Quantification of the developmental synaptic accumulation of GABAARγ2, gephyrin, and β-dystroglycan
| 1 week | 2 weeks | 3 weeks | 5 weeks | |
|---|---|---|---|---|
| Number of synaptic clusters/100 μm dendrite length | ||||
| GABAARγ2 subunit | 6 ± 1 | 18 ± 1 | 23 ± 2 | 32 ± 2 |
| Gephyrin | 6 ± 1 | 21 ± 2 | 29 ± 4 | 29 ± 2 |
| β-dystroglycan | 2 ± 0.5 | 4 ± 1 | 9 ± 1 | 12 ± 2 |
| % of synaptic GABAARγ2 colocalized with: | ||||
| Gephyrin | 64 ± 5 | 84 ± 3 | 86 ± 3 | 75 ± 3 |
| β-dystroglycan | 5 ± 2 | 14 ± 4 | 28 ± 4 | 35 ± 4 |
| % of postsynaptic marker colocalized with GABAARγ2 | ||||
| Gephyrin | n.d. | n.d. | 76 ± 3 | 82 ± 4 |
| β-dystroglycan | n.d. | n.d. | 70 ± 7 | 74 ± 5 |
Neurons were fixed after 1, 2, 3, or 5 weeks in culture and triple stained for synapsin, GABAARγ2, and either gephyrin or β-dystroglycan. The quantitative analysis was performed on digital images using Metamorph imaging software. Ten neurons from two independent experiments were analyzed for each combination of markers. Results are expressed as mean ± SEM; n.d., not determined.