Recent optical approaches for anatomical and functional dissection of neuron-astrocyte circuitry

Astrocytes, the most abundant glial cells in the brain, are wired into neural circuits through close contact with neuronal pre- and post-synapses, called tripartite synapses. The mutual communication between neurons and astrocytes is crucial for neural circuit dynamics and animal behaviour. Recent advancements in imaging, manipulation and transcriptomics in astrocytes have revealed that astrocytes exhibit spatiotemporally complex computations and represent circuit-specialised functions and molecular makeups. However, understanding the neuron-astrocyte circuitry by means of conventional anatomical methods is hindered due to technical limitations. In this review, we highlight recently developed optical, genetic and viral techniques that enable high-throughput identification of connected neuron-astrocyte pairs with circuit and genetic specificity. These approaches will accelerate anatomical and functional dissections of the neuron-astrocyte circuits in health and disease in future studies.