eLife assessment
This study provided a valuable finding demonstrating the spatial relationship between dendritic spines and mitochondria. The authors combined the analysis of ultra-structure data and functional data, which gives an excellent spatial and functional resolution to understand how mitochondria positioning is correlated to synaptic function and response in an in vivo model. Specifically, the authors provided convincing evidence and showed that dendritic mitochondria are positioned in spines with a diversity of orientation tuning, spines that display heterogeneous responses, and in areas of low local calcium activity.