Frequency of axon-coupled spines in different brain regions
| Brain region | Spines observed (n) | Axon-coupled spines (n) | Number of spines in a dendrite making synaptic contacts with the same axon (range) |
|---|---|---|---|
| CA1 PSR | 552 | 26 (4.7%) | 2 |
| CA1 SLM | 70 | 18 (25.7%) | 2 |
| Cortex | 221 | 12 (5.4%) | 2 |
| Striatum | 403 | 36 (8.9%) | 2 |
| CB | 824 | 215 (26.1%) | 2–4 |
Note that all the 824 spines studied in CB make synaptic contacts with the parallel fiber terminals.