Distribution of AS and SS on spines and dendritic shafts in Layers II and III of the EC
| Layer | Group | Type of synapse | On spine heads | On nf. spines | On spine necks | On aspiny dendritic shaft | On spiny dendritic shaft | Total |
|---|---|---|---|---|---|---|---|---|
| II | Control | AS | 39.68% (567) | 18.89% (270) | 0.56% (8) | 19.87% (284) | 20.99% (300) | 100% (1429) |
| SS | 9.38% (12) | 4.69% (6) | 0.78% (1) | 22.66% (29) | 62.50% (80) | 100% (128) | ||
| Alzheimer | AS | 35.19% (284) | 17.84% (144) | 0.87% (7) | 25.15% (203) | 20.94% (169) | 100% (807) | |
| SS | 10.98% (9) | 1.22% (1) | 0% (0) | 48.78% (40) | 39.02% (32) | 100% (82) | ||
| III | Control | AS | 39.68% (642) | 15.33% (248) | 0.74% (12) | 17.49% (283) | 26.79% (433) | 100% (1618) |
| SS | 11.90% (15) | 4.76% (6) | 2.38% (3) | 22.22% (28) | 58.73% (74) | 100% (126) | ||
| Alzheimer | AS | 41.67% (305) | 11.75% (86) | 0.82% (6) | 28.83% (211) | 16.94% (124) | 100% (732) | |
| SS | 5.88% (5) | 1.18% (1) | 3.53% (3) | 40% (34) | 49.41% (42) | 100% (85) |
Synapses on spines have been subdivided into those that are established on spine heads and those that are established on spine necks. Moreover, we differentiated between aspiny and spiny dendritic shafts. Data are expressed as percentages with the absolute number of synapses studied given in parentheses. Data for each individual case are shown in Extended Data Table 5-1, Table 5-2. nf.: non-fully reconstructed.