Innovative ways of fast neurotransmission in the octopus brain

The octopus is a mollusk with a complex nervous system containing half a billion neurons (similar to a small primate), millisecond camouflage and sophisticated behavior suggesting complex cognition. Yet at the basic molecular and neurochemical levels the octopus brain remains enigmatic, and is likely to differ significantly from the better-studied brains of vertebrates. For example, vertebrate brains use three excitatory (glutamate, ACh and serotonin) and two inhibitory (GABA and glycine) neurotransmitters, each acting through specialized ligand-gated ion channels (LGCs). However, invertebrates such as insects and nematodes are known to contain additional LGC families with novel ligands or functional properties, which regulate neural activity in unexpected ways. Research in the Seuntjens lab indicates that Octopus vulgaris also contains novel families of neuronal LGCs, whose ligands, activities, and functional roles in the brain are completely unknown. In this proposal the Schafer team will use approaches applied successfully in nematodes to deorphanize and physiologically-characterize O vulgaris LGCs. The Seuntjens team will determine where these channels are expressed in the brain to obtain clues to their in vivo functions. Using pharmacological and genetic approaches to knock out LGC function, behavioral studies in O vulgaris larvae will then probe the roles of fast neurotransmission in the context of visual-motor behavior and color-change.

Keywords:Octopus vulgaris, neurotransmitter, ion channel, behavior, camouflage

Disciplines:Invertebrate biology, Biology of behaviour, Neurophysiology, Animal cell and molecular biology, Developmental neuroscience