Characterization of the brain of the Red Mayan octopus (Octopus Maya)

Abstract

Octopuses show a wide behavioral range that allows them great adaptability to their environment this has permitted them to be the target of great interest for biophysics, cytology, and neurobiology studies. To adequately execute these investigations, it is essential to have a thorough understanding of the neuroanatomy of species that function as good laboratory models, for example, O. Maya. In this work, we undertake the task of extracting and characterizing the various structures of the nervous system of O. Maya at the level of lobes and connectivity between them. Serial sections at 70–80µm for sagittal and coronal plains from the brains of adult and young individuals were stained using Nissl, Hematoxylin, and Eosin (H&E) to visualize the perikarya. We determined the morphology of 30 lobes in the brain of O. Maya from young and adult specimens and the cells that constitute the connectivity pathways between these regions. We also observed that the brains of O. Maya at four weeks after hatching do not show a fully mature brain, but rather that some lobes related to somatosensory memory have low cell density and a simple morphology than that of adult specimens. It is indicative of a maturation process that should be considered for future experimental designs. We hope that this nervous system mapping will increase the basis for more detailed investigations into the neurophysiology of O. Maya and other octopuses.