Spinule locations relative to perforations in the PSD on mushroom spines
| Spinule locations | Number | Percentage |
|---|---|---|
| Total at perforated synapses | 71 | |
| Center of the perforation into presynaptic axon | 29 | 40.8% |
| At the edge of the PSD into presynaptic axon | 23 | 32.4% |
| Distant from the PSD into the presynaptic axon | 12 | 16.9% |
| Into a neighboring axon | 7 | 9.9% |