EXPLORING NEURAL HALLMARKS OF CONSCIOUS STATES IN OCTOPUS. An experimental approach including the development of minimally invasive and stunning methods

Cephalopods molluscs are well known for the richness of their behavioral repertoire, learning and cognitive abilities, and a sophisticated nervous system including a highly differentiated multi lobular brain considered to rivalling higher vertebrates for the relative brain-to-body size. Functional analogies between cephalopod and vertebrate brains have been also suggested, further supporting evidence for their sentience and possession of some sort of primary consciousness. In this PhD thesis I explore in the common octopus, a cephalopod mollusc, the possession of hallmarks of consciousness as proposed by previous Authors with a focus on: i. structural and functional analogies between the cephalopod ‘brain’ structures and the thalamus-cortex ‘complex’; ii. neural dynamics, both spontaneous and evoked, from octopus central nervous system in order to search for electroencephalographic (EEG) signatures. During my PhD project, I also developed minimally invasive approaches allowing recording of neural activities in live animals, and explored the effects of stunning causing temporary electronarcosis, as a potential route to induce reduction and/or loss of consciousness and insensibility, as required for the development of humane slaughtering for cephalopods harvested for human consumption. Overall, my results are novel and provide the basis for the search of neural correlates of conscious and unconscious states in cephalopods, the sole invertebrates that have been regulated over the last few years at different geographical scale based on their sentience, complex cognition and some sort of primary consciousness. This PhD is the first designed around the experimental search of (some) hallmarks of consciousness in cephalopod molluscs, animals very distant from mammals.