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Minorsky PV. The "plant neurobiology" revolution. PLANT SIGNALING & BEHAVIOR 2024; 19:2345413. [PMID: 38709727 PMCID: PMC11085955 DOI: 10.1080/15592324.2024.2345413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 04/10/2024] [Indexed: 05/08/2024]
Abstract
The 21st-century "plant neurobiology" movement is an amalgam of scholars interested in how "neural processes", broadly defined, lead to changes in plant behavior. Integral to the movement (now called plant behavioral biology) is a triad of historically marginalized subdisciplines, namely plant ethology, whole plant electrophysiology and plant comparative psychology, that set plant neurobiology apart from the mainstream. A central tenet held by these "triad disciplines" is that plants are exquisitely sensitive to environmental perturbations and that destructive experimental manipulations rapidly and profoundly affect plant function. Since destructive measurements have been the norm in plant physiology, much of our "textbook knowledge" concerning plant physiology is unrelated to normal plant function. As such, scientists in the triad disciplines favor a more natural and holistic approach toward understanding plant function. By examining the history, philosophy, sociology and psychology of the triad disciplines, this paper refutes in eight ways the criticism that plant neurobiology presents nothing new, and that the topics of plant neurobiology fall squarely under the purview of mainstream plant physiology. It is argued that although the triad disciplines and mainstream plant physiology share the common goal of understanding plant function, they are distinct in having their own intellectual histories and epistemologies.
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Affiliation(s)
- Peter V. Minorsky
- Department of Natural Sciences, Mercy University, Dobbs Ferry, NY, USA
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2
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Bhattacharyya S, Bhattarai N, Pfannenstiel DM, Wilkins B, Singh A, Harshey RM. A heritable iron memory enables decision-making in Escherichia coli. Proc Natl Acad Sci U S A 2023; 120:e2309082120. [PMID: 37988472 PMCID: PMC10691332 DOI: 10.1073/pnas.2309082120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 10/12/2023] [Indexed: 11/23/2023] Open
Abstract
The importance of memory in bacterial decision-making is relatively unexplored. We show here that a prior experience of swarming is remembered when Escherichia coli encounters a new surface, improving its future swarming efficiency. We conducted >10,000 single-cell swarm assays to discover that cells store memory in the form of cellular iron levels. This "iron" memory preexists in planktonic cells, but the act of swarming reinforces it. A cell with low iron initiates swarming early and is a better swarmer, while the opposite is true for a cell with high iron. The swarming potential of a mother cell, which tracks with its iron memory, is passed down to its fourth-generation daughter cells. This memory is naturally lost by the seventh generation, but artificially manipulating iron levels allows it to persist much longer. A mathematical model with a time-delay component faithfully recreates the observed dynamic interconversions between different swarming potentials. We demonstrate that cellular iron levels also track with biofilm formation and antibiotic tolerance, suggesting that iron memory may impact other physiologies.
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Affiliation(s)
- Souvik Bhattacharyya
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX78712
- LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX78712
| | - Nabin Bhattarai
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX78712
- LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX78712
| | - Dylan M. Pfannenstiel
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX78712
- LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX78712
| | - Brady Wilkins
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX78712
- LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX78712
| | - Abhyudai Singh
- Department of Electrical and Computer Engineering, University of Delaware, Newark, DE19716
| | - Rasika M. Harshey
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX78712
- LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX78712
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Ros-Rocher N, Brunet T. What is it like to be a choanoflagellate? Sensation, processing and behavior in the closest unicellular relatives of animals. Anim Cogn 2023; 26:1767-1782. [PMID: 37067637 PMCID: PMC10770216 DOI: 10.1007/s10071-023-01776-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/05/2023] [Accepted: 04/07/2023] [Indexed: 04/18/2023]
Abstract
All animals evolved from a single lineage of unicellular precursors more than 600 million years ago. Thus, the biological and genetic foundations for animal sensation, cognition and behavior must necessarily have arisen by modifications of pre-existing features in their unicellular ancestors. Given that the single-celled ancestors of the animal kingdom are extinct, the only way to reconstruct how these features evolved is by comparing the biology and genomic content of extant animals to their closest living relatives. Here, we reconstruct the Umwelt (the subjective, perceptive world) inhabited by choanoflagellates, a group of unicellular (or facultatively multicellular) aquatic microeukaryotes that are the closest living relatives of animals. Although behavioral research on choanoflagellates remains patchy, existing evidence shows that they are capable of chemosensation, photosensation and mechanosensation. These processes often involve specialized sensorimotor cellular appendages (cilia, microvilli, and/or filopodia) that resemble those that underlie perception in most animal sensory cells. Furthermore, comparative genomics predicts an extensive "sensory molecular toolkit" in choanoflagellates, which both provides a potential basis for known behaviors and suggests the existence of a largely undescribed behavioral complexity that presents exciting avenues for future research. Finally, we discuss how facultative multicellularity in choanoflagellates might help us understand how evolution displaced the locus of decision-making from a single cell to a collective, and how a new space of behavioral complexity might have become accessible in the process.
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Affiliation(s)
- Núria Ros-Rocher
- Evolutionary Cell Biology and Evolution of Morphogenesis Unit, Institut Pasteur, Université Paris-Cité, CNRS UMR3691, 25-28 Rue du Docteur Roux, 75015, Paris, France
| | - Thibaut Brunet
- Evolutionary Cell Biology and Evolution of Morphogenesis Unit, Institut Pasteur, Université Paris-Cité, CNRS UMR3691, 25-28 Rue du Docteur Roux, 75015, Paris, France.
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Reid CR. Thoughts from the forest floor: a review of cognition in the slime mould Physarum polycephalum. Anim Cogn 2023; 26:1783-1797. [PMID: 37166523 PMCID: PMC10770251 DOI: 10.1007/s10071-023-01782-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/12/2023]
Abstract
Sensing, communication, navigation, decision-making, memory and learning are key components in a standard cognitive tool-kit that enhance an animal's ability to successfully survive and reproduce. However, these tools are not only useful for, or accessible to, animals-they evolved long ago in simpler organisms using mechanisms which may be either unique or widely conserved across diverse taxa. In this article, I review the recent research that demonstrates these key cognitive abilities in the plasmodial slime mould Physarum polycephalum, which has emerged as a model for non-animal cognition. I discuss the benefits and limitations of comparisons drawn between neural and non-neural systems, and the implications of common mechanisms across wide taxonomic divisions. I conclude by discussing future avenues of research that will draw the most benefit from a closer integration of Physarum and animal cognition research.
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Affiliation(s)
- Chris R Reid
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2109, Australia.
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Wan KY. Active oscillations in microscale navigation. Anim Cogn 2023; 26:1837-1850. [PMID: 37665482 PMCID: PMC10769930 DOI: 10.1007/s10071-023-01819-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/27/2023] [Accepted: 08/12/2023] [Indexed: 09/05/2023]
Abstract
Living organisms routinely navigate their surroundings in search of better conditions, more food, or to avoid predators. Typically, animals do so by integrating sensory cues from the environment with their locomotor apparatuses. For single cells or small organisms that possess motility, fundamental physical constraints imposed by their small size have led to alternative navigation strategies that are specific to the microscopic world. Intriguingly, underlying these myriad exploratory behaviours or sensory functions is the onset of periodic activity at multiple scales, such as the undulations of cilia and flagella, the vibrations of hair cells, or the oscillatory shape modes of migrating neutrophils. Here, I explore oscillatory dynamics in basal microeukaryotes and hypothesize that these active oscillations play a critical role in enhancing the fidelity of adaptive sensorimotor integration.
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Affiliation(s)
- Kirsty Y Wan
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK.
- Department of Mathematics and Statistics, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK.
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Cheng K. Learning in Cnidaria: a summary. Commun Integr Biol 2023; 16:2240669. [PMID: 37534311 PMCID: PMC10392723 DOI: 10.1080/19420889.2023.2240669] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 08/04/2023] Open
Abstract
Based on a systematic literature search, I recently reviewed learning in the phylum Cnidaria, animals possessing a nerve net as a nervous system but no centralized brain. I found abundant evidence of non-associative learning, both habituation and sensitization, but only sparse evidence of associative learning. Only one well-controlled study on classical conditioning in sea anemones provided firm evidence, and no studies firmly supported operant conditioning in Cnidaria, although several provided suggestive evidence. More research on associative learning in this phylum is needed.
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Affiliation(s)
- Ken Cheng
- School of Natural Sciences, Macquarie University, Sydney, Australia
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Bhattacharyya S, Bhattarai N, Pfannenstiel DM, Wilkins B, Singh A, Harshey RM. Iron Memory in E. coli. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.19.541523. [PMID: 37609133 PMCID: PMC10441380 DOI: 10.1101/2023.05.19.541523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
The importance of memory in bacterial decision-making is relatively unexplored. We show here that a prior experience of swarming is remembered when E. coli encounters a new surface, improving its future swarming efficiency. We conducted >10,000 single-cell swarm assays to discover that cells store memory in the form of cellular iron levels. This memory pre-exists in planktonic cells, but the act of swarming reinforces it. A cell with low iron initiates swarming early and is a better swarmer, while the opposite is true for a cell with high iron. The swarming potential of a mother cell, whether low or high, is passed down to its fourth-generation daughter cells. This memory is naturally lost by the seventh generation, but artificially manipulating iron levels allows it to persist much longer. A mathematical model with a time-delay component faithfully recreates the observed dynamic interconversions between different swarming potentials. We also demonstrate that iron memory can integrate multiple stimuli, impacting other bacterial behaviors such as biofilm formation and antibiotic tolerance.
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Affiliation(s)
- Souvik Bhattacharyya
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin; Austin, TX 78712
| | - Nabin Bhattarai
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin; Austin, TX 78712
| | - Dylan M. Pfannenstiel
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin; Austin, TX 78712
| | - Brady Wilkins
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin; Austin, TX 78712
| | - Abhyudai Singh
- Electrical & Computer Engineering, University of Delaware, Newark, DE 19716
| | - Rasika M. Harshey
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin; Austin, TX 78712
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Chistyakova LV, Faizullina DR, Shmakov SV, Petrishchev NN. A Comparative Analysis of the Distribution of Different Photosensitizers in Paramecium caudatum and Amoeba proteus. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022060059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Richardson K. Genes and knowledge: Response to Baverstock, K. the gene an appraisal. https://doi.org/10.1016/j.pbiomolbio.2021.04.005. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 167:12-17. [PMID: 34736965 DOI: 10.1016/j.pbiomolbio.2021.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 09/21/2021] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
This response aims to expand on some of the issues raised by Keith Baverstock's The Gene: An Appraisal, especially on the evolution and nature of knowledge in living things. In contrast to the simple associationism envisaged in "genetic information", it emphasises the dynamic complexity and changeability of most natural environments, and, therefore, predictability based on underlying statistical structures. That seems to be the basis of the "cognitive" functions increasingly being reported about cellular, as well as more evolved, functions, and of the autonomous agency of organisms thriving creatively in complex environments.
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Correspondence insights into the role of genes in cell functionality. Comments on "The gene: An appraisal" by K. Baverstock. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 167:152-160. [PMID: 34624359 DOI: 10.1016/j.pbiomolbio.2021.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 09/27/2021] [Accepted: 09/30/2021] [Indexed: 11/21/2022]
Abstract
One of the most important goals of the post-genomic era is to understand the different sources of molecular information that regulate the functional and structural architecture of cells. In this regard, Prof. K. Baverstock underscores in his recent article "The gene: An appraisal" (Baverstock, 2021) that genes are not the leading elements in cellular functionality, inheritance and evolution. As a consequence, the theory of evolution based on the Neo-Darwinian synthesis, is inadequate for today's scientific evidence. Conversely, the author contends that life processes viewed on the basis of thermodynamics, complex system dynamics and self-organization provide a new framework for the foundations of Biology. I consider it necessary to comment on some essential aspects of this relevant work, and here I present a short overview of the main non-genetic sources of biomolecular order and complexity that underline the molecular dynamics and functionality of cells. These sources generate different processes of complexity, which encompasses from the most elementary levels of molecular activity to the emergence of systemic behaviors, and the information necessary to sustain them is not contained in the genome.
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