Multiple neuronal networks coordinate Hydra mechanosensory behavior

Abstract

Hydra vulgaris is an emerging model organism for neuroscience due to its small size, transparency, genetic tractability, and regenerative nervous system; however, fundamental properties of its sensorimotor behaviors remain unknown. Here, we use microfluidic devices combined with fluorescent calcium imaging and surgical resectioning to study how the nervous system coordinates Hydra′s mechanosensory response. We find that mechanical stimuli cause animals to contract, and this response relies on both the oral and aboral nerve rings. We also find that these nerve rings work together to coordinate spontaneous contractions suggesting that spontaneous behavior and sensorimotor responses converge on to a common neural circuit. These findings improve our understanding of how Hydra′s diffuse nervous system supports sensorimotor behaviors, which is needed to increase the utility of Hydra as a model organism for neuroscience.

A genetically tractable jellyfish model for systems and evolutionary neuroscience

“…In neuroscience, these advances have intersected with new, genetically encoded optical techniques for measuring and manipulating neural activity, together with advances in microscopy, offering the opportunity to functionally image the entire nervous system in small, transparent animals (Ahrens and Engert, 2015). With the exception of Hydra (a hydrozoan polyp; Dupre and Yuste, 2017;Szymanski and Yuste, 2019;Badhiwala et al, 2020;Wang et al, 2020), the only transparent model organisms currently used in systems neuroscience are C. elegans and zebrafish (D. rerio) larvae, both of which are bilaterians, although others are emerging (Bezares-Calderón et al, 2018;Chartier et al, 2018). Broadening the study of neural systems across phylogeny has utility that ranges from biomimetic engineering to revealing the possibilities, constraints, and principles through which nervous systems have evolved.…”

Functional modules within a distributed neural network control feeding in a model medusa

“…An additional opportunity for comparative neuroscience would be between Clytia and Hydra, which is also emerging as a systems neuroscience model (Dupre and Yuste, 2017; Szymanski and Yuste, 2019; Badhiwala et al, 2020; Wang et al, 2020; Bosch et al, 2017) . Hydra most closely resemble the polyp stage of Clytia, but have undergone a number of remarkable modifications, including loss of the polyp colony and movement into fresh water (Chapman et al, 2010; Leclère et al, 2019; Steele et al, 2011).…”

“…An additional opportunity for comparative neuroscience would be between Clytia and Hydra, which is also emerging as a systems neuroscience model (Dupre and Yuste, 2017;Szymanski and Yuste, 2019;Badhiwala et al, 2020;Wang et al, 2020;Bosch et al, 2017).…”

From neuron to muscle to movement: a complete biomechanical model ofHydracontractile behaviors

“…We simulated the dynamics that result from setting the electrical conductance between muscles to zero and stimulating random small groups of muscle cells; this leads to slowly growing nodes of excitation via the slow chemical diffusion of IP 3 (Figure 10) . Thus we believe that electrical coupling of muscle cells is needed to explain the rapid synchronization of calcium activity in the epithelium (Badhiwala et al, 2020) . The distributed network of CB neurons are likely necessary to integrate and generate the contraction activity, and may contribute to the robustness of contraction.…”