APP release from incubated cortical and hippocampal slices, basally and with exposure to depolarizing concentrations of potassium
| Incubation period | APP release | |||
|---|---|---|---|---|
| Cortical slices | Hippocampal slices | |||
| Basal | High K+ | Basal | High K+ | |
| % of first incubation period | ||||
| Second 10 min | 95 ± 7 | 158 ± 111-a | 95 ± 7 | 162 ± 141-a |
| Third 10 min | 85 ± 8 | 99 ± 14 | 85 ± 9 | 101 ± 13 |
| Fourth 10 min | 79 ± 5 | 90 ± 12 | 89 ± 9 | N.D. |
Cortical and hippocampal slices were perfused for 60 min (0.8 ml/min) and then incubated for 20 min with Krebs’ medium. After an 80-min equilibration period, slices were incubated in 1 ml of Krebs’ medium for four consecutive 10-min periods (second through fourth periods). During the second through fourth 10-min incubation periods, some slices were depolarized by incubation in K+-containing Krebs’ buffer (50 mM KC1 plus 73.5 mM NaC1). Incubation media were removed at the end of each 10-min incubation period, and the slices were rinsed with 0.5 ml of Krebs’ medium. Incubation and rinsing media were collected in iced plastic tubes and assayed for APPs. APP release during the second through fourth incubation periods was normalized (as percent) to the APP release observed during the first 10-min period. Data are mean ± S.E.M. (n = 8–12).
↵1-a Significantly higher than corresponding basal value.
N.D., no data.