Biology subjects

Senft, S.

Publications and source records attributed to Senft, S..

3 recordsLinked to original sources

bioRxiv2026

Bio-inspired chromatophore network model generates dynamic skin patterns akin to those observed in cephalopods

Cephalopod skin exhibits a wide range of dynamic visual displays, including traveling waves, light/dark flashes, and flickering, all generated by muscle-regulated expansion and retraction of pigment-filled elastic sacs known as chromatophores. While central neural control is essential for high-level body-wide pattern coordination, experimental evidence from excised and denervated skin reveals that intricate spatiotemporal patterns can also emerge spontaneously in the skin. This raises questions about the respective roles of central versus peripheral control. To determine the simplest control necessary to generate such patterns, we developed ChromatoNet, a biophysical model of chromatophore arrays that includes mechanical interactions on 1- and 2-dimensional lattices with the excitability properties of radial muscles. With minimal external input, our modified Morris--Lecar model reproduces a rich repertoire of skin dynamics, including spontaneous flickering as well as traveling and spiral waves. Both spontaneous and stimulus-evoked waves emerge at an intrinsic resonant frequency, determined by model parameters. Propagation speeds remain stable across conditions and are consistent with the range observed in denervated skin preparations. The model generates diverse output states in response to local couplings and the time-dependence and shape of the input stimulation, with little top-down direction. The results provide a proof-of-principle that chromatophore/muscle dynamics with minimal central neural driving can produce rich dynamic patterns.

neuroscience↗

bioRxiv2026

Long-range neural pathways for octopus chemotactile processing revealed from periphery-to-brain by centimeter-field microCT

Understanding how nervous systems mediate responses to sensation requires whole-body maps of periphery-to-brain connections. Octopuses exemplify this challenge with distributed control of eight arms and hundreds of suckers, yet their long-range microanatomical wiring remains elusive due to limitations in microscopy. We extend histotomography (Ding et al. 2019), a form of soft tissue microCT customized for volumetric characterization of cells and tissues, to centimeter range with a custom micro-CT imaging system (Ding et al., 2019). With its 10-mm field of view and 0.7-{micro}m isotropic voxels we created a high-resolution digital intact small octopus. This multi-tissue 3D blueprint enabled us to (i) elucidate previously uncharacterized chemotactile pathways from the suckers to the brain, (ii) discern subdivisions of the nerve ring connecting neighboring arms, and (iii) segment over 300 structures across organ systems at histology-like resolution. We release the labeled interactive digital specimen to facilitate collaborative whole-organism phenotyping as a practical foundation for digital organismal biology. ONE-SENTENCE SUMMARYWhole-body 3D histology reveals neural and organ architecture throughout a small octopus.

systems biology↗

bioRxiv2019

FMRF Gene Expression In The Nervous System Of The Squid Doryteuthis pealei* Hatchling

FMRFamide is a neuropeptide that is widely distributed in invertebrates and known to be involved in many physiological functions. Previously we noted marked differences in expression of the fmrf gene in the stellate ganglion of Doryteuthis pealei* compared to the central nervous system. In this study we aimed to examen the brain systems of Doryteuthis pealei* for the presence and distribution of fmrf-expressing cells and fiber networks. Late squid embryos and hatchlings were examined by in situ hybridization and immunohistochemistry in whole mounts and tissue sections. All central lobes contained limited numbers of scattered neurons expressing fmrf, but the FMRFamide-containing fiber systems were abundant and extensive, mostly present in the neuropil of lobes. Main clusters of neurons were located in the magnocellular and chromatophore lobes of the posterior subesophageal mass (PSM), and in dorsal aspects of the basal lobe (BL). Dense FMRFamide-immunoreactive fibers were particularly seen in the optic lobe (OL), medial and posterior supraesophageal masses (MSM and SPM) often with a commissural organization. The data show that the central lobes of Doryteuthis pealei hatchlings have a matured FMRFamide system organized in a limited number of centers, but with widely distributed efferents. This suggests that FMRFamide neurons are already functionally engaged in the late embryo. The localization indicates that control of chromatophores and fin movement are amongst these functions.

neuroscience↗