Smart cephalopods – soft-bodied predators with the large and complex brain

Dr Wen-Sung Chung,
Queensland Brain Institute

Smart cephalopods – soft-bodied predators with the large and complex brain

Cephalopods (e.g. octopus, squid, cuttlefish and nautilus) have the most complicated central nervous system (CNS) of all invertebrates at both anatomical and functional levels as demonstrated by the pioneering neuroanatomical work of Cajal and Young decades or indeed more than a century ago. The brain of an octopus has about the same number of neurons as that of a rabbit and seven times more than a mouse. Early work on the organisation of the cephalopod sensory and motor control systems uncovered a unique model for studying sensory function, learning and memory. Many studies have focused on the behavioural neurobiology of the cephalopods such as their remarkable colour-blind camouflage, mimicry and other communication abilities. Other studies have revealed the richness of cephalopod behavioural repertoires such as bipedal walking, mate guarding, social cognition and observational learning that are comparable to the abilities of higher vertebrates. The remarkably rapid and smart reactions cephalopod show when confronted with novel challenges suggest that they have developed alternative ways of problem solving compared to standard model species such as mice, zebrafish and fruit flies. However, unlocking the cephalopod brain was forgotten in animal neuroscience once the complexity of its brain became too challenging using classical histological approaches. Here using the new technique of diffusion magnetic resonance imagery (dMRI) focused on the cephalopod CNS and validated with the same traditional Cajal-Golgi techniques combined with other neural tracers. We shed new light on this remarkable structure, mapping both new and established neural interconnecting within and between lobes. These pathways and maps will lead to a better understanding of their complex behaviours including camouflage and communication.

Please join us for morning tea on Level 5 following the seminar