Meeting Abstract

P3.154  Sunday, Jan. 6  Further Studies on the Sensory Motor Integration of Gill Lateral Cilia in the Bivalve Mollusc Crassostrea virginica WILLIAMS, P.*; AKANDE, P.; CATAPANE, E.J.; CARROLL, M.A.; Medgar Evers College; Medgar Evers College; Medgar Evers College; Medgar Evers College catapane@mec.cuny.edu

Lateral cilia of gill of Crassostrea virginica are controlled by serotonergic-dopaminergic innervation. The motor aspects have been well studied, but the sensory side has not. Here we studied effects of sensory stimulations to mantle on beating of gill cilia of C. virginica. Cilia beating was measured by stroboscopic microscopy. Applying Isochrysis, a food source, to mantle rim increased beating rates, whereas crab extract reduced beating rates. The response to crab extract was abolished by disrupting nervous innervation to gill by cutting the branchial nerve or detaching the mantle rim. Cutting the cerebrovisceral connective lowered basal cilia rates but crab extract still slowed beating. Stimulating mantle nerves with suction electrodes increased beating, which was not observed when the circumpallial nerve from mantle was cut. Histamine, which does not alter beating when applied to gill, decreased beating when applied to mantle. This was not seen when nervous innervation to gill or mantle rim was transected suggesting histamine maybe a neurotransmitter of mantle receptor cells that synapse with afferents going to the VG. The neurotransmitters/neuroactive substances: serotonin, dopamine, acetylcholine, GABA and FMRFamide had no effect on rates when applied to mantle rim. The study demonstrates sensory-motor integration of beating of lateral cilia that involves the sensory mantle rim and VG and cerebral ganglia. It appears animals can sense harmful cues and food, and adjust gill cilia beating appropriately. The results also suggest the sensory apparatus involved are sensory nerves that send axons to the VG, and sensory receptor cells that synapse in the mantle rim with afferent neurons.