Prototyping a memristive-based device to analyze neuronal excitability

Organic Bioelectronics Development in Italy: A Review

In recent years, studies concerning Organic Bioelectronics have had a constant growth due to the interest in disciplines such as medicine, biology and food safety in connecting the digital world with the biological one. Specific interests can be found in organic neuromorphic devices and organic transistor sensors, which are rapidly growing due to their low cost, high sensitivity and biocompatibility. This trend is evident in the literature produced in Italy, which is full of breakthrough papers concerning organic transistors-based sensors and organic neuromorphic devices. Therefore, this review focuses on analyzing the Italian production in this field, its trend and possible future evolutions.

Memristor-Based Neuromodulation Device for Real-Time Monitoring and Adaptive Control of Neuronal Populations

Neurons are specialized cells for information transmission and information processing. In fact, many neurologic disorders are directly linked not to cellular viability/homeostasis issues but rather to specific anomalies in electrical activity dynamics. Consequently, therapeutic strategies based on the direct modulation of neuronal electrical activity have been producing remarkable results, with successful examples ranging from cochlear implants to deep brain stimulation. Developments in these implantable devices are hindered, however, by important challenges such as power requirements, size factor, signal transduction, and adaptability/computational capabilities. Memristors, neuromorphic nanoscale electronic components able to emulate natural synapses, provide unique properties to address these constraints, and their use in neuroprosthetic devices is being actively explored. Here, we demonstrate, for the first time, the use of memristive devices in a clinically relevant setting where communication between two neuronal populations is conditioned to specific activity patterns in the source population. In our approach, the memristor device performs a pattern detection computation and acts as an artificial synapse capable of reversible short-term plasticity. Using in vitro hippocampal neuronal cultures, we show real-time adaptive control with a high degree of reproducibility using our monitor-compute-actuate paradigm. We envision very similar systems being used for the automatic detection and suppression of seizures in epileptic patients.

Functionalization of TiO2 sol-gel derived films for cell confinement

The neuroscience field has increased enormously over the last decades, achieving the possible real application of neuronal cultures not only for reproducing neural architectures resembling in vivo tissues, but also for the development of functional devices. In this context, surface patterning for cell confinement is crucial, and new active materials together with new protocols for preparing substrates suitable for confining cells, guiding their processes in the desired configuration are extremely appreciated. Here, TiO₂ sol-gel derived films were selected as proof-of-concept materials to grow neurons in suitable confined configurations, taking advantage of the biocompatible properties of modified TiO₂ substrates. TiO₂ sol-gel derived films were made compatible with the growth of neurons thanks to a stable and controlled poly-lysine coating, obtained by silanization chemistry and streptavidin-biotin interactions. Moreover, a spotting protocol, here described and optimized, allowed the simple preparation of arrays of neurons, where cell adhesion was guided in specific areas and the neurites development driven in the desired arrangement. The resulting arrays were successfully tested for the growth and differentiation of neurons, demonstrating the possible adhesion of cells in specific areas of the film, therefore paving the way to applications such as the direct growth of excitable cells nearby electrodes of devices, with an evident enhancement of cell-electrodes communication.

Characteristic Analysis of Fractional-Order Memristor-Based Hypogenetic Jerk System and Its DSP Implementation

In this paper, a fractional-order memristive model with infinite coexisting attractors is investigated. The numerical solution of the system is derived based on the Adomian decomposition method (ADM), and its dynamic behaviors are analyzed by means of phase diagrams, bifurcation diagrams, Lyapunov exponent spectrum (LEs), dynamic map based on SE complexity and maximum Lyapunov exponent (MLE). Simulation results show that it has rich dynamic characteristics, including asymmetric coexisting attractors with different structures and offset boosting. Finally, the digital signal processor (DSP) implementation verifies the correctness of the solution algorithm and the physical feasibility of the system.

SIBPA on the crest of the Adriatic Sea wave: Introduction to the SIBPA XXIV (2018 congress) special issue

The Italian Society for Pure and Applied Biophysics (SIBPA) held its XXIV National Congress in the beautiful seaside town of Ancona, Italy, on September 10-13, 2018. This special issue features a selection of contributions from the Congress in all areas of modern biophysics including molecular, cellular, applied, computational and nanoscale biophysics. SIBPA pursues its institutional tasks and carries on its successful promotion of biophysical disciplines at the national and international levels, also trough the consolidation of its partnership with Biophysical Chemistry and Elsevier.