Table 1.
Semiquantitative evaluation and final cortical location of EGFP-positive interneurons generated before and after birth
| Age at treatment, days | Treatment stage | Upper layers* | Lower layers* | Total | No. of cells, n† |
|---|---|---|---|---|---|
| 12.5 | Embryonic‡ | 70% | 46% | 60.6% | n = 546 |
| 14.5 | Embryonic | 72.8% | 47.2% | 60% | n = 590 |
| 16.5 | Embryonic | 11.1% | 26.1% | 18.1% | n = 772 |
| 19.5 | Embryonic | 4.5% | 20% | 14.3% | n = 362 |
| 4 | Postnatal§ | 2.7% | 19.6% | 14.2% | n = 1540 |
| 7 | Postnatal | 1.2% | 13.7% | 10.5% | n = 648 |
| 11 | Postnatal | 1.5% | 2.4% | 2% | n = 902 |
| 15 | Postnatal | 0.6% | 2.4% | 1.6% | n = 1817 |
| 30 | Postnatal | 0% | 0.7% | 0.4% | n = 472 |
BrdU/EGFP-double positive cells were counted 1 month after BrdU injections at the indicated ages.
*Numbers represent the percentage of EGFP-positive cells that also express BrdU.
†“n” is the number of EGFP-positive cells counted.
‡Embryonic treatment: 50 mg/kg, 5 times/day, administered i.p. to pregnant mice to establish birthdating during embryonic development based on previous studies (Xu Q, Cobos I, De La Cruz E, Rubenstein JL, Anderson SA (2004) Origins of cortical interneuron subtypes. J Neurosci 24:2612–2622) investigating birthdating of GABAergic interneurons.
§Postnatal treatment: 20 mg/kg, 5 times/day, injected i.p., and the protocol had to be slightly modified to overcome toxicity.