Biology subjects

Sorrentino, G.

Publications and source records attributed to Sorrentino, G..

22 records · Page 2Linked to original sources

bioRxiv2020

Loss of integration of brain netwroks after one night of sleep deprivation underlies worsening of attentive functions

The topology of brain networks changes according to environmental demands and can be described within the framework of graph theory. We hypothesized that 24-hours long sleep deprivation (SD) causes functional rearrangements of the brain topology so as to impair optimal communication, and that such rearrangements relate to the performance in specific cognitive tasks, namely the ones specifically requiring attention. Thirty-two young men underwent resting-state MEG recording and assessments of attention and switching abilities before and after SD. We found loss of integration of brain network and a worsening of attention but not of switching abilities. These results show that brain network changes due to SD affect switching abilities, worsened attention and induce large-scale rearrangements in the functional networks.

neuroscience↗

bioRxiv2020

A synthetic kinematic index of trunk displacement conveying the overall motor condition in Parkinson's disease

BACKGROUNDParkinsons disease (PD) is characterized by motor impairment, affecting quality of life and increasing fall risk, due to ineffective postural control. To this day, the diagnosis remains based on clinical approach. Similarly, motor evaluation is based on heterogeneous, operator-dependent observational criteria. A synthetic, replicable index to quantify motor impairment is still lacking. In this paper, we build upon the idea that the trunk is crucial in balance control. Hence, we have designed a new measure of postural stability which assesses the trunk displacement in relation to the center of mass, that we named trunk displacement index (TDI). METHODSTwenty-three PD patients and twenty-three healthy controls underwent clinical (UPDRS-III) and motor examination (3D gait analysis). The TDI was extracted from kinematic measurements using a stereophotogrammetric system. A correlation analysis was performed to assess the relationship of TDI with typical gait parameters, to verify its biomechanical value, and UPDRS-III, to observe its clinical relevance. Finally, its sensitivity was measured, comparing pre- and post-L-DOPA subclinical intake. RESULTSThe TDI showed significant correlations with many gait parameters, including both velocity and stability characteristics of gait, and with the UPDRS-III. Finally, the TDI resulted capable in discriminating between off and on state in PD, whereas typical gait parameters failed two show any difference between those two conditions. CONCLUSIONSOur results suggest that the TDI may be considered a highly sensitive biomechanical index, reflecting the overall motor condition in PD, and provided of clinical relevance due to the correlation with the clinical evaluation.

neuroscience↗

bioRxiv2019

Extensive functional repertoire underpins complex behaviours: insights from Parkinson’s disease

Rapid reconfigurations of brain activity support efficient neuronal communication and flexible behaviour. Suboptimal brain dynamics impair this adaptability, possibly leading to functional deficiencies. We hypothesize that impaired flexibility in brain activity can lead to motor and cognitive symptoms of Parkinsons disease (PD). To test this hypothesis, we studied the functional repertoire - the number of distinct configurations of neural activity - using source-reconstructed magnetoencephalography in PD patients and controls. We found stereotyped brain dynamics and reduced flexibility in PD. The intensity of this reduction was proportional to symptoms severity, which can be explained by beta-band hyper-synchronization. Moreover, the basal ganglia were prominently involved in the abnormal patterns of brain activity. Our findings support the hypotheses that: symptoms in PD reflect impaired brain flexibility, this impairment preferentially involves the basal ganglia, and beta-band hypersynchronization is associated with reduced brain flexibility. These findings highlight the importance of extensive functional repertoires for behaviour and motor.

neuroscience↗

bioRxiv2019

Mechano-modulatory synthetic niches for liver organoid derivation

The recent demonstration that primary cells from the liver can be expanded in vitro as organoids holds enormous promise for regenerative medicine and disease modeling1-5. The use of three-dimensional (3D) cultures based on ill-defined and potentially immunogenic matrices, however, hampers the translation of liver organoid technology into real-life applications6. We here used chemically defined hydrogels for the efficient derivation of both mouse and human hepatic organoids. Organoid growth was found to be highly stiffness-sensitive and dependent on yes-associated protein 1 (YAP) activity. However, in contrast to intestinal organoids7, YAP-mediated stiffness sensitivity was independent of acto-myosin contractility, requiring instead activation of the Src family of kinases (SFKs). Aberrant matrix stiffness on the other hand led to a shift in the progenitor phenotype, resulting in compromised proliferative capacity. Finally, we demonstrate the unprecedented establishment of biopsy-derived human liver organoids without the use of animal components at any step of the process. Our approach thus opens up exciting perspectives for the establishment of protocols for liver organoid-based regenerative medicine.

bioengineering↗