Table 2.
Junctional characteristics of ChAT-immunostained vs. randomly selected unlabeled axon varicosities in the monkey internal and external pallidum
| GPi (n = 4) | GPe (n = 4) | |||
|---|---|---|---|---|
| ChAT | Unlabeled | ChAT | Unlabeled | |
| Synaptic incidence (%) | ||||
| Single section | 4.2 ± 0.3*** | 24 ± 3 | 5 ± 1*** | 31 ± 2 |
| Whole volume | 12 ± 2*** | 90 ± 10 | 17 ± 3*** | 125 ± 16 |
| Length of synaptic junction (μm) | 0.21 ± 0.04 | 0.25 ± 0.02 | 0.24 ± 0.02 | 0.24 ± 0.03 |
| Junctions (%) | ||||
| Symmetrical | 88 ± 13 | 83 ± 3 | 85 ± 9 | 85 ± 5 |
| Asymmetrical | 13 ± 13 | 17 ± 3 | 15 ± 9 | 15 ± 5 |
Data are from the same sectional varicosity profiles as in Table 1 (mean ± SEM). The varicosity profiles were classified as showing or not a synaptic junction according to the criteria described in “Materials and methods”. The synaptic incidence for the whole volume of varicosities was extrapolated from the formula of Beaudet and Sotelo (1981), using the long axis as diameter of profiles (Umbriaco et al. 1994)
*** P < 0.0001 for ChAT vs. unlabeled