Figure 5.

Immunoblot analysis of tau solubility and binding to microtubules after repeated isoflurane treatment in 6.9-mo-old homozygous JNPL3 male mice. Protein extracts from cortices of control mice (Ctl; lanes 1 and 2, n=12), and mice sampled 1 wk after the last of four isoflurane treatments (4×A+1w; lanes 3 and 4, n=9) were extracted according to a modified method of Greenberg and Davies (15) (A–C). Tau from total (A), heat-stable soluble (B), and sarkosyl-insoluble (C) fractions was evaluated by immunoblot analysis with a phospho-independent tau antibody. A microtubule (MT) binding assay was performed on cortex tissue. Total (D, G), MT-free (E, H), and MT-bound (F, I) fractions were evaluated with tau (D–F, phospho-independent) and α-tubulin (G–I) antibodies. Scatterplots represent quantification of the immunoblot bands displayed above them. Levels of tau in MT-free and MT-bound fractions were normalized to total (input) tau. Graphs display immunoreactivity expressed as percentage of control (100%). Numbers in graphs indicate percentage of the tick line with which they are aligned. Data represented are means ± sd (2 representative values displayed; each lane represents an individual mouse). *P < 0.05, **P < 0.01vs. Ctl; Mann-Whitney U test.