3D neural models, commonly referred to as neural organoids or “mini-brains”, have been shown to recapitulate aspects of the multicellular organization, structure, and developmental trajectory of in vivo tissues.
Using Axion BioSystems' Maestro Pro and Edge systems, any scientist can now quickly and easily measure the functionality of neural organoids while preserving their complex structure and organization. Together, neural organoids on MEA create an ideal model for studying neural development, disease progression, and drug safety.
Simultaneous recordings of functional activity from cerebral organoids
Electrical activity is measured from organoids cultured on electrodes. Cerebral organoids generated from human induced pluripotent stem cells (hiPSCs) exhibit spontaneous neural activity, with increasing complexity as networks mature. Since the microelectrode array is two dimensional, signals recorded reflect the activity of the neurons on the bottom of the organoid. For the best results, ensure contact between the electrodes and the bottom of the organoid.
(A) Activity map displaying instantaneous firing rate of four wells with multiple cerebral organoids in each well. (B) Continuous voltage data recorded from four electrodes in one well. Activity is recorded from different sites on the same organoid. (C) Well-wide raster plot showing activity across all 16 electrodes and synchronous network bursting. Teal tick marks indicate electrode bursts, and orange boxes indicate network bursts. Data provided by Maestro customer.
Getting started with Maestro Pro and Edge couldn't be easier. Culture your neuronal organoids in an Axion multiwell MEA plate (Day 0). Load the MEA plate into the Maestro MEA system and allow the environmental chamber to automatically equilibrate. Analyze the neural activity in the MEA plate label-free and in real-time with AxIS Navigator Neural Module software (Day 1+).
The advantages of measuring neural activity from mini-brains on the Maestro MEA platform:
Measure what matters – The Maestro Pro and Edge MEA systems directly measure neuronal action potentials. Indirect measurements like calcium imaging are unable to capture important but subtle changes to neural network signaling while gene and protein expression are insufficient to characterize function. The Maestro MEA platforms track activity in real-time, enabling you to answer the question that matters: Do your neurons fire as expected?
Analyze cell activity label-free – Measure the same culture over hours, weeks, and months while avoiding dyes and reporters that can alter your biology and confound your results.
Precise assay environment – The smart environmental chamber finely controls temperature and CO₂ while rejecting electrical noise and mechanical vibrations.
See your cells – Sometimes you just want to look at your neural organoids under a microscope. CytoView MEA plates have a thin, transparent plate bottom for culture visualization and assay multiplexing.
Probe cell models in the same plate they were cultured in – Neurons exist as a functional network of inter-linked cells. The Maestro MEA platforms preserve the complex functionality of your neural models. Platforms that require single-cell suspensions (automated patch-clamp, flow cytometry), require more sample handling and destroy the networks that define the functionality of these neural cultures.
It's easy – You don't have to be an electrophysiologist to use the Maestro MEA platform. Just culture your neural organoids in an MEA plate, load your plate into the Maestro Pro or Edge system, and record your neural data. Axion’s data analysis tools will do the rest, even generating the publication-ready graphs you need.
Neural MEAShow Full Details
What is a microelectrode array (MEA)?
Microelectrode arrays (MEA), also known as multielectrode arrays, contain a grid of tightly spaced electrodes embedded in the culture surface of the well. Electrically active cells, such as neurons, are plated and cultured over the electrodes. When neurons fire action potentials, the electrodes measure the extracellular voltage on a microsecond timescale. As the neurons attach and network with one another, an MEA can simultaneously sample from many locations across the culture to detect propagation and synchronization of neural activity across the cell network.
That’s it, an electrode and your cells. Since the electrodes are extracellular, the recording is noninvasive and does not alter the electrophysiology of the cells - you can measure the activity of your culture for minutes, days, or even months!
An MEA of 64 electrodes embedded in the substate at the bottom of a well.
Neurons attach to the array and form a network. The microelectrodes detect the action potentials fired as well as their propagation across the network.
Brain waves in a dish
Neurons communicate with other cells via electrochemical signals. Many neural cell types form cellular networks, and MEAs allow us to capture and record the electrical activity that propagates through these networks.
Neurons fire action potentials that are detected by adjacent electrodes as extracellular spikes. As the network matures, neurons often synchronize their electrical activity and may exhibit network bursts, where neurons repeatedly fire groups of spikes over a short period of time.
The MEA detects each cell's activity, as well as the propagation of the activity across the network, with spatial and temporal precision. Patterns as complex as EEG-like waveforms, or "brain waves in a dish", can be observed. Axion's MEA assay captures key features of neural network behavior as functional endpoints - activity, synchrony, and network oscillations.
Action potentials are the defining feature of neuron function. High values indicate frequent action potential firing and low values indicate the neurons may have impaired function.
Synapses are functional connections between neurons. Synchrony reflects the prevalence and strength of synaptic connections, and thus how likely neurons are to generate action potentials simultaneously on millisecond time scales.
Network oscillations, or network bursting, as defined by alternating periods of high and low activity, are a hallmark of functional networks with excitatory and inhibitory neurons. Oscillation is a measure of how the spikes from all of the neurons are organized in time.
Do more with multiwell
Axion BioSystems offers multiwell plates, ranging from 6 to 96 wells, with an MEA embedded in the bottom of each well. Multiwell MEA plates allow you to study complex neural biology in a dish, from a single cell firing to network activity, across many conditions and cell types at once.