Spontaneous Calcium Oscillations of Networked Human iPSC Derived Cortical Neurons as a Sensitive Model for Neurotoxicity Screening
Poster May 31, 2019
Kurt Laha 1 , Zhong Wei Du 1
BrainXell's human neuron culture platforms provide a means to model the human brain in a dish and perform in vitro functional assays. This system enables the screening of disease phenotypes and pharmacological agents that alter neuronal activity. In the case of neurotoxicity, it is critical to use in vitro systems that more closely model the human nervous system and its response to environmental toxins. Such a platform provides greater predictive power to indicate which compounds pose a risk. Toward this goal, we have developed an assay centered on the use of BrainXell’s iPSC derived human cortical neurons and the spontaneous calcium oscillations that occur once mature networks have formed. These oscillations represent the changes in calcium concentration that are closely tied to neuronal activity as action potentials invoke large pre synaptic calcium influx and also cause a notable rise in postsynaptic calcium at excitatory synapses Fluorescent measurements of calcium oscillations can be achieved with calcium sensitive dyes that have high signal to noise ratio, efficient cellular loading, and good intracellular retention, and the oscillations are observed spontaneously when culturing neurons under suitable conditions to form mature networks. Such oscillations are reflective of a population of neurons having synchronous network activity. Using this assay, we assessed 12 potentially seizurogenic and toxic compounds and identified various ways in which they impact the spontaneous calcium oscillations. Compounds that target glutamatergic neurotransmission, GABAergic neurotransmission, and voltage gated potassium channels each had distinct effects on the spontaneous calcium oscillations. Moreover, changes were concentration dependent and were observed at low concentrations known to modulate the targets.
Spinal muscular atrophy (SMA) is an inheritable cause of infant mortality that is characterized by the loss of lower motor neurons and skeletal muscle atrophy. The degeneration of motor neurons is caused by insufficient levels of survival motor neuron (SMN) protein, which is encoded by two nearly identical genes SMN1 and SMN2. Most cases of SMA harbour homozygous deletions of the SMN1 gene and retain at least one copy of SMN2.READ MORE
In order to generate a robust protocol for MEA recording on hiPSC- derived neurons, we evaluated several conditions, which could affect culture performance (1.neuron seeding density; 2.seeding medium; 3.astrocyt eco-culture). These conditions were evaluated with BrainXell’s hiPSC-derived spinal motor neurons, cortical glutamatergic neurons and mixed cortical neurons.READ MORE