Organisms as sensors in biohybrid entities as a novel tool for in-field aquatic monitoring.

Rapidly intensifying global warming and water pollution calls for more efficient and continuous environmental monitoring methods. Biohybrid systems connect mechatronic components to living organisms and this approach can be used to extract data from the organisms. Compared to conventional monitoring methods, they allow for a broader data collection over long periods, minimizing the need for sampling processes and human labour. We aim to develop a methodology for creating various bioinspired entities, here referred to as 'biohybrids', designed for long-term aquatic monitoring. Here, we test several aspects of the development of the biohybrid entity: autonomous power source, lifeform integration and partial biodegradability. An autonomous power source was supplied by microbial fuel cells which exploit electron flows from microbial metabolic processes in the sediments. Here, we show that by stacking multiple cells, sufficient power can be supplied. We integrated lifeforms into the developed bioinspired entity which includes organisms such as the zebra musselDreissena polymorphaand water fleaDaphniaspp. The setups developed allowed for observing their stress behaviours. Through this, we can monitor changes in the environment in a continuous manner. The further development of this approach will allow for extensive, long-term aquatic data collection and create an early-warning monitoring system.

Activation of noradrenergic locus coeruleus and social behavior network nuclei varies with duration of male midshipman advertisement calls.

Vocal courtship is vital to the reproductive success of many vertebrates and is therefore a highly-motivated behavioral state. Catecholamines have been shown to play an essential role in the expression and maintenance of motivated vocal behavior, such as the coordination of vocal-motor output in songbirds. However, it is not well-understood if this relationship applies to anamniote vocal species. Using the plainfin midshipman fish model, we tested whether specific catecholaminergic (i.e., dopaminergic and noradrenergic) nuclei and nodes of the social behavior network (SBN) are differentially activated in vocally courting (humming) versus non-humming males. Herein, we demonstrate that tyrosine hydroxylase immunoreactive (TH-ir) neuron number in the noradrenergic locus coeruleus (LC) and induction of cFos (an immediate early gene product and proxy for neural activation) in the preoptic area differentiated humming from non-humming males. Furthermore, we found relationships between activation of the LC and SBN nuclei with the total amount of time that males spent humming, further reinforcing a role for these specific brain regions in the production of motivated reproductive-related vocalizations. Finally, we found that patterns of functional connectivity between catecholaminergic nuclei and nodes of the SBN differed between humming and non-humming males, supporting the notion that adaptive behaviors (such as the expression of advertisement hums) emerge from the interactions between various catecholaminergic nuclei and the SBN.

Freshwater organisms potentially useful as biosensors and power-generation mediators in biohybrid robotics.

Facing the threat of rapidly worsening water quality, there is an urgent need to develop novel approaches of monitoring its global supplies and early detection of environmental fluctuations. Global warming, urban growth and other factors have threatened not only the freshwater supply but also the well-being of many species inhabiting it. Traditionally, laboratory-based studies can be both time and money consuming and so, the development of a real-time, continuous monitoring method has proven necessary. The use of autonomous, self-actualizing entities became an efficient way of monitoring the environment. The Microbial Fuel Cells (MFC) will be investigated as an alternative energy source to allow for these entities to self-actualize. This concept has been improved with the use of various lifeforms in the role of biosensors in a structure called "biohybrid" which we aim to develop further within the framework of project Robocoenosis relying on animal-robot interaction. We introduce a novel concept of a fully autonomous biohybrid agent with various lifeforms in the role of biosensors. Herein, we identify most promising organisms in the context of underwater robotics, among others Dreissena polymorpha, Anodonta cygnaea, Daphnia sp. and various algae. Special focus is placed on the "ecosystem hacking" based on their interaction with the electronic parts. This project uses Austrian lakes of various trophic levels (Millstättersee, Hallstättersee and Neusiedlersee) as case studies and as a "proof of concept".

A swarm design paradigm unifying swarm behaviors using minimalistic communication.

Numerous nature inspired algorithms have been suggested to enable robotic swarms, mobile sensor networks and other multi-agent systems to exhibit various self-organized behaviors. Swarm intelligence and swarm robotics research have been underway for a few decades and have produced many such algorithms based on natural self-organizing systems. While a large body of research exists for variations and modifications in swarm intelligence algorithms, there have been few attempts to unify the underlying agent level design of these widely varying behaviors. In this work, a design paradigm for a swarm of agents is presented which can exhibit a wide range of collective behaviors at swarm level while using minimalistic single-bit communication at the agent level. The communication in the proposed paradigm is based on waves of 'ping'-signals inspired by strategies for communication and self organization of slime mold (Dictyostelium discoideum) and fireflies (lampyridae). The unification of common collective behaviors through this Wave Oriented Swarm Paradigm (WOSP) enables the control of swarms with minimalistic communication and yet allowing the emergence of diverse complex behaviors. It is demonstrated both in simulation and using real robotic experiments that even a single-bit communication channel between agents suffices for the design of a substantial set of behaviors. Ultimately, the reader will be enabled to combine different behaviours based on the paradigm to develop a control scheme for individual swarms.

Dopaminergic neurons are preferentially responsive to advertisement calls and co-active with social behavior network nuclei in sneaker male midshipman fish.

Vocal species use acoustic signals to facilitate diverse behaviors such as mate attraction and territorial defense. However, little is known regarding the neural substrates that interpret such divergent conspecific signals. Using the plainfin midshipman fish model, we tested whether specific catecholaminergic (i.e., dopaminergic and noradrenergic) nuclei and nodes of the social behavior network (SBN) are differentially responsive following exposure to playbacks of divergent social signals in sneaker males. We chose sneaker (type II) males since they attempt to steal fertilizations from territorial type I males who use an advertisement call (hum) to attract females yet are also subjected to vocal agonistic behavior (grunts) by type I males. We demonstrate that induction of cFos (an immediate early gene product and proxy for neural activation) in two forebrain dopaminergic nuclei is greater in sneaker males exposed to hums but not grunts compared to ambient noise, suggesting hums preferentially activate these nuclei, further asserting dopamine as an important regulator of social-acoustic behaviors. Moreover, acoustic exposure to social signals with divergent salience engendered contrasting shifts in functional connectivity between dopaminergic nuclei and nodes of the SBN, supporting the idea that interactions between these two circuits may underlie adaptive decision-making related to intraspecific male competition.