S. Vassanelli - Academia.edu (original) (raw)

Papers by S. Vassanelli

Prefazione 1 - Introduzione allo studio della Fisiologia umana (Gianluigi Monticelli) 2 - I compo... more Prefazione 1 - Introduzione allo studio della Fisiologia umana (Gianluigi Monticelli) 2 - I componenti dell\ue2 organismo umano (Lucia Martinoli) 3 - Meccanismi di trasporto e barriere biologiche (Paola Marciani, Gianluigi Monticelli) 5 - Fisiologia del muscolo (Maristella Gussoni, Gianluigi Monticelli, Alessandra Vezzoli) 6 - Il sistema nervoso: organizzazione e funzione (Maria Mariggi\uf2) 7 - Il sistema nervoso centrale: le funzioni sensoriali (Maristella Gussoni, Gianluigi Monticelli, Alessandra Vezzoli) 8 - Il sistema nervoso: le funzioni motorie (Maria Mariggi\uf2) 9 - Il sistema nervoso autonomo (Maria Mariggi\uf2) 10 - Le funzioni nervose integrate (Maria Mariggi\uf2) 11 - Il sistema endocrino (Maristella Gussoni, Gianluigi Monticelli) 12 - Il sangue e la linfa (Stefano Vassanelli) 13 - Il sistema cardiovascolare (Stefano Vassanelli) 14 - La respirazione (Patrizia Ambrogini, Carla Cuppini, Andrea Minelli) 15 - Le funzioni renali (Antonio Caretta, Carla Mucignat) 16 - La rego...

Nature Communications, 2016

Advanced brain-chip interfaces with numerous recording sites bear great potential for investigati... more Advanced brain-chip interfaces with numerous recording sites bear great potential for investigation of neuroprosthetic applications. The bottleneck towards achieving an efficient bio-electronic link is the real-time processing of neuronal signals, which imposes excessive requirements on bandwidth, energy and computation capacity. Here we present a unique concept where the intrinsic properties of memristive devices are exploited to compress information on neural spikes in real-time. We demonstrate that the inherent voltage thresholds of metal-oxide memristors can be used for discriminating recorded spiking events from background activity and without resorting to computationally heavy off-line processing. We prove that information on spike amplitude and frequency can be transduced and stored in single devices as non-volatile resistive state transitions. Finally, we show that a memristive device array allows for efficient data compression of signals recorded by a multi-electrode array,...

Biomaterials, 2011

The present study is aimed to design a prototype of hybrid silicon-muscle cell junction, analog t... more The present study is aimed to design a prototype of hybrid silicon-muscle cell junction, analog to an artificial neuromuscular junction prototype and relevant to the development of advanced neuro-prostheses and bionic systems. The device achieves focal Electric Capacitive Stimulation (ECS) by coupling of single cells and semiconductors, without electrochemical reaction with the substrate. A voltage change applied to a stimulation spot beneath an electrogenic cell leads to a capacitive current (charge accumulation) that opens voltage-gated ion channels in the membrane and generates an action potential. The myo-electronic junction was employed to chronically stimulate muscle cells via ECS and to induce cytosolic calcium transients in myotubes, fibers isolated from mouse FDB (fast [Ca 2þ ] i transients) and surprisingly also in undifferentiated myoblasts (slow [Ca 2þ ] i waves). The hybrid junction elicited, via chronic ECS, a differential reprogramming of single muscle cells by inducing early muscle contraction maturation and plasticity effects, such as NFAT-C3 nuclear translocation. In addition, in the presence of agrin, chronic ECS induced a modulation of AchR clustering which simulates in vitro synaptogenesis. This methodology can coordinate the myogenic differentiation, thus offering direct but non-invasive single cell/wiring, providing a platform for regenerative medicine strategies.

Journal of neuroscience methods, Jan 30, 2012

Rapid advances in neuronal probe technology for multisite recording of brain activity have posed ... more Rapid advances in neuronal probe technology for multisite recording of brain activity have posed a significant challenge to neuroscientists for processing and analyzing the recorded signals. To be able to infer meaningful conclusions quickly and accurately from large datasets, automated and sophisticated signal processing and analysis tools are required. This paper presents a Matlab-based novel tool, "SigMate", incorporating standard methods to analyze spikes and EEG signals, and in-house solutions for local field potentials (LFPs) analysis. Available modules at present are - 1. In-house developed algorithms for: data display (2D and 3D), file operations (file splitting, file concatenation, and file column rearranging), baseline correction, slow stimulus artifact removal, noise characterization and signal quality assessment, current source density (CSD) analysis, latency estimation from LFPs and CSDs, determination of cortical layer activation order using LFPs and CSDs, an...

iScience, 2020

Neuromorphic systems take inspiration from the principles of biological information processing to... more Neuromorphic systems take inspiration from the principles of biological information processing to form hardware platforms that enable the large-scale implementation of neural networks. The recent years have seen both advances in the theoretical aspects of spiking neural networks for their use in classification and control tasks and a progress in electrophysiological methods that is pushing the frontiers of intelligent neural interfacing and signal processing technologies. At the forefront of these new technologies, artificial and biological neural networks are tightly coupled, offering a novel ''biohybrid'' experimental framework for engineers and neurophysiologists. Indeed, biohybrid systems can constitute a new class of neuroprostheses opening important perspectives in the treatment of neurological disorders. Moreover, the use of biologically plausible learning rules allows forming an overall fault-tolerant system of co-developing subsystems. To identify opportunities and challenges in neuromorphic biohybrid systems, we discuss the field from the perspectives of neurobiology, computational neuroscience, and neuromorphic engineering.

2019 26th IEEE International Conference on Electronics, Circuits and Systems (ICECS)

This paper presents an FPGA implementation of a DSP performing real time spike detection on the e... more This paper presents an FPGA implementation of a DSP performing real time spike detection on the electrical activity of an in vitro neuronal culture of rat hippocampi. The DSP enhances the Signal-to-noise ratio (SNR) of samples recorded by a 1024 pixels Multi Transistor Array (MTA) at 9375 Samples/Sec per pixel of sim6boldsymbolmumathbfm\sim 6\ \boldsymbol{\mu}\mathbf{m}sim6boldsymbolmumathbfm pitch. The implementation integrates in the same system a Time Division Multiplexing (TDM) filter and a spatio-temporal correlation algorithm, to increase the SNR up to identify spikes as low as 215boldsymbolmumathbfV0−mathbfPEAK215\ \boldsymbol{\mu}\mathbf{V}_{0-\mathbf{PEAK}}215boldsymbolmumathbfV0−mathbfPEAK. The digital filter is a 2nd order high pass Infinite input response (IIR) Chebyshev filter. The spatio-temporal correlation exploits the MTA smaller pixels size and the high sample-rate to compute an equivalent pixel from a group of 7 pixels and 3 consecutive frames for a total of 21 samples and it is supported by a multi-channel noise power estimation. Finally, this paper shows the results achieved on the performed experiments and compares the system with others experiments using different sensors and algorithms.

13.1 Il cuore 13.2 I vasi sanguigni 13.2.1 Tipologie e funzioni dei diversi vasi nel sistema circ... more 13.1 Il cuore 13.2 I vasi sanguigni 13.2.1 Tipologie e funzioni dei diversi vasi nel sistema circolatorio Scheda 13.1 Le vene 13.2.2 Idrodinamica e sistema circolatorio 13.2.3 La legge della continuit\ue0 13.2.4 Controllo del flusso sanguigno: gli sfinteri 13.2.5 Circolazioni speciali Scheda 13.2 La circolazione coronarica 13.3 Principi di base della meccanica cardiaca 13.3.1 La pompa cardiaca 13.3.2 Il ciclo cardiaco 13.3.3 Meccanica valvolare 13.3.4 Efficienza del cuore 13.3.5 Il principio di Bernoulli 13.3.6 La gettata cardiaca 13.3.6.1 Misura della gettata cardiaca 13.3.6.2 Controllo della gettata cardiaca 13.3.7 La legge di Starling del cuore 13.3.7.1 Il preparato cuore-polmone di Starling 13.3.7.2 Misurazioni dell\u2019esperimento nella variazione del preload e dell\u2019afterload 13.4 Elettrofisiologia cardiaca 13.4.1 Potenziale di azione nei cardiomiociti - peculiarita 13.4.1.1 Durata del periodo refrattario 13.4.2 Meccanismo di contrazione e rilasciamento del cardiomiocita....

Dendritic excitability is modulated by the highly variable spatial and temporal expression patter... more Dendritic excitability is modulated by the highly variable spatial and temporal expression pattern of voltage-dependent potassium channels. Somatodendritic Kv2.1 channels contribute a major component of delayed rectifier potassium current in cultured hippocampal neurons, where Kv2.1 is localized to large clusters on the soma and proximal dendrites. Here we found that dramatic differences exist in the clustering of endogenous Kv2.1 in cultured rat hippocampal GABAergic interneurons and glutamatergic pyramidal neurons, Studies on neurons developing in culture revealed that while a similar sequence of Kv2.1 localization and clustering occurred in both cell types. the process was temporally delayed in pyramidal cells. Localization and clustering of recombinant green fluorescent protein-tagged Kv2.1 occurred by the same sequence of events. and imaging of GFP-Kv2.1 clustering in living neurons revealed dynamic fusion events that underlie cluster formation. Overexpression of GFP- Kv2.1 acc...

Frontiers in neuroscience, 2016

Future technologies aiming at restoring and enhancing organs function will intimately rely on nea... more Future technologies aiming at restoring and enhancing organs function will intimately rely on near-physiological and energy-efficient communication between living and artificial biomimetic systems. Interfacing brain-inspired devices with the real brain is at the forefront of such emerging field, with the term "neurobiohybrids" indicating all those systems where such interaction is established. We argue that achieving a "high-level" communication and functional synergy between natural and artificial neuronal networks in vivo, will allow the development of a heterogeneous world of neurobiohybrids, which will include "living robots" but will also embrace "intelligent" neuroprostheses for augmentation of brain function. The societal and economical impact of intelligent neuroprostheses is likely to be potentially strong, as they will offer novel therapeutic perspectives for a number of diseases, and going beyond classical pharmaceutical schemes. Ho...

Cognitive Computation, 2016

Rodents explore their surroundings through whisking by localizing objects and detecting textures ... more Rodents explore their surroundings through whisking by localizing objects and detecting textures very precisely. During such tactile exploration, whisker deflection is first mechanically transduced by receptors and then information encoded throughout the somatosensory pathway ending in the somatosensory 'barrel' cortex. In the barrel cortex, tactile information from a single whisker is segregated and processed in a cortical column corresponding to the deflected whisker. Local Field Potentials (LFPs) generated by whisker deflection in the barrel cortex present typical signatures in terms of shape and amplitude that are related to the activation of the local neuronal populations. Therefore, rigorous analysis of such responses may reveal important features about the function of underlying neuronal microcircuits. In this context, software methods for characterizing single-trial LFPs are needed that are also suitable for online extraction of LFP features and for brain-machine interfacing applications. In this work we present an automated and efficient method to analyze evoked LFP responses in the rat barrel cortex through automatic removal of stimulation artifacts, detection of single events and characterization of their relevant parameters. Evoked single-trial LFPs recorded under two different anesthetics are examined to demonstrate the feasibility, accuracy and applicability of the method.

Cells, 2019

To fight Alzheimer’s disease (AD), we should know when, where, and how brain network dysfunctions... more To fight Alzheimer’s disease (AD), we should know when, where, and how brain network dysfunctions initiate. In AD mouse models, relevant information can be derived from brain electrical activity. With a multi-site linear probe, we recorded local field potentials simultaneously at the posterior-parietal cortex and hippocampus of wild-type and double transgenic AD mice, under anesthesia. We focused on PS2APP (B6.152H) mice carrying both presenilin-2 (PS2) and amyloid precursor protein (APP) mutations, at three and six months of age, before and after plaque deposition respectively. To highlight defects linked to either the PS2 or APP mutation, we included in the analysis age-matched PS2.30H and APP-Swedish mice, carrying each of the mutations individually. Our study also included PSEN2−/− mice. At three months, only predeposition B6.152H mice show a reduction in the functional connectivity of slow oscillations (SO) and in the power ratio between SO and delta waves. At six months, plaqu...

Journal of Biological Chemistry, 1996

2 A preliminary report of these results has been published as an abstract (11).

Biophysical Journal, 2010

Applied Physics A: Materials Science & Processing, 1998

Abstract—The evoked potentials recorded using high resolution chips from a brain-chip interface p... more Abstract—The evoked potentials recorded using high resolution chips from a brain-chip interface provide very useful information in understanding the brain activity with greater details. In many cases, to maximize the signal detection, high precision electronics devices are employed near the recording site. This causes the recordings to be contaminated with unavoidable electrical or thermal noises. To assess the quality of the recordings in terms of signal-to-noise ratio (SNR), an automated noise characterization system is required. This ...

Journal of Neuroscience, 2011

2018 International Conference on IC Design & Technology (ICICDT), 2018

This paper presents the result of a multidisciplinary experiment where electrical activity from a... more This paper presents the result of a multidisciplinary experiment where electrical activity from a cultured rat hippocampi neuronal population is detected in real time by a FPGA implemented digital circuit. State-of-the-art EOMOSFET Multi Electrode Array (MEA) biosensors exploits a capacitive coupling between the biological environment and the sensing electronics to minimize invasiveness and cell damage, at the price of a lower SNR. For this reason, they are typically improved by noise rejection algorithms. Real time neural spikes detection opens unthinkable scenarios, allowing to stimulate single neurons in response to their behavior, possibly improving medical conditions like epilepsy. In this scenario, a spike sorting algorithm has been hardware implemented, allowing real time neural spike detection with a latency of 165ns.

Neurobiology of Aging, 2017

Alterations of brain network activity are observable in Alzheimer's disease (AD) together with th... more Alterations of brain network activity are observable in Alzheimer's disease (AD) together with the occurrence of mild cognitive impairment, before overt pathology. However, in humans as well in AD mouse models identification of early biomarkers of network dysfunction is still at its beginning. We performed in vivo recordings of local field potential (LFP) activity in the dentate gyrus (DG) of PS2APP mice expressing the human amyloid precursor protein (APP) Swedish mutation and the presenilin-2 (PS2) N141I. From a frequency-domain analysis, we uncovered network hyper-synchronicity as early as 3 months, when intracellular accumulation of amyloid-beta (Aβ) was also observable. Additionally, at 6 months of age, we identified network hyper-activity in the Beta/Gamma frequency bands, along with increased Theta-Beta and Theta-Gamma phase-amplitude cross-frequency coupling (CFC), in coincidence with the histopathological traits of the disease. Whereas hyper-activity and hyper-synchronicity were respectively detected in mice expressing the PS2-N141I or the APP Swedish mutant alone, the increase in CFC specifically characterized the 6-month-old PS2APP mice, just before the surge of the cognitive decline.