The neuroprotective transfer of mitochondria from astrocytes to neurons has been primarily investigated by labelling astrocytic mitochondria with the dye MitoTracker. Here we report that MitoTracker transfers to neurons from both astrocytes and astrocyte-conditioned media, independently of mitochondrial transfer. Our observations should prompt an essential re-evaluation of the literature concerning astrocyte-neuron mitochondrial transfer and in other systems in which contact-independent transfer has been observed using mitochondrial dyes. ### Competing Interest Statement The authors have declared no competing interest. MSD (United Kingdom), https://ror.org/004nn4n27, PRJ_20446 DEVINE MSD MRC The Francis Crick Institute, https://ror.org/04tnbqb63, CC2206

Wu et al. used extracellularly displayed horseradish peroxidase (HRP) to label cell-surface proteins (CSPs) of astrocytes and neurons. By mapping CSPs to their origins, they report shared interactions between astrocytes and neurons, as well as extensive interactions of astrocytes with other parenchymal cells. They provide a foundation for exploring astrocyte-neuron interactions in health and disease.

Abstract figure legend The glia-immune network involves the communication(s) of glia via immune signalling pathways. In neuro-homeostasis these pathways have been shown to modulate key processes such...

Evidence underscores the non-specificity of mitochondrial dye in assessing horizontal mitochondrial transfer, suggesting that alternative approaches should be considered for gaining nuanced insights i...