Giant neurons associated with consciousness are discovered

What is the nature of consciousness? This is one of the great mysteries of psychology, neuroscience, and the philosophy of mind, and although it may sound curious, animal research, the sense of consciousness must be different from ours, it has helped to untangle it.

In fact, a team of researchers from the Allen Institute for Brain Sciences led by Christof Koch recently reported the discovery of 3 giant neurons that connect a large part of the brain mouse; these neurons could be the physiological basis of consciousness, but other experts disagree.

    The three giant neurons

    Christof Koch and his team made a presentation to members of the neuroscientific community in which they described the methodology and results of their research on neural connectivity in the brain of mice.

    The highlight of his speech was the identification of three giant neurons that emerge from the brain structure known as the “cloister” and connect it to a large part of the brain. The largest of the three surrounds the whole brain, While the other two also cover a significant part of the hemispheres.

    As the three-dimensional images obtained from the research reveal, these three cells maintain strong synaptic connections with neurons in many different regions of the brain. This suggests that they may play an important role in the coordination of electrochemical impulses in the central nervous system.

    However, for now the existence of these three neurons in other species has not been confirmed animals, including humans, so great caution should be exercised in trying to generalize the claims of Koch’s team.

      What is the cloister?

      The cloister is a layer of neurons attached to the underside of the cerebral neocortex, adjacent to the insula and the basal ganglia; it is sometimes considered to be part of this structure. Its amplitude is irregular, measuring several millimeters in some areas and much less than a millimeter in others.

      This region of the brain synapses with many cortical and subcortical structures, Including the hippocampus, essential for long-term memory, and the amygdala, involved in emotional learning.

      Neurons in the cloister not only maintain relevant connections with other parts of the brain, but are also very closely related to each other. This was associated with a uniform treatment of the stimulation passing through the cloister.

      The proposal of the Koch team

      Based on his recent research and others with which he had previously collaborated, Koch he argues that consciousness could be located in the cloister, Which has been the main focus of his career.

      According to the proposal of this team, the three giant neurons discovered would allow the coordination of nerve impulses in the cloister: They associate the reception and sending of signals from this structure with the appearance of consciousness, considering the globality of this transmission and the functions that have been attributed to the cloister.

      Another relevant research for this hypothesis is that carried out by Mohammad Koubeissi’s group (2014) on a woman with epilepsy. This team found that stimulation of the cloister by electrodes with “deactivated” consciousness of the patient, while the interruption of this stimulation made her recover.

      Research methodology

      The Allen Institute research team elicited the production of fluorescent proteins in individual neurons from the cloisters of several mice. For this, they used a substance which, being present in the body, caused the activation of certain genes.

      By propagating through target neurons, these proteins endowed the full extent of these cells with a distinctive color. Later, they took 10,000 images of sections of the brain and used computer software to create them. three-dimensional maps of activated neurons.

      Criticisms of this hypothesis

      Several neuroscientists disagree with Koch’s team’s proposal. The localization of its hypothesis has been criticized generally, that grants to the cloister the main role in brings back to consciousness human without leaning in a solid base of investigation.

      To study the veracity of these approaches, Chau et al. (2015) conducted a study of 171 veterans with traumatic brain injury. They found that injuries in the cloister were related to slower recovery of consciousness after damage, But not with more serious long-term sequelae.

      At the moment, the evidence for the hypothesis that the cloister is the key to consciousness is inconclusive, especially when we refer to human beings. However, evidence suggests that this structure may be relevant for attentional control thanks to the connection of different regions of the two cerebral hemispheres.

      Bibliographical references:

      • Chau, A .; Salazar, AM; Krueger, F .; Cristofori, I. and Grafman, J. (2015). The effect of cloister injuries on human consciousness and functional recovery. Consciousness and Cognition, 36: 256-64.
      • Crick, FC and Koch, C. (2005). What is the function of the cloister? Philosophical Transactions of the Real Society of London B: Biological Sciences, 360 (1458): 1271-79.
      • Koubeissi, MZ; Bartolomei, F .; Beltagy, A. and Picard, F. (2014). Electrical stimulation of a small area of ​​the brain reversibly alters consciousness. Epilepsy and Behavior, 37: 32-35.
      • Torgerson, CM; Irimia, A .; Goh, SYM and Van Horn, JD (2015). The DTI connectivity of the human cloister. Mapping the Human Brain, 36: 827-38.

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