A reductionistic, bottom‐up, cellular‐based concept of the origins of sentience and consciousness has been put forward. Because all life is based on cells, any evolutionary theory of the emergence of sentience and consciousness must be grounded in mechanisms that take place in prokaryotes, the simplest unicellular species. It has been posited that subjective awareness is a fundamental property of cellular life. It emerges as an inherent feature of, and contemporaneously with, the very first life‐forms. All other varieties of mentation are (...) the result of evolutionary mechanisms based on this singular event. Therefore, all forms of sentience and consciousness evolve from this original instantiation in prokaryotes. It has also been identified that three cellular structures and mechanisms that likely play critical roles here are excitable membranes, oscillating cytoskeletal polymers, and structurally flexible proteins. Finally, basic biophysical principles are proposed to guide those processes that underly the emergence of supracellular sentience from cellular sentience in multicellular organisms. (shrink)

Our comment is based on a simple but, we believe, compelling principle. The proposed cognitive processes and functions that are components of Jablonka and Ginsburg’s Unlimited Associative Learning (UAL) are real and are fundamental elements in the varieties of consciousness, cognition, problem solving, and sentience in the species they identify. But, from our perspective, they didn’t function as the metaphoric biomolecular ship that brought consciousness into being. The UAL functions are, and should be viewed as, evolutionary steps that built upon (...) a deeper and much older cognitive foundation. The appearance of UAL didn’t allow consciousness to emerge. It allowed it to change the manner in which sentience was instantiated − just as a host of other evolutionary developments did. In short, the emergence of UAL is a _token_ on a continuum of mental experience and not a distinct _type_ of mentation. (shrink)

Cellular circadian clocks represent ancient anticipatory systems which co‐evolved with the first cells to safeguard their survival. Cyanobacteria represent one of the most ancient cells, having essentially invented photosynthesis together with redox‐based cellular circadian clocks some 2.7 billion years ago. Bioelectricity phenomena, based on redox homeostasis associated electron transfers in membranes and within protein complexes inserted in excitable membranes, play important roles, not only in the cellular circadian clocks and in anesthetics‐sensitive cellular sentience (awareness of environment), but also in the (...) coupling of single cells into tissues and organs of unitary multicellular organisms. This integration of cellular circadian clocks with cellular basis of sentience is an essential feature of the cognitive CBC‐Clock basis of cellular life. (shrink)

We are sympathic with LeDoux’s primary goal here ─ to get a solid scientific grip on what has been dubbed one of the most elusive, important questions in scientific discourse, to identify the underlying biomolecular processes that give rise to consciousness. However, we have issues with the way he goes about it and have tried to present them in a constructive manner. Our commentary is built around our theory of the origins of minds, dubbed the Cellular Basis of Consciousness (CBC), (...) and the empirical research that supports it. The CBC is based on the proposition that life and sentience are co-terminous, that life without subjectivity, feeling, without valenced perception, without the capacity to learn and lay down memories would have been an evolutionary dead-end. It could not have survived in the hostile, chaotic world in flux that dominated our planet four billion years ago. The biological sciences operate on the principle that all species, extant and extinct, evolved from the first prokaryotes. The CBC theory is founded on the principle that all expressions of emotion, perception, and cognition did as well. (shrink)

In a recent forum article, Dan Needleman and Jan Brugues argue that, despite the astonishing advances in cell biology, a fundamental understanding of even the most well-studied subcellular biological processes is lacking. This lack of understanding is evidenced by our inability to make precise predictions of subcellular and cellular behaviors. They suggest that to achieve such an under- standing, we need to apply a combination of quantitative experiments with new theoretical concepts and determine the physical principles of subcellular biological organization. (...) We discuss these issues and suggest that, besides biophysics, we need strong theoretical inputs from biocommunication theory in order to understand all the core agents of the cellular life and subcellular organization. (shrink)

Polarity is an inherent feature of almost all prokaryotic and eukaryotic cells. In most eukaryotic cells, growth polarity is due to the assembly of actin‐based growing domains at particular locations on the cell periphery. A contrasting scenario is that growth polarity results from the establishment of non‐growing domains, which are actively maintained at opposite end‐poles of the cell. This latter mode of growth is common in rod‐shaped bacteria and, surprisingly, also in the majority of plant cells, which elongate along the (...) apical–basal axes of plant organs. The available data indicate that the non‐growing end‐pole domains of plant cells are sites of intense endocytosis and recycling. These actin‐enriched end‐poles serve also as signaling platforms, allowing bidirectional exchange of diverse signals along the supracellular domains of longitudinal cell files. It is proposed that these actively remodeled end‐poles of elongating plant cells remotely resemble neuronal synapses. BioEssays 25:569–576, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

Cytokinesis ensures proper partitioning of the nucleocytoplasmic contents into two daughter cells. It has generally been thought that cytokinesis is accomplished differently in animals and plants because of the differences in the preparatory phases, into the centrosomal or acentrosomal nature of the process, the presence or absence of rigid cell walls, and on the basis of ‘outside‐in’ or ‘inside‐out’ mechanism. However, this long‐standing paradigm needs further reevaluation based on new findings. Recent advances reveal that plant cells, similarly to animal cells, (...) possess astral microtubules that regulate the cell division plane. Furthermore, endocytosis has been found to be important for cytokinesis in animal and plant cells: vesicles containing endocytosed cargo provide material for the cell plate formation in plants and for closure of the midbody channel in animals. Thus, although the preparatory phases of the cell division process differ between plant and animal cells, the later phases show similarities. We unify these findings in a model that suggests a conserved mode of cytokinesis. BioEssays 29:371–381, 2007. © 2007 Wiley Periodicals, Inc. (shrink)