Anatomy adjustment retained a negative mitochondrial volume and calcium activity relation in 105 ferret spine records

We tested whether measured spine anatomy accounts for a negative relation between mitochondrial volume and local calcium activity in public ferret visual cortex records. Calcium imaging and electron microscopy were linked in the source study. In 105 positive-volume records, the rank correlation for volume within 5 micrometres was -0.320 before adjustment and -0.336 after adjustment for head volume, postsynaptic density area, neck length, and soma distance. In 51 matched records with positive volume at both radii, the surrounding 1 to 5 micrometre shell had an adjusted correlation of -0.438 after control for inner volume and anatomy. The inner-volume correlation was -0.031 after control for shell volume and anatomy. The spatial tests use the same records. These are descriptive associations in a selected table. Missing cell and animal labels prevent population inference. The results do not prove calcium buffering or transfer across animals and conditions. We include source checks, independent table reconstruction, code, evidence tables, and a figure.

mitochondria · dendritic spines · calcium imaging · structure and function · spatial scale · ferret visual cortex