The Value of Using Cephalopods as a Model of Understanding the Human Brain
Abstract
Animal modelling remains a critical issue in human brain research. Perhaps due to neuroanatomical differences, studies using rodents, non-human primates and other animals were not always an effective way for predicting the right treatment from neurological diseases in humans (Chesselet and Carmichael, 2012), which calls for implementing/validating different animal models. Cephalopods have been used in neuroscience for over 100 years due to their distinguished features among other invertebrates and anatomical characteristics that make them easier to study compared with other animals (Fiorito et al., 2014). Today, they are model organisms in various areas of neuroscience. Unfortunately, controversy concerning the suitability of these models continue to occur (Chesselet and Carmichael, 2012). The aim of this short paper is to evaluate the validity of cephalopods models in human brain research.
Evaluate the value of using cephalopods as a model of understanding the human brain
Cephalopods are a member of the class Cephalopoda in the phylum Mollusca of the kingdom Animalia (Molluscs.at, 2016). They are renowned for their intelligence and complex behavior among the invertebrates (Tricarico et al., 2013). The interest towards Cephalopods as animal models stems from their phenotypic malleability, complex and centralized nervous system, their tameness, which facilitates behavioral and memory studies and their anatomical peculiarities related to their big size (Hochner, Shomrat and Fiorito, 2006). Areas in neuroscience using cephalopods as animal models include: physiology, behavior (behavioral plasticity, learning and memory), neurotransmitters, nociception, regeneration, neuromotor control, physiology of the sensory system, development and functional organization of the brain (Fiorito et al., 2014).
Discuccion
Studying invertebrates able of demonstrating sophisticated behavior such as octopuses and other cephalopods may substantially contribute to our understanding of the evolution of the human brain displaying complex behavior. The phylogenetic remoteness between cephalopods and vertebrates may also reveal some of the shared neurobiological mechanisms of complex behavior or the circumstances that led to the evolution of complex brains (Hochner, Shomrat and Fiorito, 2006).
One practical reason that makes cephalopods such as the octopus O.vulgaris a suitable model to study the human brain is their tameness and adaptiveness, i.e. a few days after they are captured, they are no longer frightened of the experimenter, which is important for successful memory and learning experiments. Another practical reason is that O.vulgaris demonstrate stereotypic predatory behavior that can be activated by using a prey and easily measured quantitatively. Most importantly, they are resilient to surgery under deep anesthesia and able to recover quickly following lesions in their central nervous system (Hochner, Shomrat and Fiorito, 2006).
The brain of octopuses is more similar to the vertebrates due to encephalization of the ganglionic masses. Their brain-to-body ratio of octopuses fits well in the vertebrate range and there is a dramatic difference in the number and organization of nerve cells between them and lower molluscs reaching 500 million cells as compared to 20000. Moreover, there are striking similarities, due to evolutionary convergence, between some regions of …
