Meeting Abstract
45.5 Monday, Jan. 5 Nervous control of cilia during sniffing behavior of Tritonia diomedea CAIN, S. D.*; OHMES, L. B.; TRUMAN, G. A.; Eastern Oregon University; Eastern Oregon University; Eastern Oregon University shaun.cain@eou.edu
How the brain of animals make decisions based on conflicting sensory information is an important component of the nervous control of behavior. In this study, we investigated the control of sniffing behavior that is turned off during movements activated by non-odor cues. The lateral tips of the oral veil in nudibranchs serve as a primary sensory organ, derived from the anterior tentacle of the ancestral gastropod. One feature of this organ is a dense field of cilia that line a channel on the ventral surface of the lateral tip. The beating of these cilia is hypothesized to create water currents that move odors from the substrate to the sensory cells that are clustered at the base of the lateral tips. In Tritonia diomedea, this field of cilia is innervated by a pair of peptidergic giant neurons (left and right pedal 7) that appear to function in the control of motor cilia. These same neurons have previously been shown to be inhibited by stimuli that promote directed crawling, such as magnetic field rotations. Here, we tested the role of the Pd7 in stimulating motor cilia by application of TPeps (the neurotransmitter produced by these neurons) and direct stimulation of the Pd7 neurons in a brain-lateral tip preparation. Initial results suggest that the both application of TPeps and direct stimulation of Pd7 increase the rate of ciliary transport in the ciliated channel. Further work suggests that the inhibition observed during crawling is controlled by the Swim CPG. The results suggest that one function of the CPG is to decrease or abolish olfactory information entering the brain by turning off the motor cilia of the lateral tip. This could potentially eliminate activation of neuronal networks conflicting with directed movements (e.g. magnetic orientation) or the escape response to predators.
