Eashan Saikia


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Saikia

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Eashan

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0000-0002-7642-8754

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Publications1 - 3 of 3
  • Mechanical factors contributing to the Venus flytrap's rate-dependent response to stimuli
    Item type: Journal Article
    Saikia, Eashan; Läubli, Nino; Vogler, Hannes; et al. (2021)
    Biomechanics and Modeling in Mechanobiology
    The sensory hairs of the Venus flytrap (Dionaea muscipula Ellis) detect mechanical stimuli imparted by their prey and fire bursts of electrical signals called action potentials (APs). APs are elicited when the hairs are sufficiently stimulated and two consecutive APs can trigger closure of the trap. Earlier experiments have identified thresholds for the relevant stimulus parameters, namely the angular displacement theta and angular velocity omega. However, these experiments could not trace the deformation of the trigger hair's sensory cells, which are known to transduce the mechanical stimulus. To understand the kinematics at the cellular level, we investigate the role of two relevant mechanical phenomena: viscoelasticity and intercellular fluid transport using a multi-scale numerical model of the sensory hair. We hypothesize that the combined influence of these two phenomena and omega contribute to the flytrap's rate-dependent response to stimuli. In this study, we firstly perform sustained deflection tests on the hair to estimate the viscoelastic material properties of the tissue. Thereafter, through simulations of hair deflection tests at different loading rates, we were able to establish a multi-scale kinematic link between omega and the cell wall stretch delta. Furthermore, we find that the rate at which delta evolves during a stimulus is also proportional to omega. This suggests that mechanosensitive ion channels, expected to be stretch-activated and localized in the plasma membrane of the sensory cells, could be additionally sensitive to the rate at which stretch is applied.
  • Kinematics Governing Mechanotransduction in the Sensory Hair of the Venus flytrap
    Item type: Journal Article
    Saikia, Eashan; Läubli, Nino; Burri, Jan T.; et al. (2021)
    International Journal of Molecular Sciences
    Insects fall prey to the Venus flytrap (Dionaea muscipula) when they touch the sensory hairs located on the flytrap lobes, causing sudden trap closure. The mechanical stimulus imparted by the touch produces an electrical response in the sensory cells of the trigger hair. These cells are found in a constriction near the hair base, where a notch appears around the hair’s periphery. There are mechanosensitive ion channels (MSCs) in the sensory cells that open due to a change in membrane tension; however, the kinematics behind this process is unclear. In this study, we investigate how the stimulus acts on the sensory cells by building a multi-scale hair model, using morphometric data obtained from μ-CT scans. We simulated a single-touch stimulus and evaluated the resulting cell wall stretch. Interestingly, the model showed that high stretch values are diverted away from the notch periphery and, instead, localized in the interior regions of the cell wall. We repeated our simulations for different cell shape variants to elucidate how the morphology influences the location of these high-stretch regions. Our results suggest that there is likely a higher mechanotransduction activity in these ’hotspots’, which may provide new insights into the arrangement and functioning of MSCs in the flytrap.
  • Mechanotransduction in the sensory hairs of the Venus flytrap
    Item type: Doctoral Thesis
    Saikia, Eashan (2021)
Publications1 - 3 of 3