Fig. 4

Astrocytes from P301S and P301L tau mice develop a reduced capacity to support neuronal survival during the first postnatal week. Serum-free medium conditioned by pure astrocytes derived from ≥7 day-old C57, P301S and P301L tau mice over 24 h was centrifuged to remove cellular debris and immediately added to 7 day cultured neurons extracted from 7 day-old mice. After 8 days, cells were fixed, stained with β-III-tubulin and counted. Mean ± SEM of four independent experiments where a single value is from four technical replicates (wells) in which at least five fields per well were analyzed. a Images of neurons treated with the various ACMs as indicated. b ACM from 7 day-old C57 and P301S mice; *p < 0.05 for these comparisons: no ACM C57N vs C57N + C57ACM; no ACM P301SN vs C57N + C57ACM; C57N + C57ACM vs P301SN + C57ACM, C57N + C57ACM vs C57N + P301SACM, C57N + C57ACM vs P301SN + P301SACM, P301SN + C57ACM vs P301SN + P301SACM. c ACM from 7 day-old C57A and P301LA; *p < 0.05 for these comparisons: no ACM C57N vs C57N + C57ACM; C57N + C57ACM vs C57N + P301LACM; Tukey’s multiple comparisons test. For 8 day of cultures, ANOVA revealed no interaction between genotype and culture conditions [F (2, 18) = 1.174; p = 0.3317], significant effect of culture condition [F (2, 18) = 19.73; p = 0.0001] and significant effect of genotype [F (1, 18) = 8.725; p = 0.0085]. d Neurons from 1 to 2 day-old mice were cultured for 4 days after which ACM derived from astrocytes cultured from 1 to 2 day-old mice was added for 4 days. e Neurons from 7 day-old mice were cultured for 4 days after which ACM derived from astrocytes cultured from 1 to 2 day-old mice was added for 4 days. Note that in both cases, there is no difference between the effects of ACMs from C57 or P301S mice. Mean ± SEM from three independent experiments; each value was obtained from four technical replicates (wells) in which at least five fields were examined. Values were analysed by the Mann–Whitney test