Development of a Behavioral Assay using a Fluidic Device to Study Learning and Memory in Cuttlefish Larvae

Cuttlefish are marine organisms that exhibit complex social behaviors: they camouflage in response to visual stimuli, display intellectual behaviors such as flashing and stunning of prey, or avoid predators, suggesting that a cuttlefish brain has evolved learning and memory mechanisms. Early exposure of cuttlefish larvae to cues from predator and prey shows embryonic learning, as they know to differentiate between them for life. In this work we developed a behavioral assay to investigate complex behaviors by designing a fluidic device to manipulate flow of chemicals, delivery times, and allow event recording. We used mathematical models to predict diffusion coefficients of molecules based on molecular shape, bond lengths and angles. Since behavioral assays for aquatic species require a flow-through design, our chip consists of joined channels, and diffusion coefficients allow calculation of lateral diffusion lengths, rate of flows, and channel size limitations. Controls are used to verify our model's accuracy. Analysis of cuttlefish behavior to selected stimuli and response are presented. Such results allow one to quantify the learning and behavior in the embryos. This work can stimulate further studies in learning and memory mechanisms displayed by the cuttlefish.