5-HT for 5 hours, then transferred to one of several concentrations of muscimol for the remainder of the experiment (Biscocho et al., 2018).
Above Left: GABA inhibits serotonergically induced metamorphosis in competent larva of Tritia obsoleta.
Above Right: Muscimol, a GABA agonist, inhibits serotonergically induced metamorphosis in competent Tritia.
