Unveiling Circuit and Behavioral Functions of Astrocytes Using Improved Tools

Besides neurons, the other half of central nerve system (CNS) cells are glia. Astrocytes, the most abundant glia, were first found together with neurons around 150 years ago, and have long been considered as merely supportive cells. Recent studies suggest that, far from being a "glue", they are specialized contributors to brain physiology and disease. Astrocytes contact neurons and synapses via their myriad fine processes. They exert versatile homeostatic and neuro-modulatory functions to regulate CNS activity. As the term neuroscience suggests, brain research in the twentieth century was dominated by neuronal studies. In contrast, astrocytes, without which neurons cannot properly function, have been understudied partially due to a lack of tools. Fortunately, recent genetics, optics and protein engineering now provide the tools needed for astrocytes to tackle an exciting area of integrative brain cell biology. This paper presents a summary of the improved tools, the insights that they delivere, and the potential directions of future developments.