sara mirsadeghi

topological data analysis (TDA) in neural network and its advantages over traditional graph theory methods by capturing higher-order relationships and complex structures within the brain examined in this research. TDA provides insights into cognitive processes by analyzing multi-scale interactions among neural activities and is increasingly utilized in both brain science and psychological research.

The methodology explores neural data from various sources, including multi-electrode arrays (MEAs), to study neural ensemble behaviors and connectivity. Additionally, it critiques existing methods like Granger causality analysis (GCA) for their limitations in interpreting neural data.

According to our findings, the number of spiking activities and active channels rise from the 10th to the 60th day in vitro (DIV). Burst activities peaked between 30 and 50 DIV, while the firing rate in active channels continued to increase until 30 DIV. Furthermore, the average burst length exhibited a consistent rise until 50 DIV. However, the percentage of spikes involved in burst activities displayed a non-monotonic pattern, initially declining until 30 DIV and rising again in subsequent days. The fluctuations in average spike amplitudes can be attributed to factors such as the distance between neurons and electrodes, as well as the ongoing neuronal plasticity and migration.

In summary, TCA provides qualitative insights into network status based on quantitative metrics and established thresholds. While we focused on primary neuronal cells derived from rat cortices, MEA technology is versatile enough to monitor the developmental stages of any neuronal type, including those derived from human sources

The sensory and mobility failure associated with spinal cord injury (SCI) is desperately complicated due to the pathological events that occur sequentially in consequent to the injury.

Herein, we applied neural stem cells, derived from human iPSCs (hiPSC-NSCs), to ameliorate the behavioral complications of contusive SCI in Rhesus monkeys, in sub-acute phase.

hiPSC-NSCs were maintained and characterized in vitro for general NSCs as well as hind-limb specific gene and protein expression prior to transplantation. Moreover, Masson's trichrome staining (MTS) in addition to luxol fast blue (LFB) were performed to determine the fibrotic scar reduction and myelination respectively. Tarlov’s scale were utilized to score the motor improvement, plus, sensory perception evaluation throughout six months following the injury.

hiPSC-NSCs were identified to own NSCs’ exclusive properties in vitro by SOX2, DCX and NESTIN in addition to NESTIN , PAX6 , SOX1 , HOXA2 and HOXB2 protein and gene expression. Additionally, hiPSC-NSCs caused remarkable depletion in fibrotic scar and enhance myelination; spinal shock, sensory responses, reflexes and motor function were improved over six months.

Our findings suggest that hiPSC-NSCs lead to promising recovery after SCI, therefore, this source of NSCs provide a therapeutic potential in clinical studies.

Obsessive-Compulsive Disorder (OCD) is one of the most common debilitating mental disorders with a prevalence rate of 2% to 3% in the general population. Previous studies have indicated abnormalities in the dorsolateral prefrontal cortex (DLPFC) of OCD patients; thus, we decided to use transcranial Direct Current Stimulation (tDCS) to decline these patients’ symptoms.

A total of 24 patients with OCD participated in this study with the hope of improvement after the application of tDCS. The subjects were randomly assigned to three groups of Sham, Right DLPFC, and Left DLPFC. tDCS was applied for five consecutive days and in each session, patients were subjected to 2 mA current flow for two 15 minutes followed by a 10-minute rest in between (every session lasted for 40 minutes).

Subsequently, the changes in obsessive-compulsive level and cognitive functions were evaluated via Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and Depression, Anxiety, and Stress Scale 21 (DASS-21) by comparing the results before (pre-test) and after (post-test) tDCS treatment.

Ultimately, the scores of the Yale-Brown scale in the Left DLPFC group showed significant changes after treatment with tDCS (mean difference compared to the sham group: -6.18 and P≤0.05). Hereupon, this study demonstrated that transcranial direct current stimulation may cause improvements in symptoms of OCD.