I’m working with primary hippocampal neurons, isolating them from wistar rat embryos at E17-19 and culturing them in PLL-coated plates. I’ve noticed that compared to the first times the cells were cultured, their development times change (i.e., while the cells cultured from the first isolations took about 7 DIV to turn into mature neurons, now we see the same level of development at DIV2-3.

Does anyone know why this happens/have any experience with this? Our culturing protocol and conditions haven’t changed.