Biology subjects

Santaniello, S.

Publications and source records attributed to Santaniello, S..

6 recordsLinked to original sources

bioRxiv2025

EEG-derived Brain Connectivity in Theta/Alpha Frequency Bands Increases During Reading of Individual Words

ObjectiveAlthough extensive insights about the neural mechanisms of reading have been gained via magnetic and electrographic imaging, the temporal evolution of the brain network during sight reading remains unclear. We tested whether the temporal dynamics of the brain functional connectivity involved in sight reading can be tracked using high-density scalp EEG recordings. ApproachTwenty-eight healthy subjects were asked to read words in a rapid serial visual presentation task while recording scalp EEG, and phase locking value was used to estimate the functional connectivity between EEG channels in the theta, alpha, beta, and gamma frequency bands. The resultant networks were then tracked through time. Main resultsThe networks graph density gradually increases as the task unfolds, peaks 150-250-ms after the appearance of each word, and returns to resting-state values, while the shortest path length between non-adjacent functional areas decreases as the density increases, thus indicating that a progressive integration between regions can be detected at the scalp level. This pattern was independent of the words type or position in the sentence, occurred in the theta/alpha band but not in beta/gamma range, and peaked earlier in the alpha band compared to the theta band (alpha: 184{+/-}61.48-ms; theta: 237{+/-}65.32-ms, P-value P<0.01). Nodes in occipital and frontal regions had the highest eigenvector centrality throughout the words presentation, and no significant lead-lag relationship between frontal/occipital regions and parietal/temporal regions was found, which indicates a consistent pattern in information flow. In the source space, this pattern was driven by a cluster of nodes linked to sensorimotor processing, memory, and semantic integration, with the most central regions being similar across subjects. SignificanceThese findings indicate that the brain network connectivity can be tracked via scalp EEG as reading unfolds, and EEG-retrieved networks follow highly repetitive patterns lateralized to frontal/occipital areas during reading.

neuroscience↗

bioRxiv2025

Computational Methods for Optimal Coil Placement and Maximization of Lobule-Focused Cortical Activation in Cerebellar TMS

BackgroundCoil placement on the cerebellum lacks accuracy in targeting the intended lobules and limits the efficacy of cerebellar transcranial magnetic stimulation (TMS) in treating movement disorders. ObjectiveDevelop a multiscale computational pipeline and method to rapidly predict the cellular response to cerebellar TMS and optimize the coil placement accordingly for lobule-specific activation. MethodsThe pipeline integrates 3T T1/T2-weighted MRI scans of the human cerebellum, lobule parcellation, and finite element models of the TMS-induced electric (E-) fields for figure-of-eight coils (MagStim D70) and double-cone coils (Deymed 120BFV). A constrained optimization method is developed to estimate the fiber bundles from cerebellar cortices to deep nuclei and, for both coil types, find the coil placement and orientation that maximize the E-field intensity in a user-selected lobule. Multicompartmental Purkinje cell models with realistic axon geometries and Gaussian process regression are added to predict the recruitment in the Purkinje layer. ResultsOur pipeline was tested in five individuals to target the left lobule VIII and resulted in normalized E-field intensities at the target 49.6{+/-}25.6% (D70) and 29.3{+/-}17.7% (120BFV) higher compared to standard coil positions (i.e., 3 cm left, 1 cm below the inion), mean{+/-}S.D. The minimum pulse intensity to recruit Purkinje cells on a 4 mm2-surface in the target decreased by 21.6% (range: 4.7-55.0%) and 10.7% (range: 7.9-18.2%), and the spillover to adjacent lobules decreased by 70.6{+/-}16.3% and 71.7{+/-}20.8% compared to standard positions (D70 and 120BFV, respectively). ConclusionOur tools are effective at targeting specific lobules and pave the way toward patient-specific setups.

neuroscience↗

bioRxiv2023

Long-Term In Vivo Molecular Monitoring Using Aptamer-Graphene Microtransistors

Long-term, real-time molecular monitoring in complex biological environments is critical for our ability to understand, prevent, diagnose, and manage human diseases. Aptamer-based electrochemical biosensors possess the promise due to their generalizability and a high degree of selectivity. Nevertheless, the operation of existing aptamer-based biosensors in vivo is limited to a few hours. Here, we report a first-generation long-term in vivo molecular monitoring platform, named aptamer-graphene microtransistors (AGMs). The AGM incorporates a layer of pyrene- (polyethylene glycol)5-alcohol and DNase inhibitor-doped polyacrylamide hydrogel coating to reduce biofouling and aptamer degradation. As a demonstration of function and generalizability, the AGM achieves the detection of biomolecules such as dopamine and serotonin in undiluted whole blood at 37 {degrees}C for 11 days. Furthermore, the AGM successfully captures optically evoked dopamine release in vivo in mice for over one week and demonstrates the capability to monitor behaviorally-induced endogenous dopamine release even after eight days of implantation in freely moving mice. The results reported in this work establish the potential for chronic aptamer-based molecular monitoring platforms, and thus serve as a new benchmark for molecular monitoring using aptamer-based technology.

bioengineering↗

bioRxiv2023

Electrically Conductive DNA-Inspired Coating for Intracortical Neural Microelectrodes

Different from conventional electrodes, intracortical neural microelectrodes are the size of one or several neural cells. Due to the limited space for cell-electrode connections, the bio-integration between each neural cell and the electrode surface is critical. To improve bio-integration and electrode functions, various coating materials (such as conductive polymers (CPs), carbon nanotubes (CNTs), and natural hydrogels) have been developed aiming to provide an enhanced interface for neuron recruitment, bio-anchorage, and electrical function. However, synthetic materials usually have limited biocompatibility and/or relatively high cytotoxicity, while biological materials present poor electrical functions. Therefore, current coatings possess biological, functional or electrochemical limitations that are not optimal for intracortical neural microelectrodes. To overcome this obstacle, we developed an electrically conductive coating based on biological molecules, named Janus base nano-coating (JBNc). JBNc is formed by Janus base nanotubes (JBNts) which are a family of nanotubes assembled from engineered DNA base pair units. Based on the long-distance translocation ability of the {pi} electrons of JBNts, we developed them into an electrically conductive coating on the electrode surface. For the first time, we reported the DNA-inspired JBNc had an electrochemical performance that met and exceeded standard metal electrode surface in cyclic voltammetry, impedance spectroscopy, charge injection capacity tests, and neural recording. Moreover, we demonstrated enhanced bio-anchorage and microelectrode interface integration using SEM and AFM. Importantly, we demonstrated enhanced functional response to JBNc microelectrodes with immunohistochemical staining and RNA sequencing (RNAseq) analysis. Using cell viability assays, we also showed the benefits of DNA-mimicking chemistry of Janus base nanomaterials compared to conventional microelectrode coatings. We anticipate that these results will serve as a foundation for the continued development and study of JBNc to enhance interface dynamics and ultimately the performance and reliability of brain microelectrodes.

bioengineering↗

bioRxiv2020

Non-invasive Amelioration of Essential Tremor via Phase-Locked Disruption of its Temporal Coherence

Aberrant neural oscillations hallmark numerous brain disorders. Here, we first report a method to track the phase of neural oscillations in real-time via endpoint-corrected Hilbert transform (ecHT) that mitigates the characteristic Gibbs distortion. We then used ecHT to show that the aberrant neural oscillation that hallmarks essential tremor (ET) syndrome, the most common adult movement disorder, can be noninvasively suppressed via electrical stimulation of the cerebellum phase-locked to the tremor. The tremor suppression is sustained after the end of the stimulation and can be phenomenologically predicted. Finally, using feature-based statistical-learning and neurophysiological-modelling we show that the suppression of ET is mechanistically attributed to a disruption of the temporal coherence of the oscillation via perturbation of the tremor generating a cascade of synchronous activity in the olivocerebellar loop. The suppression of aberrant neural oscillation via phase-locked driven disruption of temporal coherence may represent a powerful neuromodulatory strategy to treat brain disorders.

neuroscience↗

bioRxiv2019

Functional maturation of human neural stem cells in a 3D bioengineered brain model enriched with fetal brain matrix

Brain extracellular matrix (ECM) is often overlooked in vitro brain tissue models, despite its instructive roles during development. Using developmental stage-sourced brain ECM in reproducible 3D bioengineered culture systems, we demonstrate enhanced functional differentiation of human induced neural stem cells (hiNSCs) into healthy neurons and astrocytes. Particularly, fetal brain tissue-derived ECM supported long-term maintenance of differentiated neurons, demonstrated by morphology, gene expression and secretome profiling. Astrocytes were evident within the second month of differentiation, and reactive astrogliosis was inhibited in brain ECM-enriched cultures when compared to unsupplemented cultures. Functional maturation of the differentiated hiNSCs within fetal ECM-enriched cultures was confirmed by calcium signaling and unsupervised cluster analysis. Additionally, the study identified native biochemical cues in decellularized ECM with notable comparisons between fetal and adult brain-derived ECMs. The development of novel brain-specific biomaterials for generating mature in vitro brain models provides an important path forward for interrogation of neuron-glia interactions.

developmental biology↗